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Sample records for nanostructured electrodes fabricated

  1. Fabrication of Dye-Sensitized Solar Cells with a 3D Nanostructured Electrode

    Directory of Open Access Journals (Sweden)

    Guo-Yang Chen

    2010-01-01

    Full Text Available A novel Dye-Sensitized Solar Cell (DSSC scheme for better solar conversion efficiency is proposed. The distinctive characteristic of this novel scheme is that the conventional thin film electrode is replaced by a 3D nanostructured indium tin oxide (ITO electrode, which was fabricated using RF magnetron sputtering with an anodic aluminum oxide (AAO template. The template was prepared by immersing the barrier-layer side of an AAO film into a 30 wt% phosphoric acid solution to produce a contrasting surface. RF magnetron sputtering was then used to deposit a 3D nanostructured ITO thin film on the template. The crystallinity and conductivity of the 3D ITO films were further enhanced by annealing. Titanium dioxide nanoparticles were electrophoretically deposited on the 3D ITO film after which the proposed DSSC was formed by filling vacant spaces in the 3D nanostructured ITO electrode with dye. The measured solar conversion efficiency of the device was 0.125%. It presents a 5-fold improvement over that of conventional spin-coated TiO2 film electrode DSSCs.

  2. Single-step fabrication of electrodes with controlled nanostructured surface roughness using optically-induced electrodeposition

    Science.gov (United States)

    Liu, N.; Li, M.; Liu, L.; Yang, Y.; Mai, J.; Pu, H.; Sun, Y.; Li, W. J.

    2018-02-01

    The customized fabrication of microelectrodes from gold nanoparticles (AuNPs) has attracted much attention due to their numerous applications in chemistry and biomedical engineering, such as for surface-enhanced Raman spectroscopy (SERS) and as catalyst sites for electrochemistry. Herein, we present a novel optically-induced electrodeposition (OED) method for rapidly fabricating gold electrodes which are also surface-modified with nanoparticles in one single step. The electrodeposition mechanism, with respect to the applied AC voltage signal and the elapsed deposition time, on the resulting morphology and particle sizes was investigated. The results from SEM and AFM analysis demonstrated that 80-200 nm gold particles can be formed on the surface of the gold electrodes. Simultaneously, both the size of the nanoparticles and the roughness of the fabricated electrodes can be regulated by the deposition time. Compared to state-of-the-art methods for fabricating microelectrodes with AuNPs, such as nano-seed-mediated growth and conventional electrodeposition, this OED technique has several advantages including: (1) electrode fabrication and surface modification using nanoparticles are completed in a single step, eliminating the need for prefabricating micro electrodes; (2) the patterning of electrodes is defined using a digitally-customized, projected optical image rather than using fixed physical masks; and (3) both the fabrication and surface modification processes are rapid, and the entire fabrication process only requires less than 6 s.

  3. Nanostructured Electrode Materials for Electrochemical Capacitor Applications

    OpenAIRE

    Hojin Choi; Hyeonseok Yoon

    2015-01-01

    The advent of novel organic and inorganic nanomaterials in recent years, particularly nanostructured carbons, conducting polymers, and metal oxides, has enabled the fabrication of various energy devices with enhanced performance. In this paper, we review in detail different nanomaterials used in the fabrication of electrochemical capacitor electrodes and also give a brief overview of electric double-layer capacitors, pseudocapacitors, and hybrid capacitors. From a materials point of view, t...

  4. Fabrication and characterization of buckypaper-based nanostructured electrodes as a novel material for biofuel cell applications.

    Science.gov (United States)

    Hussein, Laith; Urban, Gerald; Krüger, Michael

    2011-04-07

    The fabrication process of buckypapers (BPs) made from stable suspensions of as-received or functionalized multi-walled carbon nanotubes (MWCNTs) with high purity (97.5 wt%, Baytubes), their characterization and their utilization towards novel biofuel cell electrode applications are reported. The BPs can vary in thickness between 1 μm and 200 μm, are mechanically robust, flexible, stable in solvents, possess high meso-porosities as well as high apparent electrical conductivities of up to 2500 S m(-1). Potentiodynamic measurements of biocathodes based on bilirubin oxidase (BOD)-decorated BPs for the oxygen reduction reaction (ORR) in neutral media (phosphate buffer solution) containing glucose indicate that BP electrodes based on functionalized MWCNTs (fBPs) perform better than BP electrodes of as-received MWCNTs and have high potential as an effective electrode material in biofuel cells and biosensors.

  5. Nanostructured Electrode Materials for Electrochemical Capacitor Applications.

    Science.gov (United States)

    Choi, Hojin; Yoon, Hyeonseok

    2015-06-02

    The advent of novel organic and inorganic nanomaterials in recent years, particularly nanostructured carbons, conducting polymers, and metal oxides, has enabled the fabrication of various energy devices with enhanced performance. In this paper, we review in detail different nanomaterials used in the fabrication of electrochemical capacitor electrodes and also give a brief overview of electric double-layer capacitors, pseudocapacitors, and hybrid capacitors. From a materials point of view, the latest trends in electrochemical capacitor research are also discussed through extensive analysis of the literature and by highlighting notable research examples (published mostly since 2013). Finally, a perspective on next-generation capacitor technology is also given, including the challenges that lie ahead.

  6. Fabrication of nanowires and nanostructures

    DEFF Research Database (Denmark)

    Mátéfi-Tempfli, Stefan; Mátéfi-Tempfli, M.; Piraux, L.

    2009-01-01

    We report on different approaches that we have adopted and developed for the fabrication of nanowires and nanostructures. Methods based on template synthesis and on self organization seem to be the most promising for the fabrication of nanomaterials and nanostructures due to their easiness and low...... cost. The development of a supported nanoporous alumina template and the possibility of using this template to combine electrochemical synthesis with lithographic methods open new ways for the fabrication of complex nanostructures. The numerous advantages of the supported template and its compatibility...

  7. Fabrication and characterization of nanostructured mechanically alloyed Pt-Co catalyst for oxygen gas-diffusion-electrode

    International Nuclear Information System (INIS)

    Pharkya, P.; Farhat, Z.; Czech, E.; Hawthorne, H.; Alfantazi, A.

    2003-01-01

    The use of PEM fuel cells depends largely upon the cost of materials, processing and fabrication. The cost of Pt catalyst is a significant cost of a fuel cell. Alternative low cost catalyst that promotes high rate of oxygen reduction is needed. To achieve this, a mechanochemical technique was employed to refine the catalyst layer structure (i.e. increasing the effective catalyst surface area) and reducing the amount of Pt used, by alloying with a cheaper element. An investigation is carried out to study the relationship between the new catalyst structure refinement, morphology, microstructure and its electrocatalytic behaviour. Nanostructured Pt, Co and Pt 0.2 5 Co 0.75 alloy was fabricated from high purity Pt (99.9%) and Co (99.5%) powders using a Laboratory Planetary Ball Mill 'Pulverisette 6'. Optimum milling conditions, that produce fine, uniform and mechanically alloyed microstructure, were determined during fabrication, by varying process parameters (i.e., rpm, milling time, ball to powder ratio, milling atmosphere, surface-agents and milling/cooling cycle). Mechanically induced chemical and physical reactions and thermal effects were monitored 'in-situ' using a GTM system, which recorded temperature and pressure changes during milling. The alloy catalysts were characterized using TEM, SEM, EDX, XRD and BET techniques. Electrochemical tests were carried out on prepared powders. Exchange currents were determined from a potentiodynamic polarization tests and used to compare relative electrocatalytic behaviour of the new catalyst. Structure/property relationships were discussed and conclusions were drawn on the production of improved low cost catalyst. (author)

  8. Fabrication of zein nanostructure

    Science.gov (United States)

    Luecha, Jarupat

    resins. The soft lithography technique was mainly used to fabricate micro and nanostructures on zein films. Zein material well-replicated small structures with the smallest size at sub micrometer scale that resulted in interesting photonic properties. The bonding method was also developed for assembling portable zein microfluidic devices with small shape distortion. Zein-zein and zein-glass microfluidic devices demonstrated sufficient strength to facilitate fluid flow in a complex microfluidic design with no leakage. Aside from the fabrication technique development, several potential applications of this environmentally friendly microfluidic device were investigated. The concentration gradient manipulation of Rhodamine B solution in zein-glass microfluidic devices was demonstrated. The diffusion of small molecules such as fluorescent dye into the wall of the zein microfluidic channels was observed. However, with this formulation, zein microfluidic devices were not suitable for cell culture applications. This pioneer study covered a wide spectrum of the implementation of the two nanotechnology approaches to advance zein biomaterial which provided proof of fundamental concepts as well as presenting some limitations. The findings in this study can lead to several innovative research opportunities of advanced zein biomaterials with broad applications. The information from the study of zein nanocomposite structure allows the packaging industry to develop the low cost biodegradable materials with physical property improvement. The information from the study of the zein microfluidic devices allows agro-industry to develop the nanotechnology-enabled microfluidic sensors fabricated entirely from biodegradable polymer for on-site disease or contaminant detection in the fields of food and agriculture.

  9. Nanostructured Electrode Materials for Electrochemical Capacitor Applications

    Directory of Open Access Journals (Sweden)

    Hojin Choi

    2015-06-01

    Full Text Available The advent of novel organic and inorganic nanomaterials in recent years, particularly nanostructured carbons, conducting polymers, and metal oxides, has enabled the fabrication of various energy devices with enhanced performance. In this paper, we review in detail different nanomaterials used in the fabrication of electrochemical capacitor electrodes and also give a brief overview of electric double-layer capacitors, pseudocapacitors, and hybrid capacitors. From a materials point of view, the latest trends in electrochemical capacitor research are also discussed through extensive analysis of the literature and by highlighting notable research examples (published mostly since 2013. Finally, a perspective on next-generation capacitor technology is also given, including the challenges that lie ahead.

  10. Nanostructured micro-electrode arrays for electrophysiological measurements

    DEFF Research Database (Denmark)

    Wierzbicki, Rafal Dominik

    -dimensional electrode arrays with features able to penetrate cell membrane are currently investigated by various groups. While a number of experimental setups have been recently developed, the question remains whether the nanostructure is in fact penetrating the cellular membrane, and if the measurements are indeed......, and cost-effectiveness of the fabrication. Secondly, I worked on a reliable imaging method that would be able to directly envision nanostructure-cell membrane interface. As a result, a novel maskless patterning method of CNT forests was invented, devices with multichannel arrays of electrodes with silicon...

  11. Fabrication of a nano-structured PbO{sub 2} electrode by using printing technology: surface characterization and application

    Energy Technology Data Exchange (ETDEWEB)

    Kannan, K.; Muthuraman, G.; Cho, G.; Moon, I. S. [Sunchon National University, Suncheon (Korea, Republic of)

    2014-08-15

    This investigation aimed to introduce printing technology for the first time to prepare a nanostrucutured PbO{sub 2} electrode and its application to a cerium redox transfer process. The new method of nano-size PbO{sub 2} preparation demonstrated that nano-PbO{sub 2} could be obtained in less time and at less cost at room temperature. The prepared nano-PbO{sub 2} screen printed on a Ti electrode by three different compositions under similar conditions showed through surface and electrochemical analyses no adherence on Ti and no contact with other nano-PbO{sub 2} particles. Gravure printing of nano-PbO{sub 2} on a PET (poly ethylene thin) film at high pressure was done with two different compositions for the first time. The selective composition of 57.14 % nano-PbO{sub 2} powder with 4.28 % carbon black and 38.58 % ECA (ethyl carbitol acetate) produced a film with a nanoporous structure with an electron transfer ability. Finally, the optimized gravure-printed nano-PbO{sub 2} electrode was applied to the oxidation of Ce(III) to Ce(IV) by using cyclic voltammetry. The gravure-printed nano-PbO{sub 2} should pave the way to promising applications in electrochemical and sensor fields.

  12. Fabrication of a nano-structured PbO2 electrode by using printing technology: surface characterization and application

    International Nuclear Information System (INIS)

    Kannan, K.; Muthuraman, G.; Cho, G.; Moon, I. S.

    2014-01-01

    This investigation aimed to introduce printing technology for the first time to prepare a nanostrucutured PbO 2 electrode and its application to a cerium redox transfer process. The new method of nano-size PbO 2 preparation demonstrated that nano-PbO 2 could be obtained in less time and at less cost at room temperature. The prepared nano-PbO 2 screen printed on a Ti electrode by three different compositions under similar conditions showed through surface and electrochemical analyses no adherence on Ti and no contact with other nano-PbO 2 particles. Gravure printing of nano-PbO 2 on a PET (poly ethylene thin) film at high pressure was done with two different compositions for the first time. The selective composition of 57.14 % nano-PbO 2 powder with 4.28 % carbon black and 38.58 % ECA (ethyl carbitol acetate) produced a film with a nanoporous structure with an electron transfer ability. Finally, the optimized gravure-printed nano-PbO 2 electrode was applied to the oxidation of Ce(III) to Ce(IV) by using cyclic voltammetry. The gravure-printed nano-PbO 2 should pave the way to promising applications in electrochemical and sensor fields.

  13. Nanostructured Solid Oxide Fuel Cell Electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Sholklapper, Tal Zvi [Univ. of California, Berkeley, CA (United States)

    2007-01-01

    The ability of Solid Oxide Fuel Cells (SOFC) to directly and efficiently convert the chemical energy in hydrocarbon fuels to electricity places the technology in a unique and exciting position to play a significant role in the clean energy revolution. In order to make SOFC technology cost competitive with existing technologies, the operating temperatures have been decreased to the range where costly ceramic components may be substituted with inexpensive metal components within the cell and stack design. However, a number of issues have arisen due to this decrease in temperature: decreased electrolyte ionic conductivity, cathode reaction rate limitations, and a decrease in anode contaminant tolerance. While the decrease in electrolyte ionic conductivities has been countered by decreasing the electrolyte thickness, the electrode limitations have remained a more difficult problem. Nanostructuring SOFC electrodes addresses the major electrode issues. The infiltration method used in this dissertation to produce nanostructure SOFC electrodes creates a connected network of nanoparticles; since the method allows for the incorporation of the nanoparticles after electrode backbone formation, previously incompatible advanced electrocatalysts can be infiltrated providing electronic conductivity and electrocatalysis within well-formed electrolyte backbones. Furthermore, the method is used to significantly enhance the conventional electrode design by adding secondary electrocatalysts. Performance enhancement and improved anode contamination tolerance are demonstrated in each of the electrodes. Additionally, cell processing and the infiltration method developed in conjunction with this dissertation are reviewed.

  14. Nanostructured electrodes for high-performance pseudocapacitors.

    Science.gov (United States)

    Lu, Qi; Chen, Jingguang G; Xiao, John Q

    2013-02-11

    The depletion of traditional energy resources as well as the desire to reduce high CO(2) emissions associated with energy production means that energy storage is now becoming more important than ever. New functional electrode materials are urgently needed for next-generation energy storage systems, such as supercapacitors or batteries, to meet the ever increasing demand for higher energy and power densities. Advances in nanotechnology are essential to meet those future challenges. It is critical to develop ways of synthesizing new nanomaterials with enhanced properties or combinations of properties to meet future challenges. In this Minireview we discuss several important recent studies in developing nanostructured pseudocapacitor electrodes, and summarize three major parameters that are the most important in determining the performance of electrode materials. A technique to optimize these parameters simultaneously and to achieve both high energy and power densities is also introduced. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Device Fabrication and Probing of Discrete Carbon Nanostructures

    KAUST Repository

    Batra, Nitin M

    2015-05-06

    Device fabrication on multi walled carbon nanotubes (MWCNTs) using electrical beam lithography (EBL), electron beam induced deposition (EBID), ion beam induced deposition (IBID) methods was carried out, followed by device electrical characterization using a conventional probe station. A four-probe configuration was utilized to measure accurately the electrical resistivity of MWCNTs with similar results obtained from devices fabricated by different methods. In order to reduce the contact resistance of the beam deposited platinum electrodes, single step vacuum thermal annealing was performed. Microscopy and spectroscopy were carried out on the beam deposited electrodes to follow the structural and chemical changes occurring during the vacuum thermal annealing. For the first time, a core-shell type structure was identified on EBID Pt and IBID Pt annealed electrodes and analogous free standing nanorods previously exposed to high temperature. We believe this observation has important implications for transport properties studies of carbon materials. Apart from that, contamination of carbon nanostructure, originating from the device fabrication methods, was also studied. Finally, based on the observations of faster processing time together with higher yield and flexibility for device preparation, we investigated EBID to fabricate devices for other discrete carbon nanostructures.

  16. Fabricating solid carbon porous electrodes from powders

    Science.gov (United States)

    Kaschmitter, James L.; Tran, Tri D.; Feikert, John H.; Mayer, Steven T.

    1997-01-01

    Fabrication of conductive solid porous carbon electrodes for use in batteries, double layer capacitors, fuel cells, capacitive dionization, and waste treatment. Electrodes fabricated from low surface area (Electrodes having a higher surface area, fabricated from powdered carbon blacks, such as carbon aerogel powder, carbon aerogel microspheres, activated carbons, etc. yield high conductivity carbon compositives with excellent double layer capacity, and can be used in double layer capacitors, or for capacitive deionization and/or waste treatment of liquid streams. By adding metallic catalysts to be high surface area carbons, fuel cell electrodes can be produced.

  17. Dexamethasone electrically controlled release from polypyrrole-coated nanostructured electrodes.

    Science.gov (United States)

    Leprince, Lucas; Dogimont, Audrey; Magnin, Delphine; Demoustier-Champagne, Sophie

    2010-03-01

    One of the key challenges to engineering neural interfaces is to reduce their immune response toward implanted electrodes. One potential approach to minimize or eliminate this undesired early inflammatory tissue reaction and to maintain signal transmission quality over time is the delivery of anti-inflammatory biomolecules in the vicinity of the implant. Here, we report on a facile and reproducible method for the fabrication of high surface area nanostructured electrodes coated with an electroactive polymer, polypyrrole (PPy) that can be used to precisely release drug by applying an electrical stimuli. The method consists of the electropolymerization of PPy incorporated with drug, dexamethasone (DEX), onto a brush of metallic nanopillars, obtained by electrodeposition of the metal within the nanopores of gold-coated polycarbonate template. The study of the release of DEX triggered by electrochemical stimuli indicates that the system is a true electrically controlled release system. Moreover, it appears that the presence of metallic nanowires onto the electrode surface improves the adherence between the polymer and the electrode and increases the electroactivity of the PPy coating.

  18. Whole Wafer Design and Fabrication for the Alignment of Nanostructures for Chemical Sensor Applications

    Science.gov (United States)

    Biaggi-Labiosa, Azlin M.; Hunter, Gary W.

    2013-01-01

    A major objective in aerospace sensor development is to produce sensors that are small in size, easy to batch fabricate and low in cost, and have low power consumption The fabrication of chemical sensors involving nanostructured materials can provide these properties as well as the potential for the development of sensor systems with unique properties and improved performance. However, the fabrication and processing of nanostructures for sensor applications currently is limited in the ability to control their location on the sensor. Currently, our group at NASA Glenn Research Center has demonstrated the controlled placement of nanostructures in sensors using a sawtooth patterned electrode design. With this design the nanostructures are aligned between opposing sawtooth electrodes by applying an alternating current.

  19. Nanowires and nanostructures fabrication using template methods

    DEFF Research Database (Denmark)

    Mátéfi-Tempfli, Stefan; Mátéfi-Tempfli, M.; Vlad, A.

    2009-01-01

    One of the great challenges of today is to find reliable techniques for the fabrication of nanomaterials and nanostructures. Methods based on template synthesis and on self organization are the most promising due to their easiness and low cost. This paper focuses on the electrochemical synthesis...... of nanowires and nanostructures using nanoporous host materials such as supported anodic aluminum considering it as a key template for nanowires based devices. New ways are opened for applications by combining such template synthesis methods with nanolithographic techniques....

  20. Nanofiber membrane-electrode-assembly and method of fabricating same

    Energy Technology Data Exchange (ETDEWEB)

    Pintauro, Peter N.; Ballengee, Jason; Brodt, Matthew

    2018-01-23

    In one aspect of the present invention, a method of fabricating a fuel cell membrane-electrode-assembly (MEA) having an anode electrode, a cathode electrode, and a membrane disposed between the anode electrode and the cathode electrode, includes fabricating each of the anode electrode, the cathode electrode, and the membrane separately by electrospinning; and placing the membrane between the anode electrode and the cathode electrode, and pressing then together to form the fuel cell MEA.

  1. A study of nanostructured gold modified glassy carbon electrode for ...

    Indian Academy of Sciences (India)

    Wintec

    A study of nanostructured gold modified glassy carbon electrode for the determination of trace Cr(VI). BENZHI ... The method was applied to determine levels of chromium(VI) in tap water and sewage water. Keywords. Nanostructured gold modified ... analytical reagent-grade and double distilled water was used throughout.

  2. Metal plasmas for the fabrication of nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre

    2006-09-21

    A review is provided covering metal plasma production, theenergetic condensation of metal plasmas, and the formation ofnanostructures using such plasmas. Plasma production techniques includepulsed laser ablation, filtered cathodic arcs, and various forms ofionized physical vapor deposition, namely magnetron sputtering withionization of sputtered atoms in radio frequency discharges,self-sputtering, and high power impulse magnetron sputtering. Thediscussion of energetic condensation focuses on the control of kineticenergy by biasing and also includes considerations of the potentialenergy and the processes occurring at subplantation and implantation. Inthe final section on nanostructures, two different approaches arediscussed. In the top-down approach, the primary nanostructures arelithographically produced and metal plasma is used to coat or filltrenches and vias. Additionally, multilayers with nanosize periods(nanolaminates) can be produced. In the bottom-up approach, thermodynamicforces are used to fabricate nanocomposites and nanoporous materials bydecomposition and dealloying.

  3. Recent Developments of Nanostructured Electrodes for Bioelectrocatalysis of Dioxygen Reduction

    Directory of Open Access Journals (Sweden)

    Marcin Opallo

    2011-01-01

    Full Text Available The recent development of nanostructured electrodes for bioelectrocatalytic dioxygen reduction catalysed by two copper oxidoreductases, laccase and bilirubin oxidase, is reviewed. Carbon-based nanomaterials as carbon nanotubes or carbon nanoparticles are frequently used for electrode modification, whereas there are only few examples of biocathodes modified with metal or metal oxide nanoparticles. These nanomaterials are adsorbed on the electrode surface or embedded in multicomponent film. The nano-objects deposited act as electron shuttles between the enzyme and the electrode substrate providing favourable conditions for mediatorless bioelectrocatalysis.

  4. Electrodeposited nanostructured raspberry-like gold-modified electrodes for electrocatalytic applications

    International Nuclear Information System (INIS)

    Manivannan, Shanmugam; Ramaraj, Ramasamy

    2013-01-01

    A facile method for fabrication of raspberry-like Au nanostructures (Au NRBs)-modified electrode by electrodeposition and its applications toward the electrocatalytic oxidation of methanol (MOR) in alkaline medium and oxygen reduction reaction (ORR) in both alkaline and acidic media are demonstrated. The Au NRBs are characterized by UV–Vis absorption spectra, SEM, X-ray diffraction, and electrochemical measurements. The growth of Au NRBs was monitored by recording the in-situ absorption spectral changes during electrodeposition using spectroelectrochemical technique. Here we systematically studied the MOR by varying several reaction parameters such as potential scan rate and methanol concentration. The electrocatalytic poisoning effect due to the MOR products are not observed at the Au NRBs-modified electrode. At the alkaline medium the Au NRBs-modified electrode shows the better catalytic activities toward the MOR and ORR when compared to the poly crystalline gold and bare glassy carbon electrodes. The Au NRBs-modified electrode is a promising and inexpensive electrode material for other electrocatalytic applications.Graphical AbstractRaspberry-like Au nanostructures modified electrode is prepared and used for electrocatalytic applications

  5. Fabrication of Functional Plastic Parts Using Nanostructured Steel Mold Inserts

    Directory of Open Access Journals (Sweden)

    Nicolas Blondiaux

    2017-06-01

    Full Text Available We report on the fabrication of sub-micro and nanostructured steel mold inserts for the replication of nanostructured immunoassay biochips. Planar and microstructured stainless steel inserts were textured at the sub-micron and nanoscale by combining nanosphere lithography and electrochemical etching. This allowed the fabrication of structures with lateral dimensions of hundreds of nanometers and aspect ratios of up to 1:2. Nanostructured plastic parts were produced by means of hot embossing and injection molding. Surface nanostructuring was used to control wettability and increase the sensitivity of an immunoassay.

  6. A study of nanostructured gold modified glassy carbon electrode for ...

    Indian Academy of Sciences (India)

    A nanostructured gold modified glassy carbon electrode (Aunano/GCE) was employed for the determination of trace chromium(VI). To prepare Aunano/GCE, the GCE was immersed into KAuCl4 solution and electrodeposition was conducted at the potential of -0.4 V (vs Ag/AgCl) for 600 s. Scanning electron microscopy ...

  7. Nanostructured metal particle-modified electrodes for ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 118; Issue 6. Nanostructured ... Nanotechnology has become one of the most exciting frontier fields in analytical chemistry. The huge interest in nanomaterials, for example in chemical sensors and catalysis, is driven by their many desirable properties. Although metal ...

  8. Nanostructured Modified Electrode for Electrocatalytic Determination of Epinephrine in the Presence of Acetaminophen

    Directory of Open Access Journals (Sweden)

    M. Mazloum-Ardakani

    2011-04-01

    Full Text Available In this paper, a nanostructured modified electrode was fabricated by incorporating of 2,2′-[1,9-nonanediylbis(nitriloethylidyne]-bis-hydroquinone (NNH as a newly synthesized modifier and TiO2 nanoparticles to the carbon paste (MTCPE and then was used for the electroanalysis of epinephrine (EP. The electrochemical studies were carried out by using cyclic voltammetry, chronoamperometry and differential pulse voltammetry (DPV techniques. It has been found that the oxidation of EP at the surface of this electrode occurs at a potential about 235 mV less positive than that of an unmodified carbon paste electrode. A dynamic range of 1.0–2000.0 μM, with a detection limit of 0.37 μM for EP, was obtained using DPV. Also, this modified electrode exhibits well separated oxidation peaks for EP and acetaminophen (AC using DPV.

  9. Self-supported metallic nanopore arrays with highly oriented nanoporous structures as ideally nanostructured electrodes for supercapacitor applications.

    Science.gov (United States)

    Zhao, Huaping; Wang, Chengliang; Vellacheri, Ranjith; Zhou, Min; Xu, Yang; Fu, Qun; Wu, Minghong; Grote, Fabian; Lei, Yong

    2014-12-03

    Self-supported metallic nanopore arrays with highly oriented nanoporous structures are fabricated and applied as ideally nanostructured electrodes for supercapacitor applications. Their large specific surface area can ensure a high capacitance, and their highly oriented and stable nanoporous structure can facilitate ion transport. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Crab shells as sustainable templates from nature for nanostructured battery electrodes.

    Science.gov (United States)

    Yao, Hongbin; Zheng, Guangyuan; Li, Weiyang; McDowell, Matthew T; Seh, Zhiwei; Liu, Nian; Lu, Zhenda; Cui, Yi

    2013-07-10

    Rational nanostructure design has been a promising route to address critical materials issues for enabling next-generation high capacity lithium ion batteries for portable electronics, vehicle electrification, and grid-scale storage. However, synthesis of functional nanostructures often involves expensive starting materials and elaborate processing, both of which present a challenge for successful implementation in low-cost applications. In seeking a sustainable and cost-effective route to prepare nanostructured battery electrode materials, we are inspired by the diversity of natural materials. Here, we show that crab shells with the unique Bouligand structure consisting of highly mineralized chitin-protein fibers can be used as biotemplates to fabricate hollow carbon nanofibers; these fibers can then be used to encapsulate sulfur and silicon to form cathodes and anodes for Li-ion batteries. The resulting nanostructured electrodes show high specific capacities (1230 mAh/g for sulfur and 3060 mAh/g for silicon) and excellent cycling performance (up to 200 cycles with 60% and 95% capacity retention, respectively). Since crab shells are readily available due to the 0.5 million tons produced annually as a byproduct of crab consumption, their use as a sustainable and low-cost nanotemplate represents an exciting direction for nanostructured battery materials.

  11. Design rules of nanostructured transparent conductive electrodes for light trapping in hematite photoanodes

    Science.gov (United States)

    Eftekharinia, Behrooz; Moshaii, Ahmad; Dabirian, Ali

    2017-07-01

    Hematite is an appealing material for photoelectrochemical water splitting due to nearly ideal bandgap and Earth abundance. However, its short-distance hole transport has so far hindered exploiting its full potential. Two nanostructured transparent electrodes coated with a thin hematite layer are studied using full-field electromagnetic modeling. One structure comprises an ordered array of stripes of a transparent conductive oxide (TCO) and the other is composed of a square-lattice array of TCO nanorods. We find that height and filling ratio (FR) of the nanostructured elements constitutes the most crucial design parameter where the tall nanostructures with small FR constitute the ideal design for a nanostructured electrode with resonant-size elements. The simulations show that current densities up to 10.4 mA cm-2 can be obtained in a 20-nm thick hematite layer uniformly coated onto a properly designed nanostructured transparent conductive scaffold. Practical permittivity data are used in the simulation and the results show that these structures are quite robust against irregularities that might occur during the fabrications process.

  12. Nanostructured TiO2/carbon nanosheet hybrid electrode for high-rate thin-film lithium-ion batteries

    OpenAIRE

    Moitzheim, Sébastien; Nimisha, C S; Deng, Shaoren; Cott, Daire J; Detavernier, Christophe; Vereecken, Philippe

    2014-01-01

    Heterogeneous nanostructured electrodes using carbon nanosheets (CNS) and TiO2 exhibit high electronic and ionic conductivity. In order to realize the chip level power sources, it is necessary to employ microelectronic compatible techniques for the fabrication and characterization of TiO2-CNS thin-film electrodes. To achieve this, vertically standing CNS grown through a catalytic free approach on a TiN/SiO2/Si substrate by plasma enhanced chemical vapour deposition (PECVD) was ...

  13. Metamaterial 3D Gain Nanostructures Fabricated Using Direct Laser Writing

    Science.gov (United States)

    2015-07-11

    AFRL-AFOSR-UK-TR-2015-0033 Metamaterial 3D Gain Nanostructures Fabricated Using Direct Laser Writing Maria Farsari...abricated Direct Laser Writing 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA8655-13-1-3048 5c. PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S) Maria Farsari 5d...Standard Form 298 (Rev. 8/98) Prescribed by ANSI Std. Z39-18   1 Metamaterial 3D Gain Nanostructures Fabricated Using Direct Laser Writing EOARD

  14. Nanostructured electrodes for Solar Power Generation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The key to achieving high-power solar arrays for NASA applications is the development of high-efficiency, thin-film solar cells that can be fabricated directly on...

  15. Nanostructured Mo-based electrode materials for electrochemical energy storage.

    Science.gov (United States)

    Hu, Xianluo; Zhang, Wei; Liu, Xiaoxiao; Mei, Yueni; Huang, Yunhui

    2015-04-21

    The development of advanced energy storage devices is at the forefront of research geared towards a sustainable future. Nanostructured materials are advantageous in offering huge surface to volume ratios, favorable transport features, and attractive physicochemical properties. They have been extensively explored in various fields of energy storage and conversion. This review is focused largely on the recent progress in nanostructured Mo-based electrode materials including molybdenum oxides (MoO(x), 2 ≤ x ≤ 3), dichalconides (MoX2, X = S, Se), and oxysalts for rechargeable lithium/sodium-ion batteries, Mg batteries, and supercapacitors. Mo-based compounds including MoO2, MoO3, MoO(3-y) (0 nanostructured Mo-based compounds, as well as their energy storage applications in lithium/sodium-ion batteries, Mg batteries, and pseudocapacitors. The relationship between nanoarchitectures and electrochemical performances as well as the related charge-storage mechanism is discussed. Moreover, remarks on the challenges and perspectives of Mo-containing compounds for further development in electrochemical energy storage applications are proposed. This review sheds light on the sustainable development of advanced rechargeable batteries and supercapacitors with nanostructured Mo-based electrode materials.

  16. Facile fabrication of cobalt oxalate nanostructures with superior specific capacitance and super-long cycling stability

    Science.gov (United States)

    Cheng, Guanhua; Si, Conghui; Zhang, Jie; Wang, Ying; Yang, Wanfeng; Dong, Chaoqun; Zhang, Zhonghua

    2016-04-01

    Transition metal oxalate materials have shown huge competitive advantages for applications in supercapacitors. Herein, nanostructured cobalt oxalate supported on cobalt foils has been facilely fabricated by anodization, and could directly serve as additive/binder-free electrodes for supercapacitors. The as-prepared cobalt oxalate electrodes present superior specific capacitance of 1269 F g-1 at the current density of 6 A g-1 in the galvanostatic charge/discharge test. Moreover, the retained capacitance is as high as 87.2% as the current density increases from 6 A g-1 to 30 A g-1. More importantly, the specific capacitance of cobalt oxalate retains 91.9% even after super-long cycling of 100,000 cycles. In addition, an asymmetric supercapacitor assembled with cobalt oxalate (positive electrode) and activated carbon (negative electrode) demonstrates excellent capacitive performance with high energy density and power density.

  17. Fabrication and Characterisation of Membrane-Based Gold Electrodes

    DEFF Research Database (Denmark)

    Bakmand, Tanya; Kwasny, Dorota; Dimaki, Maria

    2015-01-01

    This work presents a versatile, membrane based electrochemical sensor with thin film electrodes fabricated through Ebeam evaporation directly on porous materials (membranes). Here, the fabrication of the electrodes is described along with possible methods for integration in fluidic systems and ch...

  18. Heterogeneous nanostructured electrode materials for electrochemical energy storage.

    Science.gov (United States)

    Liu, Ran; Duay, Jonathon; Lee, Sang Bok

    2011-02-07

    In order to fulfil the future requirements of electrochemical energy storage, such as high energy density at high power demands, heterogeneous nanostructured materials are currently studied as promising electrode materials due to their synergic properties, which arise from integrating multi-nanocomponents, each tailored to address a different demand (e.g., high energy density, high conductivity, and excellent mechanical stability). In this article, we discuss these heterogeneous nanomaterials based on their structural complexity: zero-dimensional (0-D) (e.g. core-shell nanoparticles), one-dimensional (1-D) (e.g. coaxial nanowires), two-dimensional (2-D) (e.g. graphene based composites), three-dimensional (3-D) (e.g. mesoporous carbon based composites) and the even more complex hierarchical 3-D nanostructured networks. This review tends to focus more on ordered arrays of 1-D heterogeneous nanomaterials due to their unique merits. Examples of different types of structures are listed and their advantages and disadvantages are compared. Finally a future 3-D heterogeneous nanostructure is proposed, which may set a goal toward developing ideal nano-architectured electrodes for future electrochemical energy storage devices.

  19. DNA-based Artificial Nanostructures: Fabrication, Properties, and Applications

    OpenAIRE

    Sun, Young; Kiang, Ching-Hwa

    2005-01-01

    Table of Content 1. Introduction 2. DNA fundamentals 3. Attachment of DNA to surface 4. Fabrication of nanostructures using DNA 4.1 Nanostructures of pure DNA 4.2 DNA-based assembly of metal nanoparticles 4.3 Construction of semiconductor particle arrays using DNA 4.4 DNA-directed nanowires 4.5 DNA-functionalized carbon nanotubes 4.6 Field-transistor based on DNA 4.7 Nanofabrication using artificial DNA 5. DNA-based nanostructures as biosensors 6. Properties of DNA-linked gold nanoparticles 6...

  20. Fabrication of Nanostructures Using Self-Assembled Peptides as Templates

    DEFF Research Database (Denmark)

    Castillo, Jaime

    2015-01-01

    This chapter evaluates the use of a short-aromatic dipeptide, diphenylalanine, as a template in the fabrication of new nanostructures (nanowires, coaxial nanocables, nanochannels) using materials such as silicon, conducting and non-conducting polymers. Diphenylalanine self-organize into nanostruc......This chapter evaluates the use of a short-aromatic dipeptide, diphenylalanine, as a template in the fabrication of new nanostructures (nanowires, coaxial nanocables, nanochannels) using materials such as silicon, conducting and non-conducting polymers. Diphenylalanine self......-organize into nanostructures (nanotubes, nanofibers or nanospheres) under very mild conditions; some of its properties make them excellent candidates to be use as, for instance, dry-etch masks in a reactive ion etching process for the rapid fabrication of silicon micro and nanowires. Here, the methods used to exploit...

  1. Fabrication techniques for reverse electrode coaxial germanium nuclear radiation detectors

    International Nuclear Information System (INIS)

    Hansen, W.L.; Haller, E.E.

    1980-11-01

    Germanium detectors with reverse polarity coaxial electrodes have been shown to exhibit improved resistance to radiation damage as compared with conventional electrode devices. However, the production of reverse electrode devices involves the development of new handling and fabrication techniques which has limited their wider application. We have developed novel techniques which lead to a device which is simple to fabricate, environmentally passivated and surface state adjusted

  2. Nanostructured mesophase electrode materials: modulating charge-storage behavior by thermal treatment.

    Science.gov (United States)

    Kong, Hye Jeong; Kim, Saerona; Le, Thanh-Hai; Kim, Yukyung; Park, Geunsu; Park, Chul Soon; Kwon, Oh Seok; Yoon, Hyeonseok

    2017-11-16

    3D nanostructured carbonaceous electrode materials with tunable capacitive phases were successfully developed using graphene/particulate polypyrrole (PPy) nanohybrid (GPNH) precursors without a separate process for incorporating heterogeneous species. The electrode material, namely carbonized GPNHs (CGPNHs) featured a mesophase capacitance consisting of both electric double-layer (EDL) capacitive and pseudocapacitive elements at the molecular level. The ratio of EDL capacitive element to pseudocapacitive element (E-to-P) in the mesophase electrode materials was controlled by varying the PPy-to-graphite weight (P w /G w ) ratio and by heat treatment (T H ), which was demonstrated by characterizing the CGPNHs with elemental analysis, cyclic voltammetry, and a charge/discharge test. The concept of the E-to-P ratio (EPR) index was first proposed to easily identify the capacitive characteristics of the mesophase electrode using a numerical algorithm, which was reasonably consistent with the experimental findings. Finally, the CGPNHs were integrated into symmetric two-electrode capacitor cells, which rendered excellent energy and power densities in both aqueous and ionic liquid electrolytes. It is anticipated that our approach could be widely extended to fabricating versatile hybrid electrode materials with estimation of their capacitive characteristics.

  3. Controlled Fabrication of Metallic Electrodes with Atomic Separation

    DEFF Research Database (Denmark)

    Morpurgo, A.; Robinson, D.; M. Marcus, C.

    1998-01-01

    We report a new technique for fabricating metallic electrodes on insulating substrates with separations on the 1 nm scale. The fabrication technique, which combines lithographic and electrochemical methods, provides atomic resolution without requiring sophisticated instrumentation. The process...... is simple, controllable, reversible, and robust, allowing rapid fabrication of electrode pairs with high yield. We expect the method to prove useful in interfacing molecular-scale structures to macroscopic probes and electronic devices ....

  4. Displacement Talbot lithography: an alternative technique to fabricate nanostructured metamaterials

    Science.gov (United States)

    Le Boulbar, E. D.; Chausse, P. J. P.; Lis, S.; Shields, P. A.

    2017-06-01

    Nanostructured materials are essential for many recent electronic, magnetic and optical devices. Lithography is the most common step used to fabricate organized and well calibrated nanostructures. However, feature sizes less than 200 nm usually require access to deep ultraviolet photolithography, e-beam lithography or soft lithography (nanoimprinting), which are either expensive, have low-throughput or are sensitive to defects. Low-cost, high-throughput and low-defect-density techniques are therefore of interest for the fabrication of nanostructures. In this study, we investigate the potential of displacement Talbot lithography for the fabrication of specific structures of interest within plasmonic and metamaterial research fields. We demonstrate that nanodash arrays and `fishnet'-like structures can be fabricated by using a double exposure of two different linear grating phase masks. Feature sizes can be tuned by varying the exposure doses. Such lithography has been used to fabricate metallic `fishnet'-like structures using a lift-off technique. This proof of principle paves the way to a low-cost, high-throughput, defect-free and large-scale technique for the fabrication of structures that could be useful for metamaterial and plasmonic metasurfaces. With the development of deep ultraviolet displacement Talbot lithography, the feature dimensions could be pushed lower and used for the fabrication of optical metamaterials in the visible range.

  5. 2D Hybrid Nanostructured Dirac Materials for Broadband Transparent Electrodes.

    Science.gov (United States)

    Guo, Yunfan; Lin, Li; Zhao, Shuli; Deng, Bing; Chen, Hongliang; Ma, Bangjun; Wu, Jinxiong; Yin, Jianbo; Liu, Zhongfan; Peng, Hailin

    2015-08-05

    Broadband transparent electrodes based on 2D hybrid nanostructured Dirac materials between Bi2 Se3 and graphene are synthesized using a chemical vapor deposition (CVD) method. Bi2 Se3 nanoplates are preferentially grown along graphene grain boundaries as "smart" conductive patches to bridge the graphene boundary. These hybrid films increase by one- to threefold in conductivity while remaining highly transparent over broadband wavelength. They also display outstanding chemical stability and mechanical flexibility. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Nanostructured metal oxides as electrode materials for electrochemical capacitors.

    Science.gov (United States)

    Konstantinov, Konstantin; Wang, Guoxiu; Lao, Zhuo Jin; Liu, Hua Kun; Devers, T

    2009-02-01

    In this study, nanostructured transition metal oxides, such as Co3O4, NiO and MnO2 were comprehensively studied and reported as promising electrode materials for electrochemical capacitors. The materials have been obtained by solution or spray solution techniques, which are cost-effective and promising for industry application. All materials feature a large specific surface area, which can reach up to 270 m2/g. The high surface area is a compulsory condition for high capacitance. The best MnO2 materials yielded up to 406 F/g.

  7. All Inkjet-Printed Amperometric Multiplexed Biosensors Based on Nanostructured Conductive Hydrogel Electrodes.

    Science.gov (United States)

    Li, Lanlan; Pan, Lijia; Ma, Zhong; Yan, Ke; Cheng, Wen; Shi, Yi; Yu, Guihua

    2018-02-12

    Multiplexing, one of the main trends in biosensors, aims to detect several analytes simultaneously by integrating miniature sensors on a chip. However, precisely depositing electrode materials and selective enzymes on distinct microelectrode arrays remains an obstacle to massively produced multiplexed sensors. Here, we report on a "drop-on-demand" inkjet printing process to fabricate multiplexed biosensors based on nanostructured conductive hydrogels in which the electrode material and several kinds of enzymes were printed on the electrode arrays one by one by employing a multinozzle inkjet system. The whole inkjet printing process can be finished within three rounds of printing and only one round of alignment. For a page of sensor arrays containing 96 working electrodes, the printing process took merely ∼5 min. The multiplexed assays can detect glucose, lactate, and triglycerides in real time with good selectivity and high sensitivity, and the results in phosphate buffer solutions and calibration serum samples are comparable. The inkjet printing process exhibited advantages of high efficiency and accuracy, which opens substantial possibilities for massive fabrication of integrated multiplexed biosensors for human health monitoring.

  8. Elementary development for beryllide pebble fabrication by rotating electrode method

    International Nuclear Information System (INIS)

    Uchida, M.; Kawamura, H.; Uda, M.; Ito, Y.

    2003-01-01

    Beryllides (Be 12 Ti, Be 12 V, etc.) are expected to be promising candidates for advanced neutron multipliers for the DEMO blanket. However, it has been difficult to fabricate beryllide pebbles by rotating electrode method (REM) that is the standard fabrication process for the beryllium (Be) pebbles, because of the brittleness of beryllide electrode rod. In this study, the chemical composition of the materials and the fabrication process of the electrode were surveyed. Then the small-scale electrode was fabricated and preliminary trials of pebbles production were conducted by REM. The electrode of the improved material withstood the thermal stress under arc heating and a certain amount of pebbles were obtained. These pebbles by REM were dense and had fine structure. The feasibility of the production of beryllide pebbles by REM was confirmed

  9. Fabrication of nano-structured UO2 fuel pellets

    International Nuclear Information System (INIS)

    Yang, Jae Ho; Kang, Ki Won; Rhee, Young Woo; Kim, Dong Joo; Kim, Jong Heon; Kim, Keon Sik; Song, Kun Woo

    2007-01-01

    Nano-structured materials have received much attention for their possibility for various functional materials. Ceramics with a nano-structured grain have some special properties such as super plasticity and a low sintering temperature. To reduce the fuel cycle costs and the total mass of spent LWR fuels, it is necessary to extend the fuel discharged burn-up. In order to increase the fuel burn-up, it is important to understand the fuel property of a highly irradiated fuel pellet. Especially, research has focused on the formation of a porous and small grained microstructure in the rim area of the fuel, called High Burn-up Structure (HBS). The average grain size of HBS is about 300nm. This paper deals with the feasibility study on the fabrication of nano-structured UO 2 pellets. The nano sized UO 2 particles are prepared by a combined process of a oxidation-reducing and a mechanical milling of UO 2 powder. Nano-structured UO 2 pellets (∼300nm) with a density of ∼93%TD can be obtained by sintering nano-sized UO 2 compacts. The SEM study reveals that the microstructure of the fabricated nano-structure UO 2 pellet is similar to that of HBS. Therefore, this bulk nano-structured UO 2 pellet can be used as a reference pellet for a measurement of the physical properties of HBS

  10. A top-down approach for fabricating free-standing bio-carbon supercapacitor electrodes with a hierarchical structure

    OpenAIRE

    Yingzhi Li; Qinghua Zhang; Junxian Zhang; Lei Jin; Xin Zhao; Ting Xu

    2015-01-01

    Biomass has delicate hierarchical structures, which inspired us to develop a cost-effective route to prepare electrode materials with rational nanostructures for use in high-performance storage devices. Here, we demonstrate a novel top-down approach for fabricating bio-carbon materials with stable structures and excellent diffusion pathways; this approach is based on carbonization with controlled chemical activation. The developed free-standing bio-carbon electrode exhibits a high specific ca...

  11. Nanostructured ternary electrodes for energy-storage applications

    KAUST Repository

    Baby, Rakhi Raghavan

    2012-02-13

    A three-component, flexible electrode is developed for supercapacitors over graphitized carbon fabric, utilizing γ-MnO 2 nanoflowers anchored onto carbon nanotubes (γ-MnO 2/CNT) as spacers for graphene nanosheets (GNs). The three-component, composite electrode doubles the specific capacitance with respect to GN-only electrodes, giving the highest-reported specific capacitance (308 F g -1) for symmetric supercapacitors containing MnO 2 and GNs using a two-electrode configuration, at a scan rate of 20 mV s -1. A maximum energy density of 43 W h kg -1 is obtained for our symmetric supercapacitors at a constant discharge-current density of 2.5 A g -1 using GN-(γ-MnO 2/CNT)-nanocomposite electrodes. The fabricated supercapacitor device exhibits an excellent cycle life by retaining ≈90% of the initial specific capacitance after 5000 cycles. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Fabrication of hierarchical ZnO nanostructures on cotton fabric for wearable device applications

    Science.gov (United States)

    Pandiyarasan, V.; Suhasini, S.; Archana, J.; Navaneethan, M.; Majumdar, Abhijit; Hayakawa, Y.; Ikeda, H.

    2017-10-01

    We have investigated ZnO nanostructures on cotton fabric (CF) s a flexible material for an application of wearable thermoelectric (TE) power generator which requires super-hydrophobicity, UV protection, and high TE efficiency. Field emission scanning electron microscopy images revealed that the formed ZnO nanostructures have a mixture of nanorods and nanosheets and are uniformly coated on the CF. XRD pattern and Raman spectra revealed that the ZnO nanostructure has a wurtzite structure. Contact angle measurements showed that the ZnO-nanostructures-coated CF possessed a high super hydrophobic nature with an angle of 132.5°. ZnO nanocomposite/CF sample exhibited an excellent UV protection factor 183.84. Seebeck coefficient, electrical resistivity and thermoelectric power factor of the ZnO nanostructures on cotton fabric were evaluated to be 28 μV/K, 0.04 Ω-cm, and 22 μW/m K2, respectively.

  13. Quantifying protein adsorption and function at nanostructured materials: enzymatic activity of glucose oxidase at GLAD structured electrodes.

    Science.gov (United States)

    Jensen, Uffe B; Ferapontova, Elena E; Sutherland, Duncan S

    2012-07-31

    Nanostructured materials strongly modulate the behavior of adsorbed proteins; however, the characterization of such interactions is challenging. Here we present a novel method combining protein adsorption studies at nanostructured quartz crystal microbalance sensor surfaces (QCM-D) with optical (surface plasmon resonance SPR) and electrochemical methods (cyclic voltammetry CV) allowing quantification of both bound protein amount and activity. The redox enzyme glucose oxidase is studied as a model system to explore alterations in protein functional behavior caused by adsorption onto flat and nanostructured surfaces. This enzyme and such materials interactions are relevant for biosensor applications. Novel nanostructured gold electrode surfaces with controlled curvature were fabricated using colloidal lithography and glancing angle deposition (GLAD). The adsorption of enzyme to nanostructured interfaces was found to be significantly larger compared to flat interfaces even after normalization for the increased surface area, and no substantial desorption was observed within 24 h. A decreased enzymatic activity was observed over the same period of time, which indicates a slow conformational change of the adsorbed enzyme induced by the materials interface. Additionally, we make use of inherent localized surface plasmon resonances in these nanostructured materials to directly quantify the protein binding. We hereby demonstrate a QCM-D-based methodology to quantify protein binding at complex nanostructured materials. Our approach allows label free quantification of protein binding at nanostructured interfaces.

  14. Nanowires, nanostructures and devices fabricated therefrom

    Science.gov (United States)

    Majumdar, Arun; Shakouri, Ali; Sands, Timothy D.; Yang, Peidong; Mao, Samuel S.; Russo, Richard E.; Feick, Henning; Weber, Eicke R.; Kind, Hannes; Huang, Michael; Yan, Haoquan; Wu, Yiying; Fan, Rong

    2005-04-19

    One-dimensional nanostructures having uniform diameters of less than approximately 200 nm. These inventive nanostructures, which we refer to as "nanowires", include single-crystalline homostructures as well as heterostructures of at least two single-crystalline materials having different chemical compositions. Because single-crystalline materials are used to form the heterostructure, the resultant heterostructure will be single-crystalline as well. The nanowire heterostructures are generally based on a semiconducting wire wherein the doping and composition are controlled in either the longitudinal or radial directions, or in both directions, to yield a wire that comprises different materials. Examples of resulting nanowire heterostructures include a longitudinal heterostructure nanowire (LOHN) and a coaxial heterostructure nanowire (COHN).

  15. Bulk nanostructured titanium fabricated by hydrostatic extrusion

    Energy Technology Data Exchange (ETDEWEB)

    Garbacz, Halina; Kurzydlowski, Krzysztof J. [Warsaw University of Technology, Faculty of Materials Science and Engineering, Warsaw (Poland); Pachla, Waclaw [Polish Academy of Sciences, Institute of High Pressure Physics, Warsaw (Poland); Topolski, Krzysztof

    2010-05-15

    The paper is concerned with the use of hydrostatic extrusion (HE), which is one of the methods of Severe Plastic Deformation (SPD), for grain refinement of titanium grade 2. Titanium in the form of rods was subjected to multi-stage extrusion. The aim was to optimize the HE process so as to obtain nanostructured titanium rods. The results show that it is possible to produce nanostructured Ti rods of a diameter suitable for industrial applications. The refinement to nano-sized grains is accompanied by a significant improvement of mechanical properties. The tensile strength of more than 1000MPa was achieved and the hardness increase exceeded 50%. This study was also concerned with the problem of up-scaling the dimensions of nano-refined components produced by HE. The basic condition for HE to yield nanostructured Ti is that an appropriately high accumulated strain should be applied ({epsilon}>3). The results demonstrate that, by using HE, we can produce nano-Ti rods with diameters amounting to diameter 8mm. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Fabrication and Multiprobe Electrical Characterization of Nanostructures

    DEFF Research Database (Denmark)

    Klarskov, Mikkel Buster

    2013-01-01

    Engineering of graphene for modifying electrical properties, such as opening an electronic band gap, has been shown both theoretically and experimentally by creating periodic holes in the graphene sheet, however at the price of lower carrier mobility. Such holes can be made with special fabrication...... techniques, such as colloidal lithography or block copolymers lithography, which covers the entire sample. This project presents graphene devices with periodic holes fabricated by electron beam lithography. Only partial coverage of holes are fabricated by making from one to many rows of holes perpendicular...

  17. Methods of fabricating nanostructures and nanowires and devices fabricated therefrom

    Science.gov (United States)

    Majumdar,; Arun, [Orinda, CA; Shakouri, Ali [Santa Cruz, CA; Sands, Timothy D [Moraga, CA; Yang, Peidong [Berkeley, CA; Mao, Samuel S [Berkeley, CA; Russo, Richard E [Walnut Creek, CA; Feick, Henning [Kensington, CA; Weber, Eicke R [Oakland, CA; Kind, Hannes [Schaffhausen, CH; Huang, Michael [Los Angeles, CA; Yan, Haoquan [Albany, CA; Wu, Yiying [Albany, CA; Fan, Rong [El Cerrito, CA

    2009-08-04

    One-dimensional nanostructures having uniform diameters of less than approximately 200 nm. These inventive nanostructures, which we refer to as "nanowires", include single-crystalline homostructures as well as heterostructures of at least two single-crystalline materials having different chemical compositions. Because single-crystalline materials are used to form the heterostructure, the resultant heterostructure will be single-crystalline as well. The nanowire heterostructures are generally based on a semiconducting wire wherein the doping and composition are controlled in either the longitudinal or radial directions, or in both directions, to yield a wire that comprises different materials. Examples of resulting nanowire heterostructures include a longitudinal heterostructure nanowire (LOHN) and a coaxial heterostructure nanowire (COHN).

  18. Methods of fabricating nanostructures and nanowires and devices fabricated therefrom

    Energy Technology Data Exchange (ETDEWEB)

    Majumdar, Arun; Shakouri, Ali; Sands, Timothy D.; Yang, Peidong; Mao, Samuel S.; Russo, Richard E.; Feick, Henning; Weber, Eicke R.; Kind, Hannes; Huang, Michael; Yan, Haoquan; Wu, Yiying; Fan, Rong

    2018-01-30

    One-dimensional nanostructures having uniform diameters of less than approximately 200 nm. These inventive nanostructures, which we refer to as "nanowires", include single-crystalline homostructures as well as heterostructures of at least two single-crystalline materials having different chemical compositions. Because single-crystalline materials are used to form the heterostructure, the resultant heterostructure will be single-crystalline as well. The nanowire heterostructures are generally based on a semiconducting wire wherein the doping and composition are controlled in either the longitudinal or radial directions, or in both directions, to yield a wire that comprises different materials. Examples of resulting nanowire heterostructures include a longitudinal heterostructure nanowire (LOHN) and a coaxial heterostructure nanowire (COHN).

  19. Alkaline Electrochemical Capacitor and Electrode Fabrication

    National Research Council Canada - National Science Library

    Finello, D

    1999-01-01

    .... The subject low cost alkaline electrochemical capacitor designs are based upon titanium nitride electrodes which exhibit 125 mF/sq cm surface capacitance density and remarkable electrochemical...

  20. Lithographically fabricated nanopore-based electrodes for electrochemistry

    NARCIS (Netherlands)

    Lemay, Serge Joseph Guy; van den Broek, D.M.; Storm, Arnold J.; Krapf, Diego; Smeets, Ralph M.M.; Heering, Hendrik A.; Dekker, Cees

    2005-01-01

    We report a new technique for fabricating electrodes for electrochemical applications with lateral dimensions in the range 15−200 nm and a reproducible, well-defined geometry. This technique allows determining the electrode size by electron microscopy prior to electrochemical measurements and

  1. A rechargeable Na-Zn hybrid aqueous battery fabricated with nickel hexacyanoferrate and nanostructured zinc

    Science.gov (United States)

    Lu, Ke; Song, Bin; Zhang, Jintao; Ma, Houyi

    2016-07-01

    Rechargeable aqueous batteries are very attractive as a promising alternative energy storage system, although their reversible capacity is typically limited. A new rechargeable Na-Zn hybrid aqueous battery with nickel hexacyanoferrate (NiHCF) cathode and the nanostructured zinc anode is fabricated. The rational combination of two materials with mild aqueous electrolyte renders the devices with an average operating voltage close to 1.5 V, higher specific capacity of 76.2 mAh g-1, and a good cycling stability with 81% capacity retention for 1000 cycles. These remarkable features can provide guidance for the development of rechargeable batteries from the naturally abundant electrode materials with neutral aqueous electrolytes.

  2. Fabrication and applications of copper sulfide (CuS) nanostructures

    Science.gov (United States)

    Shamraiz, Umair; Hussain, Raja Azadar; Badshah, Amin

    2016-06-01

    This review article presents different fabrication procedures (under the headlines of solvothermal routes, aerosol methods, solution methods and thermolysis), and applications (photocatalytic degradation, ablation of cancer cells, electrode material in lithium ion batteries and in gas sensing, organic solar cells, field emission properties, super capacitor applications, photoelectrochemical performance of QDSCs, photocatalytic reduction of organic pollutants, electrochemical bio sensing, enhanced PEC characteristics of pre-annealed CuS film electrodes) of copper sulfide (Covellite).

  3. Experimental and Theoretical Studies of Nanostructured Electrodes for Use in Dye-Sensitized Solar Cells

    Science.gov (United States)

    Gong, Jiawei

    Among various photovoltaic technologies available in the emerging market, dye-sensitized solar cells (DSSCs) are deemed as an effective, competitive solution to the increasing demand for high-efficiency PV devices. To move towards full commercialization, challenges remain in further improvement of device stability as well as reduction of material and manufacturing costs. This study aims at rational synthesis and photovoltaic characterization of two nanostructured electrode materials (i.e. SnO2 nanofibers and activated graphene nanoplatelets) for use as photoanode and counter electrode in dye-sensitized solar cells. The main objective is to explore the favorable charge transport features of SnO2 nanofiber network and simultaneously replace the high-priced conventional electrocatalytic nanomaterials (e.g. Pt nanoparticles) used in existing counter electrode of DSSCs. To achieve this objective, a multiphysics model of electrode kinetics was developed to optimize various design parameters and cell configurations. The porous hollow SnO2 nanofibers were successfully synthesized via a facile route consisting of electrospinning precursor polymer nanofibers, followed by controlled carbonization. The novel SnO2/TiO2 composite photoanode materials carry advantages of SnO2 nanofiber network (e.g. nanostructural continuity, high electron mobility) and TiO2 nanoparticles (e.g. high specific area), and therefore show excellent photovoltaic properties including improved short-circuit current and fill factors. In addition, hydrothermally activated graphene nanoplatelets (aGNP) were used as a catalytic counter electrode material to substitute for conventionally used platinum nanoparticles. Improved catalytic performance of aGNP electrode was achieved through increased surface area and better control of morphology. Dye-sensitized solar cells using these aGNP electrodes had power conversion efficiencies comparable to those using platinum nanoparticles with I-/I3- redox mediators

  4. Spectroscopic and electrochemical characterization of nanostructured optically transparent carbon electrodes.

    Science.gov (United States)

    Benavidez, Tomás E; Garcia, Carlos D

    2013-07-01

    The present paper describes the results related to the optical and electrochemical characterization of thin carbon films fabricated by spin coating and pyrolysis of AZ P4330-RS photoresist. The goal of this paper is to provide comprehensive information allowing for the rational selection of the conditions to fabricate optically transparent carbon electrodes (OTCE) with specific electrooptical properties. According to our results, these electrodes could be appropriate choices as electrochemical transducers to monitor electrophoretic separations. At the core of this manuscript is the development and critical evaluation of a new optical model to calculate the thickness of the OTCE by variable angle spectroscopic ellipsometry. Such data were complemented with topography and roughness (obtained by atomic force microscopy), electrochemical properties (obtained by cyclic voltammetry), electrical properties (obtained by electrochemical impedance spectroscopy), and structural composition (obtained by Raman spectroscopy). Although the described OTCE were used as substrates to investigate the effect of electrode potential on the real-time adsorption of proteins by ellipsometry, these results could enable the development of other biosensors that can be then integrated into various CE platforms. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. On the design and fabrication of nanostructures and devices

    Science.gov (United States)

    Wei, Wei

    Nanotechnology is emerging into a new frontier in science and technology with potential impact on every aspect of human life. One of the major breakthroughs in today's nanotechnology is the discovery and preparation of new classes of nanomaterials and nanostructures. A large number of nanomaterials and nanostructures are synthesized and characterized with either new or profoundly enhanced properties or phenomena. However, there are several major challenges ahead need to be overcome before any substantial benefits can be brought to the market. One of the challenges that we need to address today is how to effectively integrate useful nanomaterials and nanostrucrures into functional devices and systems. Our mother nature gives us a classic example of how living organisms are built. Starting from a single cell, through its division and growth, it can self-assemble and become functional tissues and organs. Similar self-assemble approach has been adopted as a nano-fabrication technique to assemble nanomaterials and nanostructures into functional nanodevices. This technique has advantages of high precision and nanometer scale resolution. However, it requires a lot of effort to construct a single device and since the properties of individual nanostructures can be different, the fabricated devices may have different properties. In this dissertation, we design and fabricate nanostructures and devices using novel microfabrication techniques. In the first part of the dissertation, the design and fabrication of a variety of nanostructures, such as metal nanowires array, polymer nanowells, and nanostructured surfaces are discussed. In the second part, carbon nanotubes as a novel material has been explored as an example to demonstrate the integration of nanomaterials with novel microfabrication techniques to form a functional device. First, a resistive heating technique is developed to grow carbon nanotubes in localized regions, such as a nichrome heating coil. Then, MEMS micro

  6. Fabrication of high aspect ratio micro electrode by using EDM

    International Nuclear Information System (INIS)

    Elsiti, Nagwa Mejid; Noordin, M.Y.; Alkali, Adam Umar

    2016-01-01

    The electrical discharge machining (EDM) process inherits characteristics that make it a promising micro-machining technique. Micro electrical discharge machining (micro- EDM) is a derived form of EDM, which is commonly used to manufacture micro and miniature parts and components by using the conventional electrical discharge machining fundamentals. Moving block electro discharge grinding (Moving BEDG) is one of the processes that can be used to fabricate micro-electrode. In this study, a conventional die sinker EDM machine was used to fabricate the micro-electrode. Modifications are made to the moving BEDG, which include changing the direction of movements and control gap in one electrode. Consequently current was controlled due to the use of roughing, semi-finishing and finishing parameters. Finally, a high aspect ratio micro-electrode with a diameter of 110.49μm and length of 6000μm was fabricated. (paper)

  7. Alkaline Electrochemical Capacitor and Electrode Fabrication

    National Research Council Canada - National Science Library

    Finello, D

    1999-01-01

    Highly capacitive (high surface area) electrodes that are electrochemically stable in strong alkaline electrolyte will form the basis for a new generation of electrical and electrochemical energy storage and conversion devices...

  8. Focused-ion-beam deposition for 3-D nanostructure fabrication

    Science.gov (United States)

    Matsui, Shinji

    2007-04-01

    Three-dimensional nanostructure fabrication has been demonstrated by 30 keV Ga+ focused-ion-beam chemical-vapor-deposition (FIB-CVD) using a phenanthrene (C14H10) source as a precursor. Microstructure plastic arts is advocated as a new field using micro-beam technology, presenting one example of micro-wine-glass with 2.75 μm external diameter and 12 μm height. The deposition film is a diamond like amorphous carbon. A large Young's modulus that exceeds 600 GPa seems to present great possibilities for various applications. Producing of three-dimensional nanostructure is discussed. Micro-coil, nanoelectrostatic actuator and nano-space-wiring with 0.1 μm dimension are demonstrated as parts of nanomechanical system. Furthermore, filtering tool is also fabricated as a novel nano-tool for the manipulation and analysis of subcellular organelles.

  9. Precisely controlled resorcinol-formaldehyde resin coating for fabricating core-shell, hollow, and yolk-shell carbon nanostructures.

    Science.gov (United States)

    Fang, Xiaoliang; Liu, Shengjie; Zang, Jun; Xu, Chaofa; Zheng, Ming-Sen; Dong, Quan-Feng; Sun, Daohua; Zheng, Nanfeng

    2013-08-07

    This work provides a facile one-step sol-gel route to synthesize high-quality resorcinol-formaldehyde (RF) resin coated nanocomposites that can be further used to fabricate desired carbon nanostructures. Colloidal particles with different morphologies and sizes can be coated with high-quality RF resin shells by the proposed cationic surfactant assisted RF resin coating strategy. The as-synthesized RF resin coated nanocomposites are ideal candidates for selective synthesis of core-shell, hollow, and yolk-shell carbon nanostructures. Based on the carboxylic functional RF resin coating, graphitic carbon nanostructures can also be synthesized by employing the graphitization catalyst. The as-synthesized carbon nanostructures show the advantageous performances in several applications. Hollow carbon spheres are potential electrode materials for lithium-sulfur batteries. Hollow graphitic spheres are promising catalyst supports for oxygen reduction reaction. And yolk-shell structured Au@HCS nanoreactors with ultrathin shells exhibit high catalytic activity and recyclability in confined catalysis.

  10. Enhanced photoelectrochemical performance and photocatalytic activity of ZnO/TiO2 nanostructures fabricated by an electrostatically modified electrospinning

    Science.gov (United States)

    Ramos, Pierre G.; Flores, Edson; Sánchez, Luis A.; Candal, Roberto J.; Hojamberdiev, Mirabbos; Estrada, Walter; Rodriguez, Juan

    2017-12-01

    In this work, ZnO/TiO2 nanostructures were fabricated by an electrostatically modified electrospinning technique using zinc acetate and commercially available TiO2-P25, polyvinyl alcohol, and a solvent. The ZnO/TiO2 nanostructures were fabricated on fluorine-doped tin oxide (FTO) glass substrate by electrospinning of aqueous solution containing different amounts of zinc acetate. The TiO2-P25 nanoparticles were immobilized within zinc acetate/PVA nanofibers. The precursor nanofibers obtained were converted into polycrystalline ZnO and ZnO/TiO2 by calcination at 600 °C. The structure and morphology of the obtained nanostructures were characterized by X-ray diffraction and field emission scanning electron microscopy, respectively. It was found that the TiO2-P25 nanoparticles were attached to the ZnO nanostructures, and the mean diameter of the nanoparticles forming the nanostructures ranged from 31 to 52 nm with increasing the amount of zinc acetate. The incident photon-to-current efficiency (IPCE) spectra of the fabricated nanostructures were measured in a three-electrode cell. The photocatalytic activities of ZnO and ZnO/TiO2 nanostructures were evaluated toward the decomposition of methyl orange. The obtained results evidenced that the coupling of TiO2 with ZnO enhanced the IPCE and improved the photocatalytic activity of ZnO. Particularly, the ZnO/TiO2 nanostructures fabricated with a zinc acetate-to-PVA ratio of 2:3 exhibited the highest IPCE and photocatalytic activity.

  11. Fabrication of flexible silver nanowire conductive films and transmittance improvement based on moth-eye nanostructure array

    Science.gov (United States)

    Zhang, Chengpeng; Zhu, Yuwen; Yi, Peiyun; Peng, Linfa; Lai, Xinmin

    2017-07-01

    Transparent conductive electrodes (TCEs) are widely used in optoelectronic devices, such as touch screens, liquid-crystal displays and light-emitting diodes. To date, the material of the most commonly used TCEs was indium-tin oxide (ITO), which had several intrinsic drawbacks that limited its applications in the long term, including relatively high material cost and brittleness. Silver nanowire (AgNW), as one of the alternative materials for ITO TCEs, has already gained much attention all over the world. In this paper, we reported a facile method to greatly enhance the transmittance of the AgNW TCEs without reducing the electrical conductivity based on moth-eye nanostructures, and the moth-eye nanostructures were fabricated by using a roll-to-roll ultraviolet nanoimprint lithography process. Besides, the effects of mechanical pressure and bending on the moth-eye nanostructure layer were also investigated. In the research, the optical transmittance of the flexible AgNW TCEs was enhanced from 81.3% to 86.0% by attaching moth-eye nanostructures onto the other side of the flexible polyethylene terephthalate substrate while the electrical conductivity of the AgNW TCEs was not sacrificed. This research can provide a direction for the cost-effective fabrication of moth-eye nanostructures and the transmittance improvement of the flexible transparent electrodes.

  12. Transparent nanostructured electrodes: Electrospun NiO nanofibers/NiO films

    Energy Technology Data Exchange (ETDEWEB)

    Lamastra, F.R. [Italian Interuniversity Consortium on Materials Science and Technology (INSTM), Research Unit Roma Tor Vergata, Via del Politecnico 1, 00133 Rome (Italy); Nanni, F. [Italian Interuniversity Consortium on Materials Science and Technology (INSTM), Research Unit Roma Tor Vergata, Via del Politecnico 1, 00133 Rome (Italy); Department of Enterprise Engineering, University of Rome Tor Vergata, Via del Politecnico 1, 00133 Rome (Italy); Menchini, F. [ENEA, CR Casaccia, Via Anguillarese 301, 00123 Rome (Italy); Nunziante, P. [Italian Interuniversity Consortium on Materials Science and Technology (INSTM), Research Unit Roma Tor Vergata, Via del Politecnico 1, 00133 Rome (Italy); Department of Chemical Sciences and Technologies, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome (Italy); Grilli, M.L., E-mail: marialuisa.grilli@enea.it [ENEA, CR Casaccia, Via Anguillarese 301, 00123 Rome (Italy)

    2016-02-29

    Polyvinylpyrrolidone (PVP)/nickel(II) acetate precursor fibers were deposited by electrospinning directly on radio frequency sputtered thin Ni and NiO films grown on quartz substrate, starting from Ni(II) acetate and PVP solution in ethanol. The samples were calcined in air in the temperature range 400–500 °C to obtain transparent and conductive p-type NiO nanofibers on NiO films. A higher density of nanofibers was obtained on Ni/quartz substrates, as compared to NiO/quartz ones, demonstrating the feasibility of fiber adhesion directly to an insulating substrate previously coated by a thin Ni layer. Samples were characterized by field emission-scanning electron microscopy, X-ray diffraction, spectrophotometric and resistance measurements. - Highlights: • Nanostructured electrodes: electrospun NiO nanofibers/NiO films were fabricated. • NiO fibers were directly grown on insulating substrate coated by thin Ni or NiO films. • Good quality crystalline fibers were obtained at low calcination temperatures. • Transparent and conductive p-type electrodes were fabricated.

  13. Electrochemically synthesized stretchable polypyrrole/fabric electrodes for supercapacitor

    International Nuclear Information System (INIS)

    Yue, Binbin; Wang, Caiyun; Ding, Xin; Wallace, Gordon G.

    2013-01-01

    Wearable electronics offer the combined advantages of both electronics and fabrics. Being an indispensable part of these electronics, lightweight, stretchable and wearable power sources are strongly demanded. Here we describe a daily-used cotton fabric coated with polypyrrole as electrode for stretchable supercapacitors. Polypyrrole was synthesized on the Au coated fabric via an electrochemical polymerization process with p-toluenesulfonic acid (p-TS) as dopant from acetonitrile solution. This material was characterized with FESEM, tensile stress, and studied as a supercapacitor electrode in 1.0 M NaCl. This conductive textile electrode can sustain up to 140% strain without electric failure. It delivers a high specific capacitance of 254.9 F g −1 at a scan rate of 10 mV s −1 , and keeps almost unchanged at an applied strain (i.e. 30% and 50%) but with an improved cycling stability

  14. Fabrication of hybrid nanostructures by liquid plasma for biomedical applications

    Science.gov (United States)

    Ponraj, Sri Balaji; Dai, Xiujuan Jane; Li, Luhua; Chen, Zhiqiang; Surya Narayanan, Jayanth; Kanwar, Jagat; Du Plessis, Johan

    2013-09-01

    Liquid plasma, generated by a nanosecond pulsed generator at atmospheric pressure, was used to treat bamboo-like boron nitride nanotubes (BNNTs). It was observed that the length of the BNNTs was reduced and found more cup like structures called boron nitride nanocups (BNNCs). Interestingly, a new peak appeared at 406.86 eV in the N1s X-ray photoelectron spectrum, which seems to be attributable to the oxidation of nitrogen (N-O) in BNNTs. The C1s spectrum showed that oxygen functional groups were introduced onto the BNNT/BNNC surface. The liquid plasma was also used to assemble gold nanoparticles onto the treated BNNTs/BNNCs. This hybrid nanostructure was fabricated efficiently, compared with normal equilibrium conditions. The pH values and conductivity of all samples were measured. After plasma treatment, the pH values were greatly reduced and conductivity was significantly increased. We propose that the plasma acid, hydrogen peroxide, OH-, H ions and radicals formed in liquid plasma as well as the pulsed electric field contribute to the oxidation of nitrogen, reduced length of the BNNTs(forming BNNCs), surface functionalization, and to the fabrication of hybrid nanostructure. The cytotoxic tests for these hybrid nanostructures is underway. The authors acknowledge Rosey van Driel and Prabhukumar Sellamuthu for assisting with TEM and SEM, and the access of the XPS facility at RMIT University.

  15. Fabrication and electric measurements of nanostructures inside transmission electron microscope

    International Nuclear Information System (INIS)

    Chen, Qing; Peng, Lian-Mao

    2011-01-01

    Using manipulation holders specially designed for transmission electron microscope (TEM), nanostructures can be characterized, measured, modified and even fabricated in-situ. In-situ TEM techniques not only enable real-time study of structure-property relationships of materials at atomic scale, but also provide the ability to control and manipulate materials and structures at nanoscale. This review highlights in-situ electric measurements and in-situ fabrication and structure modification using manipulation holder inside TEM. -- Research highlights: → We review in-situ works using manipulation holder in TEM. → In-situ electric measurements, fabrication and structure modification are focused. → We discuss important issues that should be considered for reliable results. → In-situ TEM is becoming a very powerful tool for many research fields.

  16. Fabrication of Dry Electrode for Recording Bio-potentials

    International Nuclear Information System (INIS)

    Wang Yu; Yang Jian-Hong; Guo Kai; Pei Wei-Hua; Gui Qiang; Li Xiao-Qian; Chen Hong-Da

    2011-01-01

    Development of minimally invasive dry electrodes for recording biopotentials is presented. The detailed fabrication process is outlined. A dry electrode is formed by a number of microneedles. The lengths of the microneedles are about 150μm and the diameters are about 50μm. The tips of the microneedles are sharp enough to penetrate into the skin. The silver/silver chloride is grown on microneedle arrays and demonstrates good character. The electrocardiogram shows that the dry electrode is suitable for recording biopotentials. (general)

  17. Fabrication of Large Area Periodic Nanostructures Using Nanosphere Photolithography

    Directory of Open Access Journals (Sweden)

    Wu Wei

    2008-01-01

    Full Text Available Abstract Large area periodic nanostructures exhibit unique optical and electronic properties and have found many applications, such as photonic band-gap materials, high dense data storage, and photonic devices. We have developed a maskless photolithography method—Nanosphere Photolithography (NSP—to produce a large area of uniform nanopatterns in the photoresist utilizing the silica micro-spheres to focus UV light. Here, we will extend the idea to fabricate metallic nanostructures using the NSP method. We produced large areas of periodic uniform nanohole array perforated in different metallic films, such as gold and aluminum. The diameters of these nanoholes are much smaller than the wavelength of UV light used and they are very uniformly distributed. The method introduced here inherently has both the advantages of photolithography and self-assembled methods. Besides, it also generates very uniform repetitive nanopatterns because the focused beam waist is almost unchanged with different sphere sizes.

  18. Nanostructuring of biosensing electrodes with nanodiamonds for antibody immobilization.

    Science.gov (United States)

    Zhang, Wenli; Patel, Kush; Schexnider, Andrew; Banu, Shirin; Radadia, Adarsh D

    2014-02-25

    While chemical vapor deposition of diamond films is currently cost prohibitive for biosensor construction, in this paper, we show that sonication-assisted nanostructuring of biosensing electrodes with nanodiamonds (NDs) allows harnessing the hydrolytic stability of the diamond biofunctionalization chemistry for real-time continuous sensing, while improving the detector sensitivity and stability. We find that the higher surface coverages were important for improved bacterial capture and can be achieved through proper choice of solvent, ND concentration, and seeding time. A mixture of methanol and dimethyl sulfoxide provides the highest surface coverage (33.6 ± 3.4%) for the NDs with positive zeta-potential, compared to dilutions of dimethyl sulfoxide with acetone, ethanol, isopropyl alcohol, or water. Through impedance spectroscopy of ND-seeded interdigitated electrodes (IDEs), we found that the ND seeds serve as electrically conductive islands only a few nanometers apart. Also we show that the seeded NDs are amply hydrogenated to be decorated with antibodies using the UV-alkene chemistry, and higher bacterial captures can be obtained compared to our previously reported work with diamond films. When sensing bacteria from 10(6) cfu/mL E. coli O157:H7, the resistance to charge transfer at the IDEs decreased by ∼ 38.8%, which is nearly 1.5 times better than that reported previously using redox probes. Further in the case of 10(8) cfu/mL E. coli O157:H7, the charge transfer resistance changed by ∼ 46%, which is similar to the magnitude of improvement reported using magnetic nanoparticle-based sample enrichment prior to impedance detection. Thus ND seeding allows impedance biosensing in low conductivity solutions with competitive sensitivity.

  19. Oxide nanostructures hyperbranched with thin and hollow metal shells for high-performance nanostructured battery electrodes.

    Science.gov (United States)

    Xia, Xinhui; Xiong, Qinqin; Zhang, Yongqi; Tu, Jiangping; Ng, Chin Fan; Fan, Hong Jin

    2014-06-25

    High-performance electrochemical energy storage (EES) devices require the ability to modify and assemble electrode materials with superior reactivity and structural stability. The fabrication of different oxide/metal core-branch nanoarrays with adjustable components and morphologies (e.g., nanowire and nanoflake) is reported on different conductive substrates. Hollow metal branches (or shells) wrapped around oxide cores are realized by electrodeposition using ZnO nanorods as a sacrificial template. In battery electrode application, the thin hollow metal branches can provide a mechanical protection of the oxide core and a highly conductive path for charges. As a demonstration, arrays of Co3O4/Ni core-branch nanowires are evaluated as the anode for lithium ion batteries. The thin metal branches evidently improve the electrochemical performance with higher specific capacity, rate capability, and capacity retention than the unmodified Co3O4 counterparts. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Nanostructured membranes and electrodes with sulfonic acid functionalized carbon nanotubes

    KAUST Repository

    Tripathi, Bijay Prakash

    2011-02-01

    Herein we report the covalent functionalization of multiwall carbon nanotubes by grafting sulfanilic acid and their dispersion into sulfonated poly(ether ether ketone). The nanocomposites were explored as an option for tuning the proton and electron conductivity, swelling, water and alcohol permeability aiming at nanostructured membranes and electrodes for application in alcohol or hydrogen fuel cells and other electrochemical devices. The nanocomposites were extensively characterized, by studying their physicochemical and electrochemical properties. They were processed as self-supporting films with high mechanical stability, proton conductivity of 4.47 × 10 -2 S cm-1 at 30 °C and 16.8 × 10-2 S cm-1 at 80 °C and 100% humidity level, electron conductivity much higher than for the plain polymer. The methanol permeability could be reduced to 1/20, keeping water permeability at reasonable values. The ratio of bound water also increases with increasing content of sulfonated filler, helping in keeping water in the polymer in conditions of low external humidity level. © 2010 Elsevier B.V.

  1. Nanostructured polyamic acid membranes as novel electrode materials.

    Science.gov (United States)

    Andreescu, Daniel; Wanekaya, Adam K; Sadik, Omowunmi A; Wang, Joseph

    2005-07-19

    This paper describes a new approach for the preparation of polyamic acid (PAA) composites containing Ag and Au nanoparticles. The composite film of PAA and metal particles were obtained upon electrodeposition of a PAA solution containing gold or silver salts with subsequent thermal treatment, while imidization to polyimide is prevented. The structural characterization of the films is provided by 1H NMR and Fourier transform infrared spectroscopy (FTIR), while the presence of metallic nanoparticles within the polymeric matrix was confirmed by scanning electron microscopy (SEM), cyclic voltammetry (CV), energy-dispersive X-ray analysis (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). This approach utilizes the unique reactivity of PAA by preventing the cyclization of the reactive soluble intermediate into polyimides at low temperature to design polymer-assisted nanostructured materials. The ability to prevent the cyclization process should enable the design of a new class of electrode materials by use of thermal reduction and/or electrodeposition.

  2. Solid gold nanostructures fabricated by electron beam deposition

    DEFF Research Database (Denmark)

    Mølhave, Kristian; Madsen, Dorte Nørgaard; Rasmussen, A.M.

    2003-01-01

    and bridges. Transmission electron microscopy was used to study how the composition of these structures was affected when the background gas in the ESEM chamber and the electron beam parameters were varied. The nanostructures were layered composites of up to three different materials each characterized...... by a certain range of gold/carbon ratios. Above a certain threshold of ESEM chamber water vapor pressure and a certain threshold of electron beam current, the deposited tips contained a solid polycrystalline gold core. The deposition technique was used to fabricate free-standing nanowires and to solder free...

  3. Design, fabrication and skin-electrode contact analysis of polymer microneedle-based ECG electrodes

    Science.gov (United States)

    O'Mahony, Conor; Grygoryev, Konstantin; Ciarlone, Antonio; Giannoni, Giuseppe; Kenthao, Anan; Galvin, Paul

    2016-08-01

    Microneedle-based ‘dry’ electrodes have immense potential for use in diagnostic procedures such as electrocardiography (ECG) analysis, as they eliminate several of the drawbacks associated with the conventional ‘wet’ electrodes currently used for physiological signal recording. To be commercially successful in such a competitive market, it is essential that dry electrodes are manufacturable in high volumes and at low cost. In addition, the topographical nature of these emerging devices means that electrode performance is likely to be highly dependent on the quality of the skin-electrode contact. This paper presents a low-cost, wafer-level micromoulding technology for the fabrication of polymeric ECG electrodes that use microneedle structures to make a direct electrical contact to the body. The double-sided moulding process can be used to eliminate post-process via creation and wafer dicing steps. In addition, measurement techniques have been developed to characterize the skin-electrode contact force. We perform the first analysis of signal-to-noise ratio dependency on contact force, and show that although microneedle-based electrodes can outperform conventional gel electrodes, the quality of ECG recordings is significantly dependent on temporal and mechanical aspects of the skin-electrode interface.

  4. Design, fabrication and skin-electrode contact analysis of polymer microneedle-based ECG electrodes

    International Nuclear Information System (INIS)

    O’Mahony, Conor; Grygoryev, Konstantin; Ciarlone, Antonio; Giannoni, Giuseppe; Kenthao, Anan; Galvin, Paul

    2016-01-01

    Microneedle-based ‘dry’ electrodes have immense potential for use in diagnostic procedures such as electrocardiography (ECG) analysis, as they eliminate several of the drawbacks associated with the conventional ‘wet’ electrodes currently used for physiological signal recording. To be commercially successful in such a competitive market, it is essential that dry electrodes are manufacturable in high volumes and at low cost. In addition, the topographical nature of these emerging devices means that electrode performance is likely to be highly dependent on the quality of the skin-electrode contact.This paper presents a low-cost, wafer-level micromoulding technology for the fabrication of polymeric ECG electrodes that use microneedle structures to make a direct electrical contact to the body. The double-sided moulding process can be used to eliminate post-process via creation and wafer dicing steps. In addition, measurement techniques have been developed to characterize the skin-electrode contact force. We perform the first analysis of signal-to-noise ratio dependency on contact force, and show that although microneedle-based electrodes can outperform conventional gel electrodes, the quality of ECG recordings is significantly dependent on temporal and mechanical aspects of the skin-electrode interface. (paper)

  5. NOVEL EMBEDDED CERAMIC ELECTRODE SYSTEM TO ACTIVATE NANOSTRUCTURED TITANIUM DIOXIDE FOR DEGRADATION OF MTBE

    Science.gov (United States)

    A novel reactor combining a flame-deposited nanostructured titanium dioxide film and a set of embedded ceramic electrodes was designed, developed and tested for degradation of methyl tert-butyl ether (MTBE) in water. On applying a voltage to the ceramic electrodes, a surface coro...

  6. High performance capacitors using nano-structure multilayer materials fabrication

    Science.gov (United States)

    Barbee, Jr., Troy W.; Johnson, Gary W.; O'Brien, Dennis W.

    1995-01-01

    A high performance capacitor fabricated from nano-structure multilayer materials, such as by controlled, reactive sputtering, and having very high energy-density, high specific energy and high voltage breakdown. The multilayer capacitors, for example, may be fabricated in a "notepad" configuration composed of 200-300 alternating layers of conductive and dielectric materials so as to have a thickness of 1 mm, width of 200 mm, and length of 300 mm, with terminals at each end of the layers suitable for brazing, thereby guaranteeing low contact resistance and high durability. The "notepad" capacitors may be stacked in single or multiple rows (series-parallel banks) to increase the voltage and energy density.

  7. Fabrication of Pillar Shaped Electrode Arrays for Artificial Retinal Implants

    Directory of Open Access Journals (Sweden)

    Sung June Kim

    2008-09-01

    Full Text Available Polyimide has been widely applied to neural prosthetic devices, such as the retinal implants, due to its well-known biocompatibility and ability to be micropatterned. However, planar films of polyimide that are typically employed show a limited ability in reducing the distance between electrodes and targeting cell layers, which limits site resolution for effective multi-channel stimulation. In this paper, we report a newly designed device with a pillar structure that more effectively interfaces with the target. Electrode arrays were successfully fabricated and safely implanted inside the rabbit eye in suprachoroidal space. Optical Coherence Tomography (OCT showed well-preserved pillar structures of the electrode without damage. Bipolar stimulation was applied through paired sites (6:1 and the neural responses were successfully recorded from several regions in the visual cortex. Electrically evoked cortical potential by the pillar electrode array stimulation were compared to visual evoked potential under full-field light stimulation.

  8. Bubble dynamic templated deposition of three-dimensional palladium nanostructure catalysts: Approach to oxygen reduction using macro-, micro-, and nano-architectures on electrode surfaces

    International Nuclear Information System (INIS)

    Yang Guimei; Chen Xing; Li Jie; Guo Zheng; Liu Jinhuai; Huang Xingjiu

    2011-01-01

    Highlights: → We synthesize the Pd nanostructures by bubbles dynamic templated. → We obtain Pd nanobuds and Pd nanodendrites by changing the reaction precursor. → We obtain Pd macroelectrode voltammertric behavior using small amount of Pd materials. → We proved a ECE process. → The Pd nanostructures/GCE for O 2 reduction is a 2-step 4-electron process. - Abstract: Three-dimensional (3D) palladium (Pd) nanostructures (that is, nano-buds or nano-dendrites) are fabricated by bubble dynamic templated deposition of Pd onto a glassy carbon electrode (GCE). The morphology can be tailored by changing the precursor concentration and reaction time. Scanning electron microscopy images reveal that nano-buds or nano-dendrites consist of nanoparticles of 40-70 nm in diameter. The electrochemical reduction of oxygen is reported at such kinds of 3D nanostructure electrodes in aqueous solution. Data were collected using cyclic voltammetry. We demonstrate the Pd macroelectrode behavior of Pd nanostructure modified electrode by exploiting the diffusion model of macro-, micro-, and nano-architectures. In contrast to bare GCE, a significant positive shift and splitting of the oxygen reduction peak (vs Ag/AgCl/saturated KCl) at Pd nanostructure modified GCE was observed.

  9. Fabric-based active electrode design and fabrication for health monitoring clothing.

    Science.gov (United States)

    Merritt, Carey R; Nagle, H Troy; Grant, Edward

    2009-03-01

    In this paper, two versions of fabric-based active electrodes are presented to provide a wearable solution for ECG monitoring clothing. The first version of active electrode involved direct attachment of surface-mountable components to a textile screen-printed circuit using polymer thick film techniques. The second version involved attaching a much smaller, thinner, and less obtrusive interposer containing the active electrode circuitry to a simplified textile circuit. These designs explored techniques for electronic textile interconnection, chip attachment to textiles, and packaging of circuits on textiles for durability. The results from ECG tests indicate that the performance of each active electrode is comparable to commercial Ag/AgCl electrodes. The interposer-based active electrodes survived a five-cycle washing test while maintaining good signal integrity.

  10. Enhancement of dielectrophoresis using fractal gold nanostructured electrodes.

    Science.gov (United States)

    Koklu, Anil; Sabuncu, Ahmet C; Beskok, Ali

    2017-06-01

    Dielectrophoretic motions of Saccharomyces cerevisiae (yeast) cells and colloidal gold are investigated using electrochemically modified electrodes exhibiting fractal topology. Electrodeposition of gold on electrodes generated repeated patterns with a fern-leaf type self-similarity. A particle tracking algorithm is used to extract dielectrophoretic particle velocities using fractal and planar electrodes in two different medium conductivities. The results show increased dielectrophoretic force when using fractal electrodes. Strong negative dielectrophoresis of yeast cells in high-conductivity media (1.5 S/m) is observed using fractal electrodes, while no significant motion is present using planar electrodes. Electrical impedance at the electrode/electrolyte interface is measured using impedance spectroscopy technique. Stronger electrode polarization (EP) effects are reported for planar electrodes. Decreased EP in fractal electrodes is considered as a reason for enhanced dielectrophoretic response. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Fabrication of Polymer Microneedle Electrodes Coated with Nanoporous Parylene

    Science.gov (United States)

    Nishinaka, Yuya; Jun, Rina; Setia Prihandana, Gunawan; Miki, Norihisa

    2013-06-01

    In this study, we demonstrate the fabrication of polymer microneedle electrodes covered with a nanoporous parylene film that can serve as flexible electrodes for a brain-machine interface. In brain wave measurement, the electric impedance of electrodes should be below 10 kΩ at 15 Hz, and the conductive layer needs to be protected to survive its insertion into the stratum corneum. Polymer microneedles can be used as substrates for flexible electrodes, which can compensate for the movement of the skin; however, the adhesion between a conductive metal film, such as a silver film, and a polymer, such as poly(dimethylsiloxane) (PDMS), is weak. Therefore, we coated the electrode surface with a nanoporous parylene film, following the vapor deposition of a silver film. When the porosity of the parylene film is appropriate, it protects the silver film while allowing the electrode to have sufficient conductivity. The porosity can be controlled by adjusting the amount of the parylene dimer used for the deposition or the parylene film thickness. We experimentally verified that a conductive membrane was successfully protected while maintaining a conductivity below 10 kΩ when the thickness of the parylene film was between 25 and 38 nm.

  12. Nanostructured platinum as an electrochemically and mechanically stable electrode coating.

    Science.gov (United States)

    Boehler, C; Oberueber, F; Stieglitz, T; Asplund, M

    2017-07-01

    Nanostructured materials exhibit large electrochemical surface areas and are thus of high interest for neural interfaces where low impedance and high charge transfer characteristics are desired. While progress in nanotechnology successively enabled smaller feature sizes and thus improved electrochemical properties, concerns were raised with respect to the mechanical stability of such nano structures for use in neural applications. In our study we address these concerns by investigating the mechanical and electrochemical stability of nanostructured platinum. Neural probes with nano-Pt were exposed to exaggerated stress tests resembling insertion into neural tissue over 60 mm distance or long-term stimulation over 240 M biphasic current pulses. Thereby only insignificant changes in electrochemical properties and morphological appearance could be observed in response to the test, proving that nanostructured platinum exhibits outstanding stability. With this finding, a major concern in using nanostructured materials for interfacing neural tissue could be eliminated, demonstrating the high potential of nanostructured platinum for neuroprosthetic devices.

  13. Rational design of hierarchically nanostructured electrodes for solid oxide fuel cells

    Science.gov (United States)

    Çelikbilek, Ӧzden; Jauffrès, David; Siebert, Elisabeth; Dessemond, Laurent; Burriel, Mónica; Martin, Christophe L.; Djurado, Elisabeth

    2016-11-01

    Understanding, controlling and optimizing the mechanisms of electrode reactions need to be addressed for high performance energy and storage conversion devices. Hierarchically structured porous films of mixed ionic electronic conductors (MIECs) and their composites with ionic conductors offer unique properties. However, correlating the intrinsic properties of electrode components to microstructural features remains a challenging task. Here, La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) and La0.6Sr0.4Co0.2Fe0.8O3-δ: Ce0.9Gd0.1O2-δ (LSCF:CGO) composite cathodes with hierarchical porosity from nano to micro range are fabricated. The LSCF film exhibits exceptional electrode performance with area specific resistance values of 0.021 and 0.065 Ω cm2 at 650 and 600 °C respectively, whereas LSCF:CGO composite is only slightly superior than pure LSCF below 450 °C. We report for the first time a numerical 3D Finite Element Model (FEM) comprising real micro/nanostructural parameters from 3D reconstructions into a simple geometry similar to experimentally observed columnar features. The model demonstrates that heterogeneities in porosity within the film thickness and percolation of the ionically conducting phase significantly impact bulk transport at low temperatures. Design guidelines relating performance to microstructure and bulk material properties in relation to experimental results are proposed. Our model has potential to be extended for rational design of larger, regular and heterogeneous microstructures.

  14. High temperature SU-8 pyrolysis for fabrication of carbon electrodes

    DEFF Research Database (Denmark)

    Hassan, Yasmin Mohamed; Caviglia, Claudia; Hemanth, Suhith

    2017-01-01

    In this work, we present the investigation of the pyrolysis parameters at high temperature (1100 °C) for the fabrication of two-dimensional pyrolytic carbon electrodes. The electrodes were fabricated by pyrolysis of lithographically patterned negative epoxy based photoresist SU-8. A central...... composite experimental design was used to identify the influence of dwell time at the highest pyrolysis temperature and heating rate on electrical, electrochemical and structural properties of the pyrolytic carbon: Van der Pauw sheet resistance measurements, cyclic voltammetry, electrochemical impedance...... spectroscopy and Raman spectroscopy were used to characterize the pyrolytic carbon. The results show that the temperature increase from 900 °C to 1100 °C improves the electrical and electrochemical properties. At 1100 °C, longer dwell time leads to lower resistivity, while the variation of the pyrolysis...

  15. Novel flame synthesis of nanostructured α-Fe2O3 electrode as high-performance anode for lithium ion batteries

    Science.gov (United States)

    Wang, Yang; Roller, Justin; Maric, Radenka

    2018-02-01

    Nanostructured electrodes have significant potential for enhancing the kinetics of lithium storage in secondary batteries. A simple and economical manufacturing approach of these electrodes is crucial to the development and application of the next generation lithium ion (Li-ion) batteries. In this study, nanostructured α-Fe2O3 electrode is fabricated by a novel one-step flame combustion synthesis method, namely Reactive Spray Deposition Technology (RSDT). This process possesses the merits of simplicity and low cost. The structure and morphology of the electrode are investigated with X-ray diffraction, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Electrochemical performance of the nanostructured α-Fe2O3 electrodes as the anodes for Li-ion batteries is evaluated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy in coin-type half-cells. The as-prepared electrodes demonstrate superior cyclic performance at high current rate, which delivers a high reversible capacity of 1239.2 mAh g-1 at 1 C after 500 cycles. In addition, a discharge capacity of 513.3 mAh g-1 can be achieved at 10 C.

  16. Sonochemical synthesis of nanostructured nickel hydroxide as an electrode material for improved electrochemical energy storage application

    Directory of Open Access Journals (Sweden)

    Arshid Numan

    2017-08-01

    Full Text Available A facile and fast approach for the synthesis of a nanostructured nickel hydroxide (Ni(OH2 via sonochemical technique is reported in the present study. The X-ray diffraction results confirmed that the synthesized Ni(OH2 was oriented in β-phase of hexagonal brucite structure. The nanostructured Ni(OH2 electrode exhibited the maximum specific capacitance of 1256 F/g at a current density of 200 mA/g in 1 M KOH(aq. Ni(OH2 electrodes exhibited the pseudocapacitive behavior due to the presence of redox reaction. It also exhibited long-term cyclic stability of 85% after 2000 cycles, suggesting that the nanostructured Ni(OH2 electrode will play a promising role for high performance supercapacitor application.

  17. Nanostructure Core Fiber With Enhanced Performances: Design, Fabrication and Devices

    DEFF Research Database (Denmark)

    Yu, X.; Yan, Min; Ren, G.B.

    2009-01-01

    -mode-area (LMA) structure with a typical high birefringence in the order of 10(-4) can be easily realized. The attenuation of the fabricated NCF is as low as 3.5 dB/km at 1550 nm. Higher macro- and micro-bending losses compared with those of the single-mode fiber (SMF) due to the reduced index difference have......We report a new type of silica-based all-solid fiber with a 2-D nanostructure core. The nanostructure core fiber (NCF) is formed by a 2-D array of high-index rods of sub-wavelength dimensions. We theoretically study the birefringence property of such fibers over a large wavelength range. Large...... been observed experimentally, which suggests that the NCF is potentially useful for curvature and strain sensing applications. A fiber Bragg grating (FBG) inscribed in such a novel fiber is side-polished to make use of its evanescent field for refractive index sensing. The refractive index sensitivity...

  18. Hydrothermally Activated Graphene Fiber Fabrics for Textile Electrodes of Supercapacitors.

    Science.gov (United States)

    Li, Zheng; Huang, Tieqi; Gao, Weiwei; Xu, Zhen; Chang, Dan; Zhang, Chunxiao; Gao, Chao

    2017-11-28

    Carbon textiles are promising electrode materials for wearable energy storage devices owing to their conductive, flexible, and lightweight features. However, there still lacks a perfect choice for high-performance carbon textile electrodes with sufficient electrochemical activity. Graphene fiber fabrics (GFFs) are newly discovered carbon textiles, exhibiting various attractive properties, especially a large variability on the microstructure. Here we report the fabrication of hierarchical GFFs with significantly enlarged specific surface area using a hydrothermal activation strategy. By carefully optimize the activation process, the hydrothermally activated graphene fiber fabrics (HAGFFs) could achieve an areal capacitance of 1060 mF cm -2 in a very thin thickness (150 μm) and the capacitance is easily magnified by overlaying several layers of HAGFFs, even up to a record value of 7398 mF cm -2 . Meanwhile, a good rate capability and a long cycle life are also attained. As compared with other carbon textiles, including the commercial carbon fiber cloths, our HAGFFs present much better capacitive performance. Therefore, the mechanically stable, flexible, conductive, and highly active HAGFFs have provided an option for high-performance textile electrodes.

  19. Electrochemical performances of asymmetric super capacitor fabricated by one-dimensional CoMoO4 nanostructure

    Science.gov (United States)

    Zhao, Yunxuan; Teng, Fei; Liu, Zailun; Du, Qian; Xu, Jingjing; Teng, Yiran

    2016-11-01

    We have prepared the CoMoO4 nanorods (NR) electrode with a specific capacitance (89.5 F g-1) at a current density of 1 mA cm-2. Moreover, the asymmetric supercapacitor (ASC) has been fabricated by using CoMoO4 NR as positive electrode and activated carbon (AC) as negative electrode. At a power density of 80 mW cm-3, the ASC can deliver an energy density of 0.226 mW h cm-3 in the voltage range of 0-1.6 V. In addition, the CoMoO4 NR-based ASC device still remains a high energy density (84.07%) after 5000 cycles, demonstrating that one-dimensional nanostructures could be promising to achieve the high-energy-density materials.

  20. A Review on Anodic Aluminum Oxide Methods for Fabrication of Nanostructures for Organic Solar Cells

    DEFF Research Database (Denmark)

    Goszczak, Arkadiusz Jaroslaw; Cielecki, Pawel Piotr

    2018-01-01

    , low fabrication cost and easy control over its nano-scale morphology, make AAO patterning methods an intriguing candidate for nanopatterning. Hence, in this work, we present a review on the fabrication techniques and on nanostructures from Anodic Aluminum Oxide (AAO) for OSC applications....... The versatility of such patterning technique is shown by pointing out the possibility of using an AAO template for the fabrication of nanowires by wetting, nanodots by evaporation, nanostructures by imprinting resists, organic layers and much more....

  1. Electrodes synthesized from carbon nanostructures coated with a smooth and conformal metal adlayer

    Science.gov (United States)

    Adzic, Radoslav; Harris, Alexander

    2014-04-15

    High-surface-area carbon nanostructures coated with a smooth and conformal submonolayer-to-multilayer thin metal films and their method of manufacture are described. The preferred manufacturing process involves the initial oxidation of the carbon nanostructures followed by a surface preparation process involving immersion in a solution with the desired pH to create negative surface dipoles. The nanostructures are subsequently immersed in an alkaline solution containing a suitable quantity of non-noble metal ions which adsorb at surface reaction sites. The metal ions are then reduced via chemical or electrical means. The nanostructures are exposed to a solution containing a salt of one or more noble metals which replace adsorbed non-noble surface metal atoms by galvanic displacement. The process can be controlled and repeated to obtain a desired film coverage. The resulting coated nanostructures may be used, for example, as high-performance electrodes in supercapacitors, batteries, or other electric storage devices.

  2. High Speed, Low Cost Fabrication of Gas Diffusion Electrodes for Membrane Electrode Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    DeCastro, Emory S.; Tsou, Yu-Min; Liu, Zhenyu

    2013-09-20

    Fabrication of membrane electrode assemblies (MEAs) depends on creating inks or pastes of catalyst and binder, and applying this suspension to either the membrane (catalyst coated membrane) or gas diffusion media (gas diffusion electrode) and respectively laminating either gas diffusion media or gas diffusion electrodes (GDEs) to the membrane. One barrier to cost effective fabrication for either of these approaches is the development of stable and consistent suspensions. This program investigated the fundamental forces that destabilize the suspensions and developed innovative approaches to create new, highly stable formulations. These more concentrated formulations needed fewer application passes, could be coated over longer and wider substrates, and resulted in significantly lower coating defects. In March of 2012 BASF Fuel Cell released a new high temperature product based on these advances, whereby our customers received higher performing, more uniform MEAs resulting in higher stack build yields. Furthermore, these new materials resulted in an “instant” increase in capacity due to higher product yields and material throughput. Although not part of the original scope of this program, these new formulations have also led us to materials that demonstrate equivalent performance with 30% less precious metal in the anode. This program has achieved two key milestones in DOE’s Manufacturing R&D program: demonstration of processes for direct coating of electrodes and continuous in-line measurement for component fabrication.

  3. Broadband solar absorption enhancement via periodic nanostructuring of electrodes.

    KAUST Repository

    Adachi, Michael M

    2013-10-14

    Solution processed colloidal quantum dot (CQD) solar cells have great potential for large area low-cost photovoltaics. However, light utilization remains low mainly due to the tradeoff between small carrier transport lengths and longer infrared photon absorption lengths. Here, we demonstrate a bottom-illuminated periodic nanostructured CQD solar cell that enhances broadband absorption without compromising charge extraction efficiency of the device. We use finite difference time domain (FDTD) simulations to study the nanostructure for implementation in a realistic device and then build proof-of-concept nanostructured solar cells, which exhibit a broadband absorption enhancement over the wavelength range of λ = 600 to 1,100 nm, leading to a 31% improvement in overall short-circuit current density compared to a planar device containing an approximately equal volume of active material. Remarkably, the improved current density is achieved using a light-absorber volume less than half that typically used in the best planar devices.

  4. A Tunable 3D Nanostructured Conductive Gel Framework Electrode for High-Performance Lithium Ion Batteries.

    Science.gov (United States)

    Shi, Ye; Zhang, Jun; Bruck, Andrea M; Zhang, Yiman; Li, Jing; Stach, Eric A; Takeuchi, Kenneth J; Marschilok, Amy C; Takeuchi, Esther S; Yu, Guihua

    2017-06-01

    This study develops a tunable 3D nanostructured conductive gel framework as both binder and conductive framework for lithium ion batteries. A 3D nanostructured gel framework with continuous electron pathways can provide hierarchical pores for ion transport and form uniform coatings on each active particle against aggregation. The hybrid gel electrodes based on a polypyrrole gel framework and Fe 3 O 4 nanoparticles as a model system in this study demonstrate the best rate performance, the highest achieved mass ratio of active materials, and the highest achieved specific capacities when considering total electrode mass, compared to current literature. This 3D nanostructured gel-based framework represents a powerful platform for various electrochemically active materials to enable the next-generation high-energy batteries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Nanostructured core-shell electrode materials for electrochemical capacitors

    Science.gov (United States)

    Jiang, Long-bo; Yuan, Xing-zhong; Liang, Jie; Zhang, Jin; Wang, Hou; Zeng, Guang-ming

    2016-11-01

    Core-shell nanostructure represents a unique system for applications in electrochemical energy storage devices. Owing to the unique characteristics featuring high power delivery and long-term cycling stability, electrochemical capacitors (ECs) have emerged as one of the most attractive electrochemical storage systems since they can complement or even replace batteries in the energy storage field, especially when high power delivery or uptake is needed. This review aims to summarize recent progress on core-shell nanostructures for advanced supercapacitor applications in view of their hierarchical architecture which not only create the desired hierarchical porous channels, but also possess higher electrical conductivity and better structural mechanical stability. The core-shell nanostructures include carbon/carbon, carbon/metal oxide, carbon/conducting polymer, metal oxide/metal oxide, metal oxide/conducting polymer, conducting polymer/conducting polymer, and even more complex ternary core-shell nanoparticles. The preparation strategies, electrochemical performances, and structural stabilities of core-shell materials for ECs are summarized. The relationship between core-shell nanostructure and electrochemical performance is discussed in detail. In addition, the challenges and new trends in core-shell nanomaterials development have also been proposed.

  6. Special Section Guest Editorial: Nanostructured Thin Films IX: Design, Fabrication, Characterization, and Modeling

    Science.gov (United States)

    Lakhtakia, Akhlesh; Mackay, Tom G.; Suzuki, Motofumi

    2017-10-01

    This guest editorial introduces the special section on Nanostructured Thin Films IX: Design, Fabrication, Characterization, and Modeling, which appears in the October-December 2017 issue of the Journal of Nanophotonics.

  7. Nanofiber membrane-electrode-assembly and method of fabricating same

    Science.gov (United States)

    Pintauro, Peter N.; Ballengee, Jason; Brodt, Matthew

    2016-02-02

    In one aspect of the present invention, a fuel cell membrane-electrode-assembly (MEA) has an anode electrode, a cathode electrode, and a membrane disposed between the anode electrode and the cathode electrode. At least one of the anode electrode, the cathode electrode and the membrane is formed of electrospun nanofibers.

  8. Facile synthesis of nanostructured transition metal oxides as electrodes for Li-ion batteries

    Science.gov (United States)

    Opra, Denis P.; Gnedenkov, Sergey V.; Sokolov, Alexander A.; Minaev, Alexander N.; Kuryavyi, Valery G.; Sinebryukhov, Sergey L.

    2017-09-01

    At all times, energy storage is one of the greatest scientific challenge. Recently, Li-ion batteries are under special attention due to high working voltage, long cycle life, low self-discharge, reliability, no-memory effect. However, commercial LIBs usage in medium- and large-scale energy storage are limited by the capacity of lithiated metal oxide cathode and unsafety of graphite anode at high-rate charge. In this way, new electrode materials with higher electrochemical performance should be designed to satisfy a requirement in both energy and power. As it known, nanostructured transition metal oxides are promising electrode materials because of their elevated specific capacity and high potential vs. Li/Li+. In this work, the perspective of an original facile technique of pulsed high-voltage plasma discharge in synthesis of nanostructured transition metal oxides as electrodes for lithium-ion batteries has been demonstrated.

  9. Microcantilever equipped with nanowire template electrodes for multiprobe measurement on fragile nanostructures

    DEFF Research Database (Denmark)

    Lin, Rong; Bøggild, Peter; Hansen, Ole

    2004-01-01

    can be done by reducing the dimensions of the electrodes to nanoscale dimensions. Here we report a fabrication method of a nanoscale four-point probe utilizing silicon nanowires as templates for metal electrodes. Using nanomanipulation, we attach 200–300 nm wide silicon nanowires to microfabricated...

  10. Using nanostructured conductive carbon tape modified with bismuth as the disposable working electrode for stripping analysis in paper-based analytical devices.

    Science.gov (United States)

    Feng, Qiu-Mei; Zhang, Qing; Shi, Chuan-Guo; Xu, Jing-Juan; Bao, Ning; Gu, Hai-Ying

    2013-10-15

    Low cost disposable working electrodes are specifically desired for practical applications of electrochemical detection considering maturity of electrochemical stations and data collection protocols. In this paper double-sided conductive adhesive carbon tape with nanostructure was applied to fabricate disposable working electrodes. Being supported by indium tin oxide glass, the prepared carbon tape electrodes were coated with bismuth film for stripping analysis of heavy metal ions. By integrating the bismuth modified electrodes with paper-based analytical devices, we were able to differentiate Zn, Cd and Pb ions with the sample volume of around 15 μL. After the optimization of parameters, including modification of bismuth film and the area of the electrodes, etc., Pb ions could be measured in the linear range from 10 to 500 μg/L with the detection limit of 2 μg/L. Our experimental results revealed that the disposable modified electrodes could be used to quantify migrated lead from toys with the results agreed well with that using atomic absorption spectrometry. Although bismuth modification and stripping analysis could be influenced by the low conductivity of the carbon tape, the low cost disposable carbon tape electrodes take the advantages of large-scaled produced double-sided carbon tape, including its reproducible nanostructure and scaled-up fabrication process. In addition, the preparation of disposable electrodes avoids time-consuming pretreatment and experienced operation. This study implied that the carbon tape might be an alternative candidate for practical applications of electrochemical detection. © 2013 Elsevier B.V. All rights reserved.

  11. Fabrication of bulk nanostructured permanent magnets with high energy density: challenges and approaches.

    Science.gov (United States)

    Yue, Ming; Zhang, Xiangyi; Liu, J Ping

    2017-03-17

    Nanostructured permanent magnetic materials, including exchange-coupled nanocomposite permanent magnets, are considered as the next generation of high-strength magnets for future applications in energy-saving and renewable energy technologies. However, fabrication of bulk nanostructured magnets remains very challenging because conventional compaction and sintering techniques cannot be used for nanostructured bulk material processing. In this paper we review recent efforts at producing bulk nanostructured single-phase and composite magnetic materials with emphasis on grain size control, anisotropy generation and interface modification.

  12. Fabrication and characterisation of nanostructures on CaF2

    International Nuclear Information System (INIS)

    Batzill, M.M.

    1999-04-01

    Novel nanostructure fabrication techniques are described in this dissertation. Furthermore, an unusual two dimensional phase segregation on CaF 2 surfaces after glancing incidence ion beam irradiation is reported. Atomic force microscope (AFM)-tip assisted self-organisation of clusters on anisotropic surfaces is illustrated. This new technique for the fabrication of periodic structures has been demonstrated using silver clusters grown on vicinal CaF 2 (111) surfaces. The scanning action of the tip aligns silver clusters along crystal step edges on the vicinal surface. Nanowire arrays of silver with a uniform periodicity of 20-50 nm and wire widths of 5-7 nm have been achieved over the entire area scanned by the AFM. Calcium remaining on CaF 2 surfaces after electron irradiation induced depletion of the surface of fluorine is found to re-organise itself into island structures. These islands show a shape transition, upon reaching a critical size of ∼ 20 nm in diameter, from a compact to an elongated island shape. Crystal step edge erosion of fluorine allows the formation of long ranging nanowires. These wires have a uniform width of ∼ 15 nm. The observed island shape transition and the width of the wires has been explained by the presence of strain in the islands. This is the first experimental observation confirming a theoretical prediction of the reduction of island width with increasing length for strained islands. A novel technique of ion beam assisted fabrication of periodic nanowire arrays over macroscopic areas is reported. Potential sputtering of CaF 2 surfaces leads to a calcium enriched surface that organised itself in stress domains due to the lattice misfit between calcium and CaF 2 . These stress domains can be oriented by directed ion beam irradiation under glancing angles in parallel stripes with a periodicity of 8-12 nm. A phase segregation on the CaF 2 (111) surface has been observed upon glancing incidence ion beam irradiation under certain

  13. Fabrication of large area homogeneous metallic nanostructures for optical sensing using colloidal lithography

    DEFF Research Database (Denmark)

    Eriksen, René Lynge; Pors, Anders; Dreier, Jes

    2010-01-01

    We propose a simple and reproducible method for fabricating large area metal films with inter-connected nanostructures using a combination of colloidal lithography, metal deposition and a template stripping technique. The method is generic in the sense that it is possible to produce a variety...... of nanostructures and the corresponding inverted nanostructure in a metal film. Within plasmonics this feature opens up obvious possibilities to design and fabricate substrates with specific and tailored optical properties applicable in optical sensing platforms. In this report the method has been employed...... to fabricate metal films with inter-connected nanostructures consisting of either partial spherical shells or the inverted structures: spherical cavities. The substrates are characterized by optical reflectance and transmittance spectroscopy. We demonstrate, in the case of partial spherical shells...

  14. A Self-Templating Scheme for the Synthesis of Nanostructured Transition Metal Chalcogenide Electrodes for Capacitive Energy Storage

    KAUST Repository

    Xia, Chuan

    2015-06-11

    Due to their unique structural features including well-defined interior voids, low density, low coefficients of thermal expansion, large surface area and surface permeability, hollow micro/nanostructured transition metal sulfides with high conductivity have been investigated as new class of electrode materials for pseudocapacitor applications. Herein, we report a novel self-templating strategy to fabricate well-defined single and double-shell NiCo2S4 hollow spheres, as a promising electrode material for pseudocapacitors. The surfaces of the NiCo2S4 hollow spheres consist of self-assembled 2D mesoporous nanosheets. This unique morphology results in a high specific capacitance (1257 F g-1 at 2 A g-1), remarkable rate performance (76.4% retention of initial capacitance from 2 A g-1 to 60 A g-1) and exceptional reversibility with a cycling efficiency of 93.8% and 87% after 10,000 and 20,000 cycles, respectively, at a high current density of 10 A g-1. The cycling stability of our ternary chalcogenides is comparable to carbonaceous electrode materials, but with much higher specific capacitance (higher than any previously reported ternary chalcogenide), suggesting that these unique chalcogenide structures have potential application in next-generation commercial pseudocapacitors.

  15. Achieving copper sulfide leaf like nanostructure electrode for high performance supercapacitor and quantum-dot sensitized solar cells

    Science.gov (United States)

    Durga, Ikkurthi Kanaka; Rao, S. Srinivasa; Reddy, Araveeti Eswar; Gopi, Chandu V. V. M.; Kim, Hee-Je

    2018-03-01

    Copper sulfide is an important multifunctional semiconductor that has attracted considerable attention owing to its outstanding properties and multiple applications, such as energy storage and electrochemical energy conversion. This paper describes a cost-effective and simple low-temperature solution approach to the preparation of copper sulfide for supercapacitors (SCs) and quantum-dot sensitized solar cells (QDSSCs). X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy confirmed that the nickel foam with a coriander leaf like nanostructure had been coated successfully with copper sulfide. As an electrode material for SCs, the CC-3 h showed excellent specific capacitance (5029.28 at 4 A g-1), energy density (169.73 W h kg-1), and superior cycling durability with 107% retention after 2000 cycles. Interestingly, the QDSSCs equipped with CC-2 h and CC-3 h counter electrodes (CEs) exhibited a maximum power conversion efficiency of 2.52% and 3.48%, respectively. The improved performance of the CC-3 h electrode was attributed mainly to the large surface area (which could contribute sufficient electroactive species), good conductivity, and high electrocatalytic activity. Overall, this work delivers novel insights into the use of copper sulfide and offers an important guidelines for the fabrication of next level energy storage and conversion devices.

  16. Temperature Prediction in a Free-Burning Arc and Electrodes for Nanostructured Materials and Systems.

    Science.gov (United States)

    Lee, Won-Ho; Kim, Youn-Jea; Lee, Jong-Chul

    2015-11-01

    Temperature in a free-burning arc used for synthesis of nanoparticles and nanostructured materials is generally around 20,000 K just below the cathode, falling to about 15,000 K just above the anode, and decreasing rapidly in the radial direction. Therefore, the electrode erosion is indispensable for these atmospheric plasma systems, as well as for switching devices, due to the high heat flux transferred from high temperature arcs to electrodes, but experimental and theoretical works have not identified the characteristic phenomena because of the complex physical processes. To the previous study, we have focused on the arc self-induced fluid flow in a free-burning arc using the computational fluid dynamics (CFD) technique. At this time, our investigation is concerned with the whole region of free-burning high-intensity arcs including the tungsten cathode, the arc plasma and the anode using a unified numerical model for applying synthesis of nanoparticles and nanostructured materials practically.

  17. Trial fabrication of Be12Ti electrode for pebble production by rotating electrode method

    International Nuclear Information System (INIS)

    Uda, M.; Iwadachi, T.; Uchida, M.; Nakamichi, M.; Kawamura, H.

    2004-01-01

    Be 12 Ti has been one of candidates for advanced neutron multipliers, due to its high melting points and good chemical stability. Although Be 12 Ti is too brittle to product pebbles for neutron multipliers with the rotating electrode method (REM), a preliminary production of the pebbles which was made of two phase material of α-beryllium (α-Be) and Be 12 Ti was successfully demonstrated with REM. In this study a trial fabrication of the Be-5at%Ti'' ingot (α-Be + Be 12 Ti) for the REM electrode was carried out with a vacuum casting process. Three kinds of refractory crucibles (MgO, CaO and BeO) were tested for the evaluation of durability to the melt of Be-5%Ti. The water-cooled copper mould was applied for the casting mold to assist a one-direction solidification. The appearance (crack(s), shrinkage, etc.), microstructure and chemical analysis of the ''Be-5at%Ti'' ingots were investigated. As for the results of the trial fabrication, it was made clear that BeO crucible is most useful for the melting of Be-5at%Ti. The ingot, which was a size of φ85 x h 150 mm, had h 40mm sound portion from the bottom. The microstructure of the ingots showed two phases (probably α-Be and Be 12 Ti). The chemical composition of the Ti in the ingot were 3.1 - 6.2at%. (author)

  18. Hydrothermal synthesis of nanostructured graphene/polyaniline composites as high-capacitance electrode materials for supercapacitors

    OpenAIRE

    Ronghua Wang; Meng Han; Qiannan Zhao; Zonglin Ren; Xiaolong Guo; Chaohe Xu; Ning Hu; Li Lu

    2017-01-01

    As known to all, hydrothermal synthesis is a powerful technique for preparing inorganic and organic materials or composites with different architectures. In this reports, by controlling hydrothermal conditions, nanostructured polyaniline (PANi) in different morphologies were composited with graphene sheets (GNS) and used as electrode materials of supercapacitors. Specifically, ultrathin PANi layers with total thickness of 10?20?nm are uniformly composited with GNS by a two-step hydrothermal-a...

  19. Nanostructured MnO₂ as Electrode Materials for Energy Storage.

    Science.gov (United States)

    Julien, Christian M; Mauger, Alain

    2017-11-17

    Manganese dioxides, inorganic materials which have been used in industry for more than a century, now find great renewal of interest for storage and conversion of energy applications. In this review article, we report the properties of MnO₂ nanomaterials with different morphologies. Techniques used for the synthesis, structural, physical properties, and electrochemical performances of periodic and aperiodic frameworks are discussed. The effect of the morphology of nanosized MnO₂ particles on their fundamental features is evidenced. Applications as electrodes in lithium batteries and supercapacitors are examined.

  20. First principles study of nanostructured TiS2 electrodes for Na and Mg ion storage

    Science.gov (United States)

    Li, S. N.; Liu, J. B.; Liu, B. X.

    2016-07-01

    The development of competitive Na- and Mg-ion batteries (NIBs and MIBs) with performance comparable to Li-ion batteries is hindered by the major challenge of finding advanced electrode materials. In this work, nanostructured TiS2 electrodes including nanosheets, nanoribbons and nanotubes are shown by first principles calculations to achieve improved Na and Mg ion diffusion as compared with the bulk phase. Comparative studies between Li, Na, and Mg reveal that the diffusion kinetics of Na ions would especially benefit from the nanostructure design of TiS2. More specifically, the Na ion diffusivity turns out to be considerably higher than Li ion diffusivity, which is opposite to that observed in bulk TiS2. However, in the case of Mg ions, fast diffusion is still beyond attainment since a relatively high degree of interaction is expected between Mg and the S atoms. Edge-induced modifications of diffusion properties appear in both Na and Mg ions, while the mobility of Li ions along the ribbon edges may not be as appealing. Effects of the curvature of nanotubes on the adsorption strength and ion conductivity are also explored. Our results highlight the nanostructure design as a rich playground for exploring electrodes in NIBs and MIBs.

  1. Optimization and fabrication of porous carbon electrodes for Fe/Cr redox flow cells

    Science.gov (United States)

    Jalan, V.; Morriseau, B.; Swette, L.

    1982-01-01

    Negative electrode development for the NASA chromous/ferric Redox battery is reported. The effects of substrate material, gold/lead catalyst composition and loading, and catalyzation procedures on the performance of the chromium electrode were investigated. Three alternative catalyst systems were also examined, and 1/3 square foot size electrodes were fabricated and delivered to NASA at the conclusion of the program.

  2. Designing 3D interconnected continuous nanoporous Co/CoO core-shell nanostructure electrodes for a high-performance pseudocapacitor

    Science.gov (United States)

    Qing, Chen; Zhou, Qin; Qu, Gan; Chen, Xinqi; Wang, Hai; Sun, Daming; Wang, Bixiao; Xu, Lifeng; Tang, Yiwen

    2017-02-01

    A high-performance supercapacitor electrode is designed and fabricated with the 3D interconnected continuous nanoporous Co/CoO core-shell hybrid nanostructure grown on nickel foam. The Co/CoO core-shell hybrid nanostructures are obtained via a hydrothermal method, followed by high-temperature annealing in hydrogen atmosphere, and finally placed in air at 50 °C for 1 h. The Co/CoO core-shell nanostructure assembled by a conductive metal-core and a CoO shell, brings low resistance, high specific capacitance of 5.632 F cm-2 and good capability stability (81.5% capacitance retention after 6000 cycles). An asymmetric supercapacitor device built by the Co/CoO (positive electrode) and activated carbon (negative electrode) can deliver a working voltage of 1.7 V and display a high energy density of 0.002 67 Wh cm-2 at a power density of 0.001 62 W cm-2, which is far superior to that of a supercapacitor at a similar power density.

  3. Electrochemical and DFT study of an anticancer and active anthelmintic drug at carbon nanostructured modified electrode

    International Nuclear Information System (INIS)

    Ghalkhani, Masoumeh; Beheshtian, Javad; Salehi, Maryam

    2016-01-01

    The electrochemical response of mebendazole (Meb), an anticancer and effective anthelmintic drug, was investigated using two different carbon nanostructured modified glassy carbon electrodes (GCE). Although, compared to unmodified GCE, both prepared modified electrodes improved the voltammetric response of Meb, the carbon nanotubes (CNTs) modified GCE showed higher sensitivity and stability. Therefore, the CNTs-GCE was chosen as a promising candidate for the further studies. At first, the electrochemical behavior of Meb was studied by cyclic voltammetry and differential pulse and square wave voltammetry. A one step reversible, pH-dependent and adsorption-controlled process was revealed for electro-oxidation of Meb. A possible mechanism for the electrochemical oxidation of Meb was proposed. In addition, electronic structure, adsorption energy, band gap, type of interaction and stable configuration of Meb on the surface of functionalized carbon nanotubes were studied by using density functional theory (DFT). Obtained results revealed that Meb is weakly physisorbed on the CNTs and that the electronic properties of the CNTs are not significantly changed. Notably, CNTs could be considered as a suitable modifier for preparation of the modified electrode for Meb analysis. Then, the experimental parameters affecting the electrochemical response of Meb were optimized. Under optimal conditions, high sensitivity (b(Meb) = dI p,a (Meb) / d[Meb] = 19.65 μA μM −1 ), a low detection limit (LOD (Meb) = 19 nM) and a wide linear dynamic range (0.06–3 μM) was resulted for the voltammetric quantification of Meb. - Highlights: • Electrochemical oxidation mechanism of Meb was investigated. • A carbon nanostructure modified electrode was developed for the determination of Meb. • The modified electrode surface was characterized by SEM and impedance studies. • This study provides an effective chemically modified electrode with satisfactory repeatability and reproducibility

  4. Direct fabrication of nano-gap electrodes by focused ion beam etching

    International Nuclear Information System (INIS)

    Nagase, Takashi; Gamo, Kenji; Kubota, Tohru; Mashiko, Shinro

    2006-01-01

    A simple approach to increase the reliability of nano-gap electrode fabrication techniques is presented. The method is based on maskless sputter etching of Au electrodes using a focused ion beam (FIB) and in-situ monitoring of the etching steps by measuring a current fed to the Au electrodes. The in-situ monitoring is crucial to form nano-gaps much narrower than a FIB spot size. By using this approach, gaps of ∼3-6 nm are fabricated with the high yield of ∼90%, and most of the fabricated nano-gap electrodes showed high resistances of 10 GΩ-1 TΩ. The controllability of the fabrication steps is significantly improved by using triple-layered films consisting of top Ti, Au, and bottom adhesion Ti layers. The applicability of the fabricated nano-gap electrodes to electron transport studies of nano-sized objects is demonstrated by electrical measurement of Au colloidal nano-particles

  5. Cobalt Phthalocyanine Modified Electrodes Utilised in Electroanalysis: Nano-Structured Modified Electrodes vs. Bulk Modified Screen-Printed Electrodes

    Science.gov (United States)

    Foster, Christopher W.; Pillay, Jeseelan; Metters, Jonathan P.; Banks, Craig E.

    2014-01-01

    Cobalt phthalocyanine (CoPC) compounds have been reported to provide electrocatalytic performances towards a substantial number of analytes. In these configurations, electrodes are typically constructed via drop casting the CoPC onto a supporting electrode substrate, while in other cases the CoPC complex is incorporated within the ink of a screen-printed sensor, providing a one-shot economical and disposable electrode configuration. In this paper we critically compare CoPC modified electrodes prepared by drop casting CoPC nanoparticles (nano-CoPC) onto a range of carbon based electrode substrates with that of CoPC bulk modified screen-printed electrodes in the sensing of the model analytes l-ascorbic acid, oxygen and hydrazine. It is found that no “electrocatalysis” is observed towards l-ascorbic acid using either of these CoPC modified electrode configurations and that the bare underlying carbon electrode is the origin of the obtained voltammetric signal, which gives rise to useful electroanalytical signatures, providing new insights into literature reports where “electrocatalysis” has been reported with no clear control experiments undertaken. On the other hand true electrocatalysis is observed towards hydrazine, where no such voltammetric features are witnessed on the bare underlying electrode substrate. PMID:25414969

  6. Cobalt phthalocyanine modified electrodes utilised in electroanalysis: nano-structured modified electrodes vs. bulk modified screen-printed electrodes.

    Science.gov (United States)

    Foster, Christopher W; Pillay, Jeseelan; Metters, Jonathan P; Banks, Craig E

    2014-11-19

    Cobalt phthalocyanine (CoPC) compounds have been reported to provide electrocatalytic performances towards a substantial number of analytes. In these configurations, electrodes are typically constructed via drop casting the CoPC onto a supporting electrode substrate, while in other cases the CoPC complex is incorporated within the ink of a screen-printed sensor, providing a one-shot economical and disposable electrode configuration. In this paper we critically compare CoPC modified electrodes prepared by drop casting CoPC nanoparticles (nano-CoPC) onto a range of carbon based electrode substrates with that of CoPC bulk modified screen-printed electrodes in the sensing of the model analytes L-ascorbic acid, oxygen and hydrazine. It is found that no "electrocatalysis" is observed towards L-ascorbic acid using either of these CoPC modified electrode configurations and that the bare underlying carbon electrode is the origin of the obtained voltammetric signal, which gives rise to useful electroanalytical signatures, providing new insights into literature reports where "electrocatalysis" has been reported with no clear control experiments undertaken. On the other hand true electrocatalysis is observed towards hydrazine, where no such voltammetric features are witnessed on the bare underlying electrode substrate.

  7. Cobalt Phthalocyanine Modified Electrodes Utilised in Electroanalysis: Nano-Structured Modified Electrodes vs. Bulk Modified Screen-Printed Electrodes

    Directory of Open Access Journals (Sweden)

    Christopher W. Foster

    2014-11-01

    Full Text Available Cobalt phthalocyanine (CoPC compounds have been reported to provide electrocatalytic performances towards a substantial number of analytes. In these configurations, electrodes are typically constructed via drop casting the CoPC onto a supporting electrode substrate, while in other cases the CoPC complex is incorporated within the ink of a screen-printed sensor, providing a one-shot economical and disposable electrode configuration. In this paper we critically compare CoPC modified electrodes prepared by drop casting CoPC nanoparticles (nano-CoPC onto a range of carbon based electrode substrates with that of CoPC bulk modified screen-printed electrodes in the sensing of the model analytes L-ascorbic acid, oxygen and hydrazine. It is found that no “electrocatalysis” is observed towards L-ascorbic acid using either of these CoPC modified electrode configurations and that the bare underlying carbon electrode is the origin of the obtained voltammetric signal, which gives rise to useful electroanalytical signatures, providing new insights into literature reports where “electrocatalysis” has been reported with no clear control experiments undertaken. On the other hand true electrocatalysis is observed towards hydrazine, where no such voltammetric features are witnessed on the bare underlying electrode substrate.

  8. Fabrication of nanostructured Al-doped ZnO thin film for methane sensing applications

    International Nuclear Information System (INIS)

    Shafura, A. K.; Azhar, N. E. I.; Uzer, M.; Mamat, M. H.; Sin, N. D. Md.; Saurdi, I.; Shuhaimi, A.; Alrokayan, Salman A. H.; Khan, Haseeb A.; Rusop, M.

    2016-01-01

    CH 4 gas sensor was fabricated using spin-coating method of the nanostructured ZnO thin film. Effect of annealing temperature on the electrical and structural properties of the film was investigated. Dense nanostructured ZnO film are obtained at higher annealing temperature. The optimal condition of annealing temperature is 500°C which has conductivity and sensitivity value of 3.3 × 10 −3 S/cm and 11.5%, respectively.

  9. Fabrication of nanostructured Al-doped ZnO thin film for methane sensing applications

    Energy Technology Data Exchange (ETDEWEB)

    Shafura, A. K., E-mail: shafura@ymail.com; Azhar, N. E. I.; Uzer, M.; Mamat, M. H. [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Sin, N. D. Md. [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Faculty of Electrical Engineering, Universiti Teknologi MARA Cawangan Johor, Kampus Pasir Gudang, 81750 Masai, Johor (Malaysia); Saurdi, I. [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Faculty of Electrical Engineering, Universiti Teknologi MARA Sarawak, Kampus Kota Samarahan Jalan Meranek, Sarawak (Malaysia); Shuhaimi, A. [Dimensional Materials Research Centre (LDMRC), Department of Physics, Faculty of Science, University ofMalaya, 50603 Kuala Lumpur (Malaysia); Alrokayan, Salman A. H.; Khan, Haseeb A. [Research Chair of Targeting and Treatment Cancer Using Nanoparticles, Department Of Biochemistry, College Of Science, King Saud University, P.O: 2454 Riyadh 11451 (Saudi Arabia); Rusop, M., E-mail: nanouitm@gmail.com [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); NANO-SciTech Centre (NST), Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia)

    2016-07-06

    CH{sub 4} gas sensor was fabricated using spin-coating method of the nanostructured ZnO thin film. Effect of annealing temperature on the electrical and structural properties of the film was investigated. Dense nanostructured ZnO film are obtained at higher annealing temperature. The optimal condition of annealing temperature is 500°C which has conductivity and sensitivity value of 3.3 × 10{sup −3} S/cm and 11.5%, respectively.

  10. Nanostructured Electrodes Via Electrostatic Spray Deposition for Energy Storage System

    KAUST Repository

    Chen, C.

    2014-10-02

    Energy storage systems such as Li-ion batteries and supercapacitors are extremely important in today’s society, and have been widely used as the energy and power sources for portable electronics, electrical vehicles and hybrid electrical vehicles. A lot of research has focused on improving their performance; however, many crucial challenges need to be addressed to obtain high performance electrode materials for further applications. Recently, the electrostatic spray deposition (ESD) technique has attracted great interest to satisfy the goals. Due to its many advantages, the ESD technique shows promising prospects compared to other conventional deposition techniques. In this paper, our recent research outcomes related to the ESD derived anodes for Li-ion batteries and other applications is summarized and discussed.

  11. Enhancing the Supercapacitor Performance of Graphene/MnO 2 Nanostructured Electrodes by Conductive Wrapping

    KAUST Repository

    Yu, Guihua

    2011-10-12

    MnO2 is considered one of the most promising pseudocapactive materials for high-performance supercapacitors given its high theoretical specific capacitance, low-cost, environmental benignity, and natural abundance. However, MnO2 electrodes often suffer from poor electronic and ionic conductivities, resulting in their limited performance in power density and cycling. Here we developed a "conductive wrapping" method to greatly improve the supercapacitor performance of graphene/MnO2-based nanostructured electrodes. By three-dimensional (3D) conductive wrapping of graphene/MnO2 nanostructures with carbon nanotubes or conducting polymer, specific capacitance of the electrodes (considering total mass of active materials) has substantially increased by ∼20% and ∼45%, respectively, with values as high as ∼380 F/g achieved. Moreover, these ternary composite electrodes have also exhibited excellent cycling performance with >95% capacitance retention over 3000 cycles. This 3D conductive wrapping approach represents an exciting direction for enhancing the device performance of metal oxide-based electrochemical supercapacitors and can be generalized for designing next-generation high-performance energy storage devices. © 2011 American Chemical Society.

  12. Enhancing the supercapacitor performance of graphene/MnO2 nanostructured electrodes by conductive wrapping.

    Science.gov (United States)

    Yu, Guihua; Hu, Liangbing; Liu, Nian; Wang, Huiliang; Vosgueritchian, Michael; Yang, Yuan; Cui, Yi; Bao, Zhenan

    2011-10-12

    MnO2 is considered one of the most promising pseudocapactive materials for high-performance supercapacitors given its high theoretical specific capacitance, low-cost, environmental benignity, and natural abundance. However, MnO2 electrodes often suffer from poor electronic and ionic conductivities, resulting in their limited performance in power density and cycling. Here we developed a "conductive wrapping" method to greatly improve the supercapacitor performance of graphene/MnO2-based nanostructured electrodes. By three-dimensional (3D) conductive wrapping of graphene/MnO2 nanostructures with carbon nanotubes or conducting polymer, specific capacitance of the electrodes (considering total mass of active materials) has substantially increased by ∼20% and ∼45%, respectively, with values as high as ∼380 F/g achieved. Moreover, these ternary composite electrodes have also exhibited excellent cycling performance with >95% capacitance retention over 3000 cycles. This 3D conductive wrapping approach represents an exciting direction for enhancing the device performance of metal oxide-based electrochemical supercapacitors and can be generalized for designing next-generation high-performance energy storage devices.

  13. Nanostructured cobalt sulfide-on-fiber with tunable morphology as electrodes for asymmetric hybrid supercapacitors

    KAUST Repository

    Baby, Rakhi Raghavan

    2014-01-01

    Porous cobalt sulfide (Co9S8) nanostructures with tunable morphology, but identical crystal phase and composition, have been directly nucleated over carbon fiber and evaluated as electrodes for asymmetric hybrid supercapacitors. As the morphology is changed from two-dimensional (2D) nanoflakes to 3D octahedra, dramatic changes in supercapacitor performance are observed. In three-electrode configuration, the binder-free Co9S82D nanoflake electrodes show a high specific capacitance of 1056 F g-1at 5 mV s-1vs. 88 F g-1for the 3D electrodes. As sulfides are known to have low operating potential, for the first time, asymmetric hybrid supercapacitors are constructed from Co9S8nanostructures and activated carbon (AC), providing an operation potential from 0 to 1.6 V. At a constant current density of 1 A g-1, the 2D Co9S8, nanoflake//AC asymmetric hybrid supercapacitor exhibits a gravimetric cell capacitance of 82.9 F g-1, which is much higher than that of an AC//AC symmetric capacitor (44.8 F g-1). Moreover, the asymmetric hybrid supercapacitor shows an excellent energy density of 31.4 W h kg-1at a power density of 200 W Kg-1and an excellent cycling stability with a capacitance retention of ∼90% after 5000 cycles. This journal is

  14. A Review on the Fabrication of Hierarchical ZnO Nanostructures for Photocatalysis Application

    Directory of Open Access Journals (Sweden)

    Yi Xia

    2016-11-01

    Full Text Available Semiconductor photocatalysis provides potential solutions for many energy and environmental-related issues. Recently, various semiconductors with hierarchical nanostructures have been fabricated to achieve efficient photocatalysts owing to their multiple advantages, such as high surface area, porous structures, as well as enhanced light harvesting. ZnO has been widely investigated and considered as the most promising alternative photocatalyst to TiO2. Herein, we present a review on the fabrication methods, growth mechanisms and photocatalytic applications of hierarchical ZnO nanostructures. Various synthetic strategies and growth mechanisms, including multistep sequential growth routes, template-based synthesis, template-free self-organization and precursor or self-templating strategies, are highlighted. In addition, the fabrication of multicomponent ZnO-based nanocomposites with hierarchical structures is also included. Finally, the application of hierarchical ZnO nanostructures and nanocomposites in typical photocatalytic reactions, such as pollutant degradation and H2 evolution, is reviewed.

  15. Carbon nanofibers grown on activated carbon fiber fabrics as electrode of supercapacitors

    International Nuclear Information System (INIS)

    Ko, T-H; Hung, K-H; Tzeng, S-S; Shen, J-W; Hung, C-H

    2007-01-01

    Carbon nanofibers (CNFs) were grown directly on activated carbon fiber fabric (ACFF), which was then used as the electrode of supercapacitors. Cyclic voltammetry and ac impedance were used to characterize the electrochemical properties of ACFF and CNF/ACFF electrodes in both aqueous and organic electrolytes. ACFF electrodes show higher specific capacitance than CNF/ACFF electrodes due to larger specific surface area. However, the spaces formed between the CNFs in the CNF/ACFF electrodes are more easily accessed than the slit-type pores of ACFF, and much higher electrical-double layer capacitance was obtained for CNF/ACFF electrodes

  16. Nanostructured carbon electrodes for laccase-catalyzed oxygen reduction without added mediators

    Energy Technology Data Exchange (ETDEWEB)

    Stolarczyk, Krzysztof; Nazaruk, Ewa [Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw (Poland); Rogalski, Jerzy [Department of Biochemistry, Maria Curie Sklodowska University, Sklodowskiej Sq 3, Lublin 20-031 (Poland); Bilewicz, Renata [Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw (Poland)], E-mail: bilewicz@chem.uw.edu.pl

    2008-04-20

    Reduction of dioxygen catalyzed by laccase was studied at carbon electrodes without any added mediators. On bare glassy carbon electrode (GCE) the catalytic reduction did not take place. However, when the same substrate was decorated with carbon nanotubes or carbon microcrystals the dioxygen reduction started at 0.6 V versus Ag/AgCl, which is close to the formal potential of the laccase used. Four different matrices: lecithin, hydrophobin, Nafion and lipid liquid-crystalline cubic phase were employed for hosting fungal laccase from Cerrena unicolor. The carbon nanotubes and nanoparticles present on the electrode provided electrical connectivity between the electrode and the enzyme active sites. Direct electrochemistry of the enzyme itself was observed in deoxygenated solutions and its catalytic activity towards dioxygen reduction was demonstrated. The stabilities of the hosted enzymes, the reduction potentials and ratios of catalytic to background currents were compared. The boron-doped diamond (BDD) electrodes prepolarized to high anodic potentials exhibited behavior similar to that of nanotube covered GCE pointing to the formation of nanostructures during the anodic pretreatment. BDD is a promising substrate in terms of potential of dioxygen reduction, however the catalytic current densities are not large enough for practical applications, therefore as shown in this paper, it should be additionally decorated with carbon particles being in direct contact with the electrode surface.

  17. The preparation and characterization of nanostructured TiO2-ZrO2 mixed oxide electrode for efficient dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Kitiyanan, Athapol; Ngamsinlapasathian, Supachai; Pavasupree, Soropong; Yoshikawa, Susumu

    2005-01-01

    The preparation of nanostructured mixed metal oxide based on a sol-gel method with surfactant-assisted mechanism, and its application for dye-sensitized solar cell (DSSC) are reported. The mixed zirconia (ZrO 2 ) and titania (TiO 2 ) mesoporous powder possessed larger surface area than the corresponding titania. For the UV action spectra of unsensitized photochemical cell, the mixed zirconia/titania electrode can absorb UV light below 380nm, corresponding to band gap (E g ) around 3.27eV, which is higher than that of pure component of titania (E g =3.2eV). Both of these improved properties, i.e., BET surface area and band gap, contributed to the improvement on a short-circuit photocurrent up to 11%, an open-circuit voltage up to 4%, and a solar energy conversion efficiency up to 17%, for the DSSC fabricated by mesoporous zirconia/titania mixed system when compared to the cell that was fabricated only by nanostructured TiO 2 . The cell fabricated by 5μm thick mixed TiO 2 -ZrO 2 electrode gave the short-circuit photocurrent about 13mA/cm 2 , open-circuit voltage about 600 mV and the conversion efficiency 5.4%

  18. Fabrication of Nanostructured Polymer Surfaces and Characterization of their Wetting Properties

    DEFF Research Database (Denmark)

    Andersen, Nis Korsgaard

    in many of the fields related to mass-fabrication of water repellent surfaces. Including: • Basic research in wetting phenomena; studying the role of multiple heights, irregular structures, and the transition to hierarchical structures. • Development of algorithms for improved contact angle fitting....... • Simulations of wetting transitions. • Clean room fabrication of functional surfaces, and production of micro- and nanostructured mold inserts. • Injection molding of micro- and nanostructured polymer parts on a commercial injection molding machine. • Co-invented a patented technique for microstructuring steel...

  19. High speed fabrication of aluminum nanostructures with 10 nm spatial resolution by electrochemical replication.

    Science.gov (United States)

    Biring, Sajal; Tsai, Kun-Tong; Sur, Ujjal Kumar; Wang, Yuh-Lin

    2008-09-03

    A high fidelity electrochemical replication technique for the rapid fabrication of Al nanostructures with 10 nm lateral resolution has been successfully demonstrated. Aluminum is electrodeposited onto a lithographically patterned Si master using a non-aqueous organic hydride bath of aluminum chloride and lithium aluminum hydride at room temperature. Chemical pretreatment of the Si surface allows a clean detachment of the replicated Al foil from the master, permitting its repetitive use for mass replication. This high throughput technique opens up new possibilities in the fabrication of Al-related nanostructures, including the growth of long range ordered anodic alumina nanochannel arrays.

  20. Cyclic voltammetry deposition of copper nanostructure on MWCNTs modified pencil graphite electrode: An ultra-sensitive hydrazine sensor

    Energy Technology Data Exchange (ETDEWEB)

    Heydari, Hamid [Faculty of Sciences, Razi University, Kermanshah (Iran, Islamic Republic of); Gholivand, Mohammad B., E-mail: mbgholivand@razi.ac.ir [Faculty of Sciences, Razi University, Kermanshah (Iran, Islamic Republic of); Abdolmaleki, Abbas [Department of Chemistry, Malek Ashtar University of Technology, Tehran (Iran, Islamic Republic of)

    2016-09-01

    In this study, Copper (Cu) nanostructures (CuNS) were electrochemically deposited on a film of multiwall carbon nanotubes (MWCNTs) modified pencil graphite electrode (MWCNTs/PGE) by cyclic voltammetry method to fabricate a CuNS–MWCNTs composite sensor (CuNS–MWCNT/PGE) for hydrazine detection. Scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDX) were used for the characterization of CuNS on the MWCNTs matrix. The composite of CuNS-MWCNTs was characterized with cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The preliminary studies showed that the proposed sensor have a synergistic electrocatalytic activity for the oxidation of hydrazine in phosphate buffer. The catalytic currents of square wave voltammetry had a linear correlation with the hydrazine concentration in the range of 0.1 to 800 μM with a low detection limit of 70 nM. Moreover, the amperometric oxidation current exhibited a linear correlation with hydrazine concentration in the concentration range of 50–800 μM with the detection limit of 4.3 μM. The proposed electrode was used for the determination of hydrazine in real samples and the results were promising. Empirical results also indicated that the sensor had good reproducibility, long-term stability, and the response of the sensor to hydrazine was free from interferences. Moreover, the proposed sensor benefits from simple preparation, low cost, outstanding sensitivity, selectivity, and reproducibility for hydrazine determination. - Highlights: • The Copper nanostructures (CuNS) were prepared by cyclic voltammetry deposition. • The CuNS-MWCNT/PGE sensor shows high activity toward hydrazine (N{sub 2}H{sub 4}). • The proposed sensor exhibits a wide linear range (0.1 to 800 μM), low detection limit (70 nM), high sensitivity and stability for hydrazine.

  1. Photosensitive-polyimide based method for fabricating various neural electrode architectures

    Directory of Open Access Journals (Sweden)

    Yasuhiro X Kato

    2012-06-01

    Full Text Available An extensive photosensitive polyimide (PSPI-based method for designing and fabricating various neural electrode architectures was developed. The method aims to broaden the design flexibility and expand the fabrication capability for neural electrodes to improve the quality of recorded signals and integrate other functions. After characterizing PSPI’s properties for micromachining processes, we successfully designed and fabricated various neural electrodes even on a non-flat substrate using only one PSPI as an insulation material and without the time-consuming dry etching processes. The fabricated neural electrodes were an electrocorticogram electrode, a mesh intracortical electrode with a unique lattice-like mesh structure to fixate neural tissue, and a guide cannula electrode with recording microelectrodes placed on the curved surface of a guide cannula as a microdialysis probe. In vivo neural recordings using anesthetized rats demonstrated that these electrodes can be used to record neural activities repeatedly without any breakage and mechanical failures, which potentially promises stable recordings for long periods of time. These successes make us believe that this PSPI-based fabrication is a powerful method, permitting flexible design and easy optimization of electrode architectures for a variety of electrophysiological experimental research with improved neural recording performance.

  2. Structural and photovoltaic characteristics of hierarchical ZnO nanostructures electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Saleem, Muhammad, E-mail: saleem.malikape@gmail.com [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Key Laboratory of Optoelectronic Technology and Systems of the Education Ministry of China, Chongqing University, Chongqing 400044 (China); Fang, L. [Key Laboratory of Optoelectronic Technology and Systems of the Education Ministry of China, Chongqing University, Chongqing 400044 (China); Shaukat, Saleem F.; Ahmad, M. Ashfaq [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Raza, Rizwan, E-mail: razahussaini786@gmail.com [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Akhtar, Majid Niaz; Jamil, Ayesha; Aslam, Samia [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Abbas, Ghazanfar [Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000 (Pakistan)

    2015-04-15

    Highlights: • Hierarchically ZnO nanostructures electrodes were grown using hot plate magnetic stirring at different growth reaction temperature. • We have investigated the effect of working temperature of 160°, 170°, 180°, and 190° on the growth mechanism of nanospheres and on the power conversion efficiency of DSSCs. • ZnO nanospheres with perfect aggregation show superior power conversion efficiency of 1.24% which is about 83% higher than nanoparticles DSSC. • An obvious vogue is that the overall power conversion efficiency decreases as the degree of the spherical aggregation is gradually destroyed. - Abstract: Structural and photovoltaic characteristics of hierarchical ZnO nanostructures solar cell have been studied in relation to growth reaction temperature. It is found that the hierarchical ZnO nanostructures network to act not only as large surface area substrates but also as a transport medium for electrons injected from the dye molecules. The incident photon-to-current conversion efficiency is decreased by increasing the growth reaction temperature of ZnO electrodes. The best conversion efficiency of a 0.25 cm{sup 2} cell is measured to be 1.24% under 100 mW cm{sup −2} irradiation.

  3. Fabrication of bioinspired nanostructured materials via colloidal self-assembly

    Science.gov (United States)

    Huang, Wei-Han

    Through millions of years of evolution, nature creates unique structures and materials that exhibit remarkable performance on mechanicals, opticals, and physical properties. For instance, nacre (mother of pearl), bone and tooth show excellent combination of strong minerals and elastic proteins as reinforced materials. Structured butterfly's wing and moth's eye can selectively reflect light or absorb light without dyes. Lotus leaf and cicada's wing are superhydrophobic to prevent water accumulation. The principles of particular biological capabilities, attributed to the highly sophisticated structures with complex hierarchical designs, have been extensively studied. Recently, a large variety of novel materials have been enabled by natural-inspired designs and nanotechnologies. These advanced materials will have huge impact on practical applications. We have utilized bottom-up approaches to fabricate nacre-like nanocomposites with "brick and mortar" structures. First, we used self-assembly processes, including convective self-assembly, dip-coating, and electrophoretic deposition to form well oriented layer structure of synthesized gibbsite (aluminum hydroxide) nanoplatelets. Low viscous monomer was permeated into layered nanoplatelets and followed by photo-curing. Gibbsite-polymer composite displays 2 times higher tensile strength and 3 times higher modulus when compared with pure polymer. More improvement occurred when surface-modified gibbsite platelets were cross-linked with the polymer matrix. We observed ˜4 times higher strength and nearly 1 order of magnitude higher modulus than pure polymer. To further improve the mechanical strength and toughness of inorganicorganic nanocomposites, we exploited ultrastrong graphene oxide (GO), a single atom thick hexagonal carbon sheet with pendant oxidation groups. GO nanocomposite is made by co-filtrating GO/polyvinyl alcohol suspension on 0.2 im pore-sized membrane. It shows ˜2 times higher strength and ˜15 times higher

  4. Massively parallel fabrication of repetitive nanostructures: nanolithography for nanoarrays

    International Nuclear Information System (INIS)

    Luttge, Regina

    2009-01-01

    This topical review provides an overview of nanolithographic techniques for nanoarrays. Using patterning techniques such as lithography, normally we aim for a higher order architecture similarly to functional systems in nature. Inspired by the wealth of complexity in nature, these architectures are translated into technical devices, for example, found in integrated circuitry or other systems in which structural elements work as discrete building blocks in microdevices. Ordered artificial nanostructures (arrays of pillars, holes and wires) have shown particular properties and bring about the opportunity to modify and tune the device operation. Moreover, these nanostructures deliver new applications, for example, the nanoscale control of spin direction within a nanomagnet. Subsequently, we can look for applications where this unique property of the smallest manufactured element is repetitively used such as, for example with respect to spin, in nanopatterned magnetic media for data storage. These nanostructures are generally called nanoarrays. Most of these applications require massively parallel produced nanopatterns which can be directly realized by laser interference (areas up to 4 cm 2 are easily achieved with a Lloyd's mirror set-up). In this topical review we will further highlight the application of laser interference as a tool for nanofabrication, its limitations and ultimate advantages towards a variety of devices including nanostructuring for photonic crystal devices, high resolution patterned media and surface modifications of medical implants. The unique properties of nanostructured surfaces have also found applications in biomedical nanoarrays used either for diagnostic or functional assays including catalytic reactions on chip. Bio-inspired templated nanoarrays will be presented in perspective to other massively parallel nanolithography techniques currently discussed in the scientific literature. (topical review)

  5. Low-Temperature Preparation of Amorphous-Shell/Nanocrystalline-Core Nanostructured TiO2 Electrodes for Flexible Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Dongshe Zhang

    2008-01-01

    Full Text Available An amorphous shell/nanocrystalline core nanostructured TiO2 electrode was prepared at low temperature, in which the mixture of TiO2 powder and TiCl4 aqueous solution was used as the paste for coating a film and in this film amorphous TiO2 resulted from direct hydrolysis of TiCl4 at 100∘C sintering was produced to connect the particles forming a thick crack-free uniform nanostructured TiO2 film (12 μm, and on which a photoelectrochemical solar cell-based was fabricated, generating a short-circuit photocurrent density of 13.58 mA/cm2, an open-circuit voltage of 0.647 V, and an overall 4.48% light-to-electricity conversion efficiency under 1 sun illumination.

  6. Fabrication, Characterization, Properties, and Applications of Low-Dimensional BiFeO3 Nanostructures

    Directory of Open Access Journals (Sweden)

    Heng Wu

    2014-01-01

    Full Text Available Low-dimensional BiFeO3 nanostructures (e.g., nanocrystals, nanowires, nanotubes, and nanoislands have received considerable attention due to their novel size-dependent properties and outstanding multiferroic properties at room temperature. In recent years, much progress has been made both in fabrications and (microstructural, electrical, and magnetic in characterizations of BiFeO3 low-dimensional nanostructures. An overview of the state of art in BiFeO3 low-dimensional nanostructures is presented. First, we review the fabrications of high-quality BiFeO3 low-dimensional nanostructures via a variety of techniques, and then the structural characterizations and physical properties of the BiFeO3 low-dimensional nanostructures are summarized. Their potential applications in the next-generation magnetoelectric random access memories and photovoltaic devices are also discussed. Finally, we conclude this review by providing our perspectives to the future researches of BiFeO3 low-dimensional nanostructures and some key problems are also outlined.

  7. Precisely controlled resorcinol-formaldehyde resin coating for fabricating core-shell, hollow, and yolk-shell carbon nanostructures

    Science.gov (United States)

    Fang, Xiaoliang; Liu, Shengjie; Zang, Jun; Xu, Chaofa; Zheng, Ming-Sen; Dong, Quan-Feng; Sun, Daohua; Zheng, Nanfeng

    2013-07-01

    This work provides a facile one-step sol-gel route to synthesize high-quality resorcinol-formaldehyde (RF) resin coated nanocomposites that can be further used to fabricate desired carbon nanostructures. Colloidal particles with different morphologies and sizes can be coated with high-quality RF resin shells by the proposed cationic surfactant assisted RF resin coating strategy. The as-synthesized RF resin coated nanocomposites are ideal candidates for selective synthesis of core-shell, hollow, and yolk-shell carbon nanostructures. Based on the carboxylic functional RF resin coating, graphitic carbon nanostructures can also be synthesized by employing the graphitization catalyst. The as-synthesized carbon nanostructures show the advantageous performances in several applications. Hollow carbon spheres are potential electrode materials for lithium-sulfur batteries. Hollow graphitic spheres are promising catalyst supports for oxygen reduction reaction. And yolk-shell structured Au@HCS nanoreactors with ultrathin shells exhibit high catalytic activity and recyclability in confined catalysis.This work provides a facile one-step sol-gel route to synthesize high-quality resorcinol-formaldehyde (RF) resin coated nanocomposites that can be further used to fabricate desired carbon nanostructures. Colloidal particles with different morphologies and sizes can be coated with high-quality RF resin shells by the proposed cationic surfactant assisted RF resin coating strategy. The as-synthesized RF resin coated nanocomposites are ideal candidates for selective synthesis of core-shell, hollow, and yolk-shell carbon nanostructures. Based on the carboxylic functional RF resin coating, graphitic carbon nanostructures can also be synthesized by employing the graphitization catalyst. The as-synthesized carbon nanostructures show the advantageous performances in several applications. Hollow carbon spheres are potential electrode materials for lithium-sulfur batteries. Hollow graphitic

  8. The design, fabrication, and photocatalytic utility of nanostructured semiconductors: focus on TiO2-based nanostructures

    Directory of Open Access Journals (Sweden)

    Arghya Narayan Banerjee

    2011-02-01

    Full Text Available Arghya Narayan BanerjeeSchool of Mechanical Engineering, Yeungnam University, Gyeongsan, South KoreaAbstract: Recent advances in basic fabrication techniques of TiO2-based nanomaterials such as nanoparticles, nanowires, nanoplatelets, and both physical- and solution-based techniques have been adopted by various research groups around the world. Our research focus has been mainly on various deposition parameters used for fabricating nanostructured materials, including TiO2-organic/inorganic nanocomposite materials. Technically, TiO2 shows relatively high reactivity under ultraviolet light, the energy of which exceeds the band gap of TiO2. The development of photocatalysts exhibiting high reactivity under visible light allows the main part of the solar spectrum to be used. Visible light-activated TiO2 could be prepared by doping or sensitizing. As far as doping of TiO2 is concerned, in obtaining tailored material with improved properties, metal and nonmetal doping has been performed in the context of improved photoactivity. Nonmetal doping seems to be more promising than metal doping. TiO2 represents an effective photocatalyst for water and air purification and for self-cleaning surfaces. Additionally, it can be used as an antibacterial agent because of its strong oxidation activity and superhydrophilicity. Therefore, applications of TiO2 in terms of photocatalytic activities are discussed here. The basic mechanisms of the photoactivities of TiO2 and nanostructures are considered alongside band structure engineering and surface modification in nanostructured TiO2 in the context of doping. The article reviews the basic structural, optical, and electrical properties of TiO2, followed by detailed fabrication techniques of 0-, 1-, and quasi-2-dimensional TiO2 nanomaterials. Applications and future directions of nanostructured TiO2 are considered in the context of various photoinduced phenomena such as hydrogen production, electricity generation via

  9. Extreme wettability of nanostructured glass fabricated by non-lithographic, anisotropic etching

    OpenAIRE

    Yu, Eusun; Kim, Seul-Cham; Lee, Heon Ju; Oh, Kyu Hwan; Moon, Myoung-Woon

    2015-01-01

    Functional glass surfaces with the properties of superhydrophobicity/or superhydrohydrophilicity, anti-condensation or low reflectance require nano- or micro-scale roughness, which is difficult to fabricate directly on glass surfaces. Here, we report a novel non-lithographic method for the fabrication of nanostructures on glass; this method introduces a sacrificial SiO2 layer for anisotropic plasma etching. The first step was to form nanopillars on SiO2 layer-coated glass by using preferentia...

  10. Nonwoven fabric active electrodes for biopotential measurement during normal daily activity.

    Science.gov (United States)

    Kang, Tae-Ho; Merritt, Carey R; Grant, Edward; Pourdeyhimi, Behnam; Nagle, H Troy

    2008-01-01

    Body movement is responsible for most of the interference during physiological data acquisition during normal daily activities. In this paper, we introduce nonwoven fabric active electrodes that provide the comfort required for clothing while robustly recording physiological data in the presence of body movement. The nonwoven fabric active electrodes were designed and fabricated using both hand- and screen-printing thick-film techniques. Nonstretchable nonwoven (Evolon 100) was chosen as the flexible fabric substrate and a silver filled polymer ink (Creative Materials CMI 112-15) was used to form a transducer layer and conductive lines on the nonwoven fabrics. These nonwoven fabric active electrodes can be easily integrated into clothing for wearable health monitoring applications. Test results indicate that nonwoven textile-based sensors show considerable promise for physiological data acquisition in wearable healthcare monitoring applications.

  11. Fabrication of bimetallic nanostructures via aerosol-assisted electroless silver deposition for catalytic CO conversion.

    Science.gov (United States)

    Byeon, Jeong Hoon; Kim, Jang-Woo

    2014-03-12

    Bimetallic nanostructures were fabricated via aerosol-assisted electroless silver deposition for catalytic CO conversion. An ambient spark discharge was employed to produce nanocatalysts, and the particles were directly deposited on a polytetrafluoroethylene substrate for initiating silver deposition to form Pd-Ag, Pt-Ag, Au-Ag bimetallic nanostructures as well as a pure Ag nanostructure. Kinetics and morphological evolutions in the silver deposition with different nanocatalysts were comparatively studied. The Pt catalyst displayed the highest catalytic activity for electroless silver deposition, followed by the order Pd > Au > Ag. Another catalytic activity of the fabricated bimetallic structures in the carbon monoxide conversion was further evaluated at low-temperature conditions. The bimetallic systems showed significantly higher catalytic activity than that from a pure Ag system.

  12. Fabrication of Defined Polydopamine Nanostructures by DNA Origami-Templated Polymerization.

    Science.gov (United States)

    Tokura, Yu; Harvey, Sean; Chen, Chaojian; Wu, Yuzhou; Ng, David Y W; Weil, Tanja

    2018-02-05

    A versatile, bottom-up approach allows the controlled fabrication of polydopamine (PD) nanostructures on DNA origami. PD is a biosynthetic polymer that has been investigated as an adhesive and promising surface coating material. However, the control of dopamine polymerization is challenged by the multistage-mediated reaction mechanism and diverse chemical structures in PD. DNA origami decorated with multiple horseradish peroxidase-mimicking DNAzyme motifs was used to control the shape and size of PD formation with nanometer resolution. These fabricated PD nanostructures can serve as "supramolecular glue" for controlling DNA origami conformations. Facile liberation of the PD nanostructures from the DNA origami templates has been achieved in acidic medium. This presented DNA origami-controlled polymerization of a highly crosslinked polymer provides a unique access towards anisotropic PD architectures with distinct shapes that were retained even in the absence of the DNA origami template. © 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  13. Top-down fabrication of plasmonic nanostructures for deterministic coupling to single quantum emitters

    NARCIS (Netherlands)

    Pfaff, W.; Vos, A.; Hanson, R.

    2013-01-01

    Metal nanostructures can be used to harvest and guide the emission of single photon emitters on-chip via surface plasmon polaritons. In order to develop and characterize photonic devices based on emitter-plasmon hybrid structures, a deterministic and scalable fabrication method for such structures

  14. Application of AFM in microscopy and fabrication of micro/nanostructures

    Czech Academy of Sciences Publication Activity Database

    Lopour, F.; Kalousek, R.; Škoda, D.; Spousta, J.; Matějka, František; Šikola, T.

    2002-01-01

    Roč. 34, č. 1 (2002), s. 352 - 355 ISSN 0142-2421 R&D Projects: GA MŠk ME 334; GA MŠk ME 480 Institutional research plan: CEZ:AV0Z2065902 Keywords : AFM fabrication * local anodic oxidation * oxide nanostructures Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.071, year: 2002

  15. High-speed micro electrode tool fabrication by a twin-wire EDM system

    International Nuclear Information System (INIS)

    Sheu, Dong-Yea

    2008-01-01

    This paper describes a new machining process which combines twin-electro-wire together with two electro discharge circuits to rapidly fabricate micro electrode tools. The results show that transistor electro discharge and RC electro discharge circuits coexist to fabricate micro tools with rough and finish machining both on the same machine. Compared to conventional wire electro discharge grinding (WEDG) technology, a twin-wire EDM system that combines rough and finish machining into one process allows the efficient fabrication of micro tools. This high-speed micro tool fabrication process can be applied not only to micro electrode machining but also to micro punching tool and micro probing tips machining

  16. A Fabrication Technique for Nano-gap Electrodes by Atomic Force Microscopy Nano lithography

    International Nuclear Information System (INIS)

    Jalal Rouhi; Shahrom Mahmud; Hutagalung, S.D.; Kakooei, S.

    2011-01-01

    A simple technique is introduced for fabrication of nano-gap electrodes by using nano-oxidation atomic force microscopy (AFM) lithography with a Cr/ Pt coated silicon tip. AFM local anodic oxidation was performed on silicon-on-insulator (SOI) surfaces by optimization of desired conditions to control process in contact mode. Silicon electrodes with gaps of sub 31 nm were fabricated by nano-oxidation method. This technique which is simple, controllable, inexpensive and fast is capable of fabricating nano-gap structures. The current-voltage measurements (I-V) of the electrodes demonstrated very good insulating characteristics. The results show that silicon electrodes have a great potential for fabrication of single molecule transistors (SMT), single electron transistors (SET) and the other nano electronic devices. (author)

  17. Iron oxide nanostructured electrodes for detection of copper(II) ions.

    Science.gov (United States)

    Santos, J G M; Souza, J R; Letti, C J; Soler, M A G; Morais, P C; Pereira-da-Silva, M A; Paterno, L G

    2014-09-01

    Iron oxide nanostructured (ION) electrodes were assembled layer-by-layer onto ITO-coated glass substrates and their structure, morphology, and electrochemical properties were investigated, the latter aiming at the development of a chemical sensor for Cu2+. The electrodes were built by immersing the substrate alternately into an aqueous colloidal suspension of positively charged magnetite nanoparticles (np-Fe3O4, 8 nm) and an aqueous solution of anionic sodium sulfonated polystyrene (PSS). The adsorbed amount of both materials was monitored ex-situ by UV-vis spectroscopy and it was found to increase linearly with the number of deposition cycles. The resulting films feature a densely-packed structure of magnetite nanoparticles, as suggested by AFM and Raman spectroscopy, respectively. Cyclic voltammograms of electrodes immersed in acetate buffer (pH 4.6) displayed three electrochemical events that were tentatively ascribed to the reduction of Fe(III) oxy-hydroxide to magnetite, reduction of maghemite to magnetite, and finally oxidation of magnetite to maghemite. The effect of np-Fe3O4/PSS bilayers on the ION electrode performance was to increase the anodic and cathodic currents produced during electrochemical oxidation-reduction of the Fe(CN)(3-/4-) redox couple. With more bilayers, the ION electrode provided higher anodic/cathodic currents. Moreover, the redox couple exhibited a quasi-reversible behavior at the ION electrode as already observed with other working electrode systems. Fitting of voltammetry data provided the apparent electron transfer constants, which were found to be higher in ION electrodes for both redox couples (Fe(CN)(3-/4-) and Cu(2+/0)). By means of differential pulsed anodic stripping voltammetry, the ION electrodes were found to respond linearly to the presence of Cu2+ in aqueous samples in the range between 1.0 and 8.0 x 10(-6) mol x L(-1) and displayed a limit of detection of 0.3 x 10(-8) mol x L(-1). The sensitivity was - 0.6μA/μmol x L

  18. Cochlear Dummy Electrodes for Insertion Training and Research Purposes: Fabrication, Mechanical Characterization, and Experimental Validation

    Directory of Open Access Journals (Sweden)

    Jan-Philipp Kobler

    2015-01-01

    Full Text Available To develop skills sufficient for hearing preservation cochlear implant surgery, surgeons need to perform several electrode insertion trials in ex vivo temporal bones, thereby consuming relatively expensive electrode carriers. The objectives of this study were to evaluate the insertion characteristics of cochlear electrodes in a plastic scala tympani model and to fabricate radio opaque polymer filament dummy electrodes of equivalent mechanical properties. In addition, this study should aid the design and development of new cochlear electrodes. Automated insertion force measurement is a new technique to reproducibly analyze and evaluate the insertion dynamics and mechanical characteristics of an electrode. Mechanical properties of MED-EL’s FLEX28, FLEX24, and FLEX20 electrodes were assessed with the help of an automated insertion tool. Statistical analysis of the overall mechanical behavior of the electrodes and factors influencing the insertion force are discussed. Radio opaque dummy electrodes of comparable characteristics were fabricated based on insertion force measurements. The platinum-iridium wires were replaced by polymer filament to provide sufficient stiffness to the electrodes and to eradicate the metallic artifacts in X-ray and computed tomography (CT images. These low-cost dummy electrodes are cheap alternatives for surgical training and for in vitro, ex vivo, and in vivo research purposes.

  19. Resin Infusion Fabrication of nanostructured PMC, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Polymer reinforced composite parts required for heavy lift launch vehicles are currently fabricated by hand lay-up or automated tape lay-up followed by curing using...

  20. Fabrication and application of nanostructured materials for sulfite biosensing

    OpenAIRE

    Hussain, Shahid

    2017-01-01

    A biosensor as an integrated miniaturized device, exploits the modern microelectronics with specific sensing probe through signal transduction. The challenge for new generation biosensors is to achieve specific analyte detection at very low concentrations, which is possible by tailoring the materials used for fabrication of these devices based on nanoscience and nanotechnology. The new approach is explored in this thesis for fabrication of novel nanobiosensors for ultrasensitive detection of ...

  1. A novel method of fabricating carbon nanotubes-polydimethylsiloxane composite electrodes for electrocardiography.

    Science.gov (United States)

    Liu, Benyan; Chen, Yingmin; Luo, Zhangyuan; Zhang, Wenzan; Tu, Quan; Jin, Xun

    2015-01-01

    Polymer-based flexible electrodes are receiving much attention in medical applications due to their good wearing comfort. The current fabrication methods of such electrodes are not widely applied. In this study, polydimethylsiloxane (PDMS) and conductive additives of carbon nanotubes (CNTs) were employed to fabricate composite electrodes for electrocardiography (ECG). A three-step dispersion process consisting of ultrasonication, stirring, and in situ polymerization was developed to yield homogenous CNTs-PDMS mixtures. The CNTs-PDMS mixtures were used to fabricate CNTs-PDMS composite electrodes by replica technology. The influence of ultrasonication time and CNT concentration on polymer electrode performance was evaluated by impedance and ECG measurements. The signal amplitude of the electrodes prepared using an ultrasonication time of 12 h and CNT content of 5 wt% was comparable to that of commercial Ag/AgCl electrodes. The polymer electrodes were easily fabricated by conventional manufacturing techniques, indicating a potential advantage of reduced cost for mass production.

  2. Fabrication of 3D nanostructures by multidirectional UV lithography and predictive structural modeling

    International Nuclear Information System (INIS)

    Kim, Jungkwun; Allen, Mark G; Kim, Cheolbok; Yoon, Yong-Kyu

    2015-01-01

    This paper presents the fabrication and modeling of three-dimensional (3D) nanostructures by automated multidirectional ultraviolet (UV) lithography, which is a fast, cost-effective, manufacturable fabrication method. Multidirectional UV exposure is performed using a static UV light source equipped with a tilt-rotational substrate holder. A glass substrate with a nanopatterned chrome layer is utilized as both a photomask and a substrate, for which a backside UV exposure scheme is used. For the analytical modeling of the shape of fabricated nanostructures, UV exposure dosage, diffraction and refraction effects, and absorption rate are taken into account. For more accurate process predictive models, a commercially available multiphysics simulation tool is used. The structural shapes predicted from analytical calculation and simulation are compared with the fabricated ones for which various 3D nanoscale test structures are fabricated such as an inclined nanopillar array and a vertical triangular slab. Also, nanostructures with multiple heights are successfully implemented from single layer photoresist by controlling the UV exposure dosage and tilt angles. A tripod embedded horn and a triangular-slab embedded horn are demonstrated. (paper)

  3. Nanostructured pseudocapacitive materials decorated 3D graphene foam electrodes for next generation supercapacitors.

    Science.gov (United States)

    Patil, Umakant; Lee, Su Chan; Kulkarni, Sachin; Sohn, Ji Soo; Nam, Min Sik; Han, Suhyun; Jun, Seong Chan

    2015-04-28

    Nowadays, advancement in performance of proficient multifarious electrode materials lies conclusively at the core of research concerning energy storage devices. To accomplish superior capacitance performance the requirements of high capacity, better cyclic stability and good rate capability can be expected from integration of electrochemical double layer capacitor based carbonaceous materials (high power density) and pseudocapacitive based metal hydroxides/oxides or conducting polymers (high energy density). The envisioned three dimensional (3D) graphene foams are predominantly advantageous to extend potential applicability by offering a large active surface area and a highly conductive continuous porous network for fast charge transfer with decoration of nanosized pseudocapacitive materials. In this article, we review the latest methodologies and performance evaluation for several 3D graphene based metal oxides/hydroxides and conducting polymer electrodes with improved electrochemical properties for next-generation supercapacitors. The most recent research advancements of our and other groups in the field of 3D graphene based electrode materials for supercapacitors are discussed. To assess the studied materials fully, a careful interpretation and rigorous scrutiny of their electrochemical characteristics is essential. Auspiciously, both nano-structuration as well as confinement of metal hydroxides/oxides and conducting polymers onto a conducting porous 3D graphene matrix play a great role in improving the performance of electrodes mainly due to: (i) active material access over large surface area with fast charge transportation; (ii) synergetic effect of electric double layer and pseudocapacitive based charge storing.

  4. Distance-dependent metal enhanced fluorescence by flowerlike silver nanostructures fabricated in liquid crystalline phase

    Science.gov (United States)

    Zhang, Ying; Yang, Chengliang; Zhang, Guiyang; Peng, Zenghui; Yao, Lishuang; Wang, Qidong; Cao, Zhaoliang; Mu, Quanquan; Xuan, Li

    2017-10-01

    Flowerlike silver nanostructure substrates were fabricated in liquid crystalline phase and the distance dependent property of metal enhanced fluorescence for such substrate was studied for the first time. The distance between silver nanostructures and fluorophore was controlled by the well-established layer-by-layer (LbL) technique constructing alternate layers of poly (allylamine hydrochloride) (PAH) and poly (sodium 4-styrenesulfonate) (PSS). The Rhodamine 6G (R6G) molecules were electrostatically attached to the outmost negative charged PSS layer. The fluorescence enhancement factor of flowerlike nanostructure substrate increased firstly and then decreased with the distance increasing. The best enhanced fluorescence intensity of 71 fold was obtained at a distance of 5.2 nm from the surface of flowerlike silver nanostructure. The distance for best enhancement effect is an instructive parameter for the applications of such substrates and could be used in the practical MEF applications with the flowerlike nanostructure substrates fabricated in such way which is simple, controllable and cost-effective.

  5. Current Advances in TiO2-Based Nanostructure Electrodes for High Performance Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Mahmoud Madian

    2018-02-01

    Full Text Available The lithium ion battery (LIB has proven to be a very reliably used system to store electrical energy, for either mobile or stationary applications. Among others, TiO2-based anodes are the most attractive candidates for building safe and durable lithium ion batteries with high energy density. A variety of TiO2 nanostructures has been thoroughly investigated as anodes in LIBs, e.g., nanoparticles, nanorods, nanoneedles, nanowires, and nanotubes discussed either in their pure form or in composites. In this review, we present the recent developments and breakthroughs demonstrated to synthesize safe, high power, and low cost nanostructured titania-based anodes. The reader is provided with an in-depth review of well-oriented TiO2-based nanotubes fabricated by anodic oxidation. Other strategies for modification of TiO2-based anodes with other elements or materials are also highlighted in this report.

  6. Fabrication of Nanostructured Omniphobic and Superomniphobic Surfaces with Inexpensive CO2Laser Engraver.

    Science.gov (United States)

    Pendurthi, Anudeep; Movafaghi, Sanli; Wang, Wei; Shadman, Soran; Yalin, Azer P; Kota, Arun K

    2017-08-09

    Superomniphobic surfaces (i.e., surfaces that are extremely repellent to both high surface tension liquids like water and low surface tension liquid like oils) can be fabricated through a combination of surface chemistry that imparts low solid surface energy with a re-entrant surface texture. Recently, surface texturing with lasers has received significant attention because laser texturing is scalable, solvent-free, and can produce a monolithic texture on virtually any material. In this work, we fabricated nanostructured omniphobic and superomniphobic surfaces with a variety of materials using a simple, inexpensive and commercially available CO 2 laser engraver. Further, we demonstrated that the nanostructured omniphobic and superomniphobic surfaces fabricated using our laser texturing technique can be used to design patterned surfaces, surfaces with discrete domains of the desired wettability, and on-surface microfluidic devices.

  7. Fabrication and characterization of highly-ordered Zinc Oxide nanorods on gold/glass electrode, and its application as a voltammetric sensor

    International Nuclear Information System (INIS)

    Hatamie, Amir; Echresh, Ahmad; Zargar, Behrooz; Nur, Omer; Willander, Magnus

    2015-01-01

    A novel voltammetric determination of amoxicillin (AMX) sensor has been fabricated, using zinc oxide nanorods (ZnO NRs) grown directly on gold/glass electrode. To prepare an electrode, ZnO NRs were directly grown on Au sputtered (thickness: 100 nm) glass substrate (gold/glass electrode) with hydrothermal method. The directly synthesized ZnO NRs on the electrode expressively increases NRs attachment vertically, and increase its specific surface area. ZnO NRs/gold/glass electrode was characterized by field emission electron microscopy (FESEM), X-ray diffractometer (XRD) techniques, and this study has shown that the grown nanostructures are highly dense, uniform, and exhibited good crystal quality. The performance of the electrode was characterized with cyclic voltammetry (CV) and chronoamperometry (CA). The parameters of charge transfer coefficient (α), diffusion coefficient (D), electrode surface area (A), and catalytic rate constant (k h ) were determined, and the results were studied. The electro catalytic current of AMX was found to have a linear relation to concentration over the range of 5 × 10 −6 M – 250 × 10 −6 M (n=6). The good performance of the electrode is due to more immobilization on the well-aligned ZnO NRs arrays, and direct electron conduction between the ZnO NRs and the electrodes. Further, the sensor also showed a promising application for detecting AMX in capsule sample. The ease of fabrication, acceptable stability, and low cost of the modified electrode are the promising features of the proposed sensor

  8. Hydrogen-bonding effects on film structure and photoelectrochemical properties of porphyrin and fullerene composites on nanostructured TiO 2 electrodes

    NARCIS (Netherlands)

    Kira, Aiko; Tanaka, Masanobu; Umeyama, Tomokazu; Matano, Yoshihiro; Yoshimoto, Naoki; Zhang, Yi; Ye, Shen; Lehtivuori, Heli; Tkachenko, Nikolai V.; Lemmetyinen, Helge; Imahori, Hiroshi

    2007-01-01

    Hydrogen-bonding effects on film structures and photophysical, photoelectrochemical, and photovoltaic properties have been examined in mixed films of porphyrin and fullerene composites with and without hydrogen bonding on nanostructured TiO2 electrodes. The nanostructured TiO2 electrodes modified

  9. Novel ZnO nanostructured electrodes for higher power conversion efficiencies in polymeric solar cells.

    Science.gov (United States)

    Ajuria, Jon; Etxebarria, Ikerne; Azaceta, Eneko; Tena-Zaera, Ramón; Fernández-Montcada, Nuria; Palomares, Emilio; Pacios, Roberto

    2011-12-14

    1-Dimensional nanostructured ZnO electrodes have been demonstrated to be potentially interesting for their application in solar cells. Herein, we present a novel procedure to control the ZnO nanowire optoelectronic properties by means of surface modification. The nanowire surface is functionalized with ZnO nanoparticles in order to provide an improved contact to the photoactive P3HT:PCBM film that enhances the overall power conversion efficiency of the resulting solar cell. Charge extraction and transient photovoltage measurements have been used to successfully demonstrate that the surface modified nanostructured electrode contributes in enhancing the exciton dissociating ratio and in enlarging the charge lifetime as a consequence of a reduced charge recombination. Under AM1.5G illumination, all these factors contribute to a considerably large increase in photocurrent yielding unusually high conversion efficiencies over 4% and external quantum efficiencies of 87% at 550 nm for commercially available P3HT:PCBM based solar cells. The same approach might be equally used for polymeric materials under development to overcome the record reported efficiencies.

  10. Nanostructured bilayered vanadium oxide electrodes for rechargeable sodium-ion batteries.

    Science.gov (United States)

    Tepavcevic, Sanja; Xiong, Hui; Stamenkovic, Vojislav R; Zuo, Xiaobing; Balasubramanian, Mahalingam; Prakapenka, Vitali B; Johnson, Christopher S; Rajh, Tijana

    2012-01-24

    Tailoring nanoarchitecture of materials offers unprecedented opportunities in utilization of their functional properties. Nanostructures of vanadium oxide, synthesized by electrochemical deposition, are studied as a cathode material for rechargeable Na-ion batteries. Ex situ and in situ synchrotron characterizations revealed the presence of an electrochemically responsive bilayered structure with adjustable intralayer spacing that accommodates intercalation of Na(+) ions. Sodium intake induces organization of overall structure with appearance of both long- and short-range order, while deintercalation is accompanied with the loss of long-range order, whereas short-range order is preserved. Nanostructured electrodes achieve theoretical reversible capacity for Na(2)V(2)O(5) stochiometry of 250 mAh/g. The stability evaluation during charge-discharge cycles at room temperature revealed an efficient 3 V cathode material with superb performance: energy density of ~760 Wh/kg and power density of 1200 W/kg. These results demonstrate feasibility of development of the ambient temperature Na-ion rechargeable batteries by employment of electrodes with tailored nanoarchitectures. © 2011 American Chemical Society

  11. Fine-tunable plasma nano-machining for fabrication of 3D hollow nanostructures: SERS application.

    Science.gov (United States)

    Mehrvar, L; Hajihoseini, H; Mahmoodi, H; Tavassoli, S H; Fathipour, M; Mohseni, S M

    2017-08-04

    Novel processing sequences for the fabrication of artificial nanostructures are in high demand for various applications. In this paper, we report on a fine-tunable nano-machining technique for the fabrication of 3D hollow nanostructures. This technique originates from redeposition effects occurring during Ar dry etching of nano-patterns. Different geometries of honeycomb, double ring, nanotube, cone and crescent arrays have been successfully fabricated from various metals such as Au, Ag, Pt and Ti. The geometrical parameters of the 3D hollow nanostructures can be straightforwardly controlled by tuning the discharge plasma pressure and power. The structure and morphology of nanostructures are probed using atomic force microscopy (AFM), scanning electron microscopy (SEM), optical emission spectroscopy (OES) and energy dispersive x-ray spectroscopy (EDS). Finally, a Ag nanotube array was assayed for application in surface enhanced Raman spectroscopy (SERS), resulting in an enhancement factor (EF) of 5.5 × 10 5 , as an experimental validity proof consistent with the presented simulation framework. Furthermore, it was found that the theoretical EF value for the honeycomb array is in the order of 10 7 , a hundred times greater than that found in nanotube array.

  12. Fabrication of 3D nano-structures using reverse imprint lithography

    International Nuclear Information System (INIS)

    Han, Kang-Soo; Cho, Joong-Yeon; Lee, Heon; Hong, Sung-Hoon; Kim, Kang-In; Choi, Kyung-woo

    2013-01-01

    In spite of the fact that the fabrication process of three-dimensional nano-structures is complicated and expensive, it can be applied to a range of devices to increase their efficiency and sensitivity. Simple and inexpensive fabrication of three-dimensional nano-structures is necessary. In this study, reverse imprint lithography (RIL) with UV-curable benzylmethacrylate, methacryloxypropyl terminated poly-dimethylsiloxane (M-PDMS) resin and ZnO-nano-particle-dispersed resin was used to fabricate three-dimensional nano-structures. UV-curable resins were placed between a silicon stamp and a PVA transfer template, followed by a UV curing process. Then, the silicon stamp was detached and a 2D pattern layer was transferred to the substrate using diluted UV-curable glue. Consequently, three-dimensional nano-structures were formed by stacking the two-dimensional nano-patterned layers. RIL was applied to a light-emitting diode (LED) to evaluate the optical effects of a nano-patterned layer. As a result, the light extraction of the patterned LED was increased by about 12% compared to an unpatterned LED. (paper)

  13. The fabrication, characterisation and electrochemical investigation of screen-printed graphene electrodes.

    Science.gov (United States)

    Randviir, Edward P; Brownson, Dale A C; Metters, Jonathan P; Kadara, Rashid O; Banks, Craig E

    2014-03-14

    We report the fabrication, characterisation (SEM, Raman spectroscopy, XPS and ATR) and electrochemical implementation of novel screen-printed graphene electrodes. Electrochemical characterisation of the fabricated graphene electrodes is undertaken using an array of electroactive redox probes and biologically relevant analytes, namely: potassium ferrocyanide(II), hexaammine-ruthenium(III) chloride, N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD), β-nicotinamide adenine dinucleotide (NADH), L-ascorbic acid (AA), uric acid (UA) and dopamine hydrochloride (DA). The electroanalytical capabilities of the fabricated electrodes are also considered towards the sensing of AA and DA. The electrochemical and (electro)analytical performances of the fabricated screen-printed graphene electrodes are considered with respect to the relative surface morphologies and material compositions (elucidated via SEM, Raman, XPS and ATR spectroscopy), the density of electronic states (% global coverage of edge-plane like sites/defects) and the specific fabrication conditions utilised. Comparisons are made between two screen-printed graphene electrodes and alternative graphite based screen-printed electrodes. The graphene electrodes are fabricated utilising two different commercially prepared 'graphene' inks, which have long screen ink lifetimes (>3 hours), thus this is the first report of a true mass-reproducible screen-printable graphene ink. Through employment of appropriate controls/comparisons we are able to report a critical assessment of these screen-printed graphene electrodes. This work is of high importance and demonstrates a proof-of-concept approach to screen-printed graphene electrodes that are highly reproducible, paving the way for mass-producible graphene sensing platforms in the future.

  14. Efficient electrocatalytic reduction and detection of hydrogen peroxide at an IrIVOx·H2O nanostructured electrode prepared by electroflocculation

    International Nuclear Information System (INIS)

    Liu, Pei-Yin; Sun, Sin-Cih; Chen, Yi-Shiang; Chuang, Min-Chieh

    2016-01-01

    An Ir IV Ox·nH 2 O nanostructured electrode prepared by electroflocculation is reported; the electrode efficiently catalyzes the electrochemical reduction of hydrogen peroxide (H 2 O 2 ). Linear sweep voltammograms reveal that the potential onset arising due to the reduction of H 2 O 2 (1 mM) occurs at -0.1 V (vs. Ag/AgCl), which is more anodic than the onset potential occurring on the glassy carbon electrode by 400 mV, thereby substantiating the catalytic utility of Ir IV Ox·nH 2 O. The number of electrons transferred in the process, estimated via the Koutecky-Levich equation, is 1.89 ± 0.30. The Tafel slope obtained from polarization measurements is ca. 240.9 mV/dec. Furthermore, the Ir IV Ox·nH 2 O nanostructured electrode exhibits response with linear relationship against H 2 O 2 concentrations ranging over 0-1 mM (when agitated) and 0-150 μM (in flow injection analysis); the limit of detection (3σ), as determined under flow injection analysis, is 5 μM. The as-fabricated electrode is insensitive to the oxidation of ascorbic acid (0.1 mM) and acetaminophen (0.1 mM) and exhibits stable amperometric response (over twenty successive trials), albeit a slight drift in the sensor response is observed during the initial six evaluations. Based on the results, the electrocatalytic mechanism involving the following steps is proposed: (1) the reduction of Ir from Ir IV to Ir III , (2) catalytic cleavage of the O-O bond to generate OH· radicals, and (3) the reduction of the OH· radicals to OH − via the reoxidation of Ir III to Ir IV .

  15. Synthesis of In2O3 nanostructures with different morphologies as potential supercapacitor electrode materials

    Science.gov (United States)

    Tuzluca, Fatma Nur; Yesilbag, Yasar Ozkan; Ertugrul, Mehmet

    2018-01-01

    In this study performed using a chemical vapor deposition (CVD) system, one-dimensional (1-D) single crystal indium oxide (In2O3) nanotowers, nanobouqets, nanocones, and nanowires were investigated as a candidate for a supercapacitor electrode material. These nanostructures were grown via Vapor-Liquid-Solid (VLS) and Vapor-Solid (VS) mechanisms according to temperature differences (1000-600 °C). The morphologies, growth mechanisms and crystal structures of these 1-D single crystal In2O3 nanostructures were defined by Field Emission Scanning Electron Microscopy (FESEM), High Resolution Transmission Electron Microscopy (HR-TEM), X-Ray Diffraction (XRD) and Raman Spectroscopy analyses. The elemental analyses of the nanostructures were carried out by energy dispersive X-Ray Spectroscopy (EDS); they gave photoluminescence (PL) spectra with 3.39, 2.65, and 1.95 eV band gap values, corresponding to 365 nm, 467 nm, and 633 wavelengths, respectively. The electrochemical performances of these 1-D single crystal In2O3 nanostructures in an aqueous electrolyte solution (1 M Na2SO4) were determined by Cyclic Voltammetry (CV), Galvanostatic Charge Discharge (GCD) and Electrochemical Impedance Spectroscopy (EIS) analyses. According to GCD measurements at 0.04 mA cm-2 current density, areal capacitance values were 10.1 mF cm-2 and 6.7 mF cm-2 for nanotowers, 12.5 mF cm-2 for nanobouquets, 4.9 mF cm-2 for nanocones, and 16.6 mF cm-2 for nanowires. The highest areal capacitance value was observed in In2O3 nanowires, which retained 66.8% of their initial areal capacitance after a 10000 charge-discharge cycle, indicating excellent cycle stability.

  16. A top-down approach for fabricating free-standing bio-carbon supercapacitor electrodes with a hierarchical structure.

    Science.gov (United States)

    Li, Yingzhi; Zhang, Qinghua; Zhang, Junxian; Jin, Lei; Zhao, Xin; Xu, Ting

    2015-09-23

    Biomass has delicate hierarchical structures, which inspired us to develop a cost-effective route to prepare electrode materials with rational nanostructures for use in high-performance storage devices. Here, we demonstrate a novel top-down approach for fabricating bio-carbon materials with stable structures and excellent diffusion pathways; this approach is based on carbonization with controlled chemical activation. The developed free-standing bio-carbon electrode exhibits a high specific capacitance of 204 F g(-1) at 1 A g(-1); good rate capability, as indicated by the residual initial capacitance of 85.5% at 10 A g(-1); and a long cycle life. These performance characteristics are attributed to the outstanding hierarchical structures of the electrode material. Appropriate carbonization conditions enable the bio-carbon materials to inherit the inherent hierarchical texture of the original biomass, thereby facilitating effective channels for fast ion transfer. The macropores and mesopores that result from chemical activation significantly increase the specific surface area and also play the role of temporary ion-buffering reservoirs, further shortening the ionic diffusion distance.

  17. Fabrication of interdigitated electrodes by inkjet printing technology for apllication in ammonia sensing

    International Nuclear Information System (INIS)

    Le, Duy Dam; Nguyen, Thi Ngoc Nhien; Doan, Duc Chanh Tin; Dang, Thi My Dung; Dang, Mau Chien

    2016-01-01

    In this paper interdigitated electrodes for gas sensors were fabricated by inkjet printing technology. Silver electrodes were inkjet printed on Si/SiO 2 substrates instead of traditional photolithography method. The inkjet printing parameters to obtain desired dimensions, thickness of the electrodes and distance between the interdigitated electrodes were optimized in this study. The fabricated interdigitated silver electrodes were tested for application in ammonia gas sensors. Conductive polyaniline (PANI) layer was coated on the silver interdigitated electrodes by drop-coating. Ammonia detection of the PANI-coated chips was characterized with a gas measurement system in which humidity and ammonia concentrations were well-controlled. The electrical conductivity of the PANI films coated on the electrodes was measured when the PANI films were exposed to nitrogen and ammonia. The conductivity of the PANI films decreased significantly due to the deprotonation process of PANI upon ammonia expodure. The recovery time was about 15 min by heating up the polymer chip at 60 °C. The results showed that the silver electrodes fabricated by inkjet printing technique could be used as a sensor platform for ammonia detection. (paper)

  18. One-step fabrication of nanostructured Ni film with lotus effect from deep eutectic solvent.

    Science.gov (United States)

    Gu, Changdong; Tu, Jiangping

    2011-08-16

    We report a procedure to fabricate nanostructured Ni films via programmed electrochemical deposition from a choline-chloride-based ionic liquid at a high temperature of 90 °C. Three electrodeposition modes using constant voltage, pulse voltage, and reverse pulse voltage produce a variety of nanostructured Ni films with micro/nanobinary surface architectures, such as nanosheets, aligned nanostrips, and hierarchical flowers. The nanostructured Ni films possess face-centered cubic crystal structure. Amazingly, it is found that the electrodeposited Ni films deliver the superhydrophobic surfaces without any further modifications by low surface-energy materials, which might be attributed to the vigorous micro/nanobinary architectures and the surface chemical composition. The electrochemical measurements reveal that the superhydrophobic Ni film exhibit an obvious passivation phenomenon, which could provide enhanced corrosion resistance for the substrate in the aqueous solutions.

  19. An investigation on the effect of deposition parameters on nanostructured electrode of lithium ion batteries and their performance

    Science.gov (United States)

    Dorri, Mehrdad; Zamani, Cyrus; Babaei, Alireza

    2018-01-01

    Nanostructured plate-like manganese cobalt oxide (MCO) was synthesized as the anode material for lithium-ion batteries. Under basic conditions and using a molar ratio of OH- /NO3-= 1.5, crystallite size of 14 nm was found for samples calcined at 350°C. The electrodes were fabricated by mixing MCO as the active material, Super P carbon as the conducting material and polyvinylidene fluoride (PVDF) as the binder in N-methyl-2-pyrrolidone (NMP) solvent. The slurry was coated onto a copper foil substrate. The aim of this investigation is the assessment of deposition parameters on different plausible defects (such as agglomeration/blisters, pinholes/divots, cracks and non-uniform coating) and also electrical behavior of the deposited layer. Because of high degree of agglomeration, mortar method was found to be ineffective while mixing using magnetic stirrer was proved to be more appropriate in terms of final rheology. The optimum value for the binder was found to be 2.73 wt% of the NMP solvent. Effective drying was achieved using hotplate followed by oven drying. SEM analysis revealed the disappearance of the surface cracks when samples are pressed after drying stage.

  20. Emerging Prototype Sodium-Ion Full Cells with Nanostructured Electrode Materials.

    Science.gov (United States)

    Ren, Wenhao; Zhu, Zixuan; An, Qinyou; Mai, Liqiang

    2017-06-01

    Due to steadily increasing energy consumption, the demand of renewable energy sources is more urgent than ever. Sodium-ion batteries (SIBs) have emerged as a cost-effective alternative because of the earth abundance of Na resources and their competitive electrochemical behaviors. Before practical application, it is essential to establish a bridge between the sodium half-cell and the commercial battery from a full cell perspective. An overview of the major challenges, most recent advances, and outlooks of non-aqueous and aqueous sodium-ion full cells (SIFCs) is presented. Considering the intimate relationship between SIFCs and electrode materials, including structure, composition and mutual matching principle, both the advance of various prototype SIFCs and the electrochemistry development of nanostructured electrode materials are reviewed. It is noted that a series of SIFCs combined with layered oxides and hard carbon are capable of providing a high specific gravimetric energy above 200 Wh kg -1 , and an NaCrO 2 //hard carbon full cell is able to deliver a high rate capability over 100 C. To achieve industrialization of SIBs, more systematic work should focus on electrode construction, component compatibility, and battery technologies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Fabrication of porous nanostructures for Raman signal amplification

    Science.gov (United States)

    Mitsai, E. V.; Syubaev, S. A.; Kuchmizhak, A. A.

    2018-01-01

    Pulsed-laser dry printing of noble-metal microrings with a tunable internal porous structure, which can be revealed via an ion-beam etching post-procedure, was demonstrated. Average size of the pores inside the microrings were shown to be tuned in a wide range by varying the incident pulse energy and a nitrogen doping level controlled in the process of magnetron deposition of the gold film in the appropriate gaseous environment. The fabricated porous microrings were shown to provide many-fold near-field enhancement of incident electromagnetic fields, which was confirmed by mapping of the characteristic Raman band of a nanometer-thick covering layer of Rhodamine 6G molecules and supporting calculations. The proposed laser-printing/ion-beam etching approach is demonstrated to be a unique tool aimed at designing and fabricating multifunctional plasmonic structures and metasurfaces for spectroscopic bioidentification based on surface-enhanced Raman scattering and photoluminescence detection schemes.

  2. Fabricating designed fullerene nanostructures for functional electronic devices

    OpenAIRE

    Larsen, Christian

    2014-01-01

    A long-term goal within the field of organic electronics has been to developflexible and functional devices, which can be processed and patterned withlow-cost and energy-efficient solution-based methods. This thesis presents anumber of functional paths towards the attainment of this goal via thedevelopment and demonstration of novel fabrication and patterningmethods involving the important organic-semiconductor family termedfullerenes.Fullerenes are soccer-shaped small molecules, with two oft...

  3. Effects of surface water on organosilane nanostructure fabrication using particle lithography

    Energy Technology Data Exchange (ETDEWEB)

    Brownfield, Amy L.; Causey, Corey P., E-mail: corey.causey@unf.edu; Mullen, Thomas J., E-mail: tj.mullen@unf.edu

    2015-11-02

    Patterned organosilane self-assembled monolayers serve as molecular platforms for electronic, optical, and sensing applications. Among the numerous strategies to pattern organosilane monolayers, particle lithography offers a high throughput means to fabricate arrays of organosilane nanopatterns across large areas. Herein, we demonstrate that the utility of particle lithography for generating nanostructures can be further controlled by changes in sample preparation. Our systematic study of various drying conditions demonstrates a correlation between sample preparation and surface water and uses these findings to form nanopores, pillars, and rings within organosilane monolayers. Silica mesospheres deposited on Si substrates that are subjected to less rigorous drying conditions (3 h at room temperature) prior to organosilane deposition yield nanopores within decyltrichlorosilane monolayers that are significantly smaller than those produced on Si substrates that are prepared under more forcing conditions (12 h at room temperature and 2 h at 140 °C). This disparity in nanopore diameter can be rationalized by the presence or absence of water between the silica mesospheres and Si substrate. Sequential deposition of two organosilanes offers further evidence for the presence or absence of water beneath the silica mesospheres. For samples that are less rigorously dried, complete organosilane pillars are observed, and for samples that are more rigorously dried, organosilane rings are observed where the inner diameter is defined by the mesosphere-substrate contact geometry. The ability to produce varied organosilane nanostructures provides valuable insights about the water that is present on the surface and within the silica mesosphere template. These insights into the surface water and the effects of sample preparation on organosilane nanostructures enable greater hierarchical control over the fabrication process. - Highlights: • Organosilane nanostructures are fabricated

  4. Fabrication and characterization of subwavelength nanostructures on freestanding GaN slab.

    Science.gov (United States)

    Wang, Yongjin; Hu, Fangren; Kanamori, Yoshiaki; Sameshima, Hidehisa; Hane, Kazuhiro

    2010-02-01

    We develop a novel way to fabricate subwavelength nanostructures on the freestanding GaN slab using a GaN-on-silicon system by combining self-assemble technique and backside thinning method. Silicon substrate beneath the GaN slab is removed by bulk silicon micromachining, generating the freestanding GaN slab and eliminating silicon absorption of the emitted light. Fast atom beam (FAB) etching is conducted to thin the freestanding GaN slab from the backside, reducing the number of confined modes inside the GaN slab. With self-assembled silica nanospheres acting as an etching mask, subwavelength nanostructures are realized on the GaN surface by FAB etching. The reflection losses at the GaN interfaces are thus suppressed. When the InGaN/GaN multiple quantum wells (MQWs) active layers are excited, the light extraction efficiency is significantly improved for the freestanding nanostructured GaN slab. This work provides a very practical approach to fabricate freestanding nanostructures on the GaN-on-silicon system for further improving the light extraction efficiency.

  5. Fabrication of superhydrophobic polymethylsilsesquioxane nanostructures on cotton textiles by a solution-immersion process.

    Science.gov (United States)

    Shirgholami, Mohammad A; Khalil-Abad, Mohammad Shateri; Khajavi, Ramin; Yazdanshenas, Mohammad E

    2011-07-15

    Superhydrophobic cotton textiles are prepared by a simple, one-step and inexpensive phase separation method under ambient conditions by which a layer of polymethylsilsesquioxane (PMSQ) nanostructures is covered onto the cellulose fibers. By changing the silane precursor concentration, PMSQ nanostructures with various shapes, morphologies and sizes were fabricated. Nanostructures were characterized using SEM, EDS, and attenuated total reflectance FTIR. The wettability of the modified cellulose surfaces was characterized with contact-angle goniometry and sliding angle technique, respectively. The water contact angle of modified cotton is measured to be higher than 150°, which is high enough to exhibit the lotus effect as a result of the superhydrophobicity. Tunable water-repellent properties of the fabric are also demonstrated, with sliding contact angles varying from "sticky" to "slippery" depending upon different nanostructures on the surface of the fibers. It is expected that this simple technique will accelerate the large-scale production of superhydrophobic cellulosic materials with new industrial applications. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. One-step fabrication of crystalline metal nanostructures by direct nanoimprinting below melting temperatures

    Science.gov (United States)

    Liu, Ze

    2017-03-01

    Controlled fabrication of metallic nanostructures plays a central role in much of modern science and technology, because changing the dimensions of a nanocrystal enables tailoring of its mechanical, electronic, optical, catalytic and antibacterial properties. Here we show direct superplastic nanoimprinting (SPNI) of crystalline metals well below their melting temperatures, generating ordered nanowire arrays with aspect ratios up to ~2,000 and imprinting features as small as 8 nm. Surface-enhanced Raman scattering (SERS) spectra reveal strongly enhanced electromagnetic signals from the prepared nanorod arrays with sizes up to ~100 nm, which indicates that our technique can provide an ideal way to fabricate robust SERS substrates. SPNI, as a one-step, controlled and reproducible nanofabrication method, could facilitate the applications of metal nanostructures in bio-sensing, diagnostic imaging, catalysis, food industry and environmental conservation.

  7. Fabrication of Biosensors Based on Nanostructured Conducting Polyaniline (NSPANI

    Directory of Open Access Journals (Sweden)

    Deepshikha SAINI

    2011-11-01

    Full Text Available In this study, glucose and hydrogen peroxide (H2O2 biosensors based on nanostructured conducting polyaniline (NSPANI (synthesized using sodiumdodecyl sulphate (SDS as structure directing agent were developed. Because of the large specific surface area, excellent conductivity of NSPANI, horseradish peroxidase (HRP and glucose oxidase (GOx could be easily immobilized with high loading and activity. In addition the small dimensions and the high surface-to-volume ratio of the NSCP allow the rapid transmission of electron and enhance current response. The linear dynamic range of optical glucose and H2O2 biosensors is 5–40 mM for glucose and 1–50 mM for H2O2, respectively where as the bulk PANI exhibits linearity between 5-20 mM/l. The miniature optical glucose biosensor also exhibits good reproducibility. The storage stability of optical glucose and H2O2 biosensors is two weeks for glucose and five days for H2O2. The high response value of NSPANI based biosensors as compared to bulk PANI based biosensor reflects higher enzymatic affinity of GOx/NSPANI and HRP/NSPANI with glucose and H2O2 due to biocompatibility, active surface area and high electron communication capability of nanobiopolymer film. In conclusion, the NSPANI based biosensors proposed herein have many advantages such as a low response time, high reproducibility, high sensitivity, stable and wide dynamic range.

  8. Platinum nanoparticles decorated dendrite-like gold nanostructure on glassy carbon electrodes for enhancing electrocatalysis performance to glucose oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Hongmei [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, School of Materials Science and Engineering, Hubei University, No. 368 Youyi Avenue, Wuchang, Wuhan 430062 (China); Chang, Gang, E-mail: changgang@hubu.edu.cn [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, School of Materials Science and Engineering, Hubei University, No. 368 Youyi Avenue, Wuchang, Wuhan 430062 (China); Lei, Ming [State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876 (China); He, Hanping [College of Chemistry and Chemical Engineer, Hubei University, Youyi Road 368, Wuchang, Wuhan, Hubei 430062 (China); Liu, Xiong; Shu, Honghui; Xia, Tiantian; Su, Jie [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, School of Materials Science and Engineering, Hubei University, No. 368 Youyi Avenue, Wuchang, Wuhan 430062 (China); He, Yunbin, E-mail: ybhe@hubu.edu.cn [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, School of Materials Science and Engineering, Hubei University, No. 368 Youyi Avenue, Wuchang, Wuhan 430062 (China)

    2016-10-30

    Highlights: • Pt/DGNs/GC composites were obtained via a clean and facile method without any templates, surfactants, or stabilizers. • Controlling chemical reduction deposition time, the amount of platinum nanoparticles on Au surface could be regulated, which further tuned electrocatalytic properties toward glucose oxidation. • The obtained Pt/DGNs/GC composites with high electrochemical active surface area (ECSA) show superior electrocatalytic activity to glucose. • The sensor based on Pt/DGNs/GC exhibited excellent sensitivity, selectivity and stability for nonenzymatic glucose detection. - Abstract: Platinum nanoparticles decorated dendrite-like gold nanostructure, bimetal composite materials on glassy carbon electrode (Pt/DGNs/GC) for enhancing electrocatalysis to glucose oxidation was designed and successfully fabricated by a facile two-step deposition method without any templates, surfactants, or stabilizers. Dendrite-like gold nanostructure was firstly deposited on the GC electrode via the potentiostatic method, and then platinum nanoparticles were decorated on the surface of gold substrate through chemical reduction deposition. X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), energy-dispersive X-ray spectroscopy (EDS) were applied to characterize the evolution of morphology and structure of the as-prepared Pt/DGNs/GC. Based on electrochemical measurements such as cyclic voltammetry, linear voltammetry and chronoamperometry, Pt/DGNs/GC exhibited significantly enhanced electrocatalytic performance to glucose oxidation compared those of pure dendrite-like Au nanoparticles in our previous report. Controlling chemical reduction deposition time, the amount of platinum nanoparticles on Au surface could be regulated, which further tuned electrocatalytic properties toward glucose oxidation. The dendrite-like gold surface partially covered by platinum nanoparticles dramatically enhanced the electrocatalytic performance for the

  9. Abnormal grain growth in the nanostructured Invar alloy fabricated by electrodeposition

    Science.gov (United States)

    Park, Hyung-Ki; Hwang, Nong-Moon; Park, Yong Bum

    2012-11-01

    Abnormal grain growth in the nanostructured Invar alloy fabricated by electrodeposition was investigated by electron backscattered diffraction. The observation showed that most of grains growing abnormally during annealing at 380°C have Σ3 boundaries. The observation could be best explained by the mechanism of solid-state wetting, where the Σ3 boundary provides the low-energy boundary, which increases the probability of solid-state wetting, leading to exclusive growth.

  10. Electrodeposition of polymer electrolyte in nanostructured electrodes for enhanced electrochemical performance of thin-film Li-ion microbatteries

    Science.gov (United States)

    Salian, Girish D.; Lebouin, Chrystelle; Demoulin, A.; Lepihin, M. S.; Maria, S.; Galeyeva, A. K.; Kurbatov, A. P.; Djenizian, Thierry

    2017-02-01

    We report that electrodeposition of polymer electrolyte in nanostructured electrodes has a strong influence on the electrochemical properties of thin-film Li-ion microbatteries. Electropolymerization of PMMA-PEG (polymethyl methacrylate-polyethylene glycol) was carried out on both the anode (self-supported titania nanotubes) and the cathode (porous LiNi0.5Mn1.5O4) by cyclic voltammetry and the resulting electrode-electrolyte interface was examined by scanning electron microscopy. The electrochemical characterizations performed by galvanostatic experiments reveal that the capacity values obtained at different C-rates are doubled when the electrodes are completely filled by the polymer electrolyte.

  11. Design and Fabrication of Nanostructures Based on DNA Ring-Protein Complex

    Science.gov (United States)

    Furukawa, Hideki; Endo, Tatsuro; Yanagida, Yasuko; Hatsuzawa, Takeshi

    2008-06-01

    In this report, we describe the design and fabrication of DNA nanostructures (“DNA glasses”, “DNA serial rings”, and “DNA chains”) using DNA ring-protein complexes. An experiment was performed to fabricate DNA ring-conjugated biotin using two types of DNA (“vector DNA” and “insert DNA”). The vector DNA was obtained by cutting plasmid DNA with restriction enzymes. The insert DNA (DNA conjugated with biotin) was obtained using a DNA synthesizer. After ligation and the introduction of streptavidin-modified gold nanoparticles, DNA structures were obtained. Subsequently, the DNA structures were observed by atomic force microscopy (AFM).

  12. Patterned TiO2 nanostructures fabricated with a novel inorganic resist

    International Nuclear Information System (INIS)

    Perotto, Giovanni; Antonello, Alessandro; Ferraro, Davide; Mattei, Giovanni; Martucci, Alessandro

    2013-01-01

    The fabrication of nanostructures is a very intense field of research in material science over the last decades. Overcoming the limit imposed by the diffraction limit in lithography was addressed in several ways: shifting to smaller wavelength, changing radiation and using electrons or ions instead of photons or using non-conventional bottom up techniques like self-assembly. There are few studies on fabrication of ordered TiO 2 nanostructures, mostly confined to non-scalable technologies, while nanostructured TiO 2 is a material used in many different fields of applications. In our work we present a hybrid nanofabrication technique based on self-assembly coupled with standard UV lithography. With this method we were able to fabricate in a single step and with the use of inexpensive equipment a 2D Nano Bowl Array of TiO 2 with sub wavelength features and easily scalable pattern features. - Highlights: • Titanate nanosheet were proven to be useful as an inorganic negative photo resist. • A Nano Bowl Array structure with features smaller than the diffraction limit of light was obtained. • 2D plasmonic gratings have been obtained by coating the Nano Bowl Array with Ag. • TiO 2 Nano Bowl Array have been used as superhydrophilic/hydrophobic surfaces

  13. Photodynamic activity of nanostructured fabrics grafted with xanthene and thiazine dyes against opportunistic fungi.

    Science.gov (United States)

    Kim, Joo Ran; Michielsen, Stephen

    2015-09-01

    Fungi are an important class of human pathogens for which considerable research has gone into defeating them. The photodynamic effects of rose bengal (RB), phloxine B (PB), azure A (AA), and toluidine blue O (TBO) dyes to inhibit Aspergillus fumigatus, Aspergillus niger, Trichoderma viride, Penicillium funiculosum, and Chaetomium globosum were investigated grafted to nano- and micro-structured fabrics. Three antifungal tests conducted: broth microdilution test of free dyes, zone of inhibition and quantitative antifungal assays on fabrics grafted with dyes. In the broth microdilution test, free RB displayed the lowest MIC at 32 μM to inhibit visible hyphal growth and germination but the antifungal ability of MIC for other photosensitizers below 63 μM was insignificant. RB and PB showed lower MIC than AA and TBO. In the inhibition zone tests, nanostructured fabrics grafted with RB and PB did not display fungal growth on the surface. Most microstructured fabrics grafted with AA and TBO showed little inhibition. In quantitative antifungal assay, nanostructured fabrics grafted with RB has the largest inhibition rate on T. viride and the lowest inhibition rate on P. funiculosum and the results showed the increasing inhibition rate in the order of AA < TBO < PB < RB. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Fabrication of catalytic electrodes for molten carbonate fuel cells

    Science.gov (United States)

    Smith, James L.

    1988-01-01

    A porous layer of catalyst material suitable for use as an electrode in a molten carbonate fuel cell includes elongated pores substantially extending across the layer thickness. The catalyst layer is prepared by depositing particulate catalyst material into polymeric flocking on a substrate surface by a procedure such as tape casting. The loaded substrate is heated in a series of steps with rising temperatures to set the tape, thermally decompose the substrate with flocking and sinter bond the catalyst particles into a porous catalytic layer with elongated pores across its thickness. Employed as an electrode, the elongated pores provide distribution of reactant gas into contact with catalyst particles wetted by molten electrolyte.

  15. Sensitive electrochemical immunosensor based on three-dimensional nanostructure gold electrode

    Directory of Open Access Journals (Sweden)

    Zhong G

    2015-03-01

    Full Text Available Guangxian Zhong,1,2,* Ruilong Lan,3,* Wenxin Zhang,1,4 Feihuan Fu,5 Yiming Sun,1,4 Huaping Peng,1,4 Tianbin Chen,3 Yishan Cai,6 Ailin Liu,1,4 Jianhua Lin,2 Xinhua Lin1,4 1Department of Pharmaceutical Analysis, Faculty of Pharmacy, Fujian Medical University, 2Department of Orthopaedics, 3The Centralab, First Affiliated Hospital of Fujian Medical University, 4Nano Medical Technology Research Institute, Fujian Medical University, Fuzhou, 5Department of Endocrinology, The County Hospital of Anxi, Anxi, 6Fujian International Travel Healthcare Center, Fujian Entry-Exit Inspection and Quarantine Bureau, Fuzhou, People’s Republic of China *These authors contributed equally to this work Abstract: A sensitive electrochemical immunosensor was developed for detection of alpha-fetoprotein (AFP based on a three-dimensional nanostructure gold electrode using a facile, rapid, “green” square-wave oxidation-reduction cycle technique. The resulting three-dimensional gold nanocomposites were characterized by scanning electron microscopy and cyclic voltammetry. A “sandwich-type” detection strategy using an electrochemical immunosensor was employed. Under optimal conditions, a good linear relationship between the current response signal and the AFP concentrations was observed in the range of 10–50 ng/mL with a detection limit of 3 pg/mL. This new immunosensor showed a fast amperometric response and high sensitivity and selectivity. It was successfully used to determine AFP in a human serum sample with a relative standard deviation of <5% (n=5. The proposed immunosensor represents a significant step toward practical application in clinical diagnosis and monitoring of prognosis. Keywords: electrochemical immunosensors, three-dimensional nanostructure gold electrode, square-wave oxidation-reduction cycle, alpha-fetoprotein 

  16. Nanotube Film Electrode and an Electroactive Device Fabricated with the Nanotube Film Electrode and Methods for Making Same

    Science.gov (United States)

    Kang, Jin Ho (Inventor); Park, Cheol (Inventor); Harrison, Joycelyn S. (Inventor)

    2017-01-01

    Disclosed is a single wall carbon nanotube (SWCNT) film electrode (FE), all-organic electroactive device systems fabricated with the SWNT-FE, and methods for making same. The SWCNT can be replaced by other types of nanotubes. The SWCNT film can be obtained by filtering SWCNT solution onto the surface of an anodized alumina membrane. A freestanding flexible SWCNT film can be collected by breaking up this brittle membrane. The conductivity of this SWCNT film can advantageously be higher than 280 S/cm. An electroactive polymer (EAP) actuator layered with the SWNT-FE shows a higher electric field-induced strain than an EAP layered with metal electrodes because the flexible SWNT-FE relieves the restraint of the displacement of the polymeric active layer as compared to the metal electrode. In addition, if thin enough, the SWNT-FE is transparent in the visible light range, thus making it suitable for use in actuators used in optical devices.

  17. Controlled hydrodynamic conditions on the formation of iron oxide nanostructures synthesized by electrochemical anodization: Effect of the electrode rotation speed

    International Nuclear Information System (INIS)

    Lucas-Granados, Bianca; Sánchez-Tovar, Rita; Fernández-Domene, Ramón M.; García-Antón, Jose

    2017-01-01

    Highlights: • Novel iron anodization process under controlled dynamic conditions was evaluated. • Iron oxide nanostructures composed mainly by hematite were synthesized. • Different morphologies were obtained depending on the electrode rotation speed. • A suitable photocatalyst was obtained by stirring the electrode at 1000 rpm.. - Abstract: Iron oxide nanostructures are of particular interest because they can be used as photocatalysts in water splitting due to their advantageous properties. Electrochemical anodization is one of the best techniques to synthesize nanostructures directly on the metal substrate (direct back contact). In the present study, a novel methodology consisting of the anodization of iron under hydrodynamic conditions is carried out in order to obtain mainly hematite (α-Fe 2 O 3 ) nanostructures to be used as photocatalysts for photoelectrochemical water splitting applications. Different rotation speeds were studied with the aim of evaluating the obtained nanostructures and determining the most attractive operational conditions. The synthesized nanostructures were characterized by means of Raman spectroscopy, Field Emission Scanning Electron Microscopy, photoelectrochemical water splitting, stability against photocorrosion tests, Mott-Schottky analysis, Electrochemical Impedance Spectroscopy (EIS) and band gap measurements. The results showed that the highest photocurrent densities for photoelectrochemical water splitting were achieved for the nanostructure synthesized at 1000 rpm which corresponds to a nanotubular structure reaching ∼0.130 mA cm −2 at 0.54 V (vs. Ag/AgCl). This is in agreement with the EIS measurements and Mott-Schottky analysis which showed the lowest resistances and the corresponding donor density values, respectively, for the nanostructure anodized at 1000 rpm.

  18. Flexible fabrication of multi-scale integrated 3D periodic nanostructures with phase mask

    Science.gov (United States)

    Yuan, Liang Leon

    Top-down fabrication of artificial nanostructures, especially three-dimensional (3D) periodic nanostructures, that forms uniform and defect-free structures over large area with the advantages of high throughput and rapid processing and in a manner that can further monolithically integrate into multi-scale and multi-functional devices is long-desired but remains a considerable challenge. This thesis study advances diffractive optical element (DOE) based 3D laser holographic nanofabrication of 3D periodic nanostructures and develops new kinds of DOEs for advanced diffracted-beam control during the fabrication. Phase masks, as one particular kind of DOE, are a promising direction for simple and rapid fabrication of 3D periodic nanostructures by means of Fresnel diffraction interference lithography. When incident with a coherent beam of light, a suitable phase mask (e.g. with 2D nano-grating) can create multiple diffraction orders that are inherently phase-locked and overlap to form a 3D light interference pattern in the proximity of the DOE. This light pattern is typically recorded in photosensitive materials including photoresist to develop into 3D photonic crystal nanostructure templates. Two kinds of advanced phase masks were developed that enable delicate phase control of multiple diffraction beams. The first exploits femtosecond laser direct writing inside fused silica to assemble multiple (up to nine) orthogonally crossed (2D) grating layers, spaced on Talbot planes to overcome the inherent weak diffraction efficiency otherwise found in low-contrast volume gratings. A systematic offsetting of orthogonal grating layers to establish phase offsets over 0 to pi/2 range provided precise means for controlling the 3D photonic crystal structure symmetry between body centered tetragonal (BCT) and woodpile-like tetragonal (wTTR). The second phase mask consisted of two-layered nanogratings with small sub-wavelength grating periods and phase offset control. That was

  19. Method of producing catalytic material for fabricating nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Seals, Roland D.; Menchhofer, Paul A.; Howe, Jane Y.; Wang, Wei

    2018-01-30

    Methods of fabricating nano-catalysts are described. In some embodiments the nano-catalyst is formed from a powder-based substrate material and is some embodiments the nano-catalyst is formed from a solid-based substrate material. In some embodiments the substrate material may include metal, ceramic, or silicon or another metalloid. The nano-catalysts typically have metal nanoparticles disposed adjacent the surface of the substrate material. The methods typically include functionalizing the surface of the substrate material with a chelating agent, such as a chemical having dissociated carboxyl functional groups (--COO), that provides an enhanced affinity for metal ions. The functionalized substrate surface may then be exposed to a chemical solution that contains metal ions. The metal ions are then bound to the substrate material and may then be reduced, such as by a stream of gas that includes hydrogen, to form metal nanoparticles adjacent the surface of the substrate.

  20. Biomimetic polymeric superhydrophobic surfaces and nanostructures: from fabrication to applications.

    Science.gov (United States)

    Wen, Gang; Guo, ZhiGuang; Liu, Weimin

    2017-03-09

    Numerous research studies have contributed to the development of mature superhydrophobic systems. The fabrication and applications of polymeric superhydrophobic surfaces have been discussed and these have attracted tremendous attention over the past few years due to their excellent properties. In general, roughness and chemical composition, the two most crucial factors with respect to surface wetting, provide the basic criteria for yielding polymeric superhydrophobic materials. Furthermore, with their unique properties and flexible configurations, polymers have been one of the most efficient materials for fabricating superhydrophobic materials. This review aims to summarize the most recent progress in polymeric superhydrophobic surfaces. Significantly, the fundamental theories for designing these materials will be presented, and the original methods will be introduced, followed by a summary of multifunctional superhydrophobic polymers and their applications. The principles of these methods can be divided into two categories: the first involves adding nanoparticles to a low surface energy polymer, and the other involves combining a low surface energy material with a textured surface, followed by chemical modification. Notably, surface-initiated radical polymerization is a versatile method for a variety of vinyl monomers, resulting in controlled molecular weights and low polydispersities. The surfaces produced by these methods not only possess superhydrophobicity but also have many applications, such as self-cleaning, self-healing, anti-icing, anti-bioadhesion, oil-water separation, and even superamphiphobic surfaces. Interestingly, the combination of responsive materials and roughness enhances the responsiveness, which allows the achievement of intelligent transformation between superhydrophobicity and superhydrophilicity. Nevertheless, surfaces with poor physical and chemical properties are generally unable to withstand the severe conditions of the outside world

  1. Fabrication of Semiconductor ZnO Nanostructures for Versatile SERS Application

    Directory of Open Access Journals (Sweden)

    Lili Yang

    2017-11-01

    Full Text Available Since the initial discovery of surface-enhanced Raman scattering (SERS in the 1970s, it has exhibited a huge potential application in many fields due to its outstanding advantages. Since the ultra-sensitive noble metallic nanostructures have increasingly exposed themselves as having some problems during application, semiconductors have been gradually exploited as one of the critical SERS substrate materials due to their distinctive advantages when compared with noble metals. ZnO is one of the most representative metallic oxide semiconductors with an abundant reserve, various and cost-effective fabrication techniques, as well as special physical and chemical properties. Thanks to the varied morphologies, size-dependent exciton, good chemical stability, a tunable band gap, carrier concentration, and stoichiometry, ZnO nanostructures have the potential to be exploited as SERS substrates. Moreover, other distinctive properties possessed by ZnO such as biocompatibility, photocatcalysis and self-cleaning, and gas- and chemo-sensitivity can be synergistically integrated and exerted with SERS activity to realize the multifunctional potential of ZnO substrates. In this review, we discuss the inevitable development trend of exploiting the potential semiconductor ZnO as a SERS substrate. After clarifying the root cause of the great disparity between the enhancement factor (EF of noble metals and that of ZnO nanostructures, two specific methods are put forward to improve the SERS activity of ZnO, namely: elemental doping and combination of ZnO with noble metals. Then, we introduce a distinctive advantage of ZnO as SERS substrate and illustrate the necessity of reporting a meaningful average EF. We also summarize some fabrication methods for ZnO nanostructures with varied dimensions (0–3 dimensions. Finally, we present an overview of ZnO nanostructures for the versatile SERS application.

  2. Fabrication of Semiconductor ZnO Nanostructures for Versatile SERS Application.

    Science.gov (United States)

    Yang, Lili; Yang, Yong; Ma, Yunfeng; Li, Shuai; Wei, Yuquan; Huang, Zhengren; Long, Nguyen Viet

    2017-11-19

    Since the initial discovery of surface-enhanced Raman scattering (SERS) in the 1970s, it has exhibited a huge potential application in many fields due to its outstanding advantages. Since the ultra-sensitive noble metallic nanostructures have increasingly exposed themselves as having some problems during application, semiconductors have been gradually exploited as one of the critical SERS substrate materials due to their distinctive advantages when compared with noble metals. ZnO is one of the most representative metallic oxide semiconductors with an abundant reserve, various and cost-effective fabrication techniques, as well as special physical and chemical properties. Thanks to the varied morphologies, size-dependent exciton, good chemical stability, a tunable band gap, carrier concentration, and stoichiometry, ZnO nanostructures have the potential to be exploited as SERS substrates. Moreover, other distinctive properties possessed by ZnO such as biocompatibility, photocatcalysis and self-cleaning, and gas- and chemo-sensitivity can be synergistically integrated and exerted with SERS activity to realize the multifunctional potential of ZnO substrates. In this review, we discuss the inevitable development trend of exploiting the potential semiconductor ZnO as a SERS substrate. After clarifying the root cause of the great disparity between the enhancement factor (EF) of noble metals and that of ZnO nanostructures, two specific methods are put forward to improve the SERS activity of ZnO, namely: elemental doping and combination of ZnO with noble metals. Then, we introduce a distinctive advantage of ZnO as SERS substrate and illustrate the necessity of reporting a meaningful average EF. We also summarize some fabrication methods for ZnO nanostructures with varied dimensions (0-3 dimensions). Finally, we present an overview of ZnO nanostructures for the versatile SERS application.

  3. Patterned zero-dimensional nanostructures: Fabrication and characterization

    Science.gov (United States)

    Dias, Neville Lourenco Antonio

    Due to the advantages arising from low-dimensional electronic systems, considerable effort has been put into the use of quantum dots and wires as the active media in optoelectronic devices. The realization of quantum dot based devices has been plagued with numerous obstacles. Conventional quantum dots are formed by strain-driven self-assembly. The stochastic nature of the process results in a distribution of dot sizes. If a device is composed of more than one quantum dot, the issue of uniformity becomes critical. Even if the device has only one quantum dot, uniformity is essential to obtain reproducible characteristics across multiple devices. Thus, the geometrical parameters of a quantum dot, such as shape and size as well as the chemical composition, need to be controlled. In this work, nanoscale selective area metal-organic chemical vapor deposition (MOCVD) has been used to define InAs dot nucleation sites with highly ordered dot-to-dot pitches down to 80 nm corresponding to densities greater than 10 10 cm-2, which are among the highest reported for site-defined dots. The fabrication approach avoids modification of the underlying surface, allowing for easier integration into a variety of devices. Patterning of an oxide film by electron beam lithography also allows for creation of arbitrary closely packed arrangements of quantum dots for novel device designs. The resulting quantum dot array has the potential to be used as a template for fabricating multi-stack structures for use in laser and photodetector applications. Although nano-fabrication methods impose a degree of determinism on the quantum dot size, the lack of coupling between individual dots in an array structure coupled with the size variation is the primary cause for inhomogeneous broadening in quantum dot based devices. In an attempt to address broadening in quantum dots, the nanopore active layer was proposed. The nanopore is in essence an inverse quantum dot structure consisting of a periodically

  4. Nanostructured p-Type Semiconductor Electrodes and Photoelectrochemistry of Their Reduction Processes

    Directory of Open Access Journals (Sweden)

    Matteo Bonomo

    2016-05-01

    Full Text Available This review reports the properties of p-type semiconductors with nanostructured features employed as photocathodes in photoelectrochemical cells (PECs. Light absorption is crucial for the activation of the reduction processes occurring at the p-type electrode either in the pristine or in a modified/sensitized state. Beside thermodynamics, the kinetics of the electron transfer (ET process from photocathode to a redox shuttle in the oxidized form are also crucial since the flow of electrons will take place correctly if the ET rate will overcome that one of recombination and trapping events which impede the charge separation produced by the absorption of light. Depending on the nature of the chromophore, i.e., if the semiconductor itself or the chemisorbed dye-sensitizer, different energy levels will be involved in the cathodic ET process. An analysis of the general properties and requirements of electrodic materials of p-type for being efficient photoelectrocatalysts of reduction processes in dye-sensitized solar cells (DSC will be given. The working principle of p-type DSCs will be described and extended to other p-type PECs conceived and developed for the conversion of the solar radiation into chemical products of energetic/chemical interest like non fossil fuels or derivatives of carbon dioxide.

  5. Fabrication of fuel cell electrodes and other catalytic structures

    Science.gov (United States)

    Smith, J.L.

    1987-02-11

    A porous layer of catalyst material suitable for use as an electrode in a molten carbonate fuel cell includes elongated pores substantially extending across the layer thickness. The catalyst layer is prepared by depositing particulate catalyst material into polymeric flocking on a substrate surface by a procedure such as tape casting. The loaded substrate is heated in a series of steps with rising temperatures to set the tape, thermally decompose the substrate with flocking and sinter bond the catalyst particles into a porous catalytic layer with elongated pores across its thickness. Employed as an electrode, the elongated pores provide distribution of reactant gas into contact with catalyst particles wetted by molten electrolyte. 1 fig.

  6. Bioinspired Structural Colors Fabricated with ZnO Quasi-Ordered Nanostructures.

    Science.gov (United States)

    Kim, Geon Hwee; An, Taechang; Lim, Geunbae

    2017-06-07

    Despite their advantages in different applications, structural colors are difficult to use because of the inability to change a structural color once it is implemented, as well as their high fabrication costs; implementing multiple structural colors simultaneously on one substrate is a challenge as well. In this study, structural colors were reproduced using quasi-ordered scattering to mitigate these issues. To this end, a ZnO flower-like structure having unimodal distributions of size and spacing was fabricated by ZnO hydrothermal growth. This fabricated nanostructure has a thickness on the order of 10 3 nm and a diameter on the order of 10 2 nm. The thickness and diameter increase in proportion with the synthesis time (thickness growth rate = 43 nm/min, diameter growth rate = 20 nm/min). The shape of the nanostructure can be easily tuned by simply adjusting the synthesis and etching times. This method combines the advantages of top-down and bottom-up synthetic approaches in that the structural color can be continuously modified once fabricated.

  7. Fabrication of graphene/polydopamine/copper foam composite material and its application as supercapacitor electrode

    Science.gov (United States)

    Zheng, Y.; Lu, S. X.; Xu, W. G.; He, G.; Cheng, Y. Y.; Xiao, F. Y.; Zhang, Y.

    2018-01-01

    In this work, a composite electrode was fabricated by chemical deposition of polydopamine (PDA) and graphene oxide (GO) on the copper foam (CF) surface, followed by annealing treatment. Owing to the cohesive effect of the PDA middle film, GO was coated on CF surface successfully, and then reduced simultaneously while annealing. The resulted rGO/PDA/CF composite electrode was directly used as a supercapacitor electrode and exhibited excellent electrochemical performance, with a high specific capacitance of 1250 F g-1 at 2 A g-1 and favorable cycle stability.

  8. Fabrication and electrochemical properties of free-standing single-walled carbon nanotube film electrodes

    International Nuclear Information System (INIS)

    Niu Zhi-Qiang; Ma Wen-Jun; Dong Hai-Bo; Li Jin-Zhu; Zhou Wei-Ya

    2011-01-01

    An easily manipulative approach was presented to fabricate electrodes using free-standing single-walled carbon nanotube (SWCNT) films grown directly by chemical vapor deposition. Electrochemical properties of the electrodes were investigated. In comparison with the post-deposited SWCNT papers, the directly grown SWCNT film electrodes manifested enhanced electrochemical properties and sensitivity of sensors as well as excellent electrocatalytic activities. A transition from macroelectrode to nanoelectrode behaviours was observed with the increase of scan rate. The heat treatment of the SWCNT film electrodes increased the current signals of electrochemical analyser and background current, because the heat-treatment of the SWCNTs in air could create more oxide defects on the walls of the SWCNTs and make the surfaces of SWCNTs more hydrophilic. The excellent electrochemical properties of the directly grown and heat-treated free-standing SWCNT film electrodes show the potentials in biological and electrocatalytic applications. (cross-disciplinary physics and related areas of science and technology)

  9. Fabrication and characterization on width of spiral interdigitated electrodes based biosensors

    Science.gov (United States)

    Adelyn, P. Y. P.; Hashim, U.; Arshad, M. K. Md; Ruslinda, A. R.; Voon, C. H.; Ayub, R. M.; Gopinath, Subash C. B.; Liu, Wei-Wen; Kahar, S. M.; Huda, A. R. N.; Lee, H. Cheun

    2017-03-01

    Simple and inexpensive mask layout design on a transparency film were demonstrated using the conventional complementary metal oxide semiconductor (CMOS) technique to produce interdigitated electrodes (IDEs) for biomedical biosensors applications. Lift-off techniques were implemented during photolithography process in order to pattern an electrode widths of 200µm, 300µm, 400µm and 500µm, respectively with a standardized 400µm gap spacing spiral IDEs. Due to the effect of the transparent mask, a fabrication of these spiral IDEs resulted in shrinkage of electrode width and increment of the gap spacing. Among these electrode sizes, the conductance of 300µm, 400µm and 500µm electrode width were successfully examined as compared to 200µm.

  10. Microwave-assisted ionothermal synthesis of nanostructured anatase titanium dioxide/activated carbon composite as electrode material for capacitive deionization

    International Nuclear Information System (INIS)

    Liu, Po-I; Chung, Li-Ching; Shao, Hsin; Liang, Teh-Ming; Horng, Ren-Yang; Ma, Chen-Chi M.; Chang, Min-Chao

    2013-01-01

    The nanostructured anatase titanium dioxide/activated carbon composite material for capacitive deionization electrode was prepared in a short time by a lower temperature two-step microwave-assisted ionothermal (sol–gel method in the presence of ionic liquid) synthesis method. This method includes a reaction and a crystallization step. In the crystallization step, the ionic liquid plays a hydrothermal analogy role in driving the surface anatase crystallization of amorphous titanium dioxide nanoparticles formed in the reaction step. The energy dispersive spectroscopic study of the composite indicates that the anatase titanium dioxide nanoparticles are evenly deposited in the matrix of activated carbon. The electrochemical property of the composite electrode was investigated. In comparison to the pristine activated carbon electrode, higher specific capacitance was observed for the nanostructured anatase titanium dioxide/activated carbon composite electrode, especially when the composite was prepared with a molar ratio of titanium tetraisopropoxide/H 2 O equal to 1:15. Its X-ray photoelectron spectroscopic result indicates that it has the highest amount of Ti-OH. The Ti-OH group can enhance the wetting ability and the specific capacitance of the composite electrode. The accompanying capacitive deionization result indicates that the decay of electrosorption capacity of this composite electrode is insignificant after five cycle tests. It means that the ion electrosorption–desorption becomes a reversible process

  11. NanoCOT: Low-Cost Nanostructured Electrode Containing Carbon, Oxygen, and Titanium for Efficient Oxygen Evolution Reaction.

    Science.gov (United States)

    Shan, Zhichao; Archana, Panikar Sathyaseelan; Shen, Gang; Gupta, Arunava; Bakker, Martin G; Pan, Shanlin

    2015-09-23

    Developing high-efficiency, durable, and low-cost catalysts based on earth-abundant elements for the oxygen evolution reaction (OER) is essential for renewable energy conversion and energy storage devices. In this study, we report a highly active nanostructured electrode, NanoCOT, which contains carbon, oxygen, and titanium, for efficient OER in alkaline solution. The NanoCOT electrode is synthesized from carbon transformation of TiO2 in an atmosphere of methane, hydrogen, and nitrogen at a high temperature. The NanoCOT exhibits enhanced OER catalytic activity in alkaline solution, providing a current density of 1.33 mA/cm(2) at an overpotential of 0.42 V. This OER current density of a NanoCOT electrode is about 4 times higher than an oxidized Ir electrode and 15 times higher than a Pt electrode because of its nanostructured high surface area and favorable OER kinetics. The enhanced catalytic activity of NanoCOT is attributed to the presence of a continuous energy band of the titanium oxide electrode with predominantly reduced defect states of Ti (e.g., Ti(1+), Ti(2+), and Ti(3+)) formed by chemical reduction with hydrogen and carbon. The OER performance of NanoCOT can also be further enhanced by decreasing its overpotential by 150 mV at a current density of 1.0 mA/cm(2) after coating its surface electrophoretically with 2.0 nm IrOx nanoparticles.

  12. Fabrication of Zircaloy-4 Fuel Cladding Pipe with Nanostructured Oxide Layer for Prevention of Hydrogen Production

    Energy Technology Data Exchange (ETDEWEB)

    Park, Y. J.; Park, J. W.; Kim, H. J.; Cho, S. O. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2015-05-15

    There has been an attempt to protect zircaloy fuel cladding by coating SiC. Research on producing oxide layer that can block fuel cladding from water on the surface of zircaloy fuel cladding by means of anodizing to reduce the rate of oxidation of fuel cladding at Loss Of Coolant Accident (LOCA) is an significant ongoing study subject. Applying nanostructured oxide layer to the prevention of thermal deformation of oxide layer was already suggested in our research group, the reasons of which is nanoporous structure is better than nanotube structure in terms of corrosion-resistant structure because nanotube structure can be easily peeled off. In this study, methods which are able to control morphology between nanoporous and nanotube structure were conducted by changing the anodizing conditions. Hence, Using glycerol and ammonium fluoride, Zircaloy-4 was anodized by varying water contents and applied voltage. Zircaloy-4 pipe with nanostructured surface was fabricated by anodization technique. The produced nanostructure is quite even but the thickness of the oxide layer is not even. The nanostructured surface can increase the thermal characteristics of the zircaloy-4 fuel cladding.

  13. Fabrication, structural characterization and photoluminescence of Q-1D semiconductor ZnS hierarchical nanostructures.

    Science.gov (United States)

    Zhang, Jun; Yang, Yongdong; Jiang, Feihong; Li, Jianping; Xu, Baolong; Wang, Xichang; Wang, Shumei

    2006-05-28

    Quasi-one-dimensional semiconductor ZnS hierarchical nanostructures have been fabricated by thermal evaporation of a mixture of ZnS nanopowders and Sn powders. Sn nanoparticles are located at or close to the tips of the nanowires (or nanoneedles) and served as the catalyst for quasi-one-dimensional ZnS nanostructure growth by a vapour-liquid-solid mechanism. The morphology and microstructure of the ZnS hierarchical nanostructures were measured by scanning electron microscopy and high-resolution transmission electron microscopy. The results show that a large number of ZnS nanoneedles were formed on the outer shells of a long and straight ZnS axial nanowire. The ZnS axial nanowires grow along the [001] direction, and ZnS nanoneedles are aligned over the surface of the ZnS nanowire in the radial direction. The room temperature photoluminescence spectrum exhibits a UV weak emission centred at 337 nm and one blue emission centred at 436 nm from the as-synthesized single-crystalline semiconductor ZnS hierarchical nanostructures.

  14. Electrochemical and DFT study of an anticancer and active anthelmintic drug at carbon nanostructured modified electrode.

    Science.gov (United States)

    Ghalkhani, Masoumeh; Beheshtian, Javad; Salehi, Maryam

    2016-12-01

    The electrochemical response of mebendazole (Meb), an anticancer and effective anthelmintic drug, was investigated using two different carbon nanostructured modified glassy carbon electrodes (GCE). Although, compared to unmodified GCE, both prepared modified electrodes improved the voltammetric response of Meb, the carbon nanotubes (CNTs) modified GCE showed higher sensitivity and stability. Therefore, the CNTs-GCE was chosen as a promising candidate for the further studies. At first, the electrochemical behavior of Meb was studied by cyclic voltammetry and differential pulse and square wave voltammetry. A one step reversible, pH-dependent and adsorption-controlled process was revealed for electro-oxidation of Meb. A possible mechanism for the electrochemical oxidation of Meb was proposed. In addition, electronic structure, adsorption energy, band gap, type of interaction and stable configuration of Meb on the surface of functionalized carbon nanotubes were studied by using density functional theory (DFT). Obtained results revealed that Meb is weakly physisorbed on the CNTs and that the electronic properties of the CNTs are not significantly changed. Notably, CNTs could be considered as a suitable modifier for preparation of the modified electrode for Meb analysis. Then, the experimental parameters affecting the electrochemical response of Meb were optimized. Under optimal conditions, high sensitivity (b(Meb)=dIp,a(Meb)/d[Meb]=19.65μAμM(-1)), a low detection limit (LOD (Meb)=19nM) and a wide linear dynamic range (0.06-3μM) was resulted for the voltammetric quantification of Meb. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Fabrication and characterization of a nanostructured TiO2/In2S3-Sb2S3/CuSCN extremely thin absorber (eta) solar cell

    Science.gov (United States)

    Huerta-Flores, Alí M.; García-Gómez, Nora A.; de la Parra-Arciniega, Salomé M.; Sánchez, Eduardo M.

    2016-08-01

    In this work we report the successful assembly and characterization of a TiO2/In2S3-Sb2S3/CuSCN extremely thin absorber solar cell. Nanostructured TiO2 deposited by screen printing on an ITO substrate was used as an n-type electrode. An ∼80 nm extremely thin layer of the system In2S3-Sb2S3 deposited by successive ionic layer adsorption and a reaction (silar) method was used as an absorber. The voids were filled with p-type CuSCN and the entire assembly was completed with a gold contact. The solar cell fabricated with this heterostructure showed an energy conversion efficiency of 4.9%, which is a promising result in the development of low cost and simple fabrication of solar cells.

  16. Electron emission from nano-structured carbon films fabricated by hot-filament chemical-vapor deposition and microwave plasma-enhanced chemical vapor deposition

    CERN Document Server

    Park, K H; Lee, K M; Oh, S G; Lee, S I; Koh, K H

    2000-01-01

    The electron-emission characteristics of nano-structured carbon films fabricated by using the HFCVD (hot- filament chemical-vapor deposition) and the MPECVD (microwave plasma-enhanced chemical-vapor deposition) methods with a metal catalyst are presented. According to our observation, neither the formation nor the alignment of nano tubes is absolutely necessary to realize carbon-based electron emitters. However, utilization of chrome as an interlayer between Si substrates and metal catalyst particles results in a great improvement in the emission characteristics and the mechanical stability. Also, fabrication of good electron-emitting carbon films on glass substrates, with sputter-deposited chrome electrodes,at a nominal temperature approx 615 .deg. C was demonstrated.

  17. Extreme wettability of nanostructured glass fabricated by non-lithographic, anisotropic etching

    Science.gov (United States)

    Yu, Eusun; Kim, Seul-Cham; Lee, Heon Ju; Oh, Kyu Hwan; Moon, Myoung-Woon

    2015-01-01

    Functional glass surfaces with the properties of superhydrophobicity/or superhydrohydrophilicity, anti-condensation or low reflectance require nano- or micro-scale roughness, which is difficult to fabricate directly on glass surfaces. Here, we report a novel non-lithographic method for the fabrication of nanostructures on glass; this method introduces a sacrificial SiO2 layer for anisotropic plasma etching. The first step was to form nanopillars on SiO2 layer-coated glass by using preferential CF4 plasma etching. With continuous plasma etching, the SiO2 pillars become etch-resistant masks on the glass; thus, the glass regions covered by the SiO2 pillars are etched slowly, and the regions with no SiO2 pillars are etched rapidly, resulting in nanopatterned glass. The glass surface that is etched with CF4 plasma becomes superhydrophilic because of its high surface energy, as well as its nano-scale roughness and high aspect ratio. Upon applying a subsequent hydrophobic coating to the nanostructured glass, a superhydrophobic surface was achieved. The light transmission of the glass was relatively unaffected by the nanostructures, whereas the reflectance was significantly reduced by the increase in nanopattern roughness on the glass. PMID:25791414

  18. Electrochemical growth of two-dimensional gold nanostructures on a thin polypyrrole film modified ITO electrode.

    Science.gov (United States)

    Li, Yin; Shi, Gaoquan

    2005-12-22

    Two-dimensional gold nanostructures have been fabricated by electrochemical deposition of gold nanoparticles onto indium tin oxide (ITO) glass substrate modified with thin polypyrrole film. By controlling the electrodeposition conditions, gold nanoparticles with dendritic rod, sheet, flower-like (consisting of staggered nanosheets), and pinecone-like structures were generated. The flower-like gold nanoparticles showed high catalytic activity on electrochemical reduction of oxygen, and its activity was measured to be approximately 25 times that of gold pinecones and 10(4) times that of gold nanosheets in terms of gold weight. The pinecone-like nanoparticles can form a compact film with nano-/microscale binary structure like a lotus leaf surface. After modification with n-dodecanethiol, the surface showed superhydrophobic properties with a water contact angle of 153.4 degrees and a tilt angle of 4.4 degrees (5 microL droplet).

  19. Nanostructured hybrid films containing nanophosphor: Fabrication and electronic spectral properties

    International Nuclear Information System (INIS)

    Camacho, S.A.; Aoki, P.H.B.; Constantino, C.J.L.; Aroca, R.F.; Pires, A.M.

    2012-01-01

    Highlights: ► Hybrid film containing the cationic polyelectrolyte PAH and Y 2 O 3 : Er, Yb nanophosphor. ► LbL film growth was monitored by absorbance x concentration in UV–Vis absorption. ► FTIR indicated existence of secondary interactions between PAH – nanophosphor layers. ► The morphology and the spatial distribution of the LbL film were analyzed by Raman. ► We observed intense electronic emission lines from doping ions in the micro-Raman. - Abstract: The intensive research of the optical properties of rare-earth ions is due to the high quantum efficiency of their emission, very narrow bands, and excellent fluorescence monochromaticity. The photoluminescence data presented here show that the nanophosphor remains a green emitter in Layer-by-Layer (LbL) films leading to potential application in optical devices or biological labeling. The LbL technique, an established method for thin film fabrication with molecular architecture control, is used in the manufacture of a hybrid film containing the cationic polyelectrolyte poly (allylamine hydrochloride) (PAH) and Y 2 O 3 : Er, Yb nanophosphor. The spectroscopic properties of this luminescent nanomaterial are extracted from the spectral data of the powder, cast film and LbL films. The growth of the LbL film was monitored by absorbance versus concentration plots in ultraviolet–visible (UV–Vis) absorption spectroscopy. The presence of both PAH and nanophosphor in the LbL film was confirmed by Fourier transform infrared (FTIR) absorption spectroscopy. The FTIR data also ruled out the existence of chemical interactions between the PAH and nanophosphor layers, which means that secondary interactions (like Van der Waals forces) might be the driving forces for LbL film growth. The morphology and the spatial distribution of the LbL film components along the film surface were probed with micrometer spatial resolution combining optical microscopy and Raman mapping. In addition, the observation of intense

  20. Low-Cost Facile Fabrication of Flexible Transparent Copper Electrodes by Nanosecond Laser Ablation

    KAUST Repository

    Paeng, Dongwoo

    2015-03-27

    © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Low-cost Cu flexible transparent conducting electrodes (FTCEs) are fabricated by facile nanosecond laser ablation. The fabricated Cu FTCEs show excellent opto-electrical properties (transmittance: 83%, sheet resistance: 17.48 Ω sq-1) with outstanding mechanical durability. Successful demonstration of a touch-screen panel confirms the potential applicability of Cu FTCEs to the flexible optoelectronic devices.

  1. Fabrication and electrochemical characterization of multi-walled carbon nanotube electrodes for applications to nano-electrochemical sensing

    International Nuclear Information System (INIS)

    Hwang, Sookhyun; Choi, Hyonkwang; Jeon, Minhyon; Vedala, Harindra; Kim, Taehyung; Choi, Wonbong

    2010-01-01

    In this study, we fabricated and electrochemically characterized two types of individual carbon nanotube electrodes: an as-produced multi-walled carbon nanotube (MWNT) electrode and a modified MWNT electrode. As-produced MWNTs were electrically contacted with Au/Ti layers by using nanolithography and RF magnetron sputtering. Open-ended modified MWNT electrodes were fabricated by using a reactive ion etching treatment under an oxygen atmosphere. We also performed cyclic voltammetry measurements to detect aqueous dopamine solutions with different concentrations. We found that an individual MWNT electrode, which had a small effective area, showed good electrochemical performance. The electrocatalytic behavior of the modified electrode, which had 'broken' open ends were better than that of the as-produced electrode with respect to sensitivity. The modified electrode was capable of detecting dopamine at the picomolar level. Therefore, an individual modified MWNT electrode has potential for applications to active components in nanobiosensors.

  2. Electrochemical fabrication of two-dimensional palladium nanostructures as substrates for surface enhanced Raman scattering.

    Science.gov (United States)

    Li, Yin; Lu, Gewu; Wu, Xufeng; Shi, Gaoquan

    2006-12-07

    Two-dimensional palladium (Pd) nanostructures have been fabricated by electrochemical deposition of Pd onto an indium tin oxide glass substrate modified with a thin flat film of polypyrrole or a nanofibril film of polyaniline. The experimental results demonstrated that the morphology of Pd nanoparticles strongly depended on the properties of conducting polymers and the conditions of electrochemical deposition. Two-dimensional nanostructures composed of flower-like (consisting of staggered nanosheets) or pinecone-like Pd nanoparticles were successfully synthesized. They can be used as substrates for surface-enhanced Raman scattering after partly decomposing the polymer components by heating in air, and the enhancement factor of the substrate composed of flower-like Pd nanoparticles was measured to be as high as 105 for 4-mercaptopyridine.

  3. Facile synthesis of core-shell nanostructured hollow carbon nanospheres@nickel cobalt double hydroxides as high-performance electrode materials for supercapacitors.

    Science.gov (United States)

    Xu, Juan; Ma, Chaojie; Cao, Jianyu; Chen, Zhidong

    2017-03-07

    Core-shell nanostructured hollow carbon nanospheres@nickel cobalt double hydroxides (HCNs@NiCo-LDH) were fabricated using a facile hydrothermal method and investigated as high-performance electrode materials for supercapacitors. HCNs were acquired by a successive polymerization, carbonization and etching process, which was subsequently wrapped by ultrathin NiCo-LDH nanosheets. The HCNs@NiCo-LDH electrode achieved a high specific capacitance (2558 F g -1 at 1 A g -1 ) and outstanding rate capability with 74.9% capacitance retention after a 20-fold increase in current density. Capacitances of 2405, 2310, 2168, 2006 and 1916 F g -1 can be achieved at rates of 3, 5, 10, 15 and 20 A g -1 , respectively, which are much higher than the specific capacitances of most reported carbon loaded NiCo-LDH. Specifically, the assembled HCNs@NiCo-LDH//graphene asymmetric supercapacitor displayed distinguished capacitive behaviors with a prominent specific capacitance of 172.8 F g -1 and eminent cycling stability with 93.5% capacitance retention after 3000 cycles. These remarkable electrochemical properties indicate that the unique HCNs@NiCo-LDH core-shell electrode is highly promising for application in energy storage fields.

  4. Conformal coating of thin polymer electrolyte layer on nanostructured electrode materials for three-dimensional battery applications.

    Science.gov (United States)

    Gowda, Sanketh R; Reddy, Arava Leela Mohana; Shaijumon, Manikoth M; Zhan, Xiaobo; Ci, Lijie; Ajayan, Pulickel M

    2011-01-12

    Various three-dimensional (3D) battery architectures have been proposed to address effective power delivery in micro/nanoscale devices and for increasing the stored energy per electrode footprint area. One step toward obtaining 3D configurations in batteries is the formation of core-shell nanowires that combines electrode and electrolyte materials. One of the major challenges however in creating such architectures has been the coating of conformal thin nanolayers of polymer electrolytes around nanostructured electrodes. Here we show conformal coatings of 25-30 nm poly(methyl methacralate) electrolyte layers around individual Ni-Sn nanowires used as anodes for Li ion battery. This configuration shows high discharge capacity and excellent capacity retention even at high rates over extended cycling, allowing for scalable increase in areal capacity with electrode thickness. Our results demonstrate conformal nanoscale anode-electrolyte architectures for an efficient Li ion battery system.

  5. Effective Chemical Route to 2D Nanostructured Silicon Electrode Material: Phase Transition from Exfoliated Clay Nanosheet to Porous Si Nanoplate

    International Nuclear Information System (INIS)

    Adpakpang, Kanyaporn; Patil, Sharad B.; Oh, Seung Mi; Kang, Joo-Hee; Lacroix, Marc; Hwang, Seong-Ju

    2016-01-01

    Graphical abstract: Effective morphological control of porous silicon 2D nanoplate can be achieved by the magnesiothermically-induced phase transition of exfoliated silicate clay nanosheets. The promising lithium storage performance of the obtained silicon materials with huge capacity and excellent rate characteristics underscores the prime importance of porously 2D nanostructured morphology of silicon. - Highlights: • 2D nanostructured silicon electrode materials are successfully synthesized via the magnesiothermically-induced phase transition of exfoliated clay 2D nanosheets. • High discharge capacity and rate capability are achieved from the 2D nanoplates of silicon. • Silicon 2D nanoplates can enhance both Li + diffusion and charge-transfer kinetics. • 2D nanostructured silicon is beneficial for the cycling stability by minimizing the volume change during lithiation-delithiation. - Abstract: An efficient and economical route for the synthesis of porous two-dimensional (2D) nanoplates of silicon is developed via the magnesiothermically-induced phase transition of exfoliated clay 2D nanosheets. The magnesiothermic reaction of precursor clay nanosheets prepared by the exfoliation and restacking with Mg 2+ cations yields porous 2D nanoplates of elemental silicon. The variation in the Mg:SiO 2 ratio has a significant effect on the porosity and connectivity of silicon nanoplates. The porous silicon nanoplates show a high discharge capacity of 2000 mAh g −1 after 50 cycles. Of prime importance is that this electrode material still retains a large discharge capacity at higher C-rates, which is unusual for the elemental silicon electrode. This is mainly attributed to the improved diffusion of lithium ions, charge-transfer kinetics, and the preservation of the electrical connection of the porous 2D plate-shaped morphology. This study highlights the usefulness of clay mineral as an economical and scalable precursor of high-performance silicon electrodes with

  6. Characterization and Performance Evaluation of Dye Sensitized Solar Cell Using Nanostructured TiO2 Electrode

    Directory of Open Access Journals (Sweden)

    Sule Erten-Ela

    2014-01-01

    Full Text Available Metal-free organic sensitizer consisting of donor, electron conducting, and anchoring anhydride groups was engineered at molecular level and synthesized. Dye sensitized solar cells based on conjugated naphthalene dye were fabricated using nanoporous electrode. Photoelectrodes with a 7 μm thick nanoporous layer and a 5 μm thick light-scattering layer were used to fabricate dye sensitized solar cells. DSSCs were fabricated in a FTO/nc-TiO2/organic dye/I-/I3-/Pt/FTO device geometry. Dye sensitized solar cell was characterized by current density-voltage (J-V measurement. All current-voltage (I-V measurements were done under 100 mW/cm2 light intensity and AM 1.5 conditions. The photovoltaic data revealed a short circuit photocurrent density of 1.86 mA/cm2, an open circuit voltage of 430 mV, and a fill factor of 0.63, corresponding to an overall conversion efficiency of 0.53%.

  7. Fabrication of chitosan/Au-TiO2nanotube-based dry electrodes for electroencephalography recording.

    Science.gov (United States)

    Song, Yanjuan; Li, Penghai; Li, Mingji; Li, Hongji; Li, Cuiping; Sun, Dazhi; Yang, Baohe

    2017-10-01

    In this paper, we describe a method for fabricating dry electrodes for use in recording electroencephalograms (EEGs), which are based on the use of chitosan (Ch), gold (Au) particles, and titanium dioxide (TiO 2 ) nanotube arrays deposited on titanium (Ti) thin sheets. The samples were characterized by scanning electron microscopy, X-ray diffraction, electrochemical impedance spectroscopy, and EEG signal collection. The TiO 2 nanotube arrays were grown on the Ti thin sheet by an electrochemical anodic oxidation method. The Au particles were deposited on the bottom and surface layers of the TiO 2 nanotube array using an electrochemistry-based multi-potential step technology. The fabricated dry Ch/Au-TiO 2 electrodes have an efficient conversion interface for ion current/electron current, a high biocompatible contact surface, and a fast electron transfer channel. To confirm that the Ch/Au-TiO 2 layer can be used in dry EEG electrodes, the impedance spectra of the electrodes in solution and skin were analyzed. The mean impedance values for skin were found to be approximately 169±33.0kΩ at 2.15Hz and 67.4±8.9kΩ at 100Hz. In addition, EEG signals from the forehead and sites with hair were collected using both the dry Ch/Au-TiO 2 electrode and a wet Ag/AgCl electrode for comparison purposes. It was found that high quality EEG signal recordings could be obtained using the dry electrodes. The fact that electrolytes are not required means that the electrodes are suitable for use in long-term bio-potential testing. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Novel Fabrication of CA Membrane Bound Carbon Electrode for Bi-enzymatic Determination of Lactate

    Directory of Open Access Journals (Sweden)

    VIKAS

    2006-12-01

    Full Text Available Lactate oxidase from Pediococcus species has been immobilized onto cellulose acetate (CA membrane to form an enzymatic membrane. HRP has been incorporated into carbon paste electrode. Enzymatic membrane was mounted over the HRP-carbon paste electrode with the help of dialyses membrane, which acts as working electrode. Lactate biosensor was constructed by connecting this fabricated working electrode to Ag/AgCl reference electrode along with platinum wire auxiliary electrode through potentiostate. The biosensor showed an excellent performance with a linear response range between 5µM to 1mML-1 of lactate with a correlation coefficient (r of .94 for n=30, when compared to standard colorimetric methods. The optimum pH of the biosensor is 6.5 and incubation temperature is 25°C. This bi-enzyme electrode can be used for 150 determinants; over 45 days with out any considerable lose of activity, when stored at 4°C in 0.5M sodium phosphate buffer (pH 6.5. The response time was 1 second and no major metabolic interference was observed.

  9. A novel fabrication method of carbon electrodes using 3D printing and chemical modification process.

    Science.gov (United States)

    Tian, Pan; Chen, Chaoyang; Hu, Jie; Qi, Jin; Wang, Qianghua; Chen, Jimmy Ching-Ming; Cavanaugh, John; Peng, Yinghong; Cheng, Mark Ming-Cheng

    2017-11-23

    Three-dimensional (3D) printing is an emerging technique in the field of biomedical engineering and electronics. This paper presents a novel biofabrication method of implantable carbon electrodes with several advantages including fast prototyping, patient-specific and miniaturization without expensive cleanroom. The method combines stereolithography in additive manufacturing and chemical modification processes to fabricate electrically conductive carbon electrodes. The stereolithography allows the structures to be 3D printed with very fine resolution and desired shapes. The resin is then chemically modified to carbon using pyrolysis to enhance electrochemical performance. The electrochemical characteristics of 3D printing carbon electrodes are assessed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The specific capacitance of 3D printing carbon electrodes is much higher than the same sized platinum (Pt) electrode. In-vivo electromyography (EMG) recording, 3D printing carbon electrodes exhibit much higher signal-to-noise ratio (40.63 ± 7.73) than Pt electrodes (14.26 ± 6.83). The proposed biofabrication method is envisioned to enable 3D printing in many emerging applications in biomedical engineering and electronics.

  10. Fabrication and Applications of Micro/Nanostructured Devices for Tissue Engineering

    KAUST Repository

    Limongi, Tania

    2016-09-02

    Nanotechnology allows the realization of new materials and devices with basic structural unit in the range of 1-100 nm and characterized by gaining control at the atomic, molecular, and supramolecular level. Reducing the dimensions of a material into the nanoscale range usually results in the change of its physiochemical properties such as reactivity, crystallinity, and solubility. This review treats the convergence of last research news at the interface of nanostructured biomaterials and tissue engineering for emerging biomedical technologies such as scaffolding and tissue regeneration. The present review is organized into three main sections. The introduction concerns an overview of the increasing utility of nanostructured materials in the field of tissue engineering. It elucidates how nanotechnology, by working in the submicron length scale, assures the realization of a biocompatible interface that is able to reproduce the physiological cell-matrix interaction. The second, more technical section, concerns the design and fabrication of biocompatible surface characterized by micro- and submicroscale features, using microfabrication, nanolithography, and miscellaneous nanolithographic techniques. In the last part, we review the ongoing tissue engineering application of nanostructured materials and scaffolds in different fields such as neurology, cardiology, orthopedics, and skin tissue regeneration.

  11. Fabrication of subwavelength periodic nanostructures using liquid immersion Lloyd's mirror interference lithography.

    Science.gov (United States)

    Bagal, Abhijeet; Chang, Chih-Hao

    2013-07-15

    We have developed a liquid immersion Lloyd's mirror interference lithography system to fabricate subwavelength periodic nanostructures. In this approach, we construct the Lloyd's mirror interferometer within a liquid medium to increase the ambient index. The light wavelength is scaled by the refractive index of the immersion fluid, reducing the minimum interference pattern period and increasing the spatial resolution. The all-liquid system ensures continuous fluid contact with the sample without an external mechanism, allows rapid adjustment of pattern period with subwavelength resolution, and retains the passive vibration-correction capability of Lloyd's mirror interferometers. Using this approach, we have successfully fabricated a grating structure with 112 nm period using a laser with 325 nm wavelength, attaining a numerical aperture of 1.45. The proposed immersion strategy can be adapted to improve pattern resolution of more complex interference lithography systems.

  12. Hydrothermal synthesis of nanostructured graphene/polyaniline composites as high-capacitance electrode materials for supercapacitors

    Science.gov (United States)

    Wang, Ronghua; Han, Meng; Zhao, Qiannan; Ren, Zonglin; Guo, Xiaolong; Xu, Chaohe; Hu, Ning; Lu, Li

    2017-03-01

    As known to all, hydrothermal synthesis is a powerful technique for preparing inorganic and organic materials or composites with different architectures. In this reports, by controlling hydrothermal conditions, nanostructured polyaniline (PANi) in different morphologies were composited with graphene sheets (GNS) and used as electrode materials of supercapacitors. Specifically, ultrathin PANi layers with total thickness of 10-20 nm are uniformly composited with GNS by a two-step hydrothermal-assistant chemical oxidation polymerization process; while PANi nanofibers with diameter of 50~100 nm are obtained by a one-step direct hydrothermal process. Benefitting from the ultrathin layer and porous structure, the sheet-like GNS/PANi composites can deliver specific capacitances of 532.3 to 304.9 F/g at scan rates of 2 to 50 mV/s. And also, this active material showed very good stability with capacitance retention as high as ~99.6% at scan rate of 50 mV/s, indicating a great potential for using in supercapacitors. Furthermore, the effects of hydrothermal temperatures on the electrochemical performances were systematically studied and discussed.

  13. Fabrication of a Polyaniline Ultramicroelectrode via a Self Assembled Monolayer Modified Gold Electrode

    Science.gov (United States)

    Bolat, Gulcin; Kuralay, Filiz; Eroglu, Gunes; Abaci, Serdar

    2013-01-01

    Herein, we report a simple and inexpensive way for the fabrication of an ultramicroelectrode and present its characterization by electrochemical techniques. The fabrication of polyaniline UME involves only two steps: modification of a gold (Au) electrode by self assembled monolayers (SAM) and then electrodeposition of polyaniline film on this thiol-coated Au electrode by using cyclic voltammetry and constant potential electrolysis methods. Two types of self-assembled monolayers (4-mercapto-1-butanol, MB, and 11-mercaptoundecanoic acid, MUA) were used, respectively, to see the effect of chain length on microelectrode formation. Microelectrode fabrication and utility of the surface was investigated by cyclic voltammetric measurements in a redox probe. The thus prepared polyaniline microelectrode was then used for DNA immobilization. Discrimination between double-stranded DNA (dsDNA) and single-stranded DNA (ssDNA) was obtained with enhanced electrochemical signals compared to a polyaniline-coated Au electrode. Different modifications on the electrode surfaces were examined using scanning electron microscopy (SEM). PMID:23797740

  14. Facile 3D Metal Electrode Fabrication for Energy Applications via Inkjet Printing and Shape Memory Polymer

    International Nuclear Information System (INIS)

    Roberts, R C; Wu, J; Li, D C; Hau, N Y; Chang, Y H; Feng, S P

    2014-01-01

    This paper reports on a simple 3D metal electrode fabrication technique via inkjet printing onto a thermally contracting shape memory polymer (SMP) substrate. Inkjet printing allows for the direct patterning of structures from metal nanoparticle bearing liquid inks. After deposition, these inks require thermal curing steps to render a stable conductive film. By printing onto a SMP substrate, the metal nanoparticle ink can be cured and substrate shrunk simultaneously to create 3D metal microstructures, forming a large surface area topology well suited for energy applications. Polystyrene SMP shrinkage was characterized in a laboratory oven from 150-240°C, resulting in a size reduction of 1.97-2.58. Silver nanoparticle ink was patterned into electrodes, shrunk, and the topology characterized using scanning electron microscopy. Zinc-Silver Oxide microbatteries were fabricated to demonstrate the 3D electrodes compared to planar references. Characterization was performed using 10M potassium hydroxide electrolyte solution doped with zinc oxide (57g/L). After a 300s oxidation at 3Vdc, the 3D electrode battery demonstrated a 125% increased capacity over the reference cell. Reference cells degraded with longer oxidations, but the 3D electrodes were fully oxidized for 4 hours, and exhibited a capacity of 5.5mA-hr/cm 2 with stable metal performance

  15. Electrical performance of polymer ferroelectric capacitors fabricated on plastic substrate using transparent electrodes

    KAUST Repository

    Bhansali, Unnat Sampatraj

    2012-09-01

    Polymer-based flexible ferroelectric capacitors have been fabricated using a transparent conducting oxide (ITO) and a transparent conducting polymer (PEDOT:PSS). It is found that the polarization fatigue performance with transparent oxide electrodes exhibits a significant improvement over the polymer electrodes (20% vs 70% drop in polarization after 10 6 cycles). This result can be explained based on a charge injection model that is controlled by interfacial band-offsets, and subsequent pinning of ferroelectric domain walls by the injected carriers. Furthermore, the coercive field (E c) of devices with our polymer electrodes is nearly 40% lower than reported values with similar polymer electrodes. Surprisingly, this difference was found to be related to the dry etching process used to define the top electrodes, which is reported for the first time by this group. The temperature dependence of relative permittivity of both devices shows a typical first order ferroelectric-to-paraelectric phase transition, but with a reduced Curie temperature compared to reference devices fabricated on Pt. © 2012 Elsevier B.V. All rights reserved.

  16. Fabrication of Cu/Pd bimetallic nanostructures with high gas sorption ability towards development of LPG sensor

    Energy Technology Data Exchange (ETDEWEB)

    Jaiswal, Aashit Kumar [Department of Physics, University of Allahabad, Allahabad 211002, U.P. (India); Singh, Satyendra, E-mail: satyendra_nano84@rediffmail.com [Department of Physics, University of Allahabad, Allahabad 211002, U.P. (India); Singh, Archana [Department of Physics, University of Lucknow, Lucknow 226007, U.P. (India); Yadav, R.R. [Department of Physics, University of Allahabad, Allahabad 211002, U.P. (India); Tandon, Poonam [Department of Physics, University of Lucknow, Lucknow 226007, U.P. (India); Yadav, B.C. [Department of Applied Physics, School for Physical Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow 226025, U.P. (India)

    2015-03-15

    A one-step synthesis of bimetallic Cu/Pd nanorods with rod's diameter ∼3 nm and their length in the range 10–15 nm is presented. The average size, size distribution, surface morphology and structure of the bimetallic Cu/Pd have been determined by transmission electron microscope (TEM), acoustic particle sizer (APS), scanning electron microscope (SEM) and X-ray diffraction (XRD), respectively. Further, thin films of bimetallic Cu/Pd nanostructures have been fabricated via spin-coating method. Fabricated films are, then, investigated for humidity and liquefied petroleum gas (LPG) sensors for the first time. The sensitivity and sensor response of the films towards the LPG are found better in comparison to the humidity. The investigated sensing parameters demonstrate that the fabricated LPG sensor using Cu/Pd bimetallic nanostructures is challenging for the detection of LPG at room temperature. - Highlights: • Fabrication of Cu/Pd meso-porous bimetallic thin film. • Cu/Pd nanostructures were characterized by SEM, TEM, APS and XRD. • Bimetallic nanostructures with smaller sizes and narrower size distributions. • First report on Cu/Pd bimetallic nanostructures as sensors. • Sensitivity of the sensor was simply enhanced by Cu-incorporation.

  17. Fabrication of nanostructures on Si(1 0 0) and GaAs(1 0 0) by local anodic oxidation

    International Nuclear Information System (INIS)

    Cervenka, Jiri; Kalousek, Radek; Bartosik, Miroslav; Skoda, David; Tomanec, Ondrej; Sikola, Tomas

    2006-01-01

    Atomic force microscopes have become useful tools not only for observing surface morphology and nanostructure topography but also for fabrication of various nanostructures itself. In this paper, the application of AFM for fabrication of nanostructures by local anodic oxidation (LAO) of Si(1 0 0) and GaAs(1 0 0) surfaces is presented. A special attention is paid to finding relations between the size of oxide nanolines (height and half-width) and operational parameters as tip-sample voltage and tip writing speed. It was demonstrated that the formation of silicon oxide lines obeys the Cabrera-Mott theory, i.e. the height of the lines grow, linearly with tip-sample voltage and is inversely proportional to logarithm of tip writing speed. As for GaAs substrates, the oxide line height grows linearly with tip-sample voltage as well but LAO exhibits a certain deviation from this theory. It is shown that the selective chemical etching of Si or GaAs ultrathin films processed by LAO makes it possible to use these films as nanolithographic masks for further nanotechnologies, e.g. fabrication of metallic nanostructures by ion-beam bombardment. The ability to control LAO and tip motion can be utilized in fabrication of complex nanostructures finding their applications in nanoelectronic devices, nanophotonics and other high-tech areas

  18. Fabrication of n-type Si nanostructures by direct nanoimprinting with liquid-Si ink

    Science.gov (United States)

    Takagishi, Hideyuki; Masuda, Takashi; Yamazaki, Ken; Shimoda, Tatsuya

    2018-01-01

    Nanostructures of n-type amorphous silicon (a-Si) and polycrystalline silicon (poly-Si) with a height of 270 nm and line widths of 110-165 nm were fabricated directly onto a substrate through a simple imprinting process that does not require vacuum conditions or photolithography. The n-type Liquid-Si ink was synthesized via photopolymerization of cyclopentasilane (Si5H10) and white phosphorus (P4). By raising the temperature from 160 °C to 200 °C during the nanoimprinting process, well-defined angular patterns were fabricated without any cracking, peeling, or deflections. After the nanoimprinting process, a-Si was produced by heating the nanostructures at 400°C-700 °C, and poly-Si was produced by heating at 800 °C. The dopant P diffuses uniformly in the Si films, and its concentration can be controlled by varying the concentration of P4 in the ink. The specific resistance of the n-type poly-Si pattern was 7.0 × 10-3Ω ṡ cm, which is comparable to the specific resistance of flat n-type poly-Si films.

  19. Three-Dimensional Nanostructure Fabrication by Focused Ion Beam Chemical Vapor Deposition

    Science.gov (United States)

    Matsui, Shinji

    In this chapter, we describe three-dimensional nanostructure fabrication using 30 keV Ga+ focused ion beam chemical vapor deposition (FIB-CVD) and a phenanthrene (C14H10) source as a precursor. We also consider microstructure plastic art, which is a new field that has been made possible by microbeam technology, and we present examples of such art, including a "micro wine glass" with an external diameter of 2.75 μm and a height of 12 μm. The film deposited during such processes is diamond-like amorphous carbon, which has a Young's modulus exceeding 600 GPa, appearing to make it highly desirable for various applications. The production of three-dimensional nanostructures is also discussed. The fabrication of microcoils, nanoelectrostatic actuators, and 0.1 μm nanowiring - all potential components of nanomechanical systems - is explained. The chapter ends by describing the realization of nanoinjectors and nanomanipulators, novel nanotools for manipulating and analyzing subcellular organelles.

  20. Large scale fabrication of nitrogen vacancy-embedded diamond nanostructures for single-photon source applications

    Science.gov (United States)

    Jiang, Qianqing; Li, Wuxia; Tang, Chengchun; Chang, Yanchun; Hao, Tingting; Pan, Xinyu; Ye, Haitao; Li, Junjie; Gu, Changzhi

    2016-11-01

    Some color centers in diamond can serve as quantum bits which can be manipulated with microwave pulses and read out with laser, even at room temperature. However, the photon collection efficiency of bulk diamond is greatly reduced by refraction at the diamond/air interface. To address this issue, we fabricated arrays of diamond nanostructures, differing in both diameter and top end shape, with HSQ and Cr as the etching mask materials, aiming toward large scale fabrication of single-photon sources with enhanced collection efficiency made of nitrogen vacancy (NV) embedded diamond. With a mixture of O2 and CHF3 gas plasma, diamond pillars with diameters down to 45 nm were obtained. The top end shape evolution has been represented with a simple model. The tests of size dependent single-photon properties confirmed an improved single-photon collection efficiency enhancement, larger than tenfold, and a mild decrease of decoherence time with decreasing pillar diameter was observed as expected. These results provide useful information for future applications of nanostructured diamond as a single-photon source. Project supported by the National Key Research and Development Plan of China (Grant No. 2016YFA0200402), the National Natural Science Foundation of China (Grants Nos. 11574369, 11574368, 91323304, 11174362, and 51272278), and the FP7 Marie Curie Action (project No. 295208) sponsored by the European Commission.

  1. Investigation of Electrochemically Deposited and Chemically Reduced Platinum Nanostructured Thin Films as Counter Electrodes in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Chih-Hung Tsai

    2018-02-01

    Full Text Available In this paper, we demonstrated that platinum (Pt counter electrodes (CEs fabricated using electrochemical deposition and chemical reduction can replace conventional high-temperature thermally decomposed Pt electrodes. In this study, Pt electrodes were fabricated using thermal decomposition, electrochemical deposition, and chemical reduction, and the influence of the different Pt counter electrodes on the efficiency of the dye-sensitized solar cells (DSSCs was analyzed. The properties of the various Pt CEs were analyzed using scanning electron microscopy (SEM, surface area analysis, X-ray diffraction (XRD, electrochemical impedance spectroscopy (EIS, and cyclic voltammetry (CV. DSSCs with various Pt CEs were characterized using current density-voltage (J-V, incident photo-current conversion efficiency (IPCE, and EIS measurements. The results show that the power conversion efficiencies of these three types of DSSC devices were between 7.43% and 7.72%. The DSSCs based on the Pt electrode fabricated through electrochemical deposition exhibited the optimal power conversion efficiency. Because the processes of electrochemical deposition and chemical reduction do not require high-temperature sintering, these two methods are suitable for the fabrication of Pt on flexible plastic substrates.

  2. Fabrication of carbon nanotube nanogap electrodes by helium ion sputtering for molecular contacts

    International Nuclear Information System (INIS)

    Thiele, Cornelius; Vieker, Henning; Beyer, André; Gölzhäuser, Armin; Flavel, Benjamin S.; Hennrich, Frank; Muñoz Torres, David; Eaton, Thomas R.; Mayor, Marcel; Kappes, Manfred M.; Löhneysen, Hilbert v.

    2014-01-01

    Carbon nanotube nanogaps have been used to contact individual organic molecules. However, the reliable fabrication of a truly nanometer-sized gap remains a challenge. We use helium ion beam lithography to sputter nanogaps of only (2.8 ± 0.6) nm size into single metallic carbon nanotubes embedded in a device geometry. The high reproducibility of the gap size formation provides a reliable nanogap electrode testbed for contacting small organic molecules. To demonstrate the functionality of these nanogap electrodes, we integrate oligo(phenylene ethynylene) molecular rods, and measure resistance before and after gap formation and with and without contacted molecules

  3. Electrochemical growth of high-aspect ratio nanostructured silver chloride on silver and its application to miniaturized reference electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Safari, S; Selvaganapathy, P R [Department of Mechanical Engineering, McMaster University, Hamilton, ON, L8S 4L7 (Canada); Derardja, A [Faculty of Science and Engineering, University of Batna (Algeria); Deen, M J, E-mail: selvaga@mcmaster.ca, E-mail: jamal@mcmaster.ca [Electrical and Computer Engineering, McMaster University, Hamilton, ON, L8S 4L8 (Canada)

    2011-08-05

    The sensitivity of many biological and chemical sensors is critically dependent on the stability of the potential of the reference electrode being used. The stability of a reference electrode's potential is highly influenced by the properties of its surface. In this paper, for the first time, the formation of nanosheets of silver chloride on silver wire is observed and controlled using high anodic constant potential (>0.5 V) and pulsed electrodeposition. The resulting nanostructured morphology substantially improves the electrode's potential stability in comparison with the conventional globular surface structure. The increased stability is attributed to the increase in the surface area of the silver chloride produced by the nanosheet formation.

  4. Functionalization of indium-tin-oxide electrodes by laser-nanostructured gold thin films for biosensing applications

    Energy Technology Data Exchange (ETDEWEB)

    Grochowska, Katarzyna, E-mail: kgrochowska@imp.gda.pl [Centre for Plasma and Laser Engineering, The Szewalski Institute, Polish Academy of Sciences, 14 Fiszera St, 80-231 Gdańsk (Poland); Siuzdak, Katarzyna [Centre for Plasma and Laser Engineering, The Szewalski Institute, Polish Academy of Sciences, 14 Fiszera St, 80-231 Gdańsk (Poland); Karczewski, Jakub [Solid State Physics Department, Faculty of Applied Physics and Mathematics, Gdańsk University of Technology, 11/12 Narutowicza St, 80-233, Gdańsk (Poland); Śliwiński, Gerard [Centre for Plasma and Laser Engineering, The Szewalski Institute, Polish Academy of Sciences, 14 Fiszera St, 80-231 Gdańsk (Poland)

    2015-12-01

    Graphical abstract: - Highlights: • ITO electrodes modified by NP arrays prepared by laser dewetting of thin Au films. • Enhanced activity, linear response and high sensitivity towards glucose. • Promising biosensor material AuNP-modified ITO of improved performance. - Abstract: The production and properties of the indium-tin-oxide (ITO) electrodes functionalized by Au nanoparticle (NP) arrays of a relatively large area formed by pulsed laser nanostructuring of thin gold films are reported and discussed. The SEM inspection of modified electrodes reveals the presence of the nearly spherical and disc-shaped particles of dimensions in the range of 40–120 nm. The NP-array geometry can be controlled by selection of the laser processing conditions. It is shown that particle size and packing density of the array are important factors which determine the electrode performance. In the case of NP-modified electrodes the peak current corresponding to the glucose direct oxidation process shows rise with increasing glucose concentration markedly higher comparing to the reference Au disc electrode. The detection limit reaches 12 μM and linear response of the sensor is observed from 0.1 to 47 mM that covers the normal physiological range of the blood sugar detection.

  5. Fabrication and integration of planar electrodes for contactless conductivity detection on polyester-toner electrophoresis microchips.

    Science.gov (United States)

    Coltro, Wendell Karlos Tomazelli; da Silva, José Alberto Fracassi; Carrilho, Emanuel

    2008-06-01

    In this report, we describe the microfabrication and integration of planar electrodes for contactless conductivity detection on polyester-toner (PT) electrophoresis microchips using toner masks. Planar electrodes were fabricated by three simple steps: (i) drawing and laser-printing the electrode geometry on polyester films, (ii) sputtering deposition onto substrates, and (iii) removal of toner layer by a lift-off process. The polyester film with anchored electrodes was integrated to PT electrophoresis microchannels by lamination at 120 degrees C in less than 1 min. The electrodes were designed in an antiparallel configuration with 750 microm width and 750 microm gap between them. The best results were recorded with a frequency of 400 kHz and 10 Vpp using a sinusoidal wave. The analytical performance of the proposed microchip was evaluated by electrophoretic separation of potassium, sodium and lithium in 150 microm wide x 6 microm deep microchannels. Under an electric field of 250 V/cm the analytes were successfully separated in less than 90 s with efficiencies ranging from 7000 to 13,000 plates. The detection limits (S/N = 3) found for K+, Na+, and Li+ were 3.1, 4.3, and 7.2 micromol/L, respectively. Besides the low-cost and instrumental simplicity, the integrated PT chip eliminates the problem of manual alignment and gluing of the electrodes, permitting more robustness and better reproducibility, therefore, more suitable for mass production of electrophoresis microchips.

  6. Fabrication of 3D detectors with columnar electrodes of the same doping type

    International Nuclear Information System (INIS)

    Ronchin, Sabina; Boscardin, Maurizio; Piemonte, Claudio; Pozza, Alberto; Zorzi, Nicola; Dalla Betta, Gian-Franco; Bosisio, Luciano; Pellegrini, Giulio

    2007-01-01

    Recently, we presented a new 3D detector architecture aimed at simplifying the manufacturing process, making it more suitable for high-volume production. In particular, the proposed device features electrodes of one doping type only, e.g., n + columns in a p-type substrate. In this paper we report on the fabrication at ITC-irst of the first batch of prototypes. The main issues related to the fabrication process along with preliminary results from the electrical characterization of different detectors and test structures are discussed

  7. Gold-mask technique for fabricating segmented-electrode germanium detectors

    International Nuclear Information System (INIS)

    Luke, P.N.

    1984-01-01

    A simple gold-mask technique has been developed for use in the fabrication of germanium nuclear radiation detectors. A layer of gold deposited over the contacts of the detectors acts as masks for chemical etching and surface treatments. It also serves as a reliable, low resistance electrical connection to the underlying germanium contact. This technique greatly facilitates the fabrication of a wide variety of segmented-electrode planar and coaxial detectors. Examples of these detectors with applications in medical imaging, gamma-ray astronomy and high-energy physics are presented

  8. Diffusion-free mediator based miniature biofuel cell anode fabricated on a carbon-MEMS electrode.

    Science.gov (United States)

    Bisht, Gobind S; Holmberg, Sunny; Kulinsky, Lawrence; Madou, Marc

    2012-10-02

    We report on the functionalization of a micropatterned carbon electrode fabricated using the carbon-MEMS process for its use as a miniature diffusion-free glucose oxidase anode. Carbon-MEMS based electrodes offer precise manufacturing control on both the micro- and nanoscale and possess higher electron conductivity than redox hydrogels. However, the process involves pyrolysis in a reducing environment that renders the electrode surface less reactive and introduction of a high density of functional groups becomes challenging. Our functionalization strategy involves the electrochemical oxidation of amine linkers onto the electrode. This strategy works well with both aliphatic and aryl linkers and uses stable compounds. The anode is designed to operate through mediated electron transfer between 2,5-dihydroxybenzaldehyde (DHB) based redox mediator and glucose oxidase enzyme. The electrode was first functionalized with ethylene diamine (EDA) to serve as a linker for the redox mediator. The redox mediator was then grafted through reductive amination, and attachment was confirmed through cyclic voltammetry. The enzyme immobilization was carried out through either adsorption or attachment, and their efficiency was compared. For enzyme attachment, the DHB attached electrode was functionalized again through electro-oxidation of aminobenzoic acid (ABA) linker. The ABA functionalization resulted in reduction of the DHB redox current, perhaps due to increased steric hindrance on the electrode surface, but the mediator function was preserved. Enzyme attachment was then carried out through a coupling reaction between the free carboxyl group on the ABA linker and the amine side chains on the enzyme. The enzyme incubation for both adsorption and attachment was done either through a dry spotting method or wet spotting method. The dry spotting method calls for the evaporation of enzyme droplet to form a thin film before sealing the electrode environment, to increase the effective

  9. Nafion® modified-screen printed gold electrodes and their carbon nanostructuration for electrochemical sensors applications.

    Science.gov (United States)

    García-González, Raquel; Fernández-Abedul, M Teresa; Costa-García, Agustín

    2013-03-30

    Screen printed electrodes are frequently used in electroanalytical applications because of their properties such as small size, low detection limit, fast response time, high reproducibility and disposable nature. On the other hand, since the discovery of carbon nanotubes there has been enormous interest in exploring and exploiting their properties, especially for their use in chemical (bio)sensors and nanoscale electronic devices. This paper reports the characterization of gold screen printed electrodes, modified with Nafion(®) and nanostructured with carbon nanotubes and carbon nanofibers dispersed on Nafion(®). The dispersing agent and the nanostructure have a marked effect on the analytical signal that, in turn depends on the intrinsic characteristics of the analyte. Several model analytes have been employed in this study. Anionic, cationic and neutral species such as methylene blue, dopamine, iron (III) sulfate, potassium ferrycianide and urea were considered. The importance for the development of nanostructured sensors relies on the fact that depending on these factors the situation may vary from a notorious enhancement of the signal to a blocking or even decrease. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Fabrication of periodic nanostructures using dynamic plowing lithography with the tip of an atomic force microscope

    Science.gov (United States)

    He, Yang; Yan, Yongda; Geng, Yanquan; Brousseau, Emmanuel

    2018-01-01

    The fabrication of periodic nanostructures with a fine control of their dimensions is performed on poly(methyl methacrylate) (PMMA) thin films using an atomic force microscope technique called dynamic plowing lithography (DPL). Different scratching directions are investigated first when generating single grooves with DPL. In particular, the depth, the width and the periodicity of the machined grooves as well the height of the pile-up, formed on the side of the grooves, are assessed. It was found that these features are not significantly affected by the scratching direction, except when processing took place in a direction away from the cantilever probe and parallel to its main axis. For a given scratching direction, arrays of regular grooves are then obtained by controlling the feed, i.e. the distance between two machining lines. A scan-scratch tip trace is also used to reduce processing time and tip wear. However, irregular patterns are created when combining two layers oriented at different angles and where each layer defines an array of grooves. Thus, a ;combination writing; method was implemented to fabricate arrays of grooves with a well-defined wavelength of 30 nm, which was twice the feed value utilized. Checkerboard, diamond-shaped, and hexagonal nanodots were also fabricated. These were obtained by using the combination writing method and by varying the orientation and the number of layers. The density of the nanodots achieved could be as high as 1.9 × 109 nanodots per mm2.

  11. Effect of nanostructured electrode architecture and semiconductor deposition strategy on the photovoltaic performance of quantum dot sensitized solar cells

    International Nuclear Information System (INIS)

    Samadpour, Mahmoud; Giménez, Sixto; Boix, Pablo P.; Shen, Qing; Calvo, Mauricio E.; Taghavinia, Nima; Azam Iraji zad; Toyoda, Taro; Míguez, Hernán

    2012-01-01

    Highlights: ► Electrode nanostructure and quantum dot growth method have a clear influence in the final quantum dot solar cell performance. ► Higher V oc values are systematically obtained for TiO 2 morphologies with decreasing surface area. ► Higher V oc values are systematically obtained for cells using CBD growth method in comparison with SILAR method. - Abstract: Here we analyze the effect of two relevant aspects related to cell preparation on quantum dot sensitized solar cells (QDSCs) performance: the architecture of the TiO 2 nanostructured electrode and the growth method of quantum dots (QD). Particular attention is given to the effect on the photovoltage, V oc , since this parameter conveys the main current limitation of QDSCs. We have analyzed electrodes directly sensitized with CdSe QDs grown by chemical bath deposition (CBD) and successive ionic layer adsorption and reaction (SILAR). We have carried out a systematic study comprising structural, optical, photophysical and photoelectrochemical characterization in order to correlate the material properties of the photoanodes with the functional performance of the manufactured QDSCs. The results show that the correspondence between photovoltaic conversion efficiency and the surface area of TiO 2 depends on the QDs deposition method. Higher V oc values are systematically obtained for TiO 2 morphologies with decreasing surface area and for cells using CBD growth method. This is systematically correlated to a higher recombination resistance of CBD sensitized electrodes. Electron injection kinetics from QDs into TiO 2 also depends on both the TiO 2 structure and the QDs deposition method, being systematically faster for CBD. Only for electrodes prepared with small TiO 2 nanoparticles SILAR method presents better performance than CBD, indicating that the small pore size disturb the CBD growth method. These results have important implications for the optimization of QDSCs.

  12. Fabrication of large scale nanostructures based on a modified atomic force microscope nanomechanical machining system.

    Science.gov (United States)

    Hu, Z J; Yan, Y D; Zhao, X S; Gao, D W; Wei, Y Y; Wang, J H

    2011-12-01

    The atomic force microscope (AFM) tip-based nanomechanical machining has been demonstrated to be a powerful tool for fabricating complex 2D∕3D nanostructures. But the machining scale is very small, which holds back this technique severely. How to enlarge the machining scale is always a major concern for the researches. In the present study, a modified AFM tip-based nanomechanical machining system is established through combination of a high precision X-Y stage with the moving range of 100 mm × 100 mm and a commercial AFM in order to enlarge the machining scale. It is found that the tracing property of the AFM system is feasible for large scale machining by controlling the constant normal load. Effects of the machining parameters including the machining direction and the tip geometry on the uniform machined depth with a large scale are evaluated. Consequently, a new tip trace and an increasing load scheme are presented to achieve a uniform machined depth. Finally, a polymer nanoline array with the dimensions of 1 mm × 0.7 mm, the line density of 1000 lines/mm and the average machined depth of 150 nm, and a 20 × 20 polymer square holes array with the scale of 380 μm × 380 μm and the average machined depth of 250 nm are machined successfully. The uniform of the machined depths for all the nanostructures is acceptable. Therefore, it is verified that the AFM tip-based nanomechanical machining method can be used to machine millimeter scale nanostructures.

  13. Functionalization of indium-tin-oxide electrodes by laser-nanostructured gold thin films for biosensing applications

    Science.gov (United States)

    Grochowska, Katarzyna; Siuzdak, Katarzyna; Karczewski, Jakub; Śliwiński, Gerard

    2015-12-01

    The production and properties of the indium-tin-oxide (ITO) electrodes functionalized by Au nanoparticle (NP) arrays of a relatively large area formed by pulsed laser nanostructuring of thin gold films are reported and discussed. The SEM inspection of modified electrodes reveals the presence of the nearly spherical and disc-shaped particles of dimensions in the range of 40-120 nm. The NP-array geometry can be controlled by selection of the laser processing conditions. It is shown that particle size and packing density of the array are important factors which determine the electrode performance. In the case of NP-modified electrodes the peak current corresponding to the glucose direct oxidation process shows rise with increasing glucose concentration markedly higher comparing to the reference Au disc electrode. The detection limit reaches 12 μM and linear response of the sensor is observed from 0.1 to 47 mM that covers the normal physiological range of the blood sugar detection.

  14. Surface Area Expansion of Electrodes with Grass-like Nanostructures to Enhance Electricity Generation in Microbial Fuel Cells

    DEFF Research Database (Denmark)

    Al Atraktchi, Fatima Al-Zahraa; Zhang, Yifeng; Noori, Jafar Safaa

    2012-01-01

    of plain silicium showed a maximum power density of 86.0 mW/m2. Further expanding the surface area of carbon paper electrodes with gold nanoparticles resulted in a maximum stable power density of 346.9 mW/m2 which is 2.9 times higher than that achieved with conventional carbon paper. These results show......Microbial fuel cells (MFCs) have applications possibilities for wastewater treatment, biotransformation, and biosensor, but the development of highly efficient electrode materials is critical for enhancing the power generation. Two types of electrodes modified with nanoparticles or grass......-like nanostructure (termed nanograss) were used. A two-chamber MFC with plain silicium electrodes achieved a maximum power density of 0.002 mW/m2, while an electrode with nanograss of titanium and gold deposited on one side gave a maximum power density of 2.5 mW/m2. Deposition of titanium and gold on both sides...

  15. Washable and Reliable Textile Electrodes Embedded into Underwear Fabric for Electrocardiography (ECG Monitoring

    Directory of Open Access Journals (Sweden)

    Amale Ankhili

    2018-02-01

    Full Text Available A medical quality electrocardiogram (ECG signal is necessary for permanent monitoring, and an accurate heart examination can be obtained from instrumented underwear only if it is equipped with high-quality, flexible, textile-based electrodes guaranteeing low contact resistance with the skin. The main objective of this article is to develop reliable and washable ECG monitoring underwear able to record and wirelessly send an ECG signal in real time to a smart phone and further to a cloud. The article focuses on textile electrode design and production guaranteeing optimal contact impedance. Therefore, different types of textile fabrics were coated with modified poly(3,4-ethylenedioxythiophene:poly(styrenesulfonate (PEDOT:PSS in order to develop and manufacture reliable and washable textile electrodes assembled to female underwear (bras, by sewing using commercially available conductive yarns. Washability tests of connected underwear containing textile electrodes and conductive threads were carried out up to 50 washing cycles. The influence of standardized washing cycles on the quality of ECG signals and the electrical properties of the textile electrodes were investigated and characterized.

  16. Fabrication of Flexible Microneedle Array Electrodes for Wearable Bio-Signal Recording.

    Science.gov (United States)

    Ren, Lei; Xu, Shujia; Gao, Jie; Lin, Zi; Chen, Zhipeng; Liu, Bin; Liang, Liang; Jiang, Lelun

    2018-04-13

    Laser-direct writing (LDW) and magneto-rheological drawing lithography (MRDL) have been proposed for the fabrication of a flexible microneedle array electrode (MAE) for wearable bio-signal monitoring. Conductive patterns were directly written onto the flexible polyethylene terephthalate (PET) substrate by LDW. The microneedle array was rapidly drawn and formed from the droplets of curable magnetorheological fluid with the assistance of an external magnetic field by MRDL. A flexible MAE can maintain a stable contact interface with curved human skin due to the flexibility of the PET substrate. Compared with Ag/AgCl electrodes and flexible dry electrodes (FDE), the electrode-skin interface impedance of flexible MAE was the minimum even after a 50-cycle bending test. Flexible MAE can record electromyography (EMG), electroencephalography (EEG) and static electrocardiography (ECG) signals with good fidelity. The main features of the dynamic ECG signal recorded by flexible MAE are the most distinguishable with the least moving artifacts. Flexible MAE is an attractive candidate electrode for wearable bio-signal monitoring.

  17. Washable and Reliable Textile Electrodes Embedded into Underwear Fabric for Electrocardiography (ECG) Monitoring.

    Science.gov (United States)

    Ankhili, Amale; Tao, Xuyuan; Cochrane, Cédric; Coulon, David; Koncar, Vladan

    2018-02-07

    A medical quality electrocardiogram (ECG) signal is necessary for permanent monitoring, and an accurate heart examination can be obtained from instrumented underwear only if it is equipped with high-quality, flexible, textile-based electrodes guaranteeing low contact resistance with the skin. The main objective of this article is to develop reliable and washable ECG monitoring underwear able to record and wirelessly send an ECG signal in real time to a smart phone and further to a cloud. The article focuses on textile electrode design and production guaranteeing optimal contact impedance. Therefore, different types of textile fabrics were coated with modified poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) in order to develop and manufacture reliable and washable textile electrodes assembled to female underwear (bras), by sewing using commercially available conductive yarns. Washability tests of connected underwear containing textile electrodes and conductive threads were carried out up to 50 washing cycles. The influence of standardized washing cycles on the quality of ECG signals and the electrical properties of the textile electrodes were investigated and characterized.

  18. Fabrication and characterization of nanostructured Ba-doped BiFeO3 porous ceramics

    Directory of Open Access Journals (Sweden)

    Mostafavi E.

    2016-03-01

    Full Text Available Nanostructured barium doped bismuth ferrite, Bi₀.₈Ba₀.₂FeO₃ porous ceramics with a relatively high magnetic coercivity was fabricated via sacrificial pore former method. X-ray diffraction results showed that 20 wt.% Ba doping induces a structural phase transition from rhombohedral to distorted pseudo-cubic structure in the final porous samples. Moreover, utilizing Bi₀.₈Ba₀.₂FeO₃ as the starting powder reduces the destructive interactions between the matrix phase and pore former, leading to an increase in stability of bismuth ferrite phase in the final porous ceramics. Urea-derived Bi₀.₈Ba₀.₂FeO₃ porous ceramic exhibits density of 4.74 g/cm³ and porosity of 45 % owing the uniform distribution of interconnected pores with a mean pore size of 7.5 μm. Well defined nanostructured cell walls with a mean grain size of 90 nm were observed in the above sample, which is in a good accordance with the grain size obtained from BET measurements. Saturation magnetization decreased from 2.31 in the Bi₀.₈Ba₀.₂FeO₃ compact sample to 1.85 A m²/kg in urea-derived Bi₀.₈Ba₀.₂FeO₃ porous sample; moreover, coercivity increased from 284 to 380 kA/m.

  19. Beam-induced magnetic property modifications: Basics, nanostructure fabrication and potential applications

    International Nuclear Information System (INIS)

    Devolder, T.; Bernas, H.; Ravelosona, D.; Chappert, C.; Pizzini, S.; Vogel, J.; Ferre, J.; Jamet, J.-P.; Chen, Y.; Mathet, V.

    2001-01-01

    We have developed an irradiation technique that allows us to tune the magnetic properties of thin films without affecting their roughness. We discuss the mechanisms involved and the applications. He + ion irradiation of Co/Pt multilayers lowers their magnetic anisotropy in a controlled way, reducing the coercive force and then leading to in-plane magnetization. By X-ray reflectometry, we study how irradiation-induced structural modifications correlate with magnetic properties. We also report the L1 0 chemical ordering of FePt by irradiation at 280 deg. C, and the consequent increase of magnetic anisotropy. Planar magnetic patterning at the sub 50 nm scale can be achieved when the irradiation is performed through a mask. New magnetic behaviors result from the fabrication process. They appear to arise from collateral damage. We model these effects in the case of SiO 2 and W masks. The planarity of irradiation-induced patterning and its ability to independently control nanostructure size and coercivity make it very appealing for magnetic recording on nanostructured media. Finally, possible applications to the granular media used in current hard disk drive storage technology are discussed

  20. Chemical tuning of PtC nanostructures fabricated via focused electron beam induced deposition

    International Nuclear Information System (INIS)

    Plank, Harald; Gspan, Christian; Kothleitner, Gerald; Hofer, Ferdinand; Haber, Thomas

    2013-01-01

    The fundamental dependence between process parameters during focused electron beam induced deposition and the chemistry of functional PtC nanostructures have been studied via a multi-technique approach using SEM, (S)TEM, EELS, AFM, and EFM. The study reveals that the highest Pt contents can only be achieved by an ideal balance between potentially dissociating electrons and available precursor molecules on the surface. For precursor regimes apart from this situation, an unwanted increase of carbon is observed which originates from completely different mechanisms: (1) an excess of electrons leads to polymerization of precursor fragments whereas (2) a lack of electrons leads to incompletely dissociated precursor molecules incorporated into the nanostructures. While the former represents an unwanted class of carbon, the latter condition maximizes the volume growth rates and allows for post-growth curing strategies which can strongly increase the functionality. Furthermore, the study gives an explanation of why growing deposits can dynamically change their chemistry and provides a straightforward guide towards more controlled fabrication conditions. (paper)

  1. Surface functionalization of nanostructured LaB{sub 6}-coated Poly Trilobal fabric by magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yan, E-mail: wuyanchn@hotmail.com [Mechanical and Electrical Engineering Branch, Jiaxing Nanyang Polytechnic Institute, Jiaxing 314003 (China); Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061 (China); Zhang, Lin, E-mail: zhanglin2007@sdu.edu.cn [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061 (China); Min, Guanghui, E-mail: ghmin@sdu.edu.cn [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061 (China); Yu, Huashun; Gao, Binghuan; Liu, Huihui; Xing, Shilong; Pang, Tao [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061 (China)

    2016-10-30

    Highlights: • Nanostructured LaB{sub 6} films were deposited on flexible textile substrates by dc magnetron sputtering. • The pronounced influence of the working pressure on the morphologies and optical properties of LaB{sub 6} films has been revealed. • The concept of Ultraviolet Protection Factor (UPF) was employed and LaB{sub 6}-coated PET textiles with ultraviolet protection ability were obtained. - Abstract: Nanostructured LaB{sub 6} films were deposited on flexible Poly Trilobal substrates (PET textiles) through direct current magnetron sputtering in order to broaden its applications and realize surface functionalization of polyester fabrics. Characterizations and performances were investigated by employing a scanning electron microscope (SEM), Fourier transformation infrared spectroscopy (FT-IR) and ultraviolet-visible (UV–vis) spectrophotometer. Ultraviolet Protection Factor (UPF) conducted by the integral conversion was employed to measure the ultraviolet protection ability. As expected, the growth of LaB{sub 6} film depending on the pressure variation enhanced UV-blocking ability (UPF rating at 30.17) and absorption intensity of the textiles.

  2. Fabrication, characterization, and functionalization of dual carbon electrodes as probes for scanning electrochemical microscopy (SECM).

    Science.gov (United States)

    McKelvey, Kim; Nadappuram, Binoy Paulose; Actis, Paolo; Takahashi, Yasufumi; Korchev, Yuri E; Matsue, Tomokazu; Robinson, Colin; Unwin, Patrick R

    2013-08-06

    Dual carbon electrodes (DCEs) are quickly, easily, and cheaply fabricated by depositing pyrolytic carbon into a quartz theta nanopipet. The size of DCEs can be controlled by adjusting the pulling parameters used to make the nanopipet. When operated in generation/collection (G/C) mode, the small separation between the electrodes leads to reasonable collection efficiencies of ca. 30%. A three-dimensional finite element method (FEM) simulation is developed to predict the current response of these electrodes as a means of estimating the probe geometry. Voltammetric measurements at individual electrodes combined with generation/collection measurements provide a reasonable guide to the electrode size. DCEs are employed in a scanning electrochemical microscopy (SECM) configuration, and their use for both approach curves and imaging is considered. G/C approach curve measurements are shown to be particularly sensitive to the nature of the substrate, with insulating surfaces leading to enhanced collection efficiencies, whereas conducting surfaces lead to a decrease of collection efficiency. As a proof-of-concept, DCEs are further used to locally generate an artificial electron acceptor and to follow the flux of this species and its reduced form during photosynthesis at isolated thylakoid membranes. In addition, 2-dimensional images of a single thylakoid membrane are reported and analyzed to demonstrate the high sensitivity of G/C measurements to localized surface processes. It is finally shown that individual nanometer-size electrodes can be functionalized through the selective deposition of platinum on one of the two electrodes in a DCE while leaving the other one unmodified. This provides an indication of the future versatility of this type of probe for nanoscale measurements and imaging.

  3. Fabrication of nano-structure anti-reflective lens using platinum nanoparticles in injection moulding

    International Nuclear Information System (INIS)

    Kurihara, K; Nakano, T; Saitou, Y; Kato, H; Souma, N; Makihara, S

    2015-01-01

    We provide a lens mould to attain an anti-reflection sub-wavelength structure (SWS) for plastic replica in the injection moulding process. To obtain the SWS on the lens mould, platinum nanoparticles formed by decomposition of a platinum oxide were employed. The fabricated platinum nanoparticles were estimated to be 90 nm in diameter, on average, and the dispersion of the particle diameter was evaluated to be ±20 nm. Through nanostructure replication by injection moulding, antireflection of less than 0.5% was achieved, and transmittance increased over 98%. In addition, a high-replication durability of over 10 000 times was attained. The variation of the minimum reflection ratio was evaluated to be 0.38% ± 0.04%. The usefulness of the proposed SWS mould for mass-production was confirmed, as it allows for high durability and SWS formation on the lens surface. (paper)

  4. Extremely superhydrophobic surfaces with micro- and nanostructures fabricated by copper catalytic etching.

    Science.gov (United States)

    Lee, Jung-Pil; Choi, Sinho; Park, Soojin

    2011-01-18

    We demonstrate a simple method for the fabrication of rough silicon surfaces with micro- and nanostructures, which exhibited superhydrophobic behaviors. Hierarchically rough silicon surfaces were prepared by copper (Cu)-assisted chemical etching process where Cu nanoparticles having particle size of 10-30 nm were deposited on silicon surface, depending on the period of time of electroless Cu plating. Surface roughness was controlled by both the size of Cu nanoparticles and etching conditions. As-synthesized rough silicon surfaces showed water contact angles ranging from 93° to 149°. Moreover, the hierarchically rough silicon surfaces were chemically modified by spin-coating of a thin layer of Teflon precursor with low surface energy. And thus it exhibited nonsticky and enhanced hydrophobic properties with extremely high contact angle of nearly 180°.

  5. Evaluation of novel textile electrodes for ECG signals monitoring based on PEDOT:PSS-treated woven fabrics.

    Science.gov (United States)

    Pani, Danilo; Dessi, Alessia; Gusai, Elisa; Saenz-Cogollo, Jose F; Barabino, Gianluca; Fraboni, Beatrice; Bonfiglio, Annalisa

    2015-01-01

    Despite surface electrodes technology for biopotential recording is well established, different researches are aimed at overcoming the limitations exhibited by the available solutions. In this paper, a proposal for the low-cost development of textile electrodes based on woven fabrics treated with polymer poly-3,4-ethylenedioxythiophene doped with poly(styrene sulfonate) ( PSS), is presented. Compared to other approaches, the proposed one can be exploited on any finished fabric. An accurate analysis of the electrodes performance, based on impedance measurements and signal processing techniques, both in wet and dry conditions, reveals the virtues and vices of the proposed solution, when used for electrocardiogram recording. In particular, the potentialities of these electrodes clearly emerge, in terms of ability to work without any electrolyte, providing a valuable interface between the skin and the electrode, in some cases achieving better performance than commercial disposable electrodes.

  6. Fabrication of a Microfluidic Device with Boron-doped Diamond Electrodes for Electrochemical Analysis

    International Nuclear Information System (INIS)

    Watanabe, Takeshi; Shibano, Shuhei; Maeda, Hideto; Sugitani, Ai; Katayama, Michinobu; Matsumoto, Yoshinori; Einaga, Yasuaki

    2016-01-01

    A prototype microfluidic device using boron-doped diamond (BDD) electrodes patterned on an alumina chip was designed and fabricated. Electrochemical microfluidic devices have advantages in that the amount of sample required is small, the measurement throughput is high, different functions can be integrated on a single device, and they are highly durable. In using the device for the flow injection analysis of oxalic acid, the application of a brief conditioning step ensured that the reproducibility of the current signal was excellent. Furthermore, the fabricated system also performed as a prototype of “elimination-detection flow system”, in which interfering species are eliminated using “elimination electrodes” prior to the species reaching the “detection electrode”. The fabricated device reduced the current due to interfering species by 78%. Designs of devices to improve this efficiency are also discussed.

  7. Reactive-ion etching of nylon fabric meshes using oxygen plasma for creating surface nanostructures

    International Nuclear Information System (INIS)

    Salapare, Hernando S.; Darmanin, Thierry; Guittard, Frédéric

    2015-01-01

    Graphical abstract: - Highlights: • Reactive-ion etching (RIE) is employed to nylon 6,6 fabrics to achieve surface texturing and improved wettability. • FTIR spectra of the treated samples exhibited decreased transmittance of amide and carboxylic acid groups due to etching. • Etching is enhanced for higher power plasma treatments and for samples with larger mesh sizes. • Decreased crystallinity was achieved after plasma treatment. • Higher power induced higher negative DC self-bias voltage on the samples that favored anisotropic and aggressive etching. - Abstract: A facile one-step oxygen plasma irradiation in reactive ion etching (RIE) configuration is employed to nylon 6,6 fabrics with different mesh sizes to achieve surface nanostructures and improved wettability for textile and filtration applications. To observe the effects of power and irradiation time on the samples, the experiments were performed using constant irradiation time in varying power and using constant power in varying irradiation times. Results showed improved wettability after the plasma treatment. The FTIR spectra of all the treated samples exhibited decreased transmittance of the amide and carboxylic acid groups due to surface etching. The changes in the surface chemistry are supported by the SEM data wherein etching and surface nanostructures were observed for the plasma-treated samples. The etching of the surfaces is enhanced for higher power plasma treatments. The thermal analysis showed that the plasma treatment resulted in decreased crystallinity. Surface chemistry showed that the effects of the plasma treatment on the samples have no significant difference for all the mesh sizes. However, surface morphology showed that the sizes of the surface cracks are the same for all the mesh sizes but samples with larger mesh sizes exhibited enhanced etching as compared to the samples with smaller mesh sizes. Higher power induced higher negative DC self-bias voltage on the samples that

  8. Molecular separations using nanostructured porous thin films fabricated by glancing angle deposition

    Science.gov (United States)

    Bezuidenhout, Louis Wentzel

    Biomolecular separation techniques are an enabling technology that indirectly in.uence many aspects of our lives. Advances have led to faster analyses, reduced costs, higher specificity, and new analytical techniques, impacting areas such as health care, environmental monitoring, polymer sciences, agriculture, and nutrition. Further development of separations technology is anticipated to follow the path of computing technology such that miniaturization through the development of microfluidics technology, lab-on-a-chip systems, and other integrative, multi-component systems will further extend our analysis capabilities. Creation of new and improvement of existing separation technologies is an integral part of the pathway to miniaturized systems. the work of this thesis investigates molecular separations using porous nanostructured films fabricated by the thin film process glancing angle deposition (GLAD). Structural architecture, pore size and shape, and film density can be finely controlled to produce high-surface area thin films with engineered morphology. The characteristic size scales and structural control of GLAD films are well-suited to biomolecules and separation techniques, motivating investigation into the utility and performance of GLAD films for biomolecular separations. This project consisted of three phases. First, chromatographic separation of dye molecules on silica GLAD films was demonstrated by thin layer chromatography Direct control of film nanostructure altered the separation characteristics; most strikingly, anisotropic structures provided two-dimensional analyte migration. Second, nanostructures made with GLAD were integrated in PDMS microfluidic channels using a sacrificial etching process; DNA molecules (10/48 kbp and 6/10/20 kbp mixtures) were electrophoretically separated on a microfluidic chip using a porous bed of SiO2 vertical posts. Third, mass spectrometry of proteins and drugs in the mass range of 100-1300 m/z was performed using

  9. Investigation of the fabrication parameters of thick film metal oxide-polymer pH electrodes

    International Nuclear Information System (INIS)

    Gac, Arnaud

    2002-01-01

    This thesis describes a study into the development of an optimum material and fabrication process for the production of thick film pH electrodes. These devices consist of low cost, miniature and rugged pH sensors formed by screen printing a metal oxide bearing paste onto a high temperature (∼850 deg C) fired metal back contact supported on a standard alumina substrate. The pH sensitive metal oxide layer must be fabricated at relatively low temperatures (<300 deg C) in order to maintain the pH sensitivity of the layer and hence requires the use of a suitably stable low temperature curing binder. Bespoke fabricated inks are derived from a Taguchi style factorial experimental plans in which, different binder types, curing temperatures, hydration level and percentage mixtures of different metal oxides and layer thicknesses were investigated. The pH responses of 18 printed electrodes per batch were assessed in buffer solutions with respect to a commercial reference electrode forming a complete potentiometric circuit. The evaluation criteria used in the study included the device-to-device variation in sensitivity of the pH sensors and their sensitivity variation as a function of time. The results indicated the importance of the choice of binder type in particular on the performance characteristics. Reproducible device-to-device variation in sensitivity was determined for the best inks found, whatever the ink fabrication batch. A reduction in the sensitivity variation with time has been determined using the mathematical models derived from an experimental plan. The lack of reproducibility of the sensitivity magnitude, regardless of the ink manufacturing batch, seems to be a recurrent problem with prototype inks. Experimental sub-Nernstian responses are discussed in the light of possible pH mechanisms. (author)

  10. Fabrication of nanostructured ZnO film as a hole-conducting layer of organic photovoltaic cell

    Science.gov (United States)

    Kim, Hyomin; Kwon, Yiseul; Choe, Youngson

    2013-05-01

    We have investigated the effect of fibrous nanostructured ZnO film as a hole-conducting layer on the performance of polymer photovoltaic cells. By increasing the concentration of zinc acetate dihydrate, the changes of performance characteristics were evaluated. Fibrous nanostructured ZnO film was prepared by sol-gel process and annealed on a hot plate. As the concentration of zinc acetate dihydrate increased, ZnO fibrous nanostructure grew from 300 to 600 nm. The obtained ZnO nanostructured fibrous films have taken the shape of a maze-like structure and were characterized by UV-visible absorption, scanning electron microscopy, and X-ray diffraction techniques. The intensity of absorption bands in the ultraviolet region was increased with increasing precursor concentration. The X-ray diffraction studies show that the ZnO fibrous nanostructures became strongly (002)-oriented with increasing concentration of precursor. The bulk heterojunction photovoltaic cells were fabricated using poly(3-hexylthiophene-2,5-diyl) and indene-C60 bisadduct as active layer, and their electrical properties were investigated. The external quantum efficiency of the fabricated device increased with increasing precursor concentration.

  11. The fabrication of diversiform nanostructure forests based on residue nanomasks synthesized by oxygen plasma removal of photoresist

    Energy Technology Data Exchange (ETDEWEB)

    Mao Haiyang; Wu Di; Wu Wengang; Hao Yilong [National Key Laboratory of Science and Technology on Micro/Nano Fabrication, Institute of Microelectronics, Peking University, Beijing 100871 (China); Xu Jun, E-mail: wuwg@ime.pku.edu.c [Electron Microscopy Laboratory, Peking University, Beijing 100871 (China)

    2009-11-04

    A simple lithography-free approach for fabricating diversiform nanostructure forests is presented. The key technique of the approach is that randomly distributed nanoscale residues can be synthesized on substrates simply by removing photoresist with oxygen plasma bombardment. These nanoresidues can function as masks in the subsequent etching process for nanopillars. By further spacer and then deep etching processes, a variety of forests composed of regular, tulip-like or hollow-head nanopillars as well as nanoneedles are successfully achieved in different etching conditions. The pillars have diameters of 30-200 nm and heights of 400 nm-3 {mu}m. The needles reach several microns in height, with their tips less than 10 nm in diameter. Moreover, microstructures containing these nanostructure forests, such as surface microchannels, have also been fabricated. This approach is compatible with conventional micro/nano-electromechanical system (MEMS/NEMS) fabrication.

  12. The fabrication of diversiform nanostructure forests based on residue nanomasks synthesized by oxygen plasma removal of photoresist

    International Nuclear Information System (INIS)

    Mao Haiyang; Wu Di; Wu Wengang; Hao Yilong; Xu Jun

    2009-01-01

    A simple lithography-free approach for fabricating diversiform nanostructure forests is presented. The key technique of the approach is that randomly distributed nanoscale residues can be synthesized on substrates simply by removing photoresist with oxygen plasma bombardment. These nanoresidues can function as masks in the subsequent etching process for nanopillars. By further spacer and then deep etching processes, a variety of forests composed of regular, tulip-like or hollow-head nanopillars as well as nanoneedles are successfully achieved in different etching conditions. The pillars have diameters of 30-200 nm and heights of 400 nm-3 μm. The needles reach several microns in height, with their tips less than 10 nm in diameter. Moreover, microstructures containing these nanostructure forests, such as surface microchannels, have also been fabricated. This approach is compatible with conventional micro/nano-electromechanical system (MEMS/NEMS) fabrication.

  13. Fabrication of self-assembled epitaxial nanostructures consisting of multiferroic heterostructures

    Science.gov (United States)

    Stern, Ilan

    As the field of epitaxial, self-assembled, thin film nanostructures continues to evolve, we have seen the emergence of novel growth techniques, exciting new multiferroic heterostructures and the increase in strain control engineering. The interest in such heterostructures ranges from high speed computing and storage devices, to smart sensors and actuators. Magnetic tunneling junctions and the development of highly efficient composites in the use of photovoltaics is certainly a direction of the future of thin film physics. Through the method of pulsed laser deposition (PLD), we have developed and engineered complex multiferroic transition metal oxides. By examining the structural and physical characterization of BiFeO3-CoFe2O4 epitaxially grown on spinel MgAl2O4 (001) by way of HR-XRD, AFM, TEM SEM, SQUID, and VSM, we have added additional growth parameters, i.e., the role of substrate structure, which can be used in the control of the structural formation of spinel and perovskite multiferroic heterostructures. This additional growth parameter is a critical step in the advancement in structural control and growth morphology. Additionally, control engineering of ferromagnetic vertically aligned nanostructures (VAN's), embedded in a ferroelectric matrix was accomplished using a 1:1 molar ratio of ferromagnetic NiCO2O4 and ferroelectric BaTiO3, which is to be used in the study of electrical transport, and 3-dimensional strain control. Finally, a conducting bottom electrode (Nb-STO) was developed to allow for the out-of-plane transport measurements on the NCO-BTO heterocomposite.

  14. Design of micro, flexible light-emitting diode arrays and fabrication of flexible electrodes

    International Nuclear Information System (INIS)

    Gao, Dan; Wang, Weibiao; Liang, Zhongzhu; Liang, Jingqiu; Qin, Yuxin; Lv, Jinguang

    2016-01-01

    In this study, we design micro, flexible light-emitting diode (LED) array devices. Using theoretical calculations and finite element simulations, we analyze the deformation of the conventional single electrode bar. Through structure optimization, we obtain a three-dimensional (3D), chain-shaped electrode structure, which has a greater bending degree. The optimized electrodes not only have a bigger bend but can also be made to spin. When the supporting body is made of polydimethylsiloxane (PDMS), the maximum bending degree of the micro, flexible LED arrays (4  ×  1 arrays) was approximately 230 µ m; this was obtained using the finite element method. The device (4  ×  1 arrays) can stretch to 15%. This paper describes the fabrication of micro, flexible LED arrays using microelectromechancial (MEMS) technology combined with electroplating technology. Specifically, the isolated grooves are made by dry etching which can isolate and protect the light-emitting units. A combination of MEMS technology and wet etching is used to fabricate the large size spacing. (paper)

  15. High-resolution and high-conductive electrode fabrication on a low thermal resistance flexible substrate

    International Nuclear Information System (INIS)

    Kang, Bongchul; Kno, Jinsung; Yang, Minyang

    2011-01-01

    Processes based on the liquid-state pattern transfer, like inkjet printing, have critical limitations including low resolution and low electrical conductivity when fabricating electrodes on low thermal resistance flexible substrates such as polyethylene terephthalate (PET). Those are due to the nonlinear transfer mechanism and the limit of the sintering temperature. Although the laser direct curing (LDC) of metallic inks is an alternative process to improve the resolution, it is also associated with the disadvantages of causing thermal damage to the polymer substrate. This paper suggests the laser induced pattern adhesion transfer method to fabricate electrodes of both high electrical conductivity and high resolution on a PET substrate. First, solid patterns are cost-effectively created by the LDC of the organometallic silver ink on a glass that is optically and thermally stable. The solid patterns sintered on the glass are transferred to the PET substrate by the photo-thermally generated adhesion force of the substrate. Therefore, we achieved electrodes with a minimum line width of 10 µm and a specific resistance of 3.6 μΩcm on the PET substrate. The patterns also showed high mechanical reliability

  16. High-resolution and high-conductive electrode fabrication on a low thermal resistance flexible substrate

    Science.gov (United States)

    Kang, Bongchul; Kno, Jinsung; Yang, Minyang

    2011-07-01

    Processes based on the liquid-state pattern transfer, like inkjet printing, have critical limitations including low resolution and low electrical conductivity when fabricating electrodes on low thermal resistance flexible substrates such as polyethylene terephthalate (PET). Those are due to the nonlinear transfer mechanism and the limit of the sintering temperature. Although the laser direct curing (LDC) of metallic inks is an alternative process to improve the resolution, it is also associated with the disadvantages of causing thermal damage to the polymer substrate. This paper suggests the laser induced pattern adhesion transfer method to fabricate electrodes of both high electrical conductivity and high resolution on a PET substrate. First, solid patterns are cost-effectively created by the LDC of the organometallic silver ink on a glass that is optically and thermally stable. The solid patterns sintered on the glass are transferred to the PET substrate by the photo-thermally generated adhesion force of the substrate. Therefore, we achieved electrodes with a minimum line width of 10 µm and a specific resistance of 3.6 μΩcm on the PET substrate. The patterns also showed high mechanical reliability.

  17. 3D direct writing fabrication of electrodes for electrochemical storage devices

    Science.gov (United States)

    Wei, Min; Zhang, Feng; Wang, Wei; Alexandridis, Paschalis; Zhou, Chi; Wu, Gang

    2017-06-01

    Among different printing techniques, direct ink writing is commonly used to fabricate 3D battery and supercapacitor electrodes. The major advantages of using the direct ink writing include effectively building 3D structure for energy storage devices and providing higher power density and higher energy density than traditional techniques due to the increased surface area of electrode. Nevertheless, direct ink writing has high standards for the printing inks, which requires high viscosity, high yield stress under shear and compression, and well-controlled viscoelasticity. Recently, a number of 3D-printed energy storage devices have been reported, and it is very important to understand the printing process and the ink preparation process for further material design and technology development. We discussed current progress of direct ink writing technologies by using various electrode materials including carbon nanotube-based material, graphene-based material, LTO (Li4Ti5O12), LFP (LiFePO4), LiMn1-xFexPO4, and Zn-based metallic oxide. Based on achieve electrochemical performance, these 3D-printed devices deliver performance comparable to the energy storage device fabricated using traditional methods still leaving large room for further improvement. Finally, perspectives are provided on the potential future direction of 3D printing for all solid-state electrochemical energy storage devices.

  18. Optimization and continuous fabrication of moth-eye nanostructure array on flexible polyethylene terephthalate substrate towards broadband antireflection.

    Science.gov (United States)

    Zhang, Chengpeng; Yi, Peiyun; Peng, Linfa; Ni, Jun

    2017-04-01

    Reflection loss can cause harmful effects on the performance of optoelectronic devices, such as cell phones, notebooks, displays, solar cells, and light-emitting diode (LED) devices. In order to obtain broadband antireflection (AR) properties, many researchers have utilized surface texture techniques to produce AR subwavelength structures on the interfaces. Among the AR subwavelength structures, the moth-eye nanostructure is one of the most promising structures, with the potential for commercialization in the near future. In this research, to obtain broadband AR performance, the optimization of moth-eye nanostructures was first carried out using the finite difference time domain method within the spectral ranges of 400-800 nm, including the optimization of shape, height, pitch, and residual layer thickness. In addition, the continuous production of moth-eye nanostructure array upon a flexible polyethylene terephthalate substrate was demonstrated by using the roll-to-roll ultraviolet nanoimprint lithography (R2R UV-NIL) process and anodic aluminum oxide mold, which provided a solution for the cost-effective fabrication of moth-eye nanostructure array. The AR performance of moth-eye nanostructure array obtained by the R2R UV-NIL process was also investigated experimentally, and good consistence was shown with the simulated results. This research can provide a beneficial direction for the optimization and cost-effective production of the moth-eye nanostructure array.

  19. Fabrication of Acrylonitrile-Butadiene-Styrene Nanostructures with Anodic Alumina Oxide Templates, Characterization and Biofilm Development Test for Staphylococcus epidermidis.

    Directory of Open Access Journals (Sweden)

    Camille Desrousseaux

    Full Text Available Medical devices can be contaminated by microbial biofilm which causes nosocomial infections. One of the strategies for the prevention of such microbial adhesion is to modify the biomaterials by creating micro or nanofeatures on their surface. This study aimed (1 to nanostructure acrylonitrile-butadiene-styrene (ABS, a polymer composing connectors in perfusion devices, using Anodic Alumina Oxide templates, and to control the reproducibility of this process; (2 to characterize the physico-chemical properties of the nanostructured surfaces such as wettability using captive-bubble contact angle measurement technique; (3 to test the impact of nanostructures on Staphylococcus epidermidis biofilm development. Fabrication of Anodic Alumina Oxide molds was realized by double anodization in oxalic acid. This process was reproducible. The obtained molds present hexagonally arranged 50 nm diameter pores, with a 100 nm interpore distance and a length of 100 nm. Acrylonitrile-butadiene-styrene nanostructures were successfully prepared using a polymer solution and two melt wetting methods. For all methods, the nanopicots were obtained but inside each sample their length was different. One method was selected essentially for industrial purposes and for better reproducibility results. The flat ABS surface presents a slightly hydrophilic character, which remains roughly unchanged after nanostructuration, the increasing apparent wettability observed in that case being explained by roughness effects. Also, the nanostructuration of the polymer surface does not induce any significant effect on Staphylococcus epidermidis adhesion.

  20. Materials and fabrication of electrode scaffolds for deposition of MnO2 and their true performance in supercapacitors

    Science.gov (United States)

    Cao, Jianyun; Li, Xiaohong; Wang, Yaming; Walsh, Frank C.; Ouyang, Jia-Hu; Jia, Dechang; Zhou, Yu

    2015-10-01

    MnO2 is a promising electrode material for high energy supercapacitors because of its large pseudo-capacitance. However, MnO2 suffers from low electronic conductivity and poor cation diffusivity, which results in poor utilization and limited rate performance of traditional MnO2 powder electrodes, obtained by pressing a mixed paste of MnO2 powder, conductive additive and polymer binder onto metallic current collectors. Developing binder-free MnO2 electrodes by loading nanoscale MnO2 deposits on pre-fabricated device-ready electrode scaffolds is an effective way to achieve both high power and energy performance. These electrode scaffolds, with interconnected skeletons and pore structures, will not only provide mechanical support and electron collection as traditional current collectors but also fast ion transfer tunnels, leading to high MnO2 utilization and rate performance. This review covers design strategies, materials and fabrication methods for the electrode scaffolds. Rational evaluation of the true performance of these electrodes is carried out, which clarifies that some of the electrodes with as-claimed exceptional performances lack potential in practical applications due to poor mass loading of MnO2 and large dead volume of inert scaffold materials/void spaces in the electrode structure. Possible ways to meet this challenge and bring MnO2 electrodes from laboratory studies to real-world applications are considered.

  1. Fabrication of a Micro-Needle Array Electrode by Thermal Drawing for Bio-Signals Monitoring

    Directory of Open Access Journals (Sweden)

    Lei Ren

    2016-06-01

    Full Text Available A novel micro-needle array electrode (MAE fabricated by thermal drawing and coated with Ti/Au film was proposed for bio-signals monitoring. A simple and effective setup was employed to form glassy-state poly (lactic-co-glycolic acid (PLGA into a micro-needle array (MA by the thermal drawing method. The MA was composed of 6 × 6 micro-needles with an average height of about 500 μm. Electrode-skin interface impedance (EII was recorded as the insertion force was applied on the MAE. The insertion process of the MAE was also simulated by the finite element method. Results showed that MAE could insert into skin with a relatively low compression force and maintain stable contact impedance between the MAE and skin. Bio-signals, including electromyography (EMG, electrocardiography (ECG, and electroencephalograph (EEG were also collected. Test results showed that the MAE could record EMG, ECG, and EEG signals with good fidelity in shape and amplitude in comparison with the commercial Ag/AgCl electrodes, which proves that MAE is an alternative electrode for bio-signals monitoring.

  2. Fabrication of Flexible Microneedle Array Electrodes for Wearable Bio-Signal Recording

    Directory of Open Access Journals (Sweden)

    Lei Ren

    2018-04-01

    Full Text Available Laser-direct writing (LDW and magneto-rheological drawing lithography (MRDL have been proposed for the fabrication of a flexible microneedle array electrode (MAE for wearable bio-signal monitoring. Conductive patterns were directly written onto the flexible polyethylene terephthalate (PET substrate by LDW. The microneedle array was rapidly drawn and formed from the droplets of curable magnetorheological fluid with the assistance of an external magnetic field by MRDL. A flexible MAE can maintain a stable contact interface with curved human skin due to the flexibility of the PET substrate. Compared with Ag/AgCl electrodes and flexible dry electrodes (FDE, the electrode–skin interface impedance of flexible MAE was the minimum even after a 50-cycle bending test. Flexible MAE can record electromyography (EMG, electroencephalography (EEG and static electrocardiography (ECG signals with good fidelity. The main features of the dynamic ECG signal recorded by flexible MAE are the most distinguishable with the least moving artifacts. Flexible MAE is an attractive candidate electrode for wearable bio-signal monitoring.

  3. Investigations of poly(pyrrole)-coated cotton fabrics prepared in blends of anionic and cationic surfactants as flexible electrode

    International Nuclear Information System (INIS)

    Liang, Guijie; Zhu, Ligen; Xu, Jie; Fang, Dong; Bai, Zikui; Xu, Weilin

    2013-01-01

    Highlights: • Poly(pyrrole)-coated cotton fabrics were prepared in mixed surfactants. • The fabrics are soft, lightweight, mechanically robust, and highly electrical conductive. • Potential applications of the fabrics as flexible electrodes were tested. • The fabric electrodes exhibited high discharge capacity and excellent cycling performance. -- Abstract: In recent years, much effort has been dedicated to achieve lightweight, stretchable and flexible energy-storage devices for wearable electronics. Here we report an everyday cotton fabric coated with poly(pyrrole) as flexible electrodes. Poly(pyrrole) nanoparticles are synthesized on the fabrics via a simple chemical polymerization process with the mixed surfactants of cetyltrimethylammonium bromide (CTAB) and sodium dodecyl benzene sulfonate (SDBS) as soft template. A highly conductive fabric with surface resistance of 14 Ω/□ can be produced by changing surfactant concentration. Such a conductive textile shows outstanding flexibility and stretchability, and demonstrates strong adhesion between the PPy and the cellulose fiber. The fabric electrode exhibits a discharge capacity of 51.7 mAh g −1 with high cycling stability (negligible decay after 100 cycles)

  4. One-Step Pyro-Synthesis of a Nanostructured Mn3O4/C Electrode with Long Cycle Stability for Rechargeable Lithium-Ion Batteries.

    Science.gov (United States)

    Alfaruqi, Muhammad Hilmy; Gim, Jihyeon; Kim, Sungjin; Song, Jinju; Duong, Pham Tung; Jo, Jeonggeun; Baboo, Joseph Paul; Xiu, Zhiliang; Mathew, Vinod; Kim, Jaekook

    2016-02-01

    A nanostructured Mn 3 O 4 /C electrode was prepared by a one-step polyol-assisted pyro-synthesis without any post-heat treatments. The as-prepared Mn 3 O 4 /C revealed nanostructured morphology comprised of secondary aggregates formed from carbon-coated primary particles of average diameters ranging between 20 and 40 nm, as evidenced from the electron microscopy studies. The N 2 adsorption studies reveal a hierarchical porous feature in the nanostructured electrode. The nanostructured morphology appears to be related to the present rapid combustion strategy. The nanostructured porous Mn 3 O 4 /C electrode demonstrated impressive electrode properties with reversible capacities of 666 mAh g -1 at a current density of 33 mA g -1 , good capacity retentions (1141 mAh g -1 with 100 % Coulombic efficiencies at the 100 th cycle), and rate capabilities (307 and 202 mAh g -1 at 528 and 1056 mA g -1 , respectively) when tested as an anode for lithium-ion battery applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Fabrication of continuous flow microfluidics device with 3D electrode structures for high throughput DEP applications using mechanical machining.

    Science.gov (United States)

    Zeinali, Soheila; Çetin, Barbaros; Oliaei, Samad Nadimi Bavil; Karpat, Yiğit

    2015-07-01

    Microfluidics is the combination of micro/nano fabrication techniques with fluid flow at microscale to pursue powerful techniques in controlling and manipulating chemical and biological processes. Sorting and separation of bio-particles are highly considered in diagnostics and biological analyses. Dielectrophoresis (DEP) has offered unique advantages for microfluidic devices. In DEP devices, asymmetric pair of planar electrodes could be employed to generate non-uniform electric fields. In DEP applications, facing 3D sidewall electrodes is considered to be one of the key solutions to increase device throughput due to the generated homogeneous electric fields along the height of microchannels. Despite the advantages, fabrication of 3D vertical electrodes requires a considerable challenge. In this study, two alternative fabrication techniques have been proposed for the fabrication of a microfluidic device with 3D sidewall electrodes. In the first method, both the mold and the electrodes are fabricated using high precision machining. In the second method, the mold with tilted sidewalls is fabricated using high precision machining and the electrodes are deposited on the sidewall using sputtering together with a shadow mask fabricated by electric discharge machining. Both fabrication processes are assessed as highly repeatable and robust. Moreover, the two methods are found to be complementary with respect to the channel height. Only the manipulation of particles with negative-DEP is demonstrated in the experiments, and the throughput values up to 105 particles / min is reached in a continuous flow. The experimental results are compared with the simulation results and the limitations on the fabrication techniques are also discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Controllable Impregnation Via Inkjet Printing for the Fabrication of Solid Oxide Cell Air Electrodes

    KAUST Repository

    Da'as, E. H.

    2013-10-07

    The impregnation method has been considered as one of the most successful techniques for the fabrication of highly efficient electrodes for solid oxide fuel and electrolysis cells (SOCs) at the lab scale. However, because the impregnation is usually performed manually, its irreproducibility remains a major problem that can be solved by using controllable techniques, such as inkjet printing. In this paper, lanthanum strontium manganite (LSM)/yttria stabilized zirconia (YSZ) air electrodes were prepared by infiltrating YSZ porous bodies with LSM precursor solution using inkjet printing, followed by annealing at 800°C for 2 hours. XRD analysis confirmed the formation of the LSM phase, which was in the form of nanoparticles with size in the 50-70 nm range on the YSZ walls, as revealed by FEG-SEM observations. The effect of printing parameters on the distribution of the impregnated phase was investigated and discussed.

  7. Applying a foil queue micro-electrode in micro-EDM to fabricate a 3D micro-structure

    Science.gov (United States)

    Xu, Bin; Guo, Kang; Wu, Xiao-yu; Lei, Jian-guo; Liang, Xiong; Guo, Deng-ji; Ma, Jiang; Cheng, Rong

    2018-05-01

    Applying a 3D micro-electrode in a micro electrical discharge machining (micro-EDM) can fabricate a 3D micro-structure with an up and down reciprocating method. However, this processing method has some shortcomings, such as a low success rate and a complex process for fabrication of 3D micro-electrodes. By focusing on these shortcomings, this paper proposed a novel 3D micro-EDM process based on the foil queue micro-electrode. Firstly, a 3D micro-electrode was discretized into several foil micro-electrodes and these foil micro-electrodes constituted a foil queue micro-electrode. Then, based on the planned process path, foil micro-electrodes were applied in micro-EDM sequentially and the micro-EDM results of each foil micro-electrode were able to superimpose the 3D micro-structure. However, the step effect will occur on the 3D micro-structure surface, which has an adverse effect on the 3D micro-structure. To tackle this problem, this paper proposes to reduce this adverse effect by rounded corner wear at the end of the foil micro-electrode and studies the impact of machining parameters on rounded corner wear and the step effect on the micro-structure surface. Finally, using a wire cutting voltage of 80 V, a current of 0.5 A and a pulse width modulation ratio of 1:4, the foil queue micro-electrode was fabricated by wire electrical discharge machining. Also, using a pulse width of 100 ns, a pulse interval of 200 ns, a voltage of 100 V and workpiece material of 304# stainless steel, the foil queue micro-electrode was applied in micro-EDM for processing of a 3D micro-structure with hemispherical features, which verified the feasibility of this process.

  8. Improvements in purification of silver nanowires by decantation and fabrication of flexible transparent electrodes. Application to capacitive touch sensors

    International Nuclear Information System (INIS)

    Mayousse, Céline; Celle, Caroline; Moreau, Eléonore; Carella, Alexandre; Simonato, Jean-Pierre; Mainguet, Jean-François

    2013-01-01

    Transparent flexible electrodes made of metallic nanowires, and in particular silver nanowires (AgNWs), appear as an extremely promising alternative to transparent conductive oxides for future optoelectronic devices. Though significant progresses have been made the last few years, there is still some room for improvement regarding the synthesis of high quality silver nanowire solutions and fabrication process of high performance electrodes. We show that the commonly used purification process can be greatly simplified through decantation. Using this process it is possible to fabricate flexible electrodes by spray coating with sheet resistance lower than 25 Ω sq −1 at 90% transparency in the visible spectrum. These electrodes were used to fabricate an operative transparent flexible touch screen. To our knowledge this is the first reported AgNW based touch sensor relying on capacitive technology. (paper)

  9. Servo scanning 3D micro EDM for array micro cavities using on-machine fabricated tool electrodes

    Science.gov (United States)

    Tong, Hao; Li, Yong; Zhang, Long

    2018-02-01

    Array micro cavities are useful in many fields including in micro molds, optical devices, biochips and so on. Array servo scanning micro electro discharge machining (EDM), using array micro electrodes with simple cross-sectional shape, has the advantage of machining complex 3D micro cavities in batches. In this paper, the machining errors caused by offline-fabricated array micro electrodes are analyzed in particular, and then a machining process of array servo scanning micro EDM is proposed by using on-machine fabricated array micro electrodes. The array micro electrodes are fabricated on-machine by combined procedures including wire electro discharge grinding, array reverse copying and electrode end trimming. Nine-array tool electrodes with Φ80 µm diameter and 600 µm length are obtained. Furthermore, the proposed process is verified by several machining experiments for achieving nine-array hexagonal micro cavities with top side length of 300 µm, bottom side length of 150 µm, and depth of 112 µm or 120 µm. In the experiments, a chip hump accumulates on the electrode tips like the built-up edge in mechanical machining under the conditions of brass workpieces, copper electrodes and the dielectric of deionized water. The accumulated hump can be avoided by replacing the water dielectric by an oil dielectric.

  10. Fabrication of gallium hexacyanoferrate modified carbon ionic liquid paste electrode for sensitive determination of hydrogen peroxide and glucose

    International Nuclear Information System (INIS)

    Haghighi, Behzad; Khosravi, Mehdi; Barati, Ali

    2014-01-01

    Gallium hexacyanoferrate (GaHCFe) and graphite powder were homogeneously dispersed into n-dodecylpyridinium hexafluorophosphate and paraffin to fabricate GaHCFe modified carbon ionic liquid paste electrode (CILPE). Mixture experimental design was employed to optimize the fabrication of GaHCFe modified CILPE (GaHCFe-CILPE). A pair of well-defined redox peaks due to the redox reaction of GaHCFe through one-electron process was observed for the fabricated electrode. The fabricated GaHCFe-CILPE exhibited good electrocatalytic activity towards reduction and oxidation of H 2 O 2 . The observed sensitivities for the electrocatalytic oxidation and reduction of H 2 O 2 at the operating potentials of + 0.8 and − 0.2 V were about 13.8 and 18.3 mA M −1 , respectively. The detection limit (S/N = 3) for H 2 O 2 was about 1 μM. Additionally, glucose oxidase (GOx) was immobilized on GaHCFe-CILPE using two methodology, entrapment into Nafion matrix and cross-linking with glutaraldehyde and bovine serum albumin, in order to fabricate glucose biosensor. Linear dynamic rage, sensitivity and detection limit for glucose obtained by the biosensor fabricated using cross-linking methodology were 0.1–6 mM, 0.87 mA M −1 and 30 μM, respectively and better than those obtained (0.2–6 mM, 0.12 mA M −1 and 50 μM) for the biosensor fabricated using entrapment methodology. - Highlights: • Gallium hexacyanoferrate modified carbon ionic liquid paste electrode was fabricated. • Mixture experimental design was used to optimize electrode fabrication. • Response trace plot was used to show the effect of electrode materials on response. • The sensor exhibited electrocatalytic activity towards H 2 O 2 reduction and oxidation. • Glucose biosensor was fabricated by immobilization of glucose oxidase on sensor

  11. Fabrication of multiplex quasi-three-dimensional grids of one-dimensional nanostructures via stepwise colloidal lithography.

    Science.gov (United States)

    Zhang, Gang; Wang, Dayang; Möhwald, Helmuth

    2007-11-01

    By using O2-plasma etched monolayers of hexagonally close-packed latex spheres as masks for metal vapor deposition, we successfully demonstrate a stepwise colloidal lithography to stepwise grow highly ordered multiplex quasi-three-dimensional grids of metallic one-dimensional nanostructures, e.g., nanowires and nanorods. The success of the present approach is centered at manipulation of the incidence angle of metal vapor beams with respect to the normal direction of colloidal masks and particularly the azimuth angle phi of the projection of the vapor beam incidence on the masks with respect to the vector from one sphere to the nearest neighbors. Stepwise deposition of different metals by regularly varying phi allows consecutively stacking of 1D nanostructures into multiplex quasi-3D grids. This stepwise angle-resolved colloidal lithography should provide a significant nanochemical complement of conventional lithographic techniques, enabling us to easily fabricate sophisticated 3D nanostructures with defined vertical and lateral heterogeneity.

  12. Fabrication and Investigation of Nickel-Alkaline Cells. Part 2. Analysis of Ethanolic Metal Nitrate Solutions Used in Fabrication of Nickel Hydroxide Electrodes

    Science.gov (United States)

    1975-10-01

    Picher Industries(8). The work at Tyco and Eagle - Picher nas been mainly sponsored by Western Electric and Bell Telephone Laboratories. The work at...resulting from this tecnnique, have demonstrated superior performance over electrodes comonly used in aerospace Ni-Cd batteries (V. J. Puglisi, H. N. Seiger...technique for fabrication of satellite battery electrodes, Seiger and Puqlisi found that isopropyl alcohol denaturant inhibited deposition (11). 2 In

  13. Single-step direct fabrication of pillar-on-pore hybrid nanostructures in anodizing aluminum for superior superhydrophobic efficiency.

    Science.gov (United States)

    Jeong, Chanyoung; Choi, Chang-Hwan

    2012-02-01

    Conventional electrochemical anodizing processes of metals such as aluminum typically produce planar and homogeneous nanopore structures. If hydrophobically treated, such 2D planar and interconnected pore structures typically result in lower contact angle and larger contact angle hysteresis than 3D disconnected pillar structures and, hence, exhibit inferior superhydrophobic efficiency. In this study, we demonstrate for the first time that the anodizing parameters can be engineered to design novel pillar-on-pore (POP) hybrid nanostructures directly in a simple one-step fabrication process so that superior surface superhydrophobicity can also be realized effectively from the electrochemical anodization process. On the basis of the characteristic of forming a self-ordered porous morphology in a hexagonal array, the modulation of anodizing voltage and duration enabled the formulation of the hybrid-type nanostructures having controlled pillar morphology on top of a porous layer in both mild and hard anodization modes. The hybrid nanostructures of the anodized metal oxide layer initially enhanced the surface hydrophilicity significantly (i.e., superhydrophilic). However, after a hydrophobic monolayer coating, such hybrid nanostructures then showed superior superhydrophobic nonwetting properties not attainable by the plain nanoporous surfaces produced by conventional anodization conditions. The well-regulated anodization process suggests that electrochemical anodizing can expand its usefulness and efficacy to render various metallic substrates with great superhydrophilicity or -hydrophobicity by directly realizing pillar-like structures on top of a self-ordered nanoporous array through a simple one-step fabrication procedure.

  14. Croissance et transfert de graphene pour la fabrication d'electrodes transparentes

    Science.gov (United States)

    Biron, Maxime

    This master's thesis focuses on the characterization and optimization of transparent and conductive electrodes made from graphene layers. We used a low pressure CVD method, with methane as the carbon source and copper as a catalyst and growth support, to synthesize graphene. Scanning electron microscopy and Raman spectroscopy were used to demonstrate that the graphene layers are complete and uniform. A method using a polymer (PMMA) as a mechanical support has been optimized for the transfer of graphene films onto various substrates, such as glass or silicon dioxide on silicon. Characterization of transferred samples by optical and scanning electron microscopy and Raman spectroscopy reveals that transferred films are undamaged and that the surface is free of visible residues. The intensity of the defect-related peak in Raman mapping measurements is low, indicating that the as-grown and transferred graphene layers are of high quality. This transfer process has been applied to fabricate transparent electrodes with one to four layers of graphene. The electrodes were characterized by Raman spectroscopy, optical transmission analyses and electrical resistance measurements using the van der Pauw method. Raman results indicate that the average doping level of the samples decreases with an increasing number of graphene layers. The optical measurements yield transparency values ranging from 97.5 to 90 % for wavelengths between 400 and 1000 nm, depending on the number of stacked layers. The sheet resistance of the electrodes varies between 560 and 360 O/□, which is an equivalent or superior performance to that of graphene electrodes reported in the literature. An electrochemical method was used to dope the samples in an ionic liquid to vary the Fermi level and to decrease the sheet resistance down to 260 O/□ for a monolayer graphene electrode. This doping allows to vary the work function of graphene between 3.9 and 5.6 eV. Taken together, these results demonstrate that

  15. Design and fabrication of capacitive interdigitated electrodes for smart gas sensors

    KAUST Repository

    Omran, Hesham

    2016-09-05

    In this paper, we study the design parameters of capacitive interdigitated electrodes (IDEs) and the effect of these parameters on the sensitivity of the IDEs when employed as a capacitive gas sensor. Finite element simulations using COMSOL Multiphysics were carried out to evaluate the sensitivity of the capacitive sensor. Simulations show that for permittivity-based sensing, the optimum thickness of the sensing film is slightly more than half the wavelength of the IDEs structure. On the other hand, sensing films that are thinner than half wavelength should be used if the required sensing mechanism is based on structural swelling. Increasing the IDEs metal thickness can increase the sensitivity by increasing the sidewall electric field, but this is only true if the sensing film is thick enough to completely fill the spacing between the electrodes. A simple and reliable IDEs structure and fabrication process are proposed. Physical dry etching provides good yield and fine resolution compared to liftoff technique. Fabricated and packaged prototype sensors are presented. © 2015 IEEE.

  16. Self-assembly of monodisperse starburst carbon spheres into hierarchically organized nanostructured supercapacitor electrodes.

    Science.gov (United States)

    Kim, Sung-Kon; Jung, Euiyeon; Goodman, Matthew D; Schweizer, Kenneth S; Tatsuda, Narihito; Yano, Kazuhisa; Braun, Paul V

    2015-05-06

    We report a three-dimensional (3D) porous carbon electrode containing both nanoscale and microscale porosity, which has been hierarchically organized to provide efficient ion and electron transport. The electrode organization is provided via the colloidal self-assembly of monodisperse starburst carbon spheres (MSCSs). The periodic close-packing of the MSCSs provides continuous pores inside the 3D structure that facilitate ion and electron transport (electrode electrical conductivity ∼0.35 S m(-1)), and the internal meso- and micropores of the MSCS provide a good specific capacitance. The capacitance of the 3D-ordered porous MSCS electrode is ∼58 F g(-1) at 0.58 A g(-1), 48% larger than that of disordered MSCS electrode at the same rate. At 1 A g(-1) the capacitance of the ordered electrode is 57 F g(-1) (95% of the 0.24 A g(-1) value), which is 64% greater than the capacitance of the disordered electrode at the same rate. The ordered electrode preserves 95% of its initial capacitance after 4000 charging/discharging cycles.

  17. IrOx-carbon nanotube hybrids: a nanostructured material for electrodes with increased charge capacity in neural systems.

    Science.gov (United States)

    Carretero, Nina M; Lichtenstein, Mathieu P; Pérez, Estela; Cabana, Laura; Suñol, Cristina; Casañ-Pastor, Nieves

    2014-10-01

    Nanostructured iridium oxide-carbon nanotube hybrids (IrOx-CNT) deposited as thin films by dynamic electrochemical methods are suggested as novel materials for neural electrodes. Single-walled carbon nanotubes (SWCNT) serve as scaffolds for growing the oxide, yielding a tridimensional structure with improved physical, chemical and electrical properties, in addition to high biocompatibility. In biological environments, SWCNT encapsulation by IrOx makes more resistant electrodes and prevents the nanotube release to the media, preventing cellular toxicity. Chemical, electrochemical, structural and surface characterization of the hybrids has been accomplished. The high performance of the material in electrochemical measurements and the significant increase in cathodal charge storage capacity obtained for the hybrid in comparison with bare IrOx represent a significant advance in electric field application in biosystems, while its cyclability is also an order of magnitude greater than pure IrOx. Moreover, experiments using in vitro neuronal cultures suggest high biocompatibility for IrOx-CNT coatings and full functionality of neurons, validating this material for use in neural electrodes. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  18. Fabrication and application of flexible graphene silk composite film electrodes decorated with spiky Pt nanospheres

    Science.gov (United States)

    Liang, Bo; Fang, Lu; Hu, Yichuan; Yang, Guang; Zhu, Qin; Ye, Xuesong

    2014-03-01

    A free-standing graphene silk composite (G/S) film was fabricated via vacuum filtration of a mixed suspension of graphene oxide and silk fibres, followed by chemical reduction. Spiky structured Pt nanospheres were grown on the film substrate by cyclic voltammetry electrodeposition. The electrical and mechanical performance of a single graphene coated silk fibre was investigated. The conductivity of a single graphene coated silk fibre is 57.9 S m-1. During 1000 bending measurements, the conductivity was stable and showed negligible variation. The G/S film has a sheet resistivity of 90 Ω □-1 with a porous and hierarchical structure. The spiky Pt nanosphere decorated G/S film was directly used as a H2O2 electrode with a sensitivity of 0.56 mA mM-1 cm-2, a linear range of 0-2.5 mM and an ultralow detection limit of 0.2 μM (S/N = 3). A glucose biosensor electrode was further fabricated by enzyme immobilization. The results show a sensitivity of 150.8 μA mM-1 cm-2 and a low detection limit of 1 μM (S/N = 3) for glucose detection. The strategy of coating graphene sheets on a silk fibre surface provides a new approach for developing electrically conductive biomaterials, tissue engineering scaffolds, bendable electrodes, and wearable biomedical devices.A free-standing graphene silk composite (G/S) film was fabricated via vacuum filtration of a mixed suspension of graphene oxide and silk fibres, followed by chemical reduction. Spiky structured Pt nanospheres were grown on the film substrate by cyclic voltammetry electrodeposition. The electrical and mechanical performance of a single graphene coated silk fibre was investigated. The conductivity of a single graphene coated silk fibre is 57.9 S m-1. During 1000 bending measurements, the conductivity was stable and showed negligible variation. The G/S film has a sheet resistivity of 90 Ω □-1 with a porous and hierarchical structure. The spiky Pt nanosphere decorated G/S film was directly used as a H2O2 electrode with a

  19. Fabrication of Nanostructured Poly-ε-caprolactone 3D Scaffolds for 3D Cell Culture Technology

    KAUST Repository

    Schipani, Rossana

    2015-04-21

    Tissue engineering is receiving tremendous attention due to the necessity to overcome the limitations related to injured or diseased tissues or organs. It is the perfect combination of cells and biomimetic-engineered materials. With the appropriate biochemical factors, it is possible to develop new effective bio-devices that are capable to improve or replace biological functions. Latest developments in microfabrication methods, employing mostly synthetic biomaterials, allow the production of three-dimensional (3D) scaffolds that are able to direct cell-to-cell interactions and specific cellular functions in order to drive tissue regeneration or cell transplantation. The presented work offers a rapid and efficient method of 3D scaffolds fabrication by using optical lithography and micro-molding techniques. Bioresorbable polymer poly-ε-caprolactone (PCL) was the material used thanks to its high biocompatibility and ability to naturally degrade in tissues. 3D PCL substrates show a particular combination in the designed length scale: cylindrical shaped pillars with 10μm diameter, 10μm height, arranged in a hexagonal lattice with spacing of 20μm were obtained. The sidewalls of the pillars were nanostructured by attributing a 3D architecture to the scaffold. The suitability of these devices as cell culture technology supports was evaluated by plating NIH/3T3 mouse embryonic fibroblasts and human Neural Stem Cells (hNSC) on them. Scanning Electron Microscopy (SEM) analysis was carried out in order to examine the micro- and nano-patterns on the surface of the supports. In addition, after seeding of cells, SEM and immunofluorescence characterization of the fabricated systems were performed to check adhesion, growth and proliferation. It was observed that cells grow and develop healthy on the bio-polymeric devices by giving rise to well-interconnected networks. 3D PCL nano-patterned pillared scaffold therefore may have considerable potential as effective tool for

  20. Structure and properties of nanostructured ZnO arrays and ZnO/Ag nanocomposites fabricated by pulsed electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Kopach, V. R.; Klepikova, K. S.; Klochko, N. P., E-mail: klochko-np@mail.ru; Khrypunov, G. S.; Korsun, V. E.; Lyubov, V. M.; Kirichenko, M. V.; Kopach, A. V. [National Technical University “Kharkiv Polytechnic Institute” (Ukraine)

    2017-03-15

    We investigate the structure, surface morphology, and optical properties of nanostructured ZnO arrays fabricated by pulsed electrodeposition, Ag nanoparticles precipitated from colloidal solutions, and a ZnO/Ag nanocomposite based on them. The electronic and electrical parameters of the ZnO arrays and ZnO/Ag nanocomposites are analyzed by studying the I–V and C–V characteristics. Optimal modes for fabricating the ZnO/Ag heterostructures with the high stability and sensitivity to ultraviolet radiation as promising materials for use in photodetectors, gas sensors, and photocatalysts are determined.

  1. A simple and fast fabrication of a both self-cleanable and deep-UV antireflective quartz nanostructured surface

    Science.gov (United States)

    Kim, Jung Suk; Jeong, Hyun Woo; Lee, Wonbae; Park, Bo Gi; Kim, Beop Min; Lee, Kyu Back

    2012-08-01

    Both self-cleanability and antireflectivity were achieved on quartz surfaces by forming heptadecafluoro-1,1,2,2-tetrahydrodecyltrichlorosilane self-assembled monolayer after fabrication of nanostructures with a mask-free method. By exposing polymethylmethacrylate spin-coated quartz plates to O2 reactive ion etching (RIE) and CF4 RIE successively, three well-defined types of nanopillar arrays were generated: A2, A8, and A11 patterns with average pillar widths of 33 ± 4 nm, 55 ± 5 nm, and 73 ± 14 nm, respectively, were formed. All the fabrication processes including the final cleaning can be finished within 4 h. All nanostructured quartz surfaces exhibited contact angles higher than 155° with minimal water droplet adhesiveness and enhanced transparency (due to antireflectivity) over a broad spectral range from 350 to 900 nm. Furthermore, A2 pattern showed an enhanced antireflective effect that extends to the deep-UV range near 190 nm, which is a drawback region in conventional thin-film-coating approaches as a result of thermal damage. Because, by changing the conditions of successive RIE, the geometrical configurations of nanostructure arrays can be easily modified to meet specific needs, the newly developed fabrication method is expected to be applied in various optic and opto-electrical areas. PACS codes: 06.60.Ei; 81.65.Cf; 81.40.Vw.

  2. Luminescent antireflective coatings with disordered surface nanostructures fabricated by liquid processes.

    Science.gov (United States)

    Tanaka, Sota; Fujihara, Shinobu

    2011-03-15

    Antireflective phosphor coatings having disordered surface nanostructures were fabricated by a sol-gel dip coating method and a subsequent hot water treatment. Thin films of a Bi(3+),Eu(3+)-codoped YVO4 red phosphor were first prepared and effects of the addition of an aluminum source to precursor solutions on their microstructure and optical properties were examined. Optical transmittance of the YVO4:Bi(3+),Eu(3+) film was lower than that of a bare quartz glass substrate due to a higher refractive index of YVO4. The addition of the aluminum source and the hot water treatment resulted in a considerable increase of transmittance and its smaller angular dependence, which could generate an antireflective effect by the phosphor thin films. Observation of the microstructure revealed that the hot water treatment brought a remarkable change in the surface as well as the cross-section structure in the aluminum-added YVO4:Bi(3+),Eu(3+) film. The film density and hence the refractive index were gradually changed like a pseudo moth-eye structure, which explained the occurrence of the antireflective effect. The microstructural change was attributed to the dissolution of alumina present in the film and the reprecipitation of boehmite on the film surface during the hot water treatment. Photoluminescence of the YVO4:Bi(3+),Eu(3+) film could also be enhanced by the antireflective effect due to the suppression of surface Fresnel reflection of incident light and total internal reflection of emitted light.

  3. Fabrication of Up-Conversion Phosphor Films on Flexible Substrates Using a Nanostructured Organo-Silicon.

    Science.gov (United States)

    Jeon, Young-Sun; Kim, Tae-Un; Kim, Seon-Hoon; Lee, Young-Hwan; Choi, Pil-Son; Hwang, Kyu-Seog

    2018-03-01

    Up-conversion phosphors have attracted considerable attention because of their applications in solid-state lasers, optical communications, flat-panel displays, photovoltaic cells, and biological labels. Among them, NaYF4 is reported as one of the most efficient hosts for infrared to visible photon up-conversion of Yb3+ and Er3+ ions. However, a low-temperature method is required for industrial scale fabrication of photonic and optoelectronic devices on flexible organic substrates. In this study, hexagonal β-NaYF4: 3 mol% Yb3+, 3 mol% Er3+ up-conversion phosphor using Ca2+ was prepared by chemical solution method. Then, we synthesized a nanostructured organo-silicon compound from methyl tri-methoxysilane and 3-glycidoxy-propyl-trimethoxy-silane. The transmittance of the organo-silicon compound was found to be over 90% in the wavelength range of 400~1500 nm. Then we prepared a fluoride-based phosphor paste by mixing the organo-silicon compound with Na(Ca)YF4:Yb3+, Er3+. Subsequently, this paste was coated on polyethylene terephthalate, followed by heat-treatment at 120 °C. The visible emission of the infrared detection card was found to be at 655 nm and 661 nm an excitation wavelength of 980 nm.

  4. Magnesium Ferrite (MgFe2O4 Nanostructures Fabricated by Electrospinning

    Directory of Open Access Journals (Sweden)

    Wiengmoon Amporn

    2008-01-01

    Full Text Available Abstract Magnesium ferrite (MgFe2O4 nanostructures were successfully fabricated by electrospinning method. X-ray diffraction, FT-IR, scanning electron microscopy, and transmission electron microscopy revealed that calcination of the as-spun MgFe2O4/poly(vinyl pyrrolidone (PVP composite nanofibers at 500–800 °C in air for 2 h resulted in well-developed spinel MgFe2O4nanostuctures. The crystal structure and morphology of the nanofibers were influenced by the calcination temperature. Crystallite size of the nanoparticles contained in nanofibers increased from 15 ± 4 to 24 ± 3 nm when calcination temperature was increased from 500 to 800 °C. Room temperature magnetization results showed a ferromagnetic behavior of the calcined MgFe2O4/PVP composite nanofibers, having their specific saturation magnetization (M s values of 17.0, 20.7, 25.7, and 31.1 emu/g at 10 Oe for the samples calcined at 500, 600, 700, and 800 °C, respectively. It is found that the increase in the tendency ofM sis consistent with the enhancement of crystallinity, and the values ofM sfor the MgFe2O4samples were observed to increase with increasing crystallite size.

  5. Fabrication of superhydrophobic polyurethane/organoclay nano-structured composites from cyclomethicone-in-water emulsions

    International Nuclear Information System (INIS)

    Bayer, I.S.; Steele, A.; Martorana, P.J.; Loth, E.

    2010-01-01

    Nano-structured polyurethane/organoclay composite films were fabricated by dispersing moisture-curable polyurethanes and fatty amine/amino-silane surface modified montmorillonite clay (organoclay) in cyclomethicone-in-water emulsions. Cyclomethicone Pickering emulsions were made by emulsifying decamethylcyclopentasiloxane (D 5 ), dodecamethylcyclohexasiloxane (D 6 ) and aminofunctional siloxane polymers with water using montmorillonite particles as emulsion stabilizers. Polyurethane and organoclay dispersed emulsions were spray coated on aluminum surfaces. Upon thermosetting, water repellent self-cleaning coatings were obtained with measured static water contact angles exceeding 155 o and low contact angle hysteresis ( o ). Electron microscopy images of the coating surfaces revealed formation of self-similar hierarchical micro- and nano-scale surface structures. The surface morphology and the coating adhesion strength to aluminum substrates were found to be sensitive to the relative amounts of dispersed polyurethane and organoclay in the emulsions. The degree of superhydrophobicity was analyzed using static water contact angles as well as contact angle hysteresis measurements. Due to biocompatibility of cyclomethicones and polyurethane, developed coatings can be considered for specific bio-medical applications.

  6. Simple approach for the fabrication of screen-printed carbon-based electrode for amperometric detection on microchip electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Petroni, Jacqueline Marques [Instituto de Química, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, 79074-460 (Brazil); Lucca, Bruno Gabriel, E-mail: bruno.lucca@ufes.br [Departamento de Ciências Naturais, Universidade Federal do Espírito Santo, São Mateus, ES, 29932-540 (Brazil); Ferreira, Valdir Souza [Instituto de Química, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, 79074-460 (Brazil)

    2017-02-15

    This paper describes a simple method for the fabrication of screen-printed based electrodes for amperometric detection on microchip electrophoresis (ME) devices. The procedure developed is quite simple and does not require expensive instrumentation or sophisticated protocols commonly employed on the production of amperometric sensors, such as photolithography or sputtering steps. The electrodes were fabricated through manual deposition of home-made conductive carbon ink over patterned acrylic substrate. Morphological structure and electrochemical behavior of the carbon electrodes were investigated by scanning electron microscopy and cyclic voltammetry. The produced amperometric sensors were coupled to polydimethylsiloxane (PDMS) microchips at end-channel configuration in order to evaluate their analytical performance. For this purpose, electrophoretic experiments were carried out using nitrite and ascorbic acid as model analytes. Separation of these substances was successfully performed within 50s with good resolution (R = 1.2) and sensitivities (713.5 pA/μM for nitrite and 255.4 pA/μM for ascorbate). The reproducibility of the fabrication method was evaluated and revealed good values concerning the peak currents obtained (8.7% for nitrite and 9.3% for ascorbate). The electrodes obtained through this method exhibited satisfactory lifetime (ca. 400 runs) over low fabrication cost (less than $1 per piece). The feasibility of the proposed device for real analysis was demonstrated through the determination of nitrite concentration levels in drinking water samples. Based on the results achieved, the approach proposed here shows itself as an interesting alternative for simple fabrication of carbon-based electrodes. Furthermore, the devices indicate great promise for other kind of analytical applications involving ME devices. - Highlights: • A novel method to fabricate screen-printed electrodes for amperometric detection in ME is demonstrated. • No sophisticated

  7. Simple approach for the fabrication of screen-printed carbon-based electrode for amperometric detection on microchip electrophoresis

    International Nuclear Information System (INIS)

    Petroni, Jacqueline Marques; Lucca, Bruno Gabriel; Ferreira, Valdir Souza

    2017-01-01

    This paper describes a simple method for the fabrication of screen-printed based electrodes for amperometric detection on microchip electrophoresis (ME) devices. The procedure developed is quite simple and does not require expensive instrumentation or sophisticated protocols commonly employed on the production of amperometric sensors, such as photolithography or sputtering steps. The electrodes were fabricated through manual deposition of home-made conductive carbon ink over patterned acrylic substrate. Morphological structure and electrochemical behavior of the carbon electrodes were investigated by scanning electron microscopy and cyclic voltammetry. The produced amperometric sensors were coupled to polydimethylsiloxane (PDMS) microchips at end-channel configuration in order to evaluate their analytical performance. For this purpose, electrophoretic experiments were carried out using nitrite and ascorbic acid as model analytes. Separation of these substances was successfully performed within 50s with good resolution (R = 1.2) and sensitivities (713.5 pA/μM for nitrite and 255.4 pA/μM for ascorbate). The reproducibility of the fabrication method was evaluated and revealed good values concerning the peak currents obtained (8.7% for nitrite and 9.3% for ascorbate). The electrodes obtained through this method exhibited satisfactory lifetime (ca. 400 runs) over low fabrication cost (less than $1 per piece). The feasibility of the proposed device for real analysis was demonstrated through the determination of nitrite concentration levels in drinking water samples. Based on the results achieved, the approach proposed here shows itself as an interesting alternative for simple fabrication of carbon-based electrodes. Furthermore, the devices indicate great promise for other kind of analytical applications involving ME devices. - Highlights: • A novel method to fabricate screen-printed electrodes for amperometric detection in ME is demonstrated. • No sophisticated

  8. Adhesive PEG-based binder for aqueous fabrication of thick Li4Ti5O12 electrode

    International Nuclear Information System (INIS)

    Tran, Binh; Oladeji, Isaiah O.; Wang, Zedong; Calderon, Jean; Chai, Guangyu; Atherton, David; Zhai, Lei

    2013-01-01

    We report the first fully compressed Li 4 Ti 5 O 12 electrode designed by an aqueous process. An adhesive, elastomeric, and lithium ion conductive PEG-based copolymer is used as a binder for the aqueous fabrication thick, flexible, and densely packed Li 4 Ti 5 O 12 (LTO) electrodes. Self-adherent cathode films exceeding 200 μm in thickness and withholding high active mass loadings of 28 mg/cm 2 deliver 4.2 mAh/cm 2 at C/2 rate. Structurally defect-free electrodes are fabricated by casting aqueous cathode slurries onto nickel foam, dried, and hard-calendared at 10 tons/cm 2 . As a multifunctional material, the binder is synthesized by the copolymerization of poly(ethylene glycol) methyl ether methacrylate (PEGMA), methyl methacrylate (MMA), and isobutyl vinyl ether (IBVE) in optimal proportions. Furthermore, coordinating the binder with lithium salt is necessary for the electrode to function

  9. Selective and lithography-independent fabrication of 20 nm nano-gap electrodes and nano-channels for nanoelectrofluidics applications

    International Nuclear Information System (INIS)

    Zhang, J Y; Wang, X F; Wang, X D; Fan, Z C; Li, Y; Ji, An; Yang, F H

    2010-01-01

    A new method has been developed to selectively fabricate nano-gap electrodes and nano-channels by conventional lithography. Based on a sacrificial spacer process, we have successfully obtained sub-100-nm nano-gap electrodes and nano-channels and further reduced the dimensions to 20 nm by shrinking the sacrificial spacer size. Our method shows good selectivity between nano-gap electrodes and nano-channels due to different sacrificial spacer etch conditions. There is no length limit for the nano-gap electrode and the nano-channel. The method reported in this paper also allows for wafer scale fabrication, high throughput, low cost, and good compatibility with modern semiconductor technology.

  10. One-step fabrication of 3D silver paste electrodes into microfluidic devices for enhanced droplet-based cell sorting

    Directory of Open Access Journals (Sweden)

    Lang Rao

    2015-05-01

    Full Text Available 3D microelectrodes are one-step fabricated into a microfluidic droplet separator by filling conductive silver paste into PDMS microchambers. The advantages of 3D silver paste electrodes in promoting droplet sorting accuracy are systematically demonstrated by theoretical calculation, numerical simulation and experimental validation. The employment of 3D electrodes also helps to decrease the droplet sorting voltage, guaranteeing that cells encapsulated in droplets undergo chip-based sorting processes are at better metabolic status for further potential cellular assays. At last, target droplet containing single cell are selectively sorted out from others by an appropriate electric pulse. This method provides a simple and inexpensive alternative to fabricate 3D electrodes, and it is expected our 3D electrode-integrated microfluidic droplet separator platform can be widely used in single cell operation and analysis.

  11. Fabrication, Light Emission, and Magnetism of Silica Nanoparticles Hybridized with AIE Luminogens and Inorganic Nanostructures

    Science.gov (United States)

    Faisal, Mahtab

    Much research efforts have been devoted in developing new synthetic approaches for fluorescent silica nanoparticles (FSNPs) due to their potential high-technological applications. However, light emissions from most of the FSNPs prepared so far have been rather weak. This is due to the emission quenching caused by the aggregation of fluorophores in the solid state. We have observed a novel phenomenon of aggregation-induced emission (AIE): a series of propeller-shaped molecules such as tetraphenylethene (TPE) and silole are induced to emit efficiently by aggregate formation. Thus, they are ideal fluorophors for the construction of FSNPs and my thesis work focuses on the synthesis of silica nanoparticles containing these luminogens and magnetic nanostructures. Highly emissive FSNPs with core-shell structures are fabricated by surfactant-free sol-gel reactions of tetraphenylethene- (TPE) and silole-functionalized siloxanes followed by the reactions with tetraethoxysilane. The FSNPs are uniformly sized, surface-charged and colloidally stable. The diameters of the FSNPs are tunable in the range of 45--295 nm by changing the reaction conditions. Whereas their TPE and silole precursors are non-emissive, the FSNPs emit strong visible lights, thanks to the novel aggregation-induced emission characteristics of the TPE and silole aggregates in the hybrid nanoparticles. The FSNPs pose no toxicity to living cells and can be utilized to selectively image cytoplasm of HeLa cells. Applying the same tool in the presence of citrate-coated magnetite nanoparticles, uniform magnetic fluorescent silica nanoparticles (MFSNPs) with smooth surfaces are fabricated. These particles exhibit appreciable surface charges and hence good colloidal stability. They are superparamagnetic, exhibiting no hysteresis at room temperature. UV irradiation of a suspension of MFSNPs in ethanol gives strong blue and green emissions. The MFSNPs can selectively stain the cytoplasmic regions of the living cells

  12. A comparative study of supercapacitive performances of nickel cobalt layered double hydroxides coated on ZnO nanostructured arrays on textile fibre as electrodes for wearable energy storage devices.

    Science.gov (United States)

    Trang, Nguyen Thi Hong; Ngoc, Huynh Van; Lingappan, Niranjanmurthi; Kang, Dae Joon

    2014-02-21

    We demonstrated an efficient method for the fabrication of novel, flexible electrodes based on ZnO nanoflakes and nickel-cobalt layered double hydroxides (denoted as ZnONF/NiCoLDH) as a core-shell nanostructure on textile substrates for wearable energy storage devices. NiCoLDH coated ZnO nanowire (denoted as ZnONW/NiCoLDH) flexible electrodes are also prepared for comparison. As an electrode for supercapacitors, ZnONF/NiCoLDH exhibits a high specific capacitance of 1624 F g(-1), which is nearly 1.6 times greater than ZnONW/NiCoLDH counterparts. It also shows a maximum energy density of 48.32 W h kg(-1) at a power density of 27.53 kW kg(-1), and an excellent cycling stability with capacitance retention of 94% and a Coulombic efficiency of 93% over 2000 cycles. We believe that the superior performance of the ZnONF/NiCoLDH hybrids is due primarily to the large surface area of the nanoflake structure and the open spaces between nanoflakes, both of which provide a large space for the deposition of NiCoLDH, resulting in reduced internal resistance and improved capacitance performance. Our results are significant for the development of electrode materials for high-performance wearable energy storage devices.

  13. LOW-TEMPERATURE, ANODE-SUPPORTED HIGH POWER DENSITY SOLID OXIDE FUEL CELLS WITH NANOSTRUCTURED ELECTRODES

    Energy Technology Data Exchange (ETDEWEB)

    Professor Anil V. Virkar

    2003-05-23

    hydrocarbon fuels where reforming was achieved internally. Significant polarization losses also occur at the anode, especially at high fuel utilizations. An analysis of polarization losses requires that various contributions are isolated, and their dependence on pertinent parameters is quantitatively described. An investigation of fuel composition on gas transport through porous anodes was investigated and the role of fuel diluents was explored. This work showed that the molecular weight of the diluent has a significant effect on anode concentration polarization. This further showed that the presence of some molecular hydrogen is necessary to minimize polarization losses. Theoretical analysis has shown that the electrode microstructure has a profound effect on cell performance. In a series of experiments, cathode microstructural parameters were varied, without altering other parameters. Cathode microstructural parameters, especially three phase boundary (TPB) length, were estimated using techniques in quantitative stereology. Cell performance was quantitatively correlated with the relevant microstructural parameters, and charge transfer resistivity was explicitly evaluated. This is the first time that a fundamental parameter, which governs the activation polarization, has been quantitatively determined. An important parameter, which governs the cathodic activation polarization, and thus cell performance, is the ionic conductivity of the composite cathode. The traditional composite cathode is a mixture of LSM and YSZ. It is well known that Sr and Mg-doped LaGaO{sub 3} (LSGM), exhibits higher oxygen ion conductivity compared to YSZ. Cells were fabricated with composite cathodes comprising a mixture of LSM and LSGM. Studies demonstrated that LSGM-based composite cathodes exhibit excellent behavior. Studies have shown that Ni + YSZ is an excellent anode. In fact, in most cells, the principal polarization losses, at least at low fuel utilizations, are associated with the cathode

  14. Wafer level fabrication of single cell dispenser chips with integrated electrodes for particle detection

    International Nuclear Information System (INIS)

    Schoendube, Jonas; Yusof, Azmi; Kalkandjiev, Kiril; Zengerle, Roland; Koltay, Peter

    2015-01-01

    This work presents the microfabrication and experimental evaluation of a dispenser chip, designed for isolation and printing of single cells by combining impedance sensing and drop-on-demand dispensing. The dispenser chip features 50  ×  55 µm (width × height) microchannels, a droplet generator and microelectrodes for impedance measurements. The chip is fabricated by sandwiching a dry film photopolymer (TMMF) between a silicon and a Pyrex wafer. TMMF has been used to define microfluidic channels, to serve as low temperature (75 °C) bonding adhesive and as etch mask during 300 µm deep HF etching of the Pyrex wafer. Due to the novel fabrication technology involving the dry film resist, it became possible to fabricate facing electrodes at the top and bottom of the channel and to apply electrical impedance sensing for particle detection with improved performance. The presented microchip is capable of dispensing liquid and detecting microparticles via impedance measurement. Single polystyrene particles of 10 µm size could be detected with a mean signal amplitude of 0.39  ±  0.13 V (n=439) at particle velocities of up to 9.6 mm s −1 inside the chip. (paper)

  15. Flexible and conductive cotton fabric counter electrode coated with graphene nanosheets for high efficiency dye sensitized solar cell

    Science.gov (United States)

    Sahito, Iftikhar Ali; Sun, Kyung Chul; Arbab, Alvira Ayoub; Qadir, Muhammad Bilal; Choi, Yun Seon; Jeong, Sung Hoon

    2016-07-01

    Textile fabric based electrodes due to their lightweight, flexibility and cost effectiveness, coupled with the ease of fabrication are recently given a huge attention as wearable energy sources. The current dye sensitized solar cells (DSSCs) are based on Platinized-Fluorinated Tin oxide (Pt-FTO) glass electrode, which is not only expensive, but also rigid and heavyweight. In this work, a highly conductive-graphene coated cotton fabric (HC-GCF) is fabricated with a surface resistance of only 7 Ω sq-1. HC-GCF is used as an efficient counter electrode (CE) in DSSC and the results are examined using photovoltaic and electrochemical analysis. HC-GCF counter electrode shows a negligible change of resistance to bending at various bending positions and is also found extremely resistant to electrolyte solution and washing with water. Cyclic voltammogram, Nyquist and the Tafel plots suggest an excellent electro catalytic activity (ECA) for the reduction of tri-iodide (I3-) ions. Symmetrical cells prepared using HC-GCF, indicate a very low charge transfer resistance (RCT) of only 1.2 Ω, which is nearly same to that of the Pt with 1.04 Ω. Furthermore, a high photovoltaic conversion efficiency (PCE) of 6.93% is achieved using HC-GCF counter electrode using polymer electrolyte.

  16. Development of new fabrication methods for solid oxide fuel cell electrodes

    Science.gov (United States)

    Jung, Suk-Won

    Solid oxide fuel cells (SOFC) have gained a great deal of attention in recent years since they have the potential to be high efficiency devices for the generation of electricity. The ability to use hydrocarbon fuels however requires the development of alternatives to conventional Ni/YSZ anodes that are prone to coking when exposed to hydrocarbons. The optimization of electrode microstructure and composition is also needed in order to maximize the electrode catalytic activity and thermal stability. In this thesis these issues were addressed through the development of new methods for anode fabrication that allowed for the incorporation of a wide range of materials and better control of electrode microstructure. The specific methods that were studied include (1) Impregnation with urea and (2) Electrochemical Deposition. First, how impregnation using Cu(NO3)2 and urea affect the microstructure of the Cu component in Cu/CeO2/YSZ (yittria-stabilized zirconia) composite anodes and how this influences anode performance were examined. This method produced a more homogeneous distribution of Cu throughout the anode than impregnation with only Cu(NO3)2. Second, Cu electrodeposition into 0.12 cm thick, highly porous Ni/YSZ cermets was investigated for the initial study to evaluate electrodeposition for the electrode fabrication method. An electrochemical cell in which the electrolyte solution was allowed to flow through the porous Ni/YSZ substrate was constructed in order to eliminate mass transfer limitations and determine conditions for which the potential drop in the electrolyte solution was minimized for the deposition of uniform Cu layer in the cermet. Finally it was demonstrated how the anodes for SOFCs could be prepared by electrodeposition. After the addition of CeO2, a 60 mum thin porous layer of YSZ was made conductive by the deposition of a conductive carbon layer with exposing the porous layer to C4H10 at 1123 K and either Ni or Co was then electrodeposited on the

  17. Properties of polymer light-emitting transistors with Ag-nanowire source/drain electrodes fabricated on polymer substrate

    Energy Technology Data Exchange (ETDEWEB)

    Hiraoka, Koichi; Kusumoto, Yusuke; Ikezoe, Ikuya; Kajii, Hirotake, E-mail: kajii@oled.eei.eng.osaka-u.ac.jp; Ohmori, Yutaka

    2014-03-03

    The properties of polymer light-emitting transistors with Ag-nanowire (AgNW) source/drain electrodes fabricated on a polymer substrate are investigated. Organic field-effect transistors (OFETs) based on poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8BT) with AgNW source/drain electrodes exhibit ambipolar characteristics. For an ambipolar F8BT OFET, yellow-green light emission is observed. The maximum external quantum efficiency is 0.6%. We demonstrate the possibility of producing flexible polymer light-emitting transistors using AgNW electrodes. - Highlights: • Fluorene-type organic field-effect transistors (OFETs) are investigated. • We use Ag-nanowire (AgNW) source/drain electrodes in the OFETs. • These OFETs exhibit ambipolar and light-emitting characteristics. • The maximum external quantum efficiency is 0.6%. • We demonstrate flexible polymer light-emitting transistors using AgNW electrodes.

  18. Fabrication of Chitosan-complexed Electrode and Evaluation of Its Efficiency in Removal of Copper Ion from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Yoon Young-Chan

    2016-01-01

    Full Text Available In this study, we fabricated chitosan/PVA/activated carbon complexed electrode to remove copper ion from aqueous solution. The prepared composite electrode was analyzed by BET and SEM to investigate its physicochemical properties. Electrochemical properties of prepared composite electrodes were analyzed via cyclic voltammetry. Adsorption performance of copper ion on chitosan composite complexed electrodes was evaluated. Almost similar pore size distribution results were observed in the series of ACP not included electrodes while observed differences in pore size distribution for the ACP included one. Cyclic voltammetry results exhibited that oxidation-reduction reaction does not occur in a potential range of -1.0 ~ 1.0 V. The amount of copper ion during adsroption reaction is increase according to increase of adsorption potential to 1.0 V.

  19. A self-regenerable soot sensor with a proton-conductive thin electrolyte and a nanostructured platinum sensing electrode

    Science.gov (United States)

    Lv, Peiling; Ito, Takenori; Oogushi, Akihide; Nakashima, Kensaku; Nagao, Masahiro; Hibino, Takashi

    2016-11-01

    In recent years, exhaust sensors have become increasingly attractive for use in energy and environmental technologies. Important issues regarding practical applications of these sensors, especially for soot measurements, include the further development of ion-conductive electrolytes and active electrode catalysts for meeting performance and durability requirements. Herein, we design a proton conductor with a high breakdown voltage and a sensing electrode with high sensitivity to electrochemical carbon oxidation, enabling continuous soot monitoring with self-regeneration of the sensor. A Si0.97Al0.03HxP2O7-δ layer with an excellent balance between proton conductivity and voltage endurance was grown on the surface of a Si0.97Al0.03O2-δ substrate by reacting it with liquid H3PO4 at 600 °C. Specific reactivity of the electrochemically formed active oxygen toward soot was accomplished by adding a Pt-impregnated Sn0.9In0.1HxP2O7-δ catalyst into a Pt sensing electrode. To make the best use of these optimized materials, a unipolar electrochemical device was fabricated by configuring the sensing and counter electrodes on the same surface of the electrolyte layer. The resulting amperometric mode sensor successfully produced a current signal that corresponded to the quantity of soot.

  20. Fabrication of Nanostructures on Implantable Biomaterials for Biocompatibility Enhancement and Infection Resistance

    Science.gov (United States)

    Liu, Luting

    simple template-molding method (in which a material with a special structure is used as a template to imprint its structure onto another material) with nanotubular anodized Ti was used to formulate a physical nanostructured pattern on a PDMS (a commonly used polymeric catheter material) surface without changing its surface chemistry. Results showed that increased PDMS surface nanoscale roughness alone inhibited both Gram-negative ( E. coli) and Gram-positive (S. aureus) bacteria adhesion and growth without using antibiotics while remaining non-toxic to fibroblasts and endothelial cells. A model was developed for the first time to correlate bacteria responses to nanoscale roughness with initial protein adsorption (specifically, casein protein, which is well known for preventing bacteria attachment). Data also revealed that an increase in nanoscale roughness and greater surface hydrophilicity together contributed to increased protein adsorption, which may decrease the interactions at the bacteria-nanorough surface interface and achieve effective antimicrobial properties. Mechanistically, this thesis also investigated the influence of specific surface properties (i.e., nanoscale surface roughness, surface wettability and associated surface energy) on cell and bacteria functions. Results showed a direct proportional linear correlation of surface energy with surface roughness. It was found that surface energy plays a major role in determining cell and bacteria functions, and specifically all proposed nanofabricated samples with an initial surface energy at 40 mJ/m2 showed relatively promising antibacterial properties and desirable cellular functions. Overall, the results of this study provided alternative, inexpensive, methods for fabricating various implant surfaces with nanostructures to enhance biocompatibility and prevent bacterial attachment simultaneously, which will be beneficial for numerous biomedical applications.

  1. Fabrication of surface micro- and nanostructures for superhydrophobic surfaces in electric and electronic applications

    Science.gov (United States)

    Xiu, Yonghao

    our understanding of the roughness effect on superhydrophobicity (both contact angle and hysteresis), structured surfaces from polybutadiene, polyurethane, silica, and Si etc. were successfully prepared. For engineering applications of superhydrophobic surfaces, stability issues regarding UV, mechanical robustness and humid environment need to be investigated. Among these factors, UV stability is the first one to be studied. However, most polymer surfaces we prepared failed the purpose. Silica surfaces with excellent UV stability were prepared. This method consists of preparation of rough silica surfaces, thermal treatment and the following surface hydrophobization by fluoroalkyl silane treatment. Fluoroalkyl groups are UV stable and the underlying species are silica which is also UV stable (UV transparent). UV stability on the surface currently is 5,500 h according the standard test method of ASTM D 4329. No degradation on surface superhydrophobicity was observed. New methods for preparing superhydrophobic and transparent silica surfaces were investigated using urea-choline chloride eutectic liquid to generate fine roughness and reduce the cost for preparation of surface structures. Another possible application for self-cleaning in photovoltaic panels was investigated on Si surfaces by construction of the two-scale rough structures followed by fluoroalkyl silane treatment. Metal (Au) assisted etching was employed to fabricate nanostructures on micrometer pyramid surfaces. The light reflection on the prepared surfaces was investigated. After surface texturing using KOH etching for micrometer pyramids and the following nanostructure using metal assisted etching, surface light reflection reduced to a minimum value which shows that this surface texturing technique is highly promising for improving the photovoltaic efficiency while imparting photovoltaics the self-cleaning feature. This surface is also expected to be UV stable due to the same fluoroalkyl silane used

  2. Gold nanoparticle arrays directly grown on nanostructured indium tin oxide electrodes: Characterization and electroanalytical application

    International Nuclear Information System (INIS)

    Zhang Jingdong; Oyama, Munetaka

    2005-01-01

    This work describes an improved seed-mediated growth approach for the direct attachment and growth of mono-dispersed gold nanoparticles on nanostructured indium tin oxide (ITO) surfaces. It was demonstrated that, when the seeding procedure of our previously reported seed-mediated growth process on an ITO surface was modified, the density of gold nanospheres directly grown on the surface could be highly improved, while the emergence of nanorods was restrained. By field emission scanning electron microscopy (FE-SEM) and cyclic voltammetry, the growth of gold nanoparticles with increasing growth time on the defect sites of nanostructured ITO surface was monitored. Using a [Fe(China) 6 ] 3- /[Fe(China) 6 ] 4- redox probe, the increasingly facile heterogeneous electron transfer kinetics resulting from the deposition and growth of gold nanoparticle arrays was observed. The as-prepared gold nanoparticle arrays exhibited high catalytic activity toward the electrooxidation of nitric oxide, which could provide electroanalytical application for nitric oxide sensing

  3. Fabrication of flexible indium tin oxide-free polymer solar cells with silver nanowire transparent electrode

    Science.gov (United States)

    Lin, Ming-Yi; Chen, Tsun-Jui; Xu, Wei-Feng; Hsiao, Li-Jen; Budiawan, Widhya; Tu, Wei-Chen; Chen, Shih-Lun; Chu, Chih-Wei; Wei, Pei-Kuen

    2018-03-01

    Flexible indium tin oxide (ITO)-free poly(3-hexylthiophene):[6,6]-phenyl C61-butyric acid methyl ester (P3HT:PC61BM) solar cells with a spin-coated silver nanowire transparent electrode are demonstrated. The solution-processed silver nanowire thin film not only exhibits high transmission (∼87%), but also shows low sheet resistance R s (∼25 Ω/sq). For solar cells with a conventional structure, the power conversion efficiency (PCE) of devices based on silver nanowires can reach around 2.29%. For the inverted structure, the PCE of devices can reach 3.39%. Conventional and inverted flexible ITO-based P3HT:PC61BM solar cells are also fabricated as a reference for comparison. For both types of solar cells, the PCE of ITO-free devices is very close that of an ITO-based polymer solar cell.

  4. Modified glassy carbon electrodes based on carbon nanostructures for ultrasensitive electrochemical determination of furazolidone

    Energy Technology Data Exchange (ETDEWEB)

    Shahrokhian, Saeed, E-mail: shahrokhian@sharif.edu [Department of Chemistry, Sharif University of Technology, Tehran 11155-9516 (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Naderi, Leila [Department of Chemistry, Sharif University of Technology, Tehran 11155-9516 (Iran, Islamic Republic of); Ghalkhani, Masoumeh [Department of Chemistry, Faculty of Science, Shahid Rajaee Teacher Training University, Lavizan, Tehran (Iran, Islamic Republic of); Institute for advanced technology, Shahid Rajaee Teacher Training University, Lavizan, Tehran, 16788 (Iran, Islamic Republic of)

    2016-04-01

    The electrochemical behavior of Furazolidone (Fu) was investigated on the surface of the glassy carbon electrode modified with different carbon nanomaterials, including carbon nanotubes (CNTs), carbon nanoparticles (CNPs), nanodiamond-graphite (NDG), graphene oxide (GO), reduced graphene oxide (RGO) and RGO-CNT hybrids (various ratios) using linear sweep voltammetry (LSV). The results of voltammetric studies exhibited a considerable increase in the cathodic peak current of Fu at the RGO modified GCE, compared to other modified electrodes and also bare GCE. The surface morphology and nature of the RGO film was thoroughly characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques. The modified electrode showed two linear dynamic ranges of 0.001–2.0 μM and 2.0–10.0 μM with a detection limit of 0.3 nM for the voltammetric determination of Fu. This sensor was used successfully for Fu determination in pharmaceutical and clinical preparations. - Highlights: • The electrochemical behavior of Furazolidone (Fu) was investigated on the surface of the modified electrode with different carbon nanomaterials by Linear sweep voltammetry. • Two linear dynamic ranges and a low detection limit were obtained. • The modified electrode was applied for the detection of Fu in pharmaceutical and clinical preparations.

  5. Fabrication of nanostructured metal oxide films with supercritical carbon dioxide: Processing and applications

    Science.gov (United States)

    You, Eunyoung

    Nanostructured metal oxide films have many applications in catalysis, microelectronics, microfluidics, photovoltaics and other fields. Since the performance of a device depends greatly on the structure of the material, the development of methodologies that enable prescriptive control of morphology are of great interest. The focus of this work is to control the structure and properties of the nanostructured metal oxide films using novel synthetic schemes in supercritical fluids and to use those films as key building components in alternative energy applications. A supercritical fluid is a substance at a temperature and pressure above its critical point. It typically exhibits gas-like transport properties and liquid-like densities. Supercritical fluid deposition (SFD) utilizes these properties of supercritical CO2 (scCO2) to deposit chemically pure metal, oxides and alloys of metal films. SFD is a chemical vapor deposition (CVD)-like process in the sense that it uses similar metal organic precursors and deposits films at elevated temperatures. Instead of vaporizing or subliming the precursors, they are dissolved in supercritical fluids. SFD has typically shown to exhibit higher precursor concentrations, lower deposition temperatures, conformal deposition of films on high aspect ratio features as compared to CVD. In2 O3, ZnO and SnO2 are attractive materials because they are used in transparent conductors. SFD of these materials were studied and In2 O3 deposition kinetics using tris(2,2,6,6-tetramethyl-3,5-heptanedionato) In (III) as precursor were determined. Growth rate dependence on the deposition temperature and the precursor concentrations were studied and the physicochemical and optical properties of In2 O3 films were characterized. Metal oxide nanochannels that can potentially be used for microfluidics have been fabricated by sequentially performing nanoimprint lithography (NIL) and SFD. NIL was used to pattern photoresist grating on substrates and SFD of TiO2

  6. Fabrication of Composite Microneedle Array Electrode for Temperature and Bio-Signal Monitoring

    Directory of Open Access Journals (Sweden)

    Yiwei Sun

    2018-04-01

    Full Text Available Body temperature and bio-signals are important health indicators that reflect the human health condition. However, monitoring these indexes is inconvenient and time-consuming, requires various instruments, and needs professional skill. In this study, a composite microneedle array electrode (CMAE was designed and fabricated. It simultaneously detects body temperature and bio-signals. The CMAE consists of a 6 × 6 microneedles array with a height of 500 μm and a base diameter of 200 μm. Multiple insertion experiments indicate that the CMAE possesses excellent mechanical properties. The CMAE can pierce porcine skin 100 times without breaking or bending. A linear calibration relationship between temperature and voltage are experimentally obtained. Armpit temperature (35.8 °C and forearm temperature (35.3 °C are detected with the CMAE, and the measurements agree well with the data acquired with a clinical thermometer. Bio-signals including EII, ECG, and EMG are recorded and compared with those obtained by a commercial Ag/AgCl electrode. The CMAE continuously monitors bio-signals and is more convenient to apply because it does not require skin preparation and gel usage. The CMAE exhibits good potential for continuous and repetitive monitoring of body temperature and bio-signals.

  7. Fabrication of Composite Microneedle Array Electrode for Temperature and Bio-Signal Monitoring.

    Science.gov (United States)

    Sun, Yiwei; Ren, Lei; Jiang, Lelun; Tang, Yong; Liu, Bin

    2018-04-13

    Body temperature and bio-signals are important health indicators that reflect the human health condition. However, monitoring these indexes is inconvenient and time-consuming, requires various instruments, and needs professional skill. In this study, a composite microneedle array electrode (CMAE) was designed and fabricated. It simultaneously detects body temperature and bio-signals. The CMAE consists of a 6 × 6 microneedles array with a height of 500 μm and a base diameter of 200 μm. Multiple insertion experiments indicate that the CMAE possesses excellent mechanical properties. The CMAE can pierce porcine skin 100 times without breaking or bending. A linear calibration relationship between temperature and voltage are experimentally obtained. Armpit temperature (35.8 °C) and forearm temperature (35.3 °C) are detected with the CMAE, and the measurements agree well with the data acquired with a clinical thermometer. Bio-signals including EII, ECG, and EMG are recorded and compared with those obtained by a commercial Ag/AgCl electrode. The CMAE continuously monitors bio-signals and is more convenient to apply because it does not require skin preparation and gel usage. The CMAE exhibits good potential for continuous and repetitive monitoring of body temperature and bio-signals.

  8. Miniaturized, Planar Ion-selective Electrodes Fabricated by Means of Thick-film Technology

    Directory of Open Access Journals (Sweden)

    Robert Koncki

    2006-04-01

    Full Text Available Various planar technologies are employed for developing solid-state sensorshaving low cost, small size and high reproducibility; thin- and thick-film technologies aremost suitable for such productions. Screen-printing is especially suitable due to itssimplicity, low-cost, high reproducibility and efficiency in large-scale production. Thistechnology enables the deposition of a thick layer and allows precise pattern control.Moreover, this is a highly economic technology, saving large amounts of the used inks. Inthe course of repetitions of the film-deposition procedure there is no waste of material dueto additivity of this thick-film technology. Finally, the thick films can be easily and quicklydeposited on inexpensive substrates. In this contribution, thick-film ion-selective electrodesbased on ionophores as well as crystalline ion-selective materials dedicated forpotentiometric measurements are demonstrated. Analytical parameters of these sensors arecomparable with those reported for conventional potentiometric electrodes. All mentionedthick-film strip electrodes have been totally fabricated in only one, fully automated thick-film technology, without any additional manual, chemical or electrochemical steps. In allcases simple, inexpensive, commercially available materials, i.e. flexible, plastic substratesand easily cured polymer-based pastes were used.

  9. Scalable fabrication of nanostructured devices on flexible substrates using additive driven self-assembly and nanoimprint lithography

    Science.gov (United States)

    Watkins, James

    2013-03-01

    Roll-to-roll (R2R) technologies provide routes for continuous production of flexible, nanostructured materials and devices with high throughput and low cost. We employ additive-driven self-assembly to produce well-ordered polymer/nanoparticle hybrid materials that can serve as active device layers, we use highly filled nanoparticle/polymer hybrids for applications that require tailored dielectric constant or refractive index, and we employ R2R nanoimprint lithography for device scale patterning. Specific examples include the fabrication of flexible floating gate memory and large area films for optical/EM management. Our newly constructed R2R processing facility includes a custom designed, precision R2R UV-assisted nanoimprint lithography (NIL) system and hybrid nanostructured materials coaters.

  10. Fabrication of organic field effect transistor by directly grown poly(3 hexylthiophene) crystalline nanowires on carbon nanotube aligned array electrode.

    Science.gov (United States)

    Sarker, Biddut K; Liu, Jianhua; Zhai, Lei; Khondaker, Saiful I

    2011-04-01

    We fabricated organic field effect transistors (OFETs) by directly growing poly (3-hexylthiophne) (P3HT) crystalline nanowires on solution processed aligned array single walled carbon nanotubes (SWNT) interdigitated electrodes by exploiting strong π-π interaction for both efficient charge injection and transport. We also compared the device properties of OFETs using SWNT electrodes with control OFETs of P3HT nanowires deposited on gold electrodes. Electron transport measurements on 28 devices showed that, compared to the OFETs with gold electrodes, the OFETs with SWNT electrodes have better mobility and better current on-off ratio with a maximum of 0.13 cm(2)/(V s) and 3.1 × 10(5), respectively. The improved device characteristics with SWNT electrodes were also demonstrated by the improved charge injection and the absence of short channel effect, which was dominant in gold electrode OFETs. The enhancement of the device performance can be attributed to the improved interfacial contact between SWNT electrodes and the crystalline P3HT nanowires as well as the improved morphology of P3HT due to one-dimensional crystalline nanowire structure. © 2011 American Chemical Society

  11. Method of fabricating electrodes including high-capacity, binder-free anodes for lithium-ion batteries

    Science.gov (United States)

    Ban, Chunmei; Wu, Zhuangchun; Dillon, Anne C.

    2017-01-10

    An electrode (110) is provided that may be used in an electrochemical device (100) such as an energy storage/discharge device, e.g., a lithium-ion battery, or an electrochromic device, e.g., a smart window. Hydrothermal techniques and vacuum filtration methods were applied to fabricate the electrode (110). The electrode (110) includes an active portion (140) that is made up of electrochemically active nanoparticles, with one embodiment utilizing 3d-transition metal oxides to provide the electrochemical capacity of the electrode (110). The active material (140) may include other electrochemical materials, such as silicon, tin, lithium manganese oxide, and lithium iron phosphate. The electrode (110) also includes a matrix or net (170) of electrically conductive nanomaterial that acts to connect and/or bind the active nanoparticles (140) such that no binder material is required in the electrode (110), which allows more active materials (140) to be included to improve energy density and other desirable characteristics of the electrode. The matrix material (170) may take the form of carbon nanotubes, such as single-wall, double-wall, and/or multi-wall nanotubes, and be provided as about 2 to 30 percent weight of the electrode (110) with the rest being the active material (140).

  12. Fabrication and characterization of a micromachined swirl-shaped ionic polymer metal composite actuator with electrodes exhibiting asymmetric resistance.

    Science.gov (United States)

    Feng, Guo-Hua; Liu, Kim-Min

    2014-05-12

    This paper presents a swirl-shaped microfeatured ionic polymer-metal composite (IPMC) actuator. A novel micromachining process was developed to fabricate an array of IPMC actuators on a glass substrate and to ensure that no shortcircuits occur between the electrodes of the actuator. We demonstrated a microfluidic scheme in which surface tension was used to construct swirl-shaped planar IPMC devices of microfeature size and investigated the flow velocity of Nafion solutions, which formed the backbone polymer of the actuator, within the microchannel. The unique fabrication process yielded top and bottom electrodes that exhibited asymmetric surface resistance. A tool for measuring surface resistance was developed and used to characterize the resistances of the electrodes for the fabricated IPMC device. The actuator, which featured asymmetric electrode resistance, caused a nonzero-bias current when the device was driven using a zero-bias square wave, and we propose a circuit model to describe this phenomenon. Moreover, we discovered and characterized a bending and rotating motion when the IPMC actuator was driven using a square wave. We observed a strain rate of 14.6% and a displacement of 700 μm in the direction perpendicular to the electrode surfaces during 4.5-V actuation.

  13. New Fabrication Method of Three-Electrode System on Cylindrical Capillary Surface as a Flexible Implantable Microneedle

    Science.gov (United States)

    Yang, Zhuoqing; Zhang, Yi; Itoh, Toshihiro; Maeda, Ryutaro

    2013-04-01

    In this present paper, a three-electrode system has been fabricated and integrated on the cylindrical polymer capillary surface by micromachining technology, which could be used as a flexible and implantable microneedle for glucose sensor application in future. A UV lithography system is successfully developed for high resolution alignment on cylindrical substrates. The multilayer alignment exposure for cylindrical polymer capillary substrate is for the first time realized utilizing the lithography system. The ±1 μm alignment precision has been realized on the 330 μm-outer diameter polymer capillary surface, on which the three-electrode structure consisting of two platinum electrodes and one Ag/AgCl reference electrode has been fabricated. The fabricated whole device as microneedle for glucose sensor application has been also characterized in 1 mol/L KCl and 0.02 mol/L K3Fe(CN)6 mix solution. The measured cyclic voltammetry curve shows that the prepared three-electrode system has a good redox property.

  14. Fabrication of flexible polymer dispersed liquid crystal films using conducting polymer thin films as the driving electrodes

    International Nuclear Information System (INIS)

    Kim, Yang-Bae; Park, Sucheol; Hong, Jin-Who

    2009-01-01

    Conducting polymers exhibit good mechanical and interfacial compatibility with plastic substrates. We prepared an optimized coating formulation based on poly(3,4-ethylenedioxythiophene) (PEDOT) and 3-(trimethoxysilyl)propyl acrylate and fabricated a transparent electrode on poly(ethylene terephthalate) (PET) substrate. The surface resistances and transmittance of the prepared thin films were 500-600 Ω/□ and 87% at 500 nm, respectively. To evaluate the performance of the conducting polymer electrode, we fabricated a five-layer flexible polymer-dispersed liquid crystal (PDLC) device as a PET-PEDOT-PDLC-PEDOT-PET flexible film. The prepared PDLC device exhibited a low driving voltage (15 VAC), high contrast ratio (60:1), and high transmittance in the ON state (60%), characteristics that are comparable with those of conventional PDLC film based on indium tin oxide electrodes. The fabrication of conducting polymer thin films as the driving electrodes in this study showed that such films can be used as a substitute for an indium tin oxide electrode, which further enhances the flexibility of PDLC film

  15. Structural Engineering of Metal-Mesh Structure Applicable for Transparent Electrodes Fabricated by Self-Formable Cracked Template

    Directory of Open Access Journals (Sweden)

    Yeong-gyu Kim

    2017-08-01

    Full Text Available Flexible and transparent conducting electrodes are essential for future electronic devices. In this study, we successfully fabricated a highly-interconnected metal-mesh structure (MMS using a self-formable cracked template. The template—fabricated from colloidal silica—can be easily formed and removed, presenting a simple and cost-effective way to construct a randomly and uniformly networked MMS. The structure of the MMS can be controlled by varying the spin-coating speed during the coating of the template solution or by stacking of metal-mesh layers. Through these techniques, the optical transparency and sheet resistance of the MMS can be designed for a specific purpose. A double-layered Al MMS showed high optical transparency (~80% in the visible region, low sheet resistance (~20 Ω/sq, and good flexibility under bending test compared with a single-layered MMS, because of its highly-interconnected wire structure. Additionally, we identified the applicability of the MMS in the case of practical devices by applying it to electrodes of thin-film transistors (TFTs. The TFTs with MMS electrodes showed comparable electrical characteristics to those with conventional film-type electrodes. The cracked template can be used for the fabrication of a mesh structure consisting of any material, so it can be used for not only transparent electrodes, but also various applications such as solar cells, sensors, etc.

  16. Maskless fabrication of a microfluidic device with interdigitated electrodes on PCB using laser ablation

    Science.gov (United States)

    Contreras-Saenz, Michael; Hassard, Christian; Vargas-Chacon, Rafael; Gordillo, Jose Luis; Camacho-Leon, Sergio

    2016-03-01

    This paper reports the maskless fabrication of a microfluidic device with interdigitated electrodes (IDE) based on the technology of MicroElectroMechanical Systems on Printed Circuit Board (PCB-MEMS) and laser ablation. The device has flame retardant (FR)-4 resin as substrate, cooper (Cu) as active material and SU-8 polymer as structural material. By adjusting the laser parameters, Cu IDEs and SU-8 microchannels were successfully patterned onto the FR-4 substrate. The respective width, gap and overlap of the IDEs were 50 μm, 25 μm and 500 μm. The respective width, depth and length of the microchannels were 210 μm, 24.6 μm and 6.3 mm. The resolution and repeatability achieved in this approach, along with the low cost of the involved materials and techniques, enable an affordable micromachining platform with rapid fabrication-test cycle to develop active multiphysic microdevices with several applications in the fields of biosensing, cell culture, drug delivery, transport and sorting of molecules, among others.

  17. Parallel oxygen and chlorine evolution on Ru1-xNixO2-y nanostructured electrodes

    Czech Academy of Sciences Publication Activity Database

    Macounová, Kateřina; Makarova, Marina; Jirkovský, Jakub; Franc, Jiří; Krtil, Petr

    2008-01-01

    Roč. 53, č. 5 (2008), s. 6126-6134 ISSN 0013-4686 R&D Projects: GA AV ČR KAN100400702 Institutional research plan: CEZ:AV0Z40400503 Keywords : OER * CER * DEMS * ruthenium electrode Subject RIV: CG - Electrochemistry Impact factor: 3.078, year: 2008

  18. Fabrication of gallium hexacyanoferrate modified carbon ionic liquid paste electrode for sensitive determination of hydrogen peroxide and glucose

    Energy Technology Data Exchange (ETDEWEB)

    Haghighi, Behzad, E-mail: haghighi@iasbs.ac.ir; Khosravi, Mehdi; Barati, Ali

    2014-07-01

    Gallium hexacyanoferrate (GaHCFe) and graphite powder were homogeneously dispersed into n-dodecylpyridinium hexafluorophosphate and paraffin to fabricate GaHCFe modified carbon ionic liquid paste electrode (CILPE). Mixture experimental design was employed to optimize the fabrication of GaHCFe modified CILPE (GaHCFe-CILPE). A pair of well-defined redox peaks due to the redox reaction of GaHCFe through one-electron process was observed for the fabricated electrode. The fabricated GaHCFe-CILPE exhibited good electrocatalytic activity towards reduction and oxidation of H{sub 2}O{sub 2}. The observed sensitivities for the electrocatalytic oxidation and reduction of H{sub 2}O{sub 2} at the operating potentials of + 0.8 and − 0.2 V were about 13.8 and 18.3 mA M{sup −1}, respectively. The detection limit (S/N = 3) for H{sub 2}O{sub 2} was about 1 μM. Additionally, glucose oxidase (GOx) was immobilized on GaHCFe-CILPE using two methodology, entrapment into Nafion matrix and cross-linking with glutaraldehyde and bovine serum albumin, in order to fabricate glucose biosensor. Linear dynamic rage, sensitivity and detection limit for glucose obtained by the biosensor fabricated using cross-linking methodology were 0.1–6 mM, 0.87 mA M{sup −1} and 30 μM, respectively and better than those obtained (0.2–6 mM, 0.12 mA M{sup −1} and 50 μM) for the biosensor fabricated using entrapment methodology. - Highlights: • Gallium hexacyanoferrate modified carbon ionic liquid paste electrode was fabricated. • Mixture experimental design was used to optimize electrode fabrication. • Response trace plot was used to show the effect of electrode materials on response. • The sensor exhibited electrocatalytic activity towards H{sub 2}O{sub 2} reduction and oxidation. • Glucose biosensor was fabricated by immobilization of glucose oxidase on sensor.

  19. Simple approach for the fabrication of screen-printed carbon-based electrode for amperometric detection on microchip electrophoresis.

    Science.gov (United States)

    Petroni, Jacqueline Marques; Lucca, Bruno Gabriel; Ferreira, Valdir Souza

    2017-02-15

    This paper describes a simple method for the fabrication of screen-printed based electrodes for amperometric detection on microchip electrophoresis (ME) devices. The procedure developed is quite simple and does not require expensive instrumentation or sophisticated protocols commonly employed on the production of amperometric sensors, such as photolithography or sputtering steps. The electrodes were fabricated through manual deposition of home-made conductive carbon ink over patterned acrylic substrate. Morphological structure and electrochemical behavior of the carbon electrodes were investigated by scanning electron microscopy and cyclic voltammetry. The produced amperometric sensors were coupled to polydimethylsiloxane (PDMS) microchips at end-channel configuration in order to evaluate their analytical performance. For this purpose, electrophoretic experiments were carried out using nitrite and ascorbic acid as model analytes. Separation of these substances was successfully performed within 50s with good resolution (R = 1.2) and sensitivities (713.5 pA/μM for nitrite and 255.4 pA/μM for ascorbate). The reproducibility of the fabrication method was evaluated and revealed good values concerning the peak currents obtained (8.7% for nitrite and 9.3% for ascorbate). The electrodes obtained through this method exhibited satisfactory lifetime (ca. 400 runs) over low fabrication cost (less than $1 per piece). The feasibility of the proposed device for real analysis was demonstrated through the determination of nitrite concentration levels in drinking water samples. Based on the results achieved, the approach proposed here shows itself as an interesting alternative for simple fabrication of carbon-based electrodes. Furthermore, the devices indicate great promise for other kind of analytical applications involving ME devices. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. The fabrication and characterization of adjustable nanogaps between gold electrodes on chip for electrical measurement of single molecules

    International Nuclear Information System (INIS)

    Tian Jinghua; Yang Yang; Liu Bo; Wu Deyin; Tian Zhongqun; Schoellhorn, Bernd; Maisonhaute, Emmanuel; Muns, Anna Serra; Chen Yong; Amatore, Christian; Tao, Nong-Jian

    2010-01-01

    This work reports on a new method to fabricate mechanically controllable break junctions (MCBJ) with finely adjustable nanogaps between two gold electrodes on solid state chips for characterizing electron transport properties of single molecules. The simple, low cost, robust and reproducible fabrication method combines conventional photolithography, chemical etching and electrodeposition to produce suspended electrodes separated with nanogaps. The MCBJ devices fabricated by the method can undergo many cycles in which the nanogap width can be precisely and repeatedly varied from zero to several nanometers. The method improves the success rate of the MCBJ experiments. Using these devices the electron transport properties of a typical molecular system, commercially available benzene-1,4-dithiol (BDT), have been studied. The I-V and G-V characteristic curves of BDT and the conductance value for a single BDT molecule established the excellent device suitability for molecular electronics research.

  1. The fabrication and characterization of adjustable nanogaps between gold electrodes on chip for electrical measurement of single molecules

    Energy Technology Data Exchange (ETDEWEB)

    Tian Jinghua; Yang Yang; Liu Bo; Wu Deyin; Tian Zhongqun [State Key Laboratory of Physical Chemistry of Solid Surfaces and LIA CNRS XiamENS ' NanoBioChem' , College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian (China); Schoellhorn, Bernd; Maisonhaute, Emmanuel; Muns, Anna Serra; Chen Yong; Amatore, Christian [UMR CNRS 8640 ' PASTEUR' and LIA CNRS XiamENS ' NanoBioChem' , Ecole Normale Superieure, Universite Pierre et Marie Curie-Paris 6, 24 rue Lhomond, 75231 Paris Cedex 05 (France); Tao, Nong-Jian, E-mail: zqtian@xmu.edu.cn, E-mail: christian.amatore@ens.fr [Ira A Fulton School of Engineering and Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University, Tempe, AZ 85287-6206 (United States)

    2010-07-09

    This work reports on a new method to fabricate mechanically controllable break junctions (MCBJ) with finely adjustable nanogaps between two gold electrodes on solid state chips for characterizing electron transport properties of single molecules. The simple, low cost, robust and reproducible fabrication method combines conventional photolithography, chemical etching and electrodeposition to produce suspended electrodes separated with nanogaps. The MCBJ devices fabricated by the method can undergo many cycles in which the nanogap width can be precisely and repeatedly varied from zero to several nanometers. The method improves the success rate of the MCBJ experiments. Using these devices the electron transport properties of a typical molecular system, commercially available benzene-1,4-dithiol (BDT), have been studied. The I-V and G-V characteristic curves of BDT and the conductance value for a single BDT molecule established the excellent device suitability for molecular electronics research.

  2. Chemically controllable fabrication of one-dimensional ZnO nanostructures and their applications in solar cells.

    Science.gov (United States)

    Zhang, Yuqi; Heng, Liping; Jiang, Lei

    2014-08-01

    One-dimensional (1D) ZnO nanostructures have attracted much attention due to their interesting optical and electronic properties, which make them suitable for a wide variety of current and future technological applications, including photodetectors, photovoltaics, photocatalysis, field emissions, gas sensors and solar cells. This review gives a comprehensive overview of recent developments in chemically controllable fabrication of 1D ZnO nanomaterials. We will cover the synthetic techniques including chemical vapor deposition (CVD), metal-organic chemical vapor deposition (MOCVD), hydrothermal technique, solvothermal synthesis, sol-gel method, electrochemical deposition, and nanosphere lithography technique. Finally, we will also highlight their application in the energy conversion system.

  3. Comparison of dye solar cell counter electrodes based on different carbon nanostructures

    International Nuclear Information System (INIS)

    Aitola, Kerttu; Halme, Janne; Halonen, Niina; Kaskela, Antti; Toivola, Minna; Nasibulin, Albert G.; Kordas, Krisztian; Toth, Geza; Kauppinen, Esko I.; Lund, Peter D.

    2011-01-01

    Three characteristically different carbon nanomaterials were compared and analyzed as platinum-free counter electrodes for dye solar cells: 1) single-walled carbon nanotube (SWCNT) random network films on glass, 2) aligned multi-walled carbon nanotube (MWCNT) forest films on Inconel steel and quartz, and 3) pressed carbon nanoparticle composite films on indium tin oxide-polyethylene terephtalate plastic. Results from electrochemical impedance spectroscopy and electron microscopy were discussed in terms of the catalytic activity, conductivity, thickness, transparency and flexibility of the electrode films. The SWCNT films showed reasonable catalytic performance at similar series resistance compared to platinized fluorine doped tin oxide-coated glass. The MWCNTs had similar catalytic activity, but the electrochemical performance of the films was limited by their high porosity. Carbon nanoparticle films had the lowest charge transfer resistance resulting from a combination of high catalytic activity and dense packing of the material.

  4. Comparison of dye solar cell counter electrodes based on different carbon nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Aitola, Kerttu, E-mail: kerttu.aitola@aalto.fi [Aalto University, Department of Applied Physics, P.O. Box 15100, 00076 Aalto (Finland); Halme, Janne [Aalto University, Department of Applied Physics, P.O. Box 15100, 00076 Aalto (Finland); Halonen, Niina [Microelectronics and Materials Physics Laboratories, Department of Electrical and Information Engineering, University of Oulu, P.O. Box 4500, FI-90014 University of Oulu (Finland); Kaskela, Antti; Toivola, Minna; Nasibulin, Albert G. [Aalto University, Department of Applied Physics, P.O. Box 15100, 00076 Aalto (Finland); Kordas, Krisztian; Toth, Geza [Microelectronics and Materials Physics Laboratories, Department of Electrical and Information Engineering, University of Oulu, P.O. Box 4500, FI-90014 University of Oulu (Finland); Kauppinen, Esko I. [Aalto University, Department of Applied Physics, P.O. Box 15100, 00076 Aalto (Finland); VTT Biotechnology, P.O. Box 1000, 02044 VTT (Finland); Lund, Peter D. [Aalto University, Department of Applied Physics, P.O. Box 15100, 00076 Aalto (Finland)

    2011-09-01

    Three characteristically different carbon nanomaterials were compared and analyzed as platinum-free counter electrodes for dye solar cells: 1) single-walled carbon nanotube (SWCNT) random network films on glass, 2) aligned multi-walled carbon nanotube (MWCNT) forest films on Inconel steel and quartz, and 3) pressed carbon nanoparticle composite films on indium tin oxide-polyethylene terephtalate plastic. Results from electrochemical impedance spectroscopy and electron microscopy were discussed in terms of the catalytic activity, conductivity, thickness, transparency and flexibility of the electrode films. The SWCNT films showed reasonable catalytic performance at similar series resistance compared to platinized fluorine doped tin oxide-coated glass. The MWCNTs had similar catalytic activity, but the electrochemical performance of the films was limited by their high porosity. Carbon nanoparticle films had the lowest charge transfer resistance resulting from a combination of high catalytic activity and dense packing of the material.

  5. Metal Nanoparticles and Carbon-Based Nanostructures as Advanced Materials for Cathode Application in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Pietro Calandra

    2010-01-01

    Full Text Available We review the most advanced methods for the fabrication of cathodes for dye-sensitized solar cells employing nanostructured materials. The attention is focused on metal nanoparticles and nanostructured carbon, among which nanotubes and graphene, whose good catalytic properties make them ideal for the development of counter electrode substrates, transparent conducting oxide, and advanced catalyst materials.

  6. Electrochemically oxidized electronic and ionic conducting nanostructured block copolymers for lithium battery electrodes.

    Science.gov (United States)

    Patel, Shrayesh N; Javier, Anna E; Balsara, Nitash P

    2013-07-23

    Block copolymers that can simultaneously conduct electronic and ionic charges on the nanometer length scale can serve as innovative conductive binder material for solid-state battery electrodes. The purpose of this work is to study the electronic charge transport of poly(3-hexylthiophene)-b-poly(ethylene oxide) (P3HT-PEO) copolymers electrochemically oxidized with lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) salt in the context of a lithium battery charge/discharge cycle. We use a solid-state three-terminal electrochemical cell that enables simultaneous conductivity measurements and control over electrochemical doping of P3HT. At low oxidation levels (ratio of moles of electrons removed to moles of 3-hexylthiophene moieties in the electrode), the electronic conductivity (σe,ox) increases from 10(-7) S/cm to 10(-4) S/cm. At high oxidation levels, σe,ox approaches 10(-2) S/cm. When P3HT-PEO is used as a conductive binder in a positive electrode with LiFePO4 active material, P3HT is electrochemically active within the voltage window of a charge/discharge cycle. The electronic conductivity of the P3HT-PEO binder is in the 10(-4) to 10(-2) S/cm range over most of the potential window of the charge/discharge cycle. This allows for efficient electronic conduction, and observed charge/discharge capacities approach the theoretical limit of LiFePO4. However, at the end of the discharge cycle, the electronic conductivity decreases sharply to 10(-7) S/cm, which means the "conductive" binder is now electronically insulating. The ability of our conductive binder to switch between electronically conducting and insulating states in the positive electrode provides an unprecedented route for automatic overdischarge protection in rechargeable batteries.

  7. Intrinsically Stretchable Nanostructured Silver Electrodes for Realizing Efficient Strain Sensors and Stretchable Organic Photovoltaics.

    Science.gov (United States)

    Yu, Yang-Yen; Chen, Chien-Hsun; Chueh, Chu-Chen; Chiang, Chun-Ying; Hsieh, Jang-Hsing; Chen, Chih-Ping; Chen, Wen-Chang

    2017-08-23

    In this study, a new hybrid electrode featuring a high gauge factor of >30, decent stretchability (100% of the original conductivity can be retained after 50 cycles of stretching under a 20% strain without prestrain treatment), high transmittance (>70%) across 400-900 nm, and a good sheet resistance (electrode is susceptible to the applied tensile strain and the ensuing change in conductivity enables the realization of an efficient strain sensor. Besides, a representative PTB7-th:PC 71 BM organic photovoltaic (OPV) using this electrode (with the assistance of a wrinkled scaffold to reinforce the stretchability of the active layer) can exhibit a power-conversion efficiency (PCE) of 6% along with high deformability, for which 75% of its original PCE is retained after 50 cycles of stretching under a 20% strain. Meanwhile, a representative all-polymer OPV consisting of a PTB7-th:N2200 blend, in which the N2200 has a better mechanical stretchability than that of PC 71 BM, can maintain over 96% of its original PCE after 50 cycles of stretching (under a 20% strain) without employing the wrinkled scaffold. Such promising performance in stretchable OPVs is among the state-of-the-art results reported to date.

  8. Modified glassy carbon electrodes based on carbon nanostructures for ultrasensitive electrochemical determination of furazolidone.

    Science.gov (United States)

    Shahrokhian, Saeed; Naderi, Leila; Ghalkhani, Masoumeh

    2016-04-01

    The electrochemical behavior of Furazolidone (Fu) was investigated on the surface of the glassy carbon electrode modified with different carbon nanomaterials, including carbon nanotubes (CNTs), carbon nanoparticles (CNPs), nanodiamond-graphite (NDG), graphene oxide (GO), reduced graphene oxide (RGO) and RGO-CNT hybrids (various ratios) using linear sweep voltammetry (LSV). The results of voltammetric studies exhibited a considerable increase in the cathodic peak current of Fu at the RGO modified GCE, compared to other modified electrodes and also bare GCE. The surface morphology and nature of the RGO film was thoroughly characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques. The modified electrode showed two linear dynamic ranges of 0.001-2.0 μM and 2.0-10.0 μM with a detection limit of 0.3 nM for the voltammetric determination of Fu. This sensor was used successfully for Fu determination in pharmaceutical and clinical preparations. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Fabrication of Micro-Needle Electrodes for Bio-Signal Recording by a Magnetization-Induced Self-Assembly Method

    Directory of Open Access Journals (Sweden)

    Keyun Chen

    2016-09-01

    Full Text Available Micro-needle electrodes (MEs have attracted more and more attention for monitoring physiological electrical signals, including electrode-skin interface impedance (EII, electromyography (EMG and electrocardiography (ECG recording. A magnetization-induced self-assembling method (MSM was developed to fabricate a microneedle array (MA. A MA coated with Ti/Au film was assembled as a ME. The fracture and insertion properties of ME were tested by experiments. The bio-signal recording performance of the ME was measured and compared with a typical commercial wet electrode (Ag/AgCl electrode. The results show that the MA self-assembled from the magnetic droplet array under the sum of gravitational surface tension and magnetic potential energies. The ME had good toughness and could easily pierce rabbit skin without being broken or buckling. When the compression force applied on the ME was larger than 2 N, ME could stably record EII, which was a lower value than that measured by Ag/AgCl electrodes. EMG signals collected by ME varied along with the contraction of biceps brachii muscle. ME could record static ECG signals with a larger amplitude and dynamic ECG signals with more distinguishable features in comparison with a Ag/AgCl electrode, therefore, ME is an alternative electrode for bio-signal monitoring in some specific situations.

  10. Fabrication of 3D core-shell multiwalled carbon nanotube@RuO2 lithium-ion battery electrodes through a RuO2 atomic layer deposition process.

    Science.gov (United States)

    Gregorczyk, Keith E; Kozen, Alexander C; Chen, Xinyi; Schroeder, Marshall A; Noked, Malachi; Cao, Anyuan; Hu, Liangbing; Rubloff, Gary W

    2015-01-27

    Pushing lithium-ion battery (LIB) technology forward to its fundamental scaling limits requires the ability to create designer heterostructured materials and architectures. Atomic layer deposition (ALD) has recently been applied to advanced nanostructured energy storage devices due to the wide range of available materials, angstrom thickness control, and extreme conformality over high aspect ratio nanostructures. A class of materials referred to as conversion electrodes has recently been proposed as high capacity electrodes. RuO2 is considered an ideal conversion material due to its high combined electronic and ionic conductivity and high gravimetric capacity, and as such is an excellent material to explore the behavior of conversion electrodes at nanoscale thicknesses. We report here a fully characterized atomic layer deposition process for RuO2, electrochemical cycling data for ALD RuO2, and the application of the RuO2 to a composite carbon nanotube electrode scaffold with nucleation-controlled RuO2 growth. A growth rate of 0.4 Å/cycle is found between ∼ 210-240 °C. In a planar configuration, the resulting RuO2 films show high first cycle electrochemical capacities of ∼ 1400 mAh/g, but the capacity rapidly degrades with charge/discharge cycling. We also fabricated core/shell MWCNT/RuO2 heterostructured 3D electrodes, which show a 50× increase in the areal capacity over their planar counterparts, with an areal lithium capacity of 1.6 mAh/cm(2).

  11. Understanding the Effects of a High Surface Area Nanostructured Indium Tin Oxide Electrode on Organic Solar Cell Performance.

    Science.gov (United States)

    Cao, Bing; He, Xiaoming; Sorge, Jason B; Lalany, Abeed; Ahadi, Kaveh; Afshar, Amir; Olsen, Brian C; Hauger, Tate C; Mobarok, Md Hosnay; Li, Peng; Cadien, Kenneth C; Brett, Michael J; Luber, Erik J; Buriak, Jillian M

    2017-11-08

    Organic solar cells (OSCs) are a complex assembly of disparate materials, each with a precise function within the device. Typically, the electrodes are flat, and the device is fabricated through a layering approach of the interfacial layers and photoactive materials. This work explores the integration of high surface area transparent electrodes to investigate the possible role(s) a three-dimensional electrode could take within an OSC, with a BHJ composed of a donor-acceptor combination with a high degree of electron and hole mobility mismatch. Nanotree indium tin oxide (ITO) electrodes were prepared via glancing angle deposition, structures that were previously demonstrated to be single-crystalline. A thin layer of zinc oxide was deposited on the ITO nanotrees via atomic layer deposition, followed by a self-assembled monolayer of C 60 -based molecules that was bound to the zinc oxide surface through a carboxylic acid group. Infiltration of these functionalized ITO nanotrees with the photoactive layer, the bulk heterojunction comprising PC 71 BM and a high hole mobility low band gap polymer (PDPPTT-T-TT), led to families of devices that were analyzed for the effect of nanotree height. When the height was varied from 0 to 50, 75, 100, and 120 nm, statistically significant differences in device performance were noted with the maximum device efficiencies observed with a nanotree height of 75 nm. From analysis of these results, it was found that the intrinsic mobility mismatch between the donor and acceptor phases could be compensated for when the electron collection length was reduced relative to the hole collection length, resulting in more balanced charge extraction and reduced recombination, leading to improved efficiencies. However, as the ITO nanotrees increased in height and branching, the decrease in electron collection length was offset by an increase in hole collection length and potential deleterious electric field redistribution effects, resulting in

  12. Nanostructured Metal Oxide Coatings for Electrochemical Energy Conversion and Storage Electrodes

    Science.gov (United States)

    Cordova, Isvar Abraxas

    The realization of an energy future based on safe, clean, sustainable, and economically viable technologies is one of the grand challenges facing modern society. Electrochemical energy technologies underpin the potential success of this effort to divert energy sources away from fossil fuels, whether one considers alternative energy conversion strategies through photoelectrochemical (PEC) production of chemical fuels or fuel cells run with sustainable hydrogen, or energy storage strategies, such as in batteries and supercapacitors. This dissertation builds on recent advances in nanomaterials design, synthesis, and characterization to develop novel electrodes that can electrochemically convert and store energy. Chapter 2 of this dissertation focuses on refining the properties of TiO2-based PEC water-splitting photoanodes used for the direct electrochemical conversion of solar energy into hydrogen fuel. The approach utilized atomic layer deposition (ALD); a growth process uniquely suited for the conformal and uniform deposition of thin films with angstrom-level thickness precision. ALD's thickness control enabled a better understanding of how the effects of nitrogen doping via NH3 annealing treatments, used to reduce TiO2's bandgap, can have a strong dependence on TiO2's thickness and crystalline quality. In addition, it was found that some of the negative effects on the PEC performance typically associated with N-doped TiO2 could be mitigated if the NH 3-annealing was directly preceded by an air-annealing step, especially for ultrathin (i.e., vs. Ag/AgCl) and charge transfer efficiency. In Chapter 3, two innovative nanoarchitectures were engineered in order to enhance the pseudocapacitive energy storage of next generation supercapacitor electrodes. The morphology and quantity of MnO2 electrodeposits was controlled by adjusting the density of graphene foliates on a novel graphenated carbon nanotube (g-CNT) scaffold. This control enabled the nanocomposite

  13. Nanostructured Semiconductor Electrodes for Solar Energy Conversion and Innovations in Undergraduate Chemical Lab Curriculum

    Science.gov (United States)

    Lee, Sudarat

    This dissertation presents the methodology and discussion of preparing nanostructured, high aspect ratio p-type phosphide-based binary and ternary semiconductors via "top-down" anodic etching, a process which creates nanostructures from a large parent entity, and "bottom-up" vapor-liquid-solid growth, a mechanism which builds up small clusters of molecules block-by-block. Such architecture is particularly useful for semiconducting materials with incompatible optical absorption depth and charge carrier diffusion length, as it not only relaxes the requirement for high-grade crystalline materials, but also increases the carrier collection efficiencies for photons with energy greater than or equal to the band gap. The main focus of this dissertation is to obtain nanostructured p-type phosphide semiconductors for photoelectrochemical (PEC) cell applications. Chapter II in the thesis describes a methodology for creating high-aspect ratio p-GaP that function as a photocathode under white light illumination. Gallium phosphide (GaP, band gap: 2.26 eV) is a suitable candidate for solar conversion and energy storage due to its ability to generate large photocurrent and photovoltage to drive fuel-forming reactions. Furthermore, the band edge positions of GaP can provide sufficient kinetics for the reduction of protons and carbon dioxide. The structure is prepared by anodic etching, and the resulting macroporous structures are subsequently doped with Zn by thermally driving in Zn from conformal ZnO films prepared by atomic layer deposition (ALD). The key finding of this work is a viable doping strategy involving ALD ZnO films for making functioning p-type GaP nanostructures. Chapter III compares the GaP nanowires grown from gold (Au) and tin (Sn) VLS catalysts in a benign solid sublimation growth scheme in terms of crystal structure and photoactivity. Sn is less noble than Au, allowing complete removal of Sn metal catalysts from the nanowires through wet chemical etching which

  14. Fabrication of ultra-high aspect ratio (>160:1) silicon nanostructures by using Au metal assisted chemical etching

    Science.gov (United States)

    Li, Hailiang; Ye, Tianchun; Shi, Lina; Xie, Changqing

    2017-12-01

    We present a facile and effective approach for fabricating high aspect ratio, dense and vertical silicon nanopillar arrays, using a combination of metal etching following electron-beam lithography and Au metal assisted chemical etching (MacEtch). Ti/Au nanostructures used as catalysts in MacEtch are formed by single layer resist-based electron-beam exposure followed by ion beam etching. The effects of MacEtch process parameters, including half period, etching time, the concentrations of H2O2 and HF, etching temperature and drying method are systematically investigated. Especially, we demonstrate an enhancement of etching quality by employing cold MacEtch process, and an enhancement in preventing the collapse of high aspect ratio nanostructures by employing low surface tension rinse liquid and natural evaporation in the drying stage. Using an optimized MacEtch process, vertical silicon nanopillar arrays with a period of 250 nm and aspect ratio up to 160:1 are realized. Our results should be instructive for exploring the achievable aspect ratio limit in silicon nanostructures and may find potential applications in photovoltaic devices, thermoelectric devices and x-ray diffractive optics.

  15. A novel AFM-based 5-axis nanoscale machine tool for fabrication of nanostructures on a micro ball.

    Science.gov (United States)

    Geng, Yanquan; Wang, Yuzhang; Yan, Yongda; Zhao, Xuesen

    2017-11-01

    This paper presents a novel atomic force microscopy (AFM)-based 5-axis nanoscale machine tool developed to fabricate nanostructures on different annuli of the micro ball. Different nanostructures can be obtained by combining the scratching trajectory of the AFM tip with the movement of the high precision air-bearing spindle. The center of the micro ball is aligned to be coincided with the gyration center of the high precision to guarantee the machining process during the rotating of the air-bearing spindle. Processing on different annuli of the micro ball is achieved by controlling the distance between the center of the micro ball and the rotation center of the AFM head. Nanostructures including square cavities, circular cavities, triangular cavities, and an annular nanochannel are machined successfully on the three different circumferences of a micro ball with a diameter of 1500 μm. Moreover, the influences of the error motions of the high precision air-bearing spindle and the eccentric between the micro ball and the gyration center of the high precision air-bearing spindle on the processing position error on the micro ball are also investigated. This proposed machining method has the potential to prepare the inertial confinement fusion target with the expected dimension defects, which would advance the application of the AFM tip-based nanomachining approach.

  16. Nanofaceted C/Re(1121): fabrication, structure, and template for synthesizing nanostructured model Pt electrocatalyst for hydrogen evolution reaction.

    Science.gov (United States)

    Yang, Xiaofang; Koel, Bruce E; Wang, Hao; Chen, Wenhua; Bartynski, Robert A

    2012-02-28

    We report the first observation of carbon-induced nanofaceting of a Re single crystal and its application in synthesizing a nanostructured model Pt electrocatalyst investigated using multiple surface science techniques, including low-energy electron diffraction, Auger electron spectroscopy, X-ray photoelectron spectroscopy, low-energy ion scattering, and scanning tunneling microscopy, combined with electrochemical reaction measurements. Upon annealing in acetylene at 700 K followed by annealing in vacuum at 1100 K, an initially planar Re(112̅1) surface becomes completely faceted and covered with three-sided nanopyramids exposing (011̅1), (101̅1), and (112̅0) faces. Using the faceted C/Re(112̅1) surface as a template, we have successfully fabricated a nanostructured Pt monolayer (ML) electrocatalyst. The Pt ML supported on the C/Re nanotemplate exhibits higher activity for the hydrogen evolution reaction than Pt(111). This is the first application of faceted metal surfaces as templates for synthesis of nanoscale model electrocatalyst with well-defined (facet) surface structure and controlled (facet) size on the nanometer scale, illustrating the potential for future studies of nanostructured bimetallic systems relevant to electrocatalytic reactions.

  17. Trace detection of herbicides by SERS technique, using SERS-active substrates fabricated from different silver nanostructures deposited on silicon

    International Nuclear Information System (INIS)

    Dao, Tran Cao; Luong, Truc Quynh Ngan; Nguyen, Ngoc Hai; Kieu, Ngoc Minh; Luong, Thi Thuy; Cao, Tuan Anh; Le, Van Vu

    2015-01-01

    In this report we present the initial results of the use of different silver nanostructures deposited on silicon for trace detection of paraquat (a commonly used herbicide) using the surface-enhanced Raman scattering (SERS) effect. More specifically, the SERS-active substrates were fabricated from silver nanoparticles (AgNPs) deposited onto the flat surface of a silicon wafer (AgNPs@Si substrate), as well as on the surface of an obliquely aligned silicon nanowire (SiNW) array (AgNPs@SiNWs substrate), and from silver nanodendrites (AgNDs) deposited onto the flat surface of a silicon wafer (AgNDs@Si substrate). Results showed that with the change of the structure of the SERS-active substrate, higher levels of SERS enhancement have been achieved. Specifically, with the fabricated AgNDs@Si substrate, paraquat concentration as low as 1 ppm can be detected. (paper)

  18. Nanostructured Sn{sub 30}Co{sub 30}C{sub 40} alloys for lithium-ion battery negative electrodes prepared by horizontal roller milling

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, P.P. [Secteur des Sciences, Université de Moncton, campus de Shippagan, Shippagan, N.B. E8S 1P6 (Canada); Le, Dinh-Ba [3M Co., 3M Center, St. Paul, MN 55144-1000 (United States); Todd, A.D.W. [NRC Institute for National Measurements Standards, Ottawa, ON K1A 0R6 (Canada); Martine, M.L. [Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Institute for Complex Materials, Helmholtzstrasse 20, D-01069 Dresden (Germany); Trussler, S. [Dept. of Physics and Atmospheric Science, Dalhousie University, Halifax, N.S. B3H 3J5 (Canada); Obrovac, M.N. [Dept. of Chemistry, Dalhousie University, Halifax, N.S. B3H 4R2 (Canada); Dahn, J.R., E-mail: jeff.dahn@dal.ca [Dept. of Physics and Atmospheric Science, Dalhousie University, Halifax, N.S. B3H 3J5 (Canada); Dept. of Chemistry, Dalhousie University, Halifax, N.S. B3H 4R2 (Canada)

    2014-05-15

    Highlights: • Horizontal roller milling used to prepare nanostructured alloys for Li-ion batteries. • Sn{sub 30}Co{sub 30}C{sub 40} prepared by horizontal roller milling shows excellent properties. • Horizontal roller milling is an economical alternative to other methods. • Nanostructured Sn{sub 30}Co{sub 30}C{sub 40} by horizontal roller milling. - Abstract: Horizontal roller milling was used to prepare Sn{sub 30}Co{sub 30}C{sub 40} electrode materials. By varying the milling conditions, it was possible to obtain nanostructured materials whose X-ray diffraction patterns mimicked the diffraction pattern of the same material obtained by vertical-axis attritor milling or by co-sputtering. Electrochemical testing showed that composite electrodes made from each of the prepared materials showed stable charge–discharge capacity for at least 100 charge discharge cycles and displayed stable differential capacity versus potential profiles. Small angle neutron scattering results showed that samples prepared by roller milling and by attriting showed similar nanostructure with Co–Sn grains of about 60 Å in a carbon matrix.

  19. Carbon nanostructures obtained by underwater arc discharge of graphite electrodes: Synthesis and characterization

    International Nuclear Information System (INIS)

    Darias Gonzalez, J. G.; Hernandez Tabare, L.; Herrera Palma, V.; Sierra Trujillo, J. S.; Desdin Garcia, L. F.; Codorniu Pujals, D.; Bermudez Martinez, A.; Arias de Fuentes, O.; Maury Toledo, A.

    2015-01-01

    In the present work, the application of the method of underwater arc discharge of graphite electrodes for obtaining several carbon nano structures is described. The analysis of the obtained products by Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Raman spectroscopy, Atomic Force Microscopy (AFM) and X-Ray Diffraction (XRD) showed that the samples collected from the material floating on the water surface were composed mainly by polyhedral onion-like particles, while those taken from the precipitate were a mixture multi walled nano-tubes, onion-like particles and other graphitic structures. The main features of the obtained nano structures are discussed. (Author)

  20. Nanostructured 3D electrode architectures for high-rate Li-ion batteries.

    Science.gov (United States)

    Haag, Jacob M; Pattanaik, Gyanaranjan; Durstock, Michael F

    2013-06-18

    By initially depositing a sub-10 nm-thick SnO2 film, the microstructural evolution that is often considered problematic can be utilized to form Sn nanoparticles on the surface of a 3D current collector for enhanced cycling stability. The work described here highlights a novel approach for the uniform deposition of Sn nanoparticles, which can be used to design electrodes with high capacities and high-rate capabilities. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Nanostructured MnO2 as Electrode Materials for Energy Storage

    Directory of Open Access Journals (Sweden)

    Christian M. Julien

    2017-11-01

    Full Text Available Manganese dioxides, inorganic materials which have been used in industry for more than a century, now find great renewal of interest for storage and conversion of energy applications. In this review article, we report the properties of MnO2 nanomaterials with different morphologies. Techniques used for the synthesis, structural, physical properties, and electrochemical performances of periodic and aperiodic frameworks are discussed. The effect of the morphology of nanosized MnO2 particles on their fundamental features is evidenced. Applications as electrodes in lithium batteries and supercapacitors are examined.

  2. Multiwalled carbon nanotube coated polyester fabric as textile based flexible counter electrode for dye sensitized solar cell.

    Science.gov (United States)

    Arbab, Alvira Ayoub; Sun, Kyung Chul; Sahito, Iftikhar Ali; Qadir, Muhammad Bilal; Jeong, Sung Hoon

    2015-05-21

    Textile wearable electronics offers the combined advantages of both electronics and textile characteristics. The essential properties of these flexible electronics such as lightweight, stretchable, and wearable power sources are in strong demand. Here, we have developed a facile route to fabricate multi walled carbon nanotube (MWCNT) coated polyester fabric as a flexible counter electrode (CE) for dye sensitized solar cells (DSSCs). A variety of MWCNT and enzymes with different structures were used to generate individual enzyme-dispersed MWCNT (E-MWCNT) suspensions by non-covalent functionalization. A highly concentrated colloidal suspension of E-MWCNT was deposited on polyester fabric via a simple tape casting method using an air drying technique. In view of the E-MWCNT coating, the surface structure is represented by topologically randomly assembled tubular graphene units. This surface morphology has a high density of colloidal edge states and oxygen-containing surface groups which execute multiple catalytic sites for iodide reduction. A highly conductive E-MWCNT coated fabric electrode with a surface resistance of 15 Ω sq(-1) demonstrated 5.69% power conversion efficiency (PCE) when used as a flexible CE for DSSCs. High photo voltaic performance of our suggested system of E-MWCNT fabric-based DSSCs is associated with high sheet conductivity, low charge transfer resistance (RCT), and excellent electro catalytic activity (ECA). Such a conductive fabric demonstrated stable conductivity against bending cycles and strong mechanical adhesion of E-MWCNT on polyester fabric. Moreover, the polyester fabric is hydrophobic and, therefore, has good sealing capacity and retains the polymer gel electrolyte without seepage. This facile E-MWCNT fabric CE configuration provides a concrete fundamental background towards the development of textile-integrated solar cells.

  3. Fabrication of multi-electrode array platforms for neuronal interfacing with bi-layer lift-off resist sputter deposition

    International Nuclear Information System (INIS)

    Kim, Yong Hee; Kim, Gook Hwa; Baek, Nam Seob; Han, Young Hwan; Kim, Ah-Young; Chung, Myung-Ae; Jung, Sang-Don

    2013-01-01

    We report a bi-layer lift-off resist (LOR) technique in combination with sputter deposition of silicon dioxide (SiO 2 ) as a new passivation method in the fabrication of a multi-electrode array (MEA). Using the photo-insensitive LOR as a sacrificial bottom layer and the negative photoresist as a patterning top layer, and performing low-temperature sputter deposition of SiO 2 followed by lift-off, we could successfully fabricate damage-free indium-tin oxide (ITO) and Au MEA. The bi-layer LOR sputter deposition processed Au MEA showed an impedance value of 6 × 10 5 Ω (at 1 kHz), with good consistency over 60 electrodes. The passivation performance of the bi-layer LOR sputter-deposited SiO 2 was tested by electrodepositing Au nanoparticles (NPs) on the Au electrode, resulting in the well-confined and uniformly coated Au NPs. The bi-layer LOR sputter deposition processed ITO, Au, and Au NP-modified MEAs were evaluated and found to have a neuronal spike recording capability at a single unit level, confirming the validity of the bi-layer LOR sputter deposition as an effective passivation technique in fabrication of a MEA. These results suggest that the damage-free Au MEA fabricated with bi-layer LOR sputter deposition would be a viable platform for screening surface modification techniques that are available in neuronal interfacing. (technical note)

  4. Low-cost optical fabrication of flexible copper electrode via laser-induced reductive sintering and adhesive transfer

    Science.gov (United States)

    Back, Seunghyun; Kang, Bongchul

    2018-02-01

    Fabricating copper electrodes on heat-sensitive polymer films in air is highly challenging owing to the need of expensive copper nanoparticles, rapid oxidation of precursor during sintering, and limitation of sintering temperature to prevent the thermal damage of the polymer film. A laser-induced hybrid process of reductive sintering and adhesive transfer is demonstrated to cost-effectively fabricate copper electrode on a polyethylene film with a thermal resistance below 100 °C. A laser-induced reductive sintering process directly fabricates a high-conductive copper electrode onto a glass donor from copper oxide nanoparticle solution via photo-thermochemical reduction and agglomeration of copper oxide nanoparticles. The sintered copper patterns were transferred in parallel to a heat-sensitive polyethylene film through self-selective surface adhesion of the film, which was generated by the selective laser absorption of the copper pattern. The method reported here could become one of the most important manufacturing technologies for fabricating low-cost wearable and disposable electronics.

  5. Superhydrophilic nanostructure

    Science.gov (United States)

    Mao, Samuel S; Zormpa, Vasileia; Chen, Xiaobo

    2015-05-12

    An embodiment of a superhydrophilic nanostructure includes nanoparticles. The nanoparticles are formed into porous clusters. The porous clusters are formed into aggregate clusters. An embodiment of an article of manufacture includes the superhydrophilic nanostructure on a substrate. An embodiment of a method of fabricating a superhydrophilic nanostructure includes applying a solution that includes nanoparticles to a substrate. The substrate is heated to form aggregate clusters of porous clusters of the nanoparticles.

  6. Fabrication of novel GMO/Eudragit E100 nanostructures for enhancing oral bioavailability of carvedilol.

    Science.gov (United States)

    Patil, Sharvil S; Roy, Krishtey; Choudhary, Bhavana; Mahadik, Kakasaheb R

    2016-08-01

    In the present work, novel nanostructures comprising of glyceryl monooleate (GMO) and Eudragit E100 were prepared using high intensity ultrasonic homogenization. 3(2) Factorial design approach was used for optimization of nanostructures. Results of regression analysis revealed that the amount of GMO and Eudragit E100 had a drastic effect on particle size and percent entrapment efficiency. Optimized carvedilol-loaded nanostructures (Car-NS) were characterized by FTIR, TEM, DSC, in vitro drug release study. Pharmacokinetic parameters such as Cmax, Tmax, Ke, Ka, Vd and AUC were estimated for Car-NS upon its oral administration in Sprague-Dawley rats. Particle size of Car-NS was found to be 183 ± 2.43 nm with an entrapment efficiency of 81.4 ± 0.512%. FTIR studies revealed loading and chemical compatibility of carvedilol with the components of nanostructures. DSC thermograms did not show endothermic peak for melting of carvedilol which could be attributed to solubilization of carvedilol in molten GMO during DSC run. The prepared Car-NS released carvedilol in sustained manner over a period of 10 h as suggested by in vitro drug release study. The pharmacokinetic study of Car-NS showed significant improvement in Cmax (two fold, p GMO/Eudragit E100 nanostructures having ability to release the drug in sustained manner with enhanced oral bioavailability can prove to be a promising carrier system for poorly water soluble drugs.

  7. Nanostructured rough gold electrodes as platforms to enhance the sensitivity of electrochemical genosensors.

    Science.gov (United States)

    García-Mendiola, T; Gamero, M; Campuzano, S; Revenga-Parra, M; Alonso, C; Pedrero, M; Pariente, F; Pingarrón, J M; Lorenzo, E

    2013-07-25

    An electrochemical DNA genosensor constructed by using rough gold as electrode support is reported in this work. The electrode surface nanopatterning was accomplished by repetitive square-wave perturbing potential (RSWPP). A synthetic 25-mer DNA capture probe, modified at the 5' end with a hexaalkylthiol, able to hybridize with a specific sequence of lacZ gene from the Enterobacteriaceae bacterial family was assembled to the rough gold surface. A 25 bases synthetic sequence fully complementary to the thiolated DNA capture probe and a 326 bases fragment of lacZ containing a fully matched sequence with the capture probe, which was amplified by a specific asymmetric polymerase chain reaction (aPCR), were employed as target sequences. The hybridization event was electrochemically monitored by using two different indicators, hexaammineruthenium (III) chloride showing an electrostatic DNA binding mode, and pentaamineruthenium-[3-(2-phenanthren-9-yl-vinyl)-pyridine] (in brief RuL) which binds to double stranded DNA (dsDNA) following an intercalative mechanism. After optimization of the different variables involved in the hybridization and detection reactions, detection limits of 5.30 pg μL(-1) and 10 pg μL(-1) were obtained for the 25-mer synthetic target DNA and the aPCR amplicon, respectively. A RSD value of 6% was obtained for measurements carried out with 3 different genosensors prepared in the same manner. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Nanostructured Electrode Materials Derived from Metal-Organic Framework Xerogels for High-Energy-Density Asymmetric Supercapacitor.

    Science.gov (United States)

    Mahmood, Asif; Zou, Ruqiang; Wang, Qingfei; Xia, Wei; Tabassum, Hassina; Qiu, Bin; Zhao, Ruo

    2016-01-27

    This work successfully demonstrates metal-organic framework (MOF) derived strategy to prepare nanoporous carbon (NPC) with or without Fe3O4/Fe nanoparticles by the optimization of calcination temperature as highly active electrode materials for asymmetric supercapacitors (ASC). The nanostructured Fe3O4/Fe/C hybrid shows high specific capacitance of 600 F/g at a current density of 1 A/g and excellent capacitance retention up to 500 F/g at 8 A/g. Furthermore, hierarchically NPC with high surface area also obtained from MOF gels displays excellent electrochemical performance of 272 F/g at 2 mV/s. Considering practical applications, aqueous ASC (aASC) was also assembled, which shows high energy density of 17.496 Wh/kg at the power density of 388.8 W/kg. The high energy density and excellent capacity retention of the developed materials show great promise for the practical utilization of these energy storage devices.

  9. The electrocatalytic oxidation of carbohydrates at a nickel/carbon paper electrode fabricated by the filtered cathodic vacuum arc technique

    International Nuclear Information System (INIS)

    Fu, Yingyi; Wang, Tong; Su, Wen; Yu, Yanan; Hu, Jingbo

    2015-01-01

    The direct electrochemical behaviour of carbohydrates at a nickel/carbon paper electrode with a novel fabrication method is investigated. The investigation is used for verification the feasibility of using monosaccharides and disaccharides in the application of fuel cell. The selected monosaccharides are glucose, fructose and galactose; the disaccharides are sucrose, maltose and lactose. The modified nickel/carbon paper electrode was prepared using a filtered cathodic vacuum arc technique. The morphology image of the nickel thin film on the carbon paper surface was characterized by scanning electron microscopy (SEM). The existence of nickel was verified by X-ray photoelectron spectroscopy (XPS). The contact angle measurement was also used to characterize the modified electrode. Cyclic voltammetry (CV) was employed to evaluate the electrochemical behaviour of monosaccharides and disaccharides in an alkaline aqueous solution. The modified electrode exhibits good electrocatalytic activities towards carbohydrates. In addition, the stability of the nickel/carbon paper electrode with six sugars was also investigated. The good catalytic effects of the nickel/carbon paper electrode allow for the use of carbohydrates as fuels in fuel cell applications

  10. Polymer solution, fiber mat, and nanofiber membrane-electrode-assembly therewith, and method of fabricating same

    DEFF Research Database (Denmark)

    2016-01-01

    In one aspect of the present invention, a fiber mat is provided. The fiber mat includes at least one type of fibers, which includes one or more polymers. The fiber mat may be a single fiber mat which includes one type of fibers, or may be a dual or multi fiber mat which includes multiple types...... of fibers. The fibers may further include particles of a catalyst. The fiber mat may be used to form an electrode or a membrane. In a further aspect, a fuel cell membrane-electrode-assembly has an anode electrode, a cathode electrode, and a membrane disposed between the anode electrode and the cathode...... electrode. Each of the anode electrode, the cathode electrode and the membrane may be formed with a fiber mat....

  11. A top-down approach for fabricating three-dimensional closed hollow nanostructures with permeable thin metal walls

    Directory of Open Access Journals (Sweden)

    Carlos Angulo Barrios

    2017-06-01

    Full Text Available We report on a top-down method for the controlled fabrication of three-dimensional (3D, closed, thin-shelled, hollow nanostructures (nanocages on planar supports. The presented approach is based on conventional microelectronic fabrication processes and exploits the permeability of thin metal films to hollow-out polymer-filled metal nanocages through an oxygen-plasma process. The technique is used for fabricating arrays of cylindrical nanocages made of thin Al shells on silicon substrates. This hollow metal configuration features optical resonance as revealed by spectral reflectance measurements and numerical simulations. The fabricated nanocages were demonstrated as a refractometric sensor with a measured bulk sensitivity of 327 nm/refractive index unit (RIU. The pattern design flexibility and controllability offered by top-down nanofabrication techniques opens the door to the possibility of massive integration of these hollow 3D nano-objects on a chip for applications such as nanocontainers, nanoreactors, nanofluidics, nano-biosensors and photonic devices.

  12. Nanostructured Cu2O thin film electrodes prepared by electrodeposition for rechargeable lithium batteries

    International Nuclear Information System (INIS)

    Bijani, S.; Gabas, M.; Martinez, L.; Ramos-Barrado, J.R.; Morales, J.; Sanchez, L.

    2007-01-01

    Uniform films of Cu 2 O with thickness below 1 μm were prepared from a Cu(II) lactate solution. The deposits were compact and of high purity with the particle size varying from 60 to 400 nm. They were tested as electrodes in lithium batteries and their electrochemical response was consistent with the Cu 2 O + 2e - + 2Li + ↔ 2Cu + Li 2 O reaction. Nevertheless, the reversibility of this reaction was dependent on thickness. Kinetic factors associated with the poor electronic conductivity of Cu 2 O could account for the relevance of the influence of film thickness. The thinnest film, about 300 nm thick, exhibited the best electrochemical performance by sustaining a specific capacity as high as 350 Ah kg -1

  13. A comparative study of supercapacitive performances of nickel cobalt layered double hydroxides coated on ZnO nanostructured arrays on textile fibre as electrodes for wearable energy storage devices

    Science.gov (United States)

    Trang, Nguyen Thi Hong; Ngoc, Huynh Van; Lingappan, Niranjanmurthi; Kang, Dae Joon

    2014-01-01

    We demonstrated an efficient method for the fabrication of novel, flexible electrodes based on ZnO nanoflakes and nickel-cobalt layered double hydroxides (denoted as ZnONF/NiCoLDH) as a core-shell nanostructure on textile substrates for wearable energy storage devices. NiCoLDH coated ZnO nanowire (denoted as ZnONW/NiCoLDH) flexible electrodes are also prepared for comparison. As an electrode for supercapacitors, ZnONF/NiCoLDH exhibits a high specific capacitance of 1624 F g-1, which is nearly 1.6 times greater than ZnONW/NiCoLDH counterparts. It also shows a maximum energy density of 48.32 W h kg-1 at a power density of 27.53 kW kg-1, and an excellent cycling stability with capacitance retention of 94% and a Coulombic efficiency of 93% over 2000 cycles. We believe that the superior performance of the ZnONF/NiCoLDH hybrids is due primarily to the large surface area of the nanoflake structure and the open spaces between nanoflakes, both of which provide a large space for the deposition of NiCoLDH, resulting in reduced internal resistance and improved capacitance performance. Our results are significant for the development of electrode materials for high-performance wearable energy storage devices.We demonstrated an efficient method for the fabrication of novel, flexible electrodes based on ZnO nanoflakes and nickel-cobalt layered double hydroxides (denoted as ZnONF/NiCoLDH) as a core-shell nanostructure on textile substrates for wearable energy storage devices. NiCoLDH coated ZnO nanowire (denoted as ZnONW/NiCoLDH) flexible electrodes are also prepared for comparison. As an electrode for supercapacitors, ZnONF/NiCoLDH exhibits a high specific capacitance of 1624 F g-1, which is nearly 1.6 times greater than ZnONW/NiCoLDH counterparts. It also shows a maximum energy density of 48.32 W h kg-1 at a power density of 27.53 kW kg-1, and an excellent cycling stability with capacitance retention of 94% and a Coulombic efficiency of 93% over 2000 cycles. We believe that the

  14. Fabrication, characterization and electrocatalytic application of a lead dioxide electrode with porous titanium substrate

    International Nuclear Information System (INIS)

    Zhang, Wenli; Kong, Haishen; Lin, Haibo; Lu, Haiyan; Huang, Weimin; Yin, Jian; Lin, Zheqi; Bao, Jinpeng

    2015-01-01

    In this study, PbO 2 electrode was prepared on porous Ti/SnO 2 –Sb 2 O 5 substrate (denoted as 3D-Ti/PbO 2 electrode), and its electrochemical properties were investigated in detail. The electrodeposition mechanism of 3D-Ti/PbO 2 electrode was investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Scanning electron microscope (SEM) result showed that the 3D-Ti/PbO 2 electrode possessed porous structure when it was electrodeposited for time less than 30 min. The 3D-Ti/PbO 2 electrode prepared for 10 min had more active sites than the lead dioxide electrode electrodeposited on planar titanium substrate (denoted as 2D-Ti/PbO 2 electrode) and its electrochemical porosity is about 54%. The embedded structure between porous Ti/SnO 2 –Sb 2 O 5 substrate and PbO 2 coating increased the stability of 3D-Ti/PbO 2 electrode. The service life of 3D-Ti/PbO 2 electrode was about 350 h which was much longer than 2D-Ti/PbO 2 electrode. What's more, 3D-Ti/PbO 2 electrode had better electrocatalytic activity towards phenol degradation than 2D-Ti/PbO 2 electrode. - Highlights: • 3D-Ti/PbO 2 electrode was prepared on a porous titanium substrate. • The electrochemical active surface area was investigated. • The activity of 3D-Ti/PbO 2 electrode towards phenol oxidation was investigated. • 3D-Ti/PbO 2 electrode shows superior electrocatalytic activity.

  15. Fabrication of ferroelectric polymer nanostructures on flexible substrates by soft-mold reverse nanoimprint lithography

    International Nuclear Information System (INIS)

    Song, Jingfeng; Lu, Haidong; Gruverman, Alexei; Ducharme, Stephen; Li, Shumin; Tan, Li

    2016-01-01

    Conventional nanoimprint lithography with expensive rigid molds is used to pattern ferroelectric polymer nanostructures on hard substrate for use in, e.g., organic electronics. The main innovation here is the use of inexpensive soft polycarbonate molds derived from recordable DVDs and reverse nanoimprint lithography at low pressure, which is compatible with flexible substrates. This approach was implemented to produce regular stripe arrays with a spacing of 700 nm from vinylidene fluoride co trifluoroethylene ferroelectric copolymer on flexible polyethylene terephthalate substrates. The nanostructures have very stable and switchable piezoelectric response and good crystallinity, and are highly promising for use in organic electronics enhanced or complemented by the unique properties of the ferroelectric polymer, such as bistable polarization, piezoelectric response, pyroelectric response, or electrocaloric function. The soft-mold reverse nanoimprint lithography also leaves little or no residual layer, affording good isolation of the nanostructures. This approach reduces the cost and facilitates large-area, high-throughput production of isolated functional polymer nanostructures on flexible substrates for the increasing application of ferroelectric polymers in flexible electronics. (paper)

  16. Influence of fabrication procedure on the electrochemical performance of Ag/AgCl reference electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Stoica, Daniela [Department of Biomedical and Inorganic Chemistry, Laboratoire National de Metrologie et d' Essais, 1 Rue Gaston Boissier, 75015 Paris (France); Brewer, Paul J., E-mail: paul.brewer@npl.co.uk [Analytical Science Division, National Physical Laboratory, Teddington, Middlesex TW11 0LW (United Kingdom); Brown, Richard J.C. [Analytical Science Division, National Physical Laboratory, Teddington, Middlesex TW11 0LW (United Kingdom); Fisicaro, Paola [Department of Biomedical and Inorganic Chemistry, Laboratoire National de Metrologie et d' Essais, 1 Rue Gaston Boissier, 75015 Paris (France)

    2011-11-30

    The influence of several parameters in the preparation procedure of thermal-electrolytic Ag/AgCl electrodes on the resulting electrode performance has been studied. In particular, we report the effect on electrode performance of subtle variations in the preparation of silver oxide paste used for electrode manufacture, in thermal annealing conditions employed and in the procedure for electrochemically converting a fraction of the electrode from silver to silver chloride. Scanning electron microscopy and electrochemical impedance spectroscopy have been used to study the characteristics of the electrodes produced. This work reveals a correlation between the electrochemical behaviour and surface physical characteristics - in particular electrode porosity. The outputs of this study have positive implications for improving the accuracy and comparability of primary pH measurement.

  17. Plasma assisted fabrication of multi-layer graphene/nickel hybrid film as enhanced micro-supercapacitor electrodes

    Science.gov (United States)

    Ding, Q.; Li, W. L.; Zhao, W. L.; Wang, J. Y.; Xing, Y. P.; Li, X.; Xue, T.; Qi, W.; Zhang, K. L.; Yang, Z. C.; Zhao, J. S.

    2017-03-01

    A facile synthesis strategy has been developed for fabricating multi-layer graphene/nickel hybrid film as micro-supercapacitor electrodes by using plasma enhanced chemical vapor deposition. The as-presented method is advantageous for rapid graphene growth at relatively low temperature of 650 °C. In addition, after pre-treating for the as-deposited nickel film by using argon plasma bombardment, the surface-to-volume ratio of graphene film on the treated nickel substrate is effectively increased by the increasing of surface roughness. This is demonstrated by the characterization results from transmission electron microscopy, scanning electron microscope and atomic force microscopy. Moreover, the electrochemical performance of the resultant graphene/nickel hybrid film as micro-supercapacitor working electrode was investigated by cyclic voltammetry and galvanostatic charge/discharge measurements. It was found that the increase of the surface-to-volume ratio of graphene/nickel hybrid film improved the specific capacitance of 10 times as the working electrode of micro-supercapacitor. Finally, by using comb columnar shadow mask pattern, the micro-supercapacitor full cell device was fabricated. The electrochemical performance measurements of the micro-supercapacitor devices indicate that the method presented in this study provides an effective way to fabricate micro-supercapacitor device with enhanced energy storage property.

  18. Application of Turkevich Method for Gold Nanoparticles Synthesis to Fabrication of SiO2@Au and TiO2@Au Core-Shell Nanostructures

    Science.gov (United States)

    Dobrowolska, Paulina; Krajewska, Aleksandra; Gajda-Rączka, Magdalena; Bartosewicz, Bartosz; Nyga, Piotr; Jankiewicz, Bartłomiej J.

    2015-01-01

    The Turkevich synthesis method of Au nanoparticles (AuNPs) was adopted for direct fabrication of SiO2@Au and TiO2@Au core-shell nanostructures. In this method, chloroauric acid was reduced with trisodium citrate in the presence of amine-functionalized silica or titania submicroparticles. Core-shells obtained in this way were compared to structures fabricated by mixing of Turkevich AuNPs with amine-functionalized silica or titania submicroparticles. It was found that by modification of reaction conditions of the first method, such as temperature and concentration of reagents, control over gold coverage on silicon dioxide particles has been achieved. Described method under certain conditions allows fabrication of semicontinuous gold films on the surface of silicon dioxide particles. To the best of our knowledge, this is the first report describing use of Turkevich method to direct fabrication of TiO2@Au core-shell nanostructures.

  19. Carbon nanostructures reduced from graphite oxide as electrode materials for supercapacitors

    Directory of Open Access Journals (Sweden)

    Yurii M. Shulga

    2015-03-01

    Full Text Available In this review we present information about obtaining and properties of carbon nanomaterials (graphite oxide, grapheme oxide, reduced graphene oxide, which are used as electrodes for supercapacitors (SC. This review describes methods of obtaining graphite oxide, followed by separation of graphene oxide and reducing graphene oxide by thermal, photochemical and chemical methods. Information on the composition and concentration of functional groups in graphene oxide and the elemental composition is described in detail. Results of the analysis of еру physical, electrochemical, thermal and optical properties of the graphene oxide and its derivatives are shown. The ratio of oxygen-containing functional groups was estimated by XPS. The presence of partial surface reduction is found. Hydroge-containing functional groups are characterized by IR spectroscopy. Method of estimating the size of graphene crystallites by Raman spectroscopy is shown. Mass loss upon heating is analyzed by thermogravimetry. The gassing of graphene oxide at thermal and photochemical reduction is studied by mass spectrometry. The difference between the abovementioned reduction methods is clearly demonstrated by the difference in the composition of the evolved gases. Also the chemical method of graphene oxide reduction with hydrazine is described. Review considers the literature data which illustrate the most interesting, from the Authors׳ point of view, aspects of that field of research.

  20. Parallel oxygen and chlorine evolution on Ru1-xNixO2-y nanostructured electrodes

    International Nuclear Information System (INIS)

    Macounova, Katerina; Makarova, Marina; Jirkovsky, Jakub; Franc, Jiri; Krtil, Petr

    2008-01-01

    Nanocrystalline materials with chemical composition corresponding to formula Ru 1-x Ni x O 2-y (0.02 1-x Ni x O 2-y with respect to parallel oxygen (oxygen evolution reaction, OER) and chlorine (chlorine evolution reaction, CER) evolution in acidic media was studied by voltammetry combined with differential electrochemical mass spectrometry (DEMS). The DEMS data indicate a significant decrease of the over-voltage for chlorine evolution with respect to that of pure RuO 2 . The oxygen evolution is slightly hindered. The increasing Ni content affects the electrode material activity and selectivity. The overall material's activity increases with increasing Ni content. The activity of the Ru-Ni-O oxides towards Cl 2 evolution shows a distinguished maximum for material containing 10% of Ni. Further increase of Ni content results in suppression of Cl 2 evolution in favor of O 2 evolution. A model reflecting the cation-cation interactions resulting from Ni-doping is proposed to explain the observed trends in electrocatalytic behavior

  1. Performance Enhancement and Side Reactions in Rechargeable Nickel-Iron Batteries with Nanostructured Electrodes.

    Science.gov (United States)

    Lei, Danni; Lee, Dong-Chan; Magasinski, Alexandre; Zhao, Enbo; Steingart, Daniel; Yushin, Gleb

    2016-01-27

    We report for the first time a solution-based synthesis of strongly coupled nanoFe/multiwalled carbon nanotube (MWCNT) and nanoNiO/MWCNT nanocomposite materials for use as anodes and cathodes in rechargeable alkaline Ni-Fe batteries. The produced aqueous batteries demonstrate very high discharge capacities (800 mAh gFe(-1) at 200 mA g(-1) current density), which exceed that of commercial Ni-Fe cells by nearly 1 order of magnitude at comparable current densities. These cells also showed the lack of any "activation", typical in commercial batteries, where low initial capacity slowly increases during the initial 20-50 cycles. The use of a highly conductive MWCNT network allows for high-capacity utilization because of rapid and efficient electron transport to active metal nanoparticles in oxidized [such as Fe(OH)2 or Fe3O4] states. The flexible nature of MWCNTs accommodates significant volume changes taking place during phase transformation accompanying reduction-oxidation reactions in metal electrodes. At the same time, we report and discuss that high surface areas of active nanoparticles lead to multiple side reactions. Dissolution of Fe anodes leads to reprecipitation of significantly larger anode particles. Dissolution of Ni cathodes leads to precipitation of Ni metal on the anode, thus blocking transport of OH(-) anions. The electrolyte molarity and composition have a significant impact on the capacity utilization and cycling stability.

  2. Development of Amperometric Biosensors Based on Nanostructured Tyrosinase-Conducting Polymer Composite Electrodes

    Directory of Open Access Journals (Sweden)

    Francisco Javier del Campo

    2013-05-01

    Full Text Available Bio-composite coatings consisting of poly(3,4-ethylenedioxythiophene (PEDOT and tyrosinase (Ty were successfully electrodeposited on conventional size gold (Au disk electrodes and microelectrode arrays using sinusoidal voltages. Electrochemical polymerization of the corresponding monomer was carried out in the presence of various Ty amounts in aqueous buffered solutions. The bio-composite coatings prepared using sinusoidal voltages and potentiostatic electrodeposition methods were compared in terms of morphology, electrochemical properties, and biocatalytic activity towards various analytes. The amperometric biosensors were tested in dopamine (DA and catechol (CT electroanalysis in aqueous buffered solutions. The analytical performance of the developed biosensors was investigated in terms of linear response range, detection limit, sensitivity, and repeatability. A semi-quantitative multi-analyte procedure for simultaneous determination of DA and CT was developed. The amperometric biosensor prepared using sinusoidal voltages showed much better analytical performance. The Au disk biosensor obtained by 50 mV alternating voltage amplitude displayed a linear response for DA concentrations ranging from 10 to 300 μM, with a detection limit of 4.18 μM.

  3. Atomic layer deposition of absorbing thin films on nanostructured electrodes for short-wavelength infrared photosensing

    International Nuclear Information System (INIS)

    Xu, Jixian; Sutherland, Brandon R.; Hoogland, Sjoerd; Fan, Fengjia; Sargent, Edward H.; Kinge, Sachin

    2015-01-01

    Atomic layer deposition (ALD), prized for its high-quality thin-film formation in the absence of high temperature or high vacuum, has become an industry standard for the large-area deposition of a wide array of oxide materials. Recently, it has shown promise in the formation of nanocrystalline sulfide films. Here, we demonstrate the viability of ALD lead sulfide for photodetection. Leveraging the conformal capabilities of ALD, we enhance the absorption without compromising the extraction efficiency in the absorbing layer by utilizing a ZnO nanowire electrode. The nanowires are first coated with a thin shunt-preventing TiO 2 layer, followed by an infrared-active ALD PbS layer for photosensing. The ALD PbS photodetector exhibits a peak responsivity of 10 −2  A W −1 and a shot-derived specific detectivity of 3 × 10 9  Jones at 1530 nm wavelength

  4. Fabrication of gallium hexacyanoferrate modified carbon ionic liquid paste electrode for sensitive determination of hydrogen peroxide and glucose.

    Science.gov (United States)

    Haghighi, Behzad; Khosravi, Mehdi; Barati, Ali

    2014-07-01

    Gallium hexacyanoferrate (GaHCFe) and graphite powder were homogeneously dispersed into n-dodecylpyridinium hexafluorophosphate and paraffin to fabricate GaHCFe modified carbon ionic liquid paste electrode (CILPE). Mixture experimental design was employed to optimize the fabrication of GaHCFe modified CILPE (GaHCFe-CILPE). A pair of well-defined redox peaks due to the redox reaction of GaHCFe through one-electron process was observed for the fabricated electrode. The fabricated GaHCFe-CILPE exhibited good electrocatalytic activity towards reduction and oxidation of H2O2. The observed sensitivities for the electrocatalytic oxidation and reduction of H2O2 at the operating potentials of +0.8 and -0.2V were about 13.8 and 18.3 mA M(-1), respectively. The detection limit (S/N=3) for H2O2 was about 1 μM. Additionally, glucose oxidase (GOx) was immobilized on GaHCFe-CILPE using two methodology, entrapment into Nafion matrix and cross-linking with glutaraldehyde and bovine serum albumin, in order to fabricate glucose biosensor. Linear dynamic rage, sensitivity and detection limit for glucose obtained by the biosensor fabricated using cross-linking methodology were 0.1-6mM, 0.87 mA M(-1) and 30 μM, respectively and better than those obtained (0.2-6mM, 0.12 mA M(-1) and 50 μM) for the biosensor fabricated using entrapment methodology. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Fabrication and in-situ STM investigation of growth dynamics of semiconductor nanostructures grown by MBE

    Energy Technology Data Exchange (ETDEWEB)

    Borisova, Svetlana

    2012-05-23

    Modern development of information technologies requires an introduction of new fundamental concepts, in order to create more efficient devices and to decrease their size. One of the most promising ways is to increase the functionality of silicon by integrating novel materials into Si-based production. This PhD thesis reports on the fabrication and investigation of the growth of semiconductor nanostructures on Si substrates by molecular beam epitaxy (MBE). In-situ scanning tunneling microscopy (STM) is a powerful technique in order to study morphological and electronic properties of the grown structures directly under ultra high vacuum (UHV) conditions. It is shown that the combination of MBE and in-situ STM enables the study of nucleation and growth dynamics at the atomic scale. It provides us with numerous information concerning the nucleation mechanism, the growth mode of the structures, adatom kinetics, influence of the lattice mismatch between the substrate and the grown structure as well as formation and morphology of crystal defects. The first part of the thesis focuses on the experimental realization based upon an existing setup. The construction of an in-situ UHV STM compatible with the MBE cluster and the technical improvement of the STM setup are described. Subsequently, test measurements are performed on the technologically most important surfaces, Ge (100) and Si (111). The second part of the thesis is dedicated to ordered small-period arrays of self-assembled Ge quantum dots (QDs) grown on pre-patterned Si (100) substrates. Small-period Ge QD crystals are highly interesting since band structure calculations indicate coupled electronic states of the QDs in the case of the small lateral period of approximately 30 nm. Small-period hole patterns with a period of 56 nm are fabricated by e-beam lithography on Si substrates. The evolution of the hole morphology during the in-situ pre-growth annealing and the Si buffer layer growth are studied. Deposition of 5

  6. Fabrication and in-situ STM investigation of growth dynamics of semiconductor nanostructures grown by MBE

    International Nuclear Information System (INIS)

    Borisova, Svetlana

    2012-01-01

    Modern development of information technologies requires an introduction of new fundamental concepts, in order to create more efficient devices and to decrease their size. One of the most promising ways is to increase the functionality of silicon by integrating novel materials into Si-based production. This PhD thesis reports on the fabrication and investigation of the growth of semiconductor nanostructures on Si substrates by molecular beam epitaxy (MBE). In-situ scanning tunneling microscopy (STM) is a powerful technique in order to study morphological and electronic properties of the grown structures directly under ultra high vacuum (UHV) conditions. It is shown that the combination of MBE and in-situ STM enables the study of nucleation and growth dynamics at the atomic scale. It provides us with numerous information concerning the nucleation mechanism, the growth mode of the structures, adatom kinetics, influence of the lattice mismatch between the substrate and the grown structure as well as formation and morphology of crystal defects. The first part of the thesis focuses on the experimental realization based upon an existing setup. The construction of an in-situ UHV STM compatible with the MBE cluster and the technical improvement of the STM setup are described. Subsequently, test measurements are performed on the technologically most important surfaces, Ge (100) and Si (111). The second part of the thesis is dedicated to ordered small-period arrays of self-assembled Ge quantum dots (QDs) grown on pre-patterned Si (100) substrates. Small-period Ge QD crystals are highly interesting since band structure calculations indicate coupled electronic states of the QDs in the case of the small lateral period of approximately 30 nm. Small-period hole patterns with a period of 56 nm are fabricated by e-beam lithography on Si substrates. The evolution of the hole morphology during the in-situ pre-growth annealing and the Si buffer layer growth are studied. Deposition of 5

  7. Electrochemical treatment of domestic wastewater using boron-doped diamond and nanostructured amorphous carbon electrodes.

    Science.gov (United States)

    Daghrir, Rimeh; Drogui, Patrick; Tshibangu, Joel; Delegan, Nazar; El Khakani, My Ali

    2014-05-01

    The performance of the electrochemical oxidation process for efficient treatment of domestic wastewater loaded with organic matter was studied. The process was firstly evaluated in terms of its capability of producing an oxidant agent (H2O2) using amorphous carbon (or carbon felt) as cathode, whereas Ti/BDD electrode was used as anode. Relatively high concentrations of H2O2 (0.064 mM) was produced after 90 min of electrolysis time, at 4.0 A of current intensity and using amorphous carbon at the cathode. Factorial design and central composite design methodologies were successively used to define the optimal operating conditions to reach maximum removal of chemical oxygen demand (COD) and color. Current intensity and electrolysis time were found to influence the removal of COD and color. The contribution of current intensity on the removal of COD and color was around 59.1 and 58.8%, respectively, whereas the contribution of treatment time on the removal of COD and color was around 23.2 and 22.9%, respectively. The electrochemical treatment applied under 3.0 A of current intensity, during 120 min of electrolysis time and using Ti/BDD as anode, was found to be the optimal operating condition in terms of cost/effectiveness. Under these optimal conditions, the average removal rates of COD and color were 78.9 ± 2 and 85.5 ± 2 %, whereas 70% of total organic carbon removal was achieved.

  8. ZnS nanoparticles electrodeposited onto ITO electrode as a platform for fabrication of enzyme-based biosensors of glucose

    International Nuclear Information System (INIS)

    Du, Jian; Yu, Xiuping; Wu, Ying; Di, Junwei

    2013-01-01

    The electrochemical and photoelectrochemical biosensors based on glucose oxidase (GOD) and ZnS nanoparticles modified indium tin oxide (ITO) electrode were investigated. The ZnS nanoparticles were electrodeposited directly on the surface of ITO electrode. The enzyme was immobilized on ZnS/ITO electrode surface by sol–gel method to fabricate glucose biosensor. GOD could electrocatalyze the reduction of dissolved oxygen, which resulted in a great increase of the reduction peak current. The reduction peak current decreased linearly with the addition of glucose, which could be used for glucose detection. Moreover, ZnS nanoparticles deposited on ITO electrode surface showed good photocurrent response under illumination. A photoelectrochemical biosensor for the detection of glucose was also developed by monitoring the decreases in the cathodic peak photocurrent. The results indicated that ZnS nanoparticles deposited on ITO substrate were a good candidate material for the immobilization of enzyme in glucose biosensor construction. - Highlights: ► ZnS nanoparticles were electrodeposited directly on ITO surface. ► The direct electron transfer of GOD immobilized on ZnS surface was obtained. ► The enzyme electrode was used to the determination of glucose in the presence of oxygen. ► The response of photoelectrochemical biosensor towards glucose was more sensitive

  9. Design, Fabrication, and Characterization of Hematite (α-Fe2O3) Nanostructures

    Science.gov (United States)

    Jansi Rani, B.; Mageswari, R.; Ravi, G.; Ganesh, V.; Yuvakkumar, R.

    2017-12-01

    The influence of processing parameters on the physicochemical properties of hematite α-Fe2O3 nanostructures was investigated. X-ray diffraction results revealed the hematite phase rhombohedral structure. Scanning electron microscope results explored nanospheres, nanohexagonal platelets, nanoellipsoids, distorted nanocubes, and interconnected platelets nanostructures. Rhombohedral single-phase hematite was confirmed through five Raman active modes. 2 P 3/2 (1) → 2 P 1/2 transition in photoluminescence spectra and Fourier-transform infrared spectroscopy band observed at 555 cm-1 revealed the hematite formation. The highest specific capacitance value of 151.09 F/g for scan rate of 10 mV/s was obtained for the hydrothermal-assisted product using an Fe(NO3)2·9H2O precursor in KOH electrolyte solutions.

  10. Fabrication of Cu-induced networks of linear nanostructures on different length scales

    International Nuclear Information System (INIS)

    Adelung, R.; Hartung, W.; Ernst, F.

    2002-01-01

    Scanning electron microscopy and atomic force microscopy revealed that the deposition Cu onto VSe 2 substrates in ultra-high vacuum leads to the self-organized formation of linear nanostructures, nanowires and nanotunnels, on the substrate surface. The nanowires and nanotunnels are approximately equi-axed and form networks with a mesh width much larger than their diameter. Surprisingly, systematic increase of the Cu coverage studied here does not simply increase the thickness of the nanowires and nanotunnels, but induces the formation of further, distinct networks with increased feature size and increased mesh width. At very high Cu coverages, eventually, we obtained a hierarchy of apparently independent nanowire and nanotunnel networks on different length scales. A model is presented for the micromechanism that leads to this complex arrangement of nanostructures

  11. Facile and green fabrication of organic single-crystal hollow micro/nanostructures.

    Science.gov (United States)

    Yang, Jun; Chen, Yingzhi; Zhang, Xiujuan; Ou, Xuemei; Zhang, Xiaohong

    2011-07-15

    Under high humidity and appropriate temperature, tris (8-hydroxyquinoline) aluminum (Alq3) solid micro/nanostructures may be etched into hollow structures and still retain their crystalline structures and surface morphologies. The shapes and sizes of the hollow structures are easily adjusted by varying the experimental parameters. Throughout the entire process, water is introduced into the system instead of organic or corrosive solvents, making this method convenient and environmentally friendly; it can also be extended to application in other materials such as TCNQ.

  12. Corundum nanostructure ITO film fabrication: An approach for physical properties assessment

    International Nuclear Information System (INIS)

    Solieman, A.; Zayed, M.K.; Alamri, S.N.; Al-Dahoudi, N.; Aegerter, M.A.

    2012-01-01

    Highlights: ► Transparent conductive nanostructured ITO films. ► Synthesis of ITO nanoparticles with corundum structure phase by the hydrothermal process. ► Deposition of nanoparticulate ITO films by spin coating technique. ► Curing of ITO films using UV irradiation at low temperatures. - Abstract: Corundum (hexagonal) structure indium tin oxide (h-ITO) nanocrystals have been synthesized by subjecting an aqueous solution of In and Sn chlorides (Sn/In 8 wt.%) to a hydrothermal process followed by annealing at 450 °C in forming gas for 1 h. The annealing temperature was selected based on thermo-gravimetric analysis (TGA) and differential thermal analysis (DTA) of the dried precipitated powder, which showed a stable weight and phase at temperatures above 420 °C. X-ray diffraction (XRD) patterns showed the formation of orthorhombic InOOH precipitates that is transformed, after annealing, into h-ITO nanocrystals with 32 nm average crystal size. For nanostructure film deposition, dispersed sols of the prepared nanocrystals were spun coated on glass substrates. The films were densified by UV irradiation, whilst four-probe method was used to measure its sheet resistance. A sheet resistance as low as 10.6 kΩ □ have been reached. Scanning electron microscope (SEM) and high resolution transmission electron microscope (HRTEM) showed that the films have high surface roughness and nanopores. The transmittance spectra of the nanostructure films were measured in the UV–vis–NIR wavelength range. In addition to its low resistivity, nanostructure h-ITO films showed a wide range of transparency.

  13. Corundum nanostructure ITO film fabrication: An approach for physical properties assessment

    Energy Technology Data Exchange (ETDEWEB)

    Solieman, A., E-mail: soliemanahmed@yahoo.com [Physics Department, Faculty of Science, Taibah University, PO Box 344, Madina (Saudi Arabia); Zayed, M.K.; Alamri, S.N. [Physics Department, Faculty of Science, Taibah University, PO Box 344, Madina (Saudi Arabia); Al-Dahoudi, N. [INM - Leibniz-Institut fuer Neue Materialien GmbH, Saarbruecken (Germany); Physics Department- Al Azhar University-Gaza, Gaza strip, Palestine (Country Unknown); Aegerter, M.A. [INM - Leibniz-Institut fuer Neue Materialien GmbH, Saarbruecken (Germany)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Transparent conductive nanostructured ITO films. Black-Right-Pointing-Pointer Synthesis of ITO nanoparticles with corundum structure phase by the hydrothermal process. Black-Right-Pointing-Pointer Deposition of nanoparticulate ITO films by spin coating technique. Black-Right-Pointing-Pointer Curing of ITO films using UV irradiation at low temperatures. - Abstract: Corundum (hexagonal) structure indium tin oxide (h-ITO) nanocrystals have been synthesized by subjecting an aqueous solution of In and Sn chlorides (Sn/In 8 wt.%) to a hydrothermal process followed by annealing at 450 Degree-Sign C in forming gas for 1 h. The annealing temperature was selected based on thermo-gravimetric analysis (TGA) and differential thermal analysis (DTA) of the dried precipitated powder, which showed a stable weight and phase at temperatures above 420 Degree-Sign C. X-ray diffraction (XRD) patterns showed the formation of orthorhombic InOOH precipitates that is transformed, after annealing, into h-ITO nanocrystals with 32 nm average crystal size. For nanostructure film deposition, dispersed sols of the prepared nanocrystals were spun coated on glass substrates. The films were densified by UV irradiation, whilst four-probe method was used to measure its sheet resistance. A sheet resistance as low as 10.6 k{Omega} {open_square} have been reached. Scanning electron microscope (SEM) and high resolution transmission electron microscope (HRTEM) showed that the films have high surface roughness and nanopores. The transmittance spectra of the nanostructure films were measured in the UV-vis-NIR wavelength range. In addition to its low resistivity, nanostructure h-ITO films showed a wide range of transparency.

  14. Fabrication of TiO2 nanostructures on porous silicon for thermoelectric application

    Science.gov (United States)

    Fahrizal, F. N.; Ahmad, M. K.; Ramli, N. M.; Ahmad, N.; Fakhriah, R.; Mohamad, F.; Nafarizal, N.; Soon, C. F.; Ameruddin, A. S.; Faridah, A. B.; Shimomura, M.; Murakami, K.

    2017-09-01

    Nowadays, technology is moving by leaps and bounds over the last several decades. This has created new opportunities and challenge in the research fields. In this study, the experiment is about to investigate the potential of Titanium Dioxide (TiO2) nanostructures that have been growth onto a layer of porous silicon (pSi) for their thermoelectric application. Basically, it is divided into two parts, which is the preparation of the porous silicon (pSi) substrate by electrochemical-etching process and the growth of the Titanium Dioxide (TiO2) nanostructures by hydrothermal method. This sample have been characterize by Field Emission Scanning Electron Microscopy (FESEM) to visualize the morphology of the TiO2 nanostructures area that formed onto the porous silicon (pSi) substrate. Besides, the sample is also used to visualize their cross-section images under the FESEM microscopy. Next, the sample is characterized by the X-Ray Diffraction (XRD) machine. The XRD machine is used to get the information about the chemical composition, crystallographic structure and physical properties of materials.

  15. ZnO nanostructure fabrication in different solvents transforms physio-chemical, biological and photodegradable properties.

    Science.gov (United States)

    Ali, Attarad; Ambreen, Sidra; Javed, Rabia; Tabassum, Saira; Ul Haq, Ihsan; Zia, Muhammad

    2017-05-01

    Zinc oxide (ZnO) nanostructures are synthesized in various organic solvents (acetone, chloroform, ethyl acetate, ethanol and methanol) and water via coprecipitation process using zinc acetate as precursor. The resultant ZnO nanoparticles, nano rods and nano sheets are characterized by UV-vis spectrophotometric analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transmission infrared spectroscopy (FTIR), and energy dispersive X-ray spectroscopy (EDX). The variable size and geometry of nanoparticles depend upon medium used for synthesis. The synthesized ZnO nanostructures exhibit minor to moderate antioxidative (DPPH based free radical scavenging activity, total antioxidative potential and total reducing power) response. Mild to moderate antibacterial and antifungal activities, excellent antileishmanial potential (IC50 up to 3.76), and good cytotoxic perspective (LD50 up to 49.4) is also observed by the synthesized ZnO NPs. The nanoparticles also exhibit moderate α-amylase inhibition response. Furthermore the nanostructures are evaluated for methylene blue photodegradation response within 60min time period. It is found that organic solvent alters shape, size and other physio-chemical properties of ZnO that ultimately modulate the biological, chemical, and environmental properties. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Fabrication and electrochemical behavior of single-walled carbon nanotube/graphite-based electrode

    International Nuclear Information System (INIS)

    Moghaddam, Abdolmajid Bayandori; Ganjali, Mohammad Reza; Dinarvand, Rassoul; Razavi, Taherehsadat; Riahi, Siavash; Rezaei-Zarchi, Saeed; Norouzi, Parviz

    2009-01-01

    An electrochemical method for determining the dihydroxybenzene derivatives on glassy carbon (GC) has been developed. In this method, the performance of a single-walled carbon nanotube (SWCNT)/graphite-based electrode, prepared by mixing SWCNTs and graphite powder, was described. The resulting electrode shows an excellent behavior for redox of 3,4-dihydroxybenzoic acid (DBA). SWCNT/graphite-based electrode presents a significant decrease in the overvoltage for DBA oxidation as well as a dramatic improvement in the reversibility of DBA redox behavior in comparison with graphite-based and glassy carbon (GC) electrodes. In addition, scanning electron microscopy (SEM) and atomic force microscopy (AFM) procedures performed for used SWCNTs

  17. Nanostructured titanium–silver coatings with good antibacterial activity and cytocompatibility fabricated by one-step magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Long [Research Institute of Surface Engineering, Taiyuan University of Technology, Taiyuan (China); Hang, Ruiqiang, E-mail: hangruiqiang@tyut.edu.cn [Research Institute of Surface Engineering, Taiyuan University of Technology, Taiyuan (China); Gao, Ang [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Zhang, Xiangyu; Huang, Xiaobo; Wang, Yueyue; Tang, Bin [Research Institute of Surface Engineering, Taiyuan University of Technology, Taiyuan (China); Zhao, Lingzhou, E-mail: zhaolingzhou1983@hotmail.com [State Key Laboratory of Military Stomatology, Department of Periodontology, School of Stomatology, The Fourth Military Medical University, Xi’an (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

    2015-11-15

    Graphical abstract: - Highlights: • We fabricate Ti–Ag coatings with different Ag contents and surface morphologies. • The Ti–Ag coatings possess long-term antibacterial ability. • Increased Ag contents in the coatings leads to enhanced osteoblast functions. - Abstract: Bacterial infection and loosing are serious complications for biomedical implants in the orthopedic, dental, and other biomedical fields and the ideal implants should combine good antibacterial ability and bioactivity. In this study, nanostructured titanium–silver (Ti–Ag) coatings with different Ag contents (1.2 to 21.6 at%) are prepared on Ti substrates by magnetron sputtering. As the Ag concentration is increased, the coatings change from having dense columnar crystals to sparse ones and eventually no columnar structure. The Ti–Ag coatings can effectively kill Staphylococcus aureus during the first few days and remain moderately antibacterial after immersion for 75 days. Compared to pure Ti, the Ti–Ag coatings show good cytocompatibility as indicated by good osteoblast adhesion, proliferation, intracellular total protein synthesis, and alkaline phosphatase (ALP) activity. In addition, cell spreading, collagen secretion, and extracellular matrix mineralization are promoted on the coatings with the proper Ag contents due to the nanostructured morphological features. Our results indicate that favorable antibacterial activity and osseointegration ability can be simultaneously achieved by regulating the Ag contents in Ti–Ag coatings.

  18. Nanostructured titanium–silver coatings with good antibacterial activity and cytocompatibility fabricated by one-step magnetron sputtering

    International Nuclear Information System (INIS)

    Bai, Long; Hang, Ruiqiang; Gao, Ang; Zhang, Xiangyu; Huang, Xiaobo; Wang, Yueyue; Tang, Bin; Zhao, Lingzhou; Chu, Paul K.

    2015-01-01

    Graphical abstract: - Highlights: • We fabricate Ti–Ag coatings with different Ag contents and surface morphologies. • The Ti–Ag coatings possess long-term antibacterial ability. • Increased Ag contents in the coatings leads to enhanced osteoblast functions. - Abstract: Bacterial infection and loosing are serious complications for biomedical implants in the orthopedic, dental, and other biomedical fields and the ideal implants should combine good antibacterial ability and bioactivity. In this study, nanostructured titanium–silver (Ti–Ag) coatings with different Ag contents (1.2 to 21.6 at%) are prepared on Ti substrates by magnetron sputtering. As the Ag concentration is increased, the coatings change from having dense columnar crystals to sparse ones and eventually no columnar structure. The Ti–Ag coatings can effectively kill Staphylococcus aureus during the first few days and remain moderately antibacterial after immersion for 75 days. Compared to pure Ti, the Ti–Ag coatings show good cytocompatibility as indicated by good osteoblast adhesion, proliferation, intracellular total protein synthesis, and alkaline phosphatase (ALP) activity. In addition, cell spreading, collagen secretion, and extracellular matrix mineralization are promoted on the coatings with the proper Ag contents due to the nanostructured morphological features. Our results indicate that favorable antibacterial activity and osseointegration ability can be simultaneously achieved by regulating the Ag contents in Ti–Ag coatings.

  19. Fabrication of Hierarchically Micro- and Nano-structured Mold Surfaces Using Laser Ablation for Mass Production of Superhydrophobic Surfaces

    Science.gov (United States)

    Noh, Jiwhan; Lee, Jae-Hoon; Na, Suckjoo; Lim, Hyuneui; Jung, Dae-Hwan

    2010-10-01

    Many studies have examined the formation of surfaces with mixed patterns of micro- and nano-sized lotus leaves that have hydrophobic properties. In this study, micro- and nano-shapes such as lotus leaves were fabricated on a metal mold surface using laser ablation and ripple formation. A microstructure on the mold surface was replicated onto poly(dimethylsiloxane) (PDMS) using the polymer casting method to manufacture low-cost hydrophobic surfaces. A PDMS surface with micro- and nano-structures that were the inverse image of a lotus leaf showed hydrophobic characteristics (water contact angle: 157°). From these results, we deduced that portions of the microstructures were wet and that air gaps existed between the microstructures and the water drops. In this paper we suggest the possibility of the mass production of hydrophobic plastic surfaces and the development of a methodology for the hydrophobic texturing of various polymer surfaces, using the polymer casting method with laser-processed molds.

  20. Phase evolution of magnetron sputtered nanostructured ATO on grid during lithiation-delithiation processes as model electrodes for Li-ion battery.

    Science.gov (United States)

    Ouyang, Pan; Zhang, Hong; Liu, Yulong; Wang, Ying; Li, Zhicheng

    2014-03-21

    Sb-doped SnO2 (ATO) nanostructured thin films were deposited on holey carbon grids by magnetron sputtering at room temperature. Li/electrolyte/ATO cells were assembled by using the deposited ATO grids as test electrodes. The phase component of the ATO electrodes deposited on grids before and after induction at different charge-discharge stages was characterized by using a transmission electron microscope. The results of the investigation show that the nanostructured ATO thin films undergo a reversible lithiation-delithiation process: the decomposition of SnO2 and the occurrence of metallic Sn followed by the formation of an Li-Sn alloy during the discharge process, and then the reversible de-alloying reaction of the Li-Sn alloy and Sn reaction with Li2O, and even partial formation of SnO2 during charge process. The work also shows that the method deposited the active materials directly on the holey carbon grids is a simple and effective way for the investigation of the phase evolution of the electrodes in electrochemical cells.

  1. Comparative study of organic transistors with different graphene electrodes fabricated using a simple patterning method

    Science.gov (United States)

    Kang, Narae; Smith, Christian W.; Ishigami, Masa; Khondaker, Saiful I.

    2017-12-01

    The performance of organic field-effect transistors (OFETs) can be greatly limited due to the inefficient charge injection caused by the large interfacial barrier at the metal/organic semiconductor interface. To improve this, two-dimensional graphene films have been suggested as alternative electrode materials; however, a comparative study of OFET performances using different types of graphene electrodes has not been systematically investigated. Here, we present a comparative study on the performance of pentacene OFETs using chemical vapor deposition (CVD) grown graphene and reduced graphene oxide (RGO) as electrodes. The large area electrodes were patterned using a simple and environmentally benign patterning technique. Although both the CVD graphene and RGO electrodes showed enhanced device performance compared to metal electrodes, we found the maximum performance enhancement from CVD grown graphene electrodes. Our study suggests that, in addition to the strong π-π interaction at the graphene/organic interface, the higher conductivity of the electrodes also plays an important role in the performance of OFETs.

  2. Fabrication and characterization of transparent metallic electrodes in the terahertz domain

    DEFF Research Database (Denmark)

    Zalkovskij, Maksim; Malureanu, Radu; Song, Zhengyong

    The demand for transparent electrodes keeps increasing as new generations of electronic devices appear, including solar cells and touch screens. Indium tin oxide (ITO) is the most promising transparent electrode material to date [1] although there are several limitations when using ITO. Firstly...

  3. Use of self-assembled peptide nanostructures for the fabrication of silicon nanowires

    DEFF Research Database (Denmark)

    Andersen, Karsten Brandt; Castillo, Jaime; Bakmand, Tania

    2011-01-01

    1. INTRODUCTION Self-assembled diphenylalanine peptide nanotubes provide a means of achieving nanostructured materials in a very simple and fast way. Recent discoveries have shown that this unique material, in addition to remaining stable under dry conditions, rapidly dissolves in water making it...... nanowires. Furthermore, the PNTs could be used as lift-off masks for the patterning during deposition of materials. REFERENCES [1] K. B. Andersen, J. Castillo-León, M. Hedstrom, W. E. Svendsen. Nanoscale. 3, 994-998, (2011)...

  4. Fabrication of micro- and nano-structured materials using mask-less processes

    International Nuclear Information System (INIS)

    Roy, Sudipta

    2007-01-01

    Micro- and nano-scale devices are used in electronics, micro-electro- mechanical, bio-analytical and medical components. An essential step for the fabrication of such small scale devices is photolithography. Photolithography requires a master mask to transfer micrometre or sub-micrometre scale patterns onto a substrate. The requirement of a physical, rigid mask can impede progress in applications which require rapid prototyping, flexible substrates, multiple alignment and 3D fabrication. Alternative technologies, which do not require the use of a physical mask, are suitable for these applications. In this paper mask-less methods of micro- and nano-scale fabrication have been discussed. The most common technique, which is the laser direct imaging (LDI), technique has been applied to fabricate micrometre scale structures on printed circuit boards, glass and epoxy. LDI can be combined with chemical methods to deposit metals, inorganic materials as well as some organic entities at the micrometre scale. Inkjet technology can be used to fabricate micrometre patterns of etch resists, organic transistors as well as arrays for bioanalysis. Electrohydrodynamic atomisation is used to fabricate micrometre scale ceramic features. Electrochemical methodologies offer a variety of technical solutions for micro- and nano-fabrication owing to the fact that electron charge transfer can be constrained to a solid-liquid interface. Electrochemical printing is an adaptation of inkjet printing which can be used for rapid prototyping of metallic circuits. Micro-machining using nano-second voltage pulses have been used to fabricate high precision features on metals and semiconductors. Optimisation of reactor, electrochemistry and fluid flow (EnFACE) has also been employed to transfer micrometre scale patterns on a copper substrate. Nano-scale features have been fabricated by using specialised tools such as scanning tunnelling microscopy, atomic force microscopy and focused ion beam. The

  5. Fabrication of copper-selective PVC membrane electrode based on newly synthesized copper complex of Schiff base as carrier

    Directory of Open Access Journals (Sweden)

    Sulekh Chandra

    2016-09-01

    Full Text Available The newly synthesized copper(II complex of Schiff base p-hydroxyacetophenone semicarbazone was explored as neutral ionophore for the fabrication of poly(vinylchloride (PVC based membrane electrode selective to Cu(II ions. The electrode shows a Nernstian slope of 29.8 ± 0.3 mV/decade with improved linear range of 1.8 × 10−7 to 1.0 × 10−1 M, comparatively lower detection limit 5.7 × 10−8 M between pH range of 2.0–8.0, giving a relatively fast response within 5s and can be used for at least 16 weeks without any divergence in potential. The selectivity coefficient was calculated using the fixed interference method (FIM. The electrode can also be used in partially non-aqueous media having up to 25% (v/v methanol, ethanol or acetone content with no significant change in the value of slope or working concentration range. It was successfully applied for the direct determination of copper content in water and tea samples with satisfactory results. The electrode has been used in the potentiometric titration of Cu2+ with EDTA.

  6. Facile in-situ fabrication of graphene/riboflavin electrode for microbial fuel cells

    International Nuclear Information System (INIS)

    Wang, Qian-Qian; Wu, Xia-Yuan; Yu, Yang-Yang; Sun, De-Zhen; Jia, Hong-Hua; Yong, Yang-Chun

    2017-01-01

    A novel graphene/riboflavin (RF) composite electrode was developed and its potential application as microbial fuel cell (MFC) anode was demonstrated. Graphene layers were first grown on the surface of graphite electrode by a one-step in-situ electrochemical exfoliation approach. Then, noncovalent functionalization of the graphene layers with RF was achieved by a simple spontaneous adsorption process. The graphene/RF electrode was extensively characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, Raman analysis, and cyclic voltammetry analysis. Remarkably, when applied as the anode of Shewanella oneidensis MR-1 inoculated MFCs, the graphene/RF electrode significantly decreased charge transfer over-potential and enhanced cell attachment, which in turn delivered about 5.3- and 2.5-fold higher power output, when compared with that produced by the bare graphite paper electrode and graphene electrode, respectively. These results demonstrated that electron shuttle immobilization on the electrode surface could be a promising and practical strategy for improving the performance of microbial electrochemical systems.

  7. Effect of Systematic Control of Pd Thickness and Annealing Temperature on the Fabrication and Evolution of Palladium Nanostructures on Si (111) via the Solid State Dewetting

    Science.gov (United States)

    Kunwar, Sundar; Pandey, Puran; Sui, Mao; Zhang, Quanzhen; Li, Ming-Yu; Lee, Jihoon

    2017-05-01

    Si-based optoelectronic devices embedded with metallic nanoparticles (NPs) have demonstrated the NP shape, size, spacing, and crystallinity dependent on light absorption and emission induced by the localized surface plasmon resonance. In this work, we demonstrate various sizes and configurations of palladium (Pd) nanostructures on Si (111) by the systematic thermal annealing with the variation of Pd thickness and annealing temperature. The evolution of Pd nanostructures are systematically controlled by the dewetting of thin film by means of the surface diffusion in conjunction with the surface and interface energy minimization and Volmer-Weber growth model. Depending on the control of deposition amount ranging between 0.5 and 100 nm at various annealing temperatures, four distinctive regimes of Pd nanostructures are demonstrated: (i) small pits and grain formation, (ii) nucleation and growth of NPs, (iii) lateral evolution of NPs, and (iv) merged nanostructures. In addition, by the control of annealing between 300 and 800 °C, the Pd nanostructures show the evolution of small pits and grains, isolated NPs, and finally, Pd NP-assisted nanohole formation along with the Si decomposition and Pd-Si inter-diffusion. The Raman analysis showed the discrepancies on phonon modes of Si (111) such that the decreased peak intensity with left shift after the fabrication of Pd nanostructures. Furthermore, the UV-VIS-NIR reflectance spectra revealed the existence of surface morphology dependent on absorption, scattering, and reflectance properties.

  8. Layer by layer assembly of ultrathin V2O5 anchored MWCNTs and graphene on textile fabrics for fabrication of high energy density flexible supercapacitor electrodes

    Science.gov (United States)

    Shakir, Imran; Ali, Zahid; Bae, Jihyun; Park, Jongjin; Kang, Dae Joon

    2014-03-01

    Among transition metal oxides, vanadium oxides have received relatively modest attention for supercapacitor applications. Yet, this material is abundant, relatively inexpensive and offer several oxidation states which can provide a broad range of redox reactions suitable for supercapacitor operation. Electrochemical supercapacitors based on nanostructured vanadium oxide (V2O5) suffer from relatively low energy densities as they have low surface area and poor electrical conductivities. To overcome these problems, we developed a layer by layer assembly (LBL) technique in which a graphene layer was alternatively inserted between MWCNT films coated with ultrathin (3 nm) V2O5. The insertion of a conductive spacer of graphene between the MWCNT films coated with V2O5 not only prevents agglomeration between the MWCNT films but also substantially enhances the specific capacitance by 67%, to as high as ~2590 F g-1. Furthermore, the LBL assembled multilayer supercapacitor electrodes exhibited an excellent cycling performance of >97%, capacitance retention over 5000 cycles and a high energy density of 96 W h kg-1 at a power density of 800 W kg-1. Our approach clearly offers an exciting opportunity for enhancing the device performance of metal oxide-based electrochemical supercapacitors suitable for next-generation flexible energy storage devices by employing a facile LBL assembly technique.Among transition metal oxides, vanadium oxides have received relatively modest attention for supercapacitor applications. Yet, this material is abundant, relatively inexpensive and offer several oxidation states which can provide a broad range of redox reactions suitable for supercapacitor operation. Electrochemical supercapacitors based on nanostructured vanadium oxide (V2O5) suffer from relatively low energy densities as they have low surface area and poor electrical conductivities. To overcome these problems, we developed a layer by layer assembly (LBL) technique in which a graphene layer

  9. Fabrication of Nanostructured TiO2 Using a Solvothermal Reaction for Lithium-ion Batteries

    Directory of Open Access Journals (Sweden)

    Jicai Liang

    2016-03-01

    Full Text Available Nanostructured TiO2 was successfully synthesized via a facile one-pot solvothermal reaction followed by calcina‐ tion. Hydrolysis and polycondensation of titanium butox‐ ide (Ti(OR4 were performed in the presence of sodium dodecylbenzenesulfonate (SDBS. The morphologies, crystallinity and compositions of obtained samples were identified by the methods of X-ray diffraction (XRD, Brunauer–Emmett–Teller (BET and transmission electron microscopy (TEM. It was found that the nanostructured TiO2 with an average diameter of 10±5 nm had the crystal type of anatase. A good specific surface was also obtained by the standard multipoint BET method (119.2 m2/g. As the anode materials for the lithium-ion batteries (LIBs, the anatase phase TiO2 demonstrated a relatively high gravi‐ metric specific capacity of 264.8 mAh g-1. The reversible capacity of TiO2 remained 196.4 mAh g-1 at a rate of 0.2 ̊C after 100 cycles. It indicated that this kind of TiO2 possessed a good electrochemical performance.

  10. Superhydrophobic multi-scale ZnO nanostructures fabricated by chemical vapor deposition method.

    Science.gov (United States)

    Zhou, Ming; Feng, Chengheng; Wu, Chunxia; Ma, Weiwei; Cai, Lan

    2009-07-01

    The ZnO nanostructures were synthesized on Si(100) substrates by chemical vapor deposition (CVD) method. Different Morphologies of ZnO nanostructures, such as nanoparticle film, micro-pillar and micro-nano multi-structure, were obtained with different conditions. The results of XRD and TEM showed the good quality of ZnO crystal growth. Selected area electron diffraction analysis indicates the individual nano-wire is single crystal. The wettability of ZnO was studied by contact angle admeasuring apparatus. We found that the wettability can be changed from hydrophobic to super-hydrophobic when the structure changed from smooth particle film to single micro-pillar, nano-wire and micro-nano multi-scale structure. Compared with the particle film with contact angle (CA) of 90.7 degrees, the CA of single scale microstructure and sparse micro-nano multi-scale structure is 130-140 degrees, 140-150 degrees respectively. But when the surface is dense micro-nano multi-scale structure such as nano-lawn, the CA can reach to 168.2 degrees . The results indicate that microstructure of surface is very important to the surface wettability. The wettability on the micro-nano multi-structure is better than single-scale structure, and that of dense micro-nano multi-structure is better than sparse multi-structure.

  11. Fabrication of Functionalized Carbon Nanotube Buckypaper Electrodes for Application in Glucose Biosensors

    Directory of Open Access Journals (Sweden)

    Henry Papa

    2014-11-01

    Full Text Available A highly sensitive glucose detection method was developed using functionalized carbon nanotube buckypaper as a free standing electrode in an electrochemical biosensor. Glucose oxidase was immobilized onto various buckypaper samples in order to oxidize glucose resulting in a measureable current/voltage signal output of the biosensor. Cyclic voltammetry (CV and amperometry were utilized to determine the sensitivity of these buckypaper electrodes. Sensors of three different types of buckypaper were prepared and compared. These modified buckypaper electrode-based sensors showed much higher sensitivity to glucose compared to other electrochemical glucose sensors.

  12. Facile fabrication of nano-structured silica hybrid film with superhydrophobicity by one-step VAFS approach

    Science.gov (United States)

    Jia, Yi; Yue, Renliang; Liu, Gang; Yang, Jie; Ni, Yong; Wu, Xiaofeng; Chen, Yunfa

    2013-01-01

    Here we report a novel one-step vapor-fed aerosol flame synthesis (VAFS) method to attain silica hybrid film with superhydrophobicity on normal glass and other engineering material substrates using hexamethyldisiloxane (HMDSO) as precursor. The deposited nano-structured silica films represent excellent superhydrophobicity with contact angle larger than 150° and sliding angle below 5°, without any surface modification or other post treatments. SEM photographs proved that flame-made SiO2 nanoparticles formed dual-scale surface roughness on the substrates. It was confirmed by FTIR and XPS that the in situ formed organic fragments on the particle surface as species like (CH3)xSiO2-x/2 (x = 1, 2, 3) which progressively lowered the surface energy of fabricated films. Thus, these combined dual-scale roughness and lowered surface energy cooperatively produced superhydrophobic films. IR camera had been used to monitor the real-time flame temperature. It is found that the inert dilution gas inflow played a critical role in attaining superhydrophobicity due to its cooling and anti-oxidation effect. This method is facile and scalable for diverse substrates, without any requirement of complex equipments and multiple processing steps. It may contribute to the industrial fabrication of superhydrophobic films.

  13. Micro-EDM process modeling and machining approaches for minimum tool electrode wear for fabrication of biocompatible micro-components

    DEFF Research Database (Denmark)

    Puthumana, Govindan

    2017-01-01

    Micro-electrical discharge machining (micro-EDM) is a potential non-contact method for fabrication of biocompatible micro devices. This paper presents an attempt to model the tool electrode wear in micro-EDM process using multiple linear regression analysis (MLRA) and artificial neural networks...... linear regression model was developed for prediction of TWR in ten steps at a significance level of 90%. The optimum architecture of the ANN was obtained with 7 hidden layers at an R-sq value of 0.98. The predicted values of TWR using ANN matched well with the practically measured and calculated values...... (ANN). The governing micro-EDM factors chosen for this investigation were: voltage (V), current (I), pulse on time (Ton) and pulse frequency (f). The proposed predictive models generate a functional correlation between the tool electrode wear rate (TWR) and the governing micro-EDM factors. A multiple...

  14. Fabrication of a Multi-Walled Nanotube (MWNT Ionic Liquid Electrode and Its Application for Sensing Phenolics in Red Wines

    Directory of Open Access Journals (Sweden)

    Kyo-Il Kim

    2009-08-01

    Full Text Available A multi-walled nanotube (MWNT ionic liquid was prepared by the immobilization of 1-butylimidazole bromide onto an epoxy group on a poly(glycidyl methacrylate-grafted MWNT, which was synthesized by radiation-induced graft polymerization of glycidyl methacrylate onto MWNT in an aqueous solution. Subsequently, a MWNT ionic liquid electrode was fabricated by hand-casting MWNT ionic liquid, tyrosinase, and chitosan solution as a binder on indium tin oxide (ITO glass. The sensing ranges of the MWNT ionic liquid electrode with immobilized tyrosinase was in the range of 0.01-0.08 mM in a phosphate buffer solution. The optimal conditions such as pH, temperature, and effects of different phenolic compounds were determined. The total phenolic compounds of three commercial red wines were also determined on the tyrosinase-immobilized biosensor.

  15. Fabrication of Flower-like ZnO Micro/Nanostructures for Photodegradation of Pre-treated Palm Oil Mill Effluent

    Science.gov (United States)

    Lam, Sze-Mun; Wong, Kok-Ann; Sin, Jin-Chung

    2018-01-01

    Flower-like ZnO micro/nanostructures were fabricated by a simple and surfactant-free reflux method. X-ray diffraction findings showed that the prepared ZnO product was highly crystallite with hexagonal wurtzite structure. The band gap energy of ZnO sample was measured to be 3.18 eV via an optical reflectance spectrum. The flower-like morphological features of ZnO micro/nanostructures were witnessed through field-emission scanning electron microscopy. Such micro/nanoparticles could be used in the photodegradation of pre-treated palm oil mil effluent (POME) under UV irradiation.

  16. Fabrication of metallic nanostructures of sub-20 nm with an optimized process of E-beam lithography and lift-off

    KAUST Repository

    Yue, Weisheng

    2012-01-01

    A process consisting of e-beam lithography and lift-off was optimized to fabricate metallic nanostructures. This optimized process successfully produced gold and aluminum nanostructures with features size less than 20 nm. These structures range from simple parallel lines to complex photonic structures. Optical properties of gold split ring resonators (SRRs) were characterized with Raman spectroscopy. Surface-Enhanced Raman Scattering (SERS) on SRRs was observed with 4-mercaptopyridine (4-MPy) as molecular probe and greatly enhanced Raman scattering was observed. Copyright © 2012 American Scientific Publishers.

  17. Fabrication and performance of Li4Ti5O12/C Li-ion battery electrodes using combined double flame spray pyrolysis and pressure-based lamination technique

    Science.gov (United States)

    Gockeln, Michael; Pokhrel, Suman; Meierhofer, Florian; Glenneberg, Jens; Schowalter, Marco; Rosenauer, Andreas; Fritsching, Udo; Busse, Matthias; Mädler, Lutz; Kun, Robert

    2018-01-01

    Reduction of lithium-ion battery (LIB) production costs is inevitable to make the use of LIB technology more viable for applications such as electric vehicles or stationary storage. To meet the requirements in today's LIB cost efficiency, our current research focuses on an alternative electrode fabrication method, characterized by a combination of double flame spray pyrolysis and lamination technique (DFSP/lamination). In-situ carbon coated nano-Li4Ti5O12 (LTO/C) was synthesized using versatile DFSP. The as-prepared composite powder was then directly laminated onto a conductive substrate avoiding the use of any solvent or binder for electrode preparation. The influence of lamination pressures on the microstructure and electrochemical performance of the electrodes was also investigated. Enhancements in intrinsic electrical conductivity were found for higher lamination pressures. Capacity retention of highest pressurized DFSP/lamination-prepared electrode was 87.4% after 200 dis-/charge cycles at 1C (vs. Li). In addition, LTO/C material prepared from the double flame spray pyrolysis was also used for fabricating electrodes via doctor blading technique. Laminated electrodes obtained higher specific discharge capacities compared to calendered and non-calendered blade-casted electrodes due to superior microstructural properties. Such a fast and industrially compelling integrative DFSP/lamination tool could be a prosperous, next generation technology for low-cost LIB electrode fabrication.

  18. Fluorescent Properties of ZnO Nanostructures Fabricated by Hydrothermal Method

    Directory of Open Access Journals (Sweden)

    Zhiwei Dong

    2012-01-01

    Full Text Available ZnO nanorods with mean diameter 200 nm on different substrates were fabricated by hydrothermal method. Fluorescent properties of fabricated ZnO nanorods were researched by both linear and nonlinear excitation using femtosecond lasers. The damage threshold of productions on Si substrate irradiated under intense femtosecond pulses was found much higher than that on Zn plate. Raman spectrum was also applied to investigate relative optical properties. The A1L optical mode was found to be important to the fluorescent properties of ZnO materials.

  19. Fabrication of Conductive Nanostructures by Femtosecond Laser Induced Reduction of Silver Ions

    Science.gov (United States)

    Barton, Peter G.

    Nanofabrication through multiphoton absorption has generated considerable interest because of its unique ability to generate 2D and 3D structures in a single laser-direct-write step as well as its ability to generate feature sizes well below the diffraction limited laser spot size. The majority of multiphoton fabrication has been used to create 3D structures of photopolymers which have applications in a wide variety of fields, but require additional post-processing steps to fabricate conductive structures. It has been shown that metal ions can also undergo multiphoton absorption, which reduces the metal ions to stable atoms/nanoparticles which are formed at the laser focal point. When the focus is located at the substrate surface, the reduced metal is deposited on the surface, which allows arbitrary 2D patterning as well as building up 3D structures from this first layer. Samples containing the metal ions can be prepared either in a liquid solution, or in a polymer film. The polymer film approach has the benefit of added support for the 3D metallic structures; however it is difficult to remove the polymer after fabrication to leave a free standing metallic structure. With the ion solution method, free standing metallic structures can be fabricated but need to be able to withstand surface tension forces when the remaining unexposed solution is washed away. So far, silver nanowires with resistivity on the order of bulk silver have been fabricated, as well as a few small 3D structures. This research focuses on the surfactant assisted multiphoton reduction of silver ions in a liquid solution. The experimental setup consists of a Coherent Micra 10 Ultrafast laser with 30fs pulse length, 80MHz repetition rate, and a wavelength centered at 800nm. This beam is focused into the sample using a 100x objective with a N.A. of 1.49. Silver structures such as nanowires and grid patterns have been produced with minimum linewidth of 180nm. Silver nanowires with resistivity down to

  20. Method for fabricating carbon/lithium-ion electrode for rechargeable lithium cell

    Science.gov (United States)

    Huang, Chen-Kuo (Inventor); Surampudi, Subbarao (Inventor); Attia, Alan I. (Inventor); Halpert, Gerald (Inventor)

    1995-01-01

    The method includes steps for forming a carbon electrode composed of graphitic carbon particles adhered by an ethylene propylene diene monomer binder. An effective binder composition is disclosed for achieving a carbon electrode capable of subsequent intercalation by lithium ions. The method also includes steps for reacting the carbon electrode with lithium ions to incorporate lithium ions into graphitic carbon particles of the electrode. An electrical current is repeatedly applied to the carbon electrode to initially cause a surface reaction between the lithium ions and to the carbon and subsequently cause intercalation of the lithium ions into crystalline layers of the graphitic carbon particles. With repeated application of the electrical current, intercalation is achieved to near a theoretical maximum. Two differing multi-stage intercalation processes are disclosed. In the first, a fixed current is reapplied. In the second, a high current is initially applied, followed by a single subsequent lower current stage. Resulting carbon/lithium-ion electrodes are well suited for use as an anode in a reversible, ambient temperature, lithium cell.

  1. Fabrication of Nickel/nanodiamond/boron-doped diamond electrode for non-enzymatic glucose biosensor

    International Nuclear Information System (INIS)

    Dai, Wei; Li, Mingji; Gao, Sumei; Li, Hongji; Li, Cuiping; Xu, Sheng; Wu, Xiaoguo; Yang, Baohe

    2016-01-01

    Highlights: • Nanodiamonds (NDs) were electrophoretically deposited on the BDD film. • The NDs significantly extended the potential window. • Ni/NDs/BDD electrode was prepared by electrodeposition. • The electrode shows good catalytic activity for glucose oxidation. - Abstract: A stable and sensitive non-enzymatic glucose sensor was prepared by modifying a boron-doped diamond (BDD) electrode with nickel (Ni) nanosheets and nanodiamonds (NDs). The NDs were electrophoretically deposited on the BDD surface, and acted as nucleation sites for the subsequent electrodeposition of Ni. The morphology and composition of the modified BDD electrodes were characterized by field-emission scanning electron microscopy and energy-dispersive X-ray spectroscopy, respectively. The Ni nanosheet-ND modified BDD electrode exhibited good current response towards the non-enzymatic oxidation of glucose in alkaline media. The NDs significantly extended the potential window. The response to glucose was linear over the 0.2–1055.4-μM range. The limit of detection was 0.05 μM, at a signal-to-noise ratio of 3. The Ni nanosheet-ND/BDD electrode exhibited good selectivity, reproducibility and stability. Its electrochemical performance, low cost and simple preparation make it a promising non-enzymatic glucose sensor.

  2. Fabrication of single-crystalline plasmonic nanostructures on transparent and flexible amorphous substrates

    Science.gov (United States)

    Mori, Tomohiro; Mori, Takeshi; Tanaka, Yasuhiro; Suzaki, Yoshifumi; Yamaguchi, Kenzo

    2017-02-01

    A new experimental technique is developed for producing a high-performance single-crystalline Ag nanostructure on transparent and flexible amorphous substrates for use in plasmonic sensors and circuit components. This technique is based on the epitaxial growth of Ag on a (001)-oriented single-crystalline NaCl substrate, which is subsequently dissolved in ultrapure water to allow the Ag film to be transferred onto a wide range of different substrates. Focused ion beam milling is then used to create an Ag nanoarray structure consisting of 200 cuboid nanoparticles with a side length of 160 nm and sharp, precise edges. This array exhibits a strong signal and a sharp peak in plasmonic properties and Raman intensity when compared with a polycrystalline Ag nanoarray.

  3. Exploring the Possibilities of Biological Fabrication of Gold Nanostructures Using Orange Peel Extract

    Directory of Open Access Journals (Sweden)

    Laura Castro

    2015-09-01

    Full Text Available Development of nanotechnology requires a constant innovation and improvement in many materials. The exploration of natural resources is a promising eco-friendly alternative for physical and chemical methods. In the present work, colloidal gold nanostructures were prepared using orange peel extract as a stabilizing and reducing agent. The initial pH value of the solution and the concentration of the gold precursor had an effect on the formation and morphology of nanoparticles. The method developed is environmentally friendly and allows control of nanoparticles. By controlling the pH and, especially, the gold concentration, we are able to synthesize crystalline gold nanowires using orange peel extract in the absence of a surfactant or polymer to direct nanoparticle growth, and without external seeding. UV-VIS spectroscopy, transmission electron microscopy (TEM, and X-ray diffraction (XRD were used to characterize the nanoparticles obtained by biosynthesis.

  4. Large flexibility of high aspect ratio carbon nanostructures fabricated by electron-beam-induced deposition

    Energy Technology Data Exchange (ETDEWEB)

    Beard, J D; Gordeev, S N, E-mail: jdb28@bath.ac.uk [Department of Physics, University of Bath, Bath BA2 7AY (United Kingdom)

    2010-11-26

    The mechanical properties of free-standing electron beam deposited amorphous carbon structures have been studied using atomic force microscopy. The fabricated carbon blades are found to be extraordinarily flexible, capable of undergoing vertical deflection up to {approx} 75% of their total length without inelastic deformation. The elastic bending modulus of these structures was calculated to be 28 {+-} 10 GPa.

  5. Emerging fabrication techniques for 3D nano-structuring in plasmonics and single molecule studies

    Science.gov (United States)

    de Angelis, F.; Liberale, C.; Coluccio, M. L.; Cojoc, G.; di Fabrizio, E.

    2011-07-01

    The application of new methods and techniques to fields such as biology and medicine is becoming more and more demanding since the request of detailed information down to single molecules is a scientific necessity and a technical realistic possibility. In this effort a key role is played by emerging fabrication techniques. One of the hardest challenges is to incorporate the third dimension in the design and fabrication of novel devices. Significantly, this means that conventional nano-fabrication methods, intrinsically useful for planar structuring, have to be substituted or complemented with new approaches. In this paper we show how emerging techniques can be used for 3D structuring of noble metals down to nanoscale. In particular, the paper deals with electroless deposition of silver, ion and electron beam induced deposition, focused ion beam milling, and two-photon lithography. We exploited these techniques to fabricate different plasmonics nanolenses, nanoprobes and novel beads for optical tweezers. In the future these devices will be used for the manipulation and chemical investigation of single cells with sensitivity down to a few molecules in label free conditions and native environment. Although this paper is only devoted to nanofabrication, we foresee that the fields of biology and medicine will directly gain substantial advantages from this approach.

  6. Fabrication of catalyst-coated membrane-electrode assemblies by doctor blade method and their performance in fuel cells

    Science.gov (United States)

    Park, In-Su; Li, Wen; Manthiram, Arumugam

    Membrane-electrode assemblies (MEAs) have been fabricated with a direct coating of the catalyst slurry by a doctor blade method on the pre-swollen Nafion membrane for proton exchange membrane (PEMFC) and direct methanol fuel cells (DMFC). The effects of various swelling agents with different boiling points such as ethylene glycol (EG), diethylene glycol (DEG), triethylene glycol (TEG), tetraethylene glycol (TEEG), and glycerol in the swelling step of the membrane and the drying step of the coated catalyst have been investigated. Also, the use of dimethyl sulfoxide (DMSO) as a dispersing agent in the catalyst slurry has been investigated. Among the various swelling agents investigated, EG gives the best results with the dispersing agent DMSO offering further improvement. The MEAs fabricated with the EG-swollen membranes and DMSO as a dispersing agent in the catalyst layer show good performance in single fuel cells with hydrogen and methanol fuels.

  7. Deposition Time and Thermal Cycles of Fabricating Thin-wall Steel Parts by Double Electrode GMAW Based Additive Manufacturing

    Directory of Open Access Journals (Sweden)

    Yang Dongqing

    2017-01-01

    Full Text Available The deposition time for fabricating the thin-wall part as well as the peak temperature of the substrate during the process was analyzed in the double electrode gas metal arc welding (DE-GMAW based additive manufacturing (AM. The total deposition time and the interlayer idle time of the manufacturing process decreased with the increasing of the bypass current under the same interlayer temperature and the same deposition rate. The thermal cycling curves illustrated that the peak temperature of the substrate was lower in the DE-GMAW base AM under the same conditions. When depositing the thin-wall parts, the DE-GMAW based AM can reduce the heat input to the substrate and improve the fabrication efficiency, compared with the GMAW based AM.

  8. Stable cycling and excess capacity of a nanostructured Sn electrode based on Sn(CH3COO)2 confined within a nanoporous carbon scaffold

    International Nuclear Information System (INIS)

    Trevey, James E; Gross, Adam F; Wang, John; Liu, Ping; Vajo, John J

    2013-01-01

    A high capacity, electrochemically stable, nanostructured Sn electrode for Li ion battery anodes is described. This electrode utilizes a rigid, electrically conductive, nanoporous carbon aerogel scaffold by incorporating tin acetate, Sn(CH 3 COO) 2 , into the scaffold pore volume through melt infusion. Incorporation of the Sn(CH 3 COO) 2 by melt infusion ensures a chemically stable contact with the scaffold. The mechanical rigidity of the pore volume confines the Sn to nanometer dimensions without sintering, leading to stable cycling. Separation of the synthesis of the scaffold from the loading with Sn(CH 3 COO) 2 permits optimized division of the scaffold pore volume for expansion and electrolyte access during reaction with Li. Using this design, an electrode based on an aerogel with a 5 nm mode pore size was cycled over 300 times without degradation. In addition, after subtracting the contribution from the carbon scaffold, the capacity exceeded the theoretical capacity for Sn, due to an oxidation reaction occurring at 1.2 V. This excess capacity may be related to the solid–solid or solid–electrolyte interfaces in the electrode, possibly representing a new reversible Li ion reaction. (paper)

  9. Fabrication and Characterization of 3D-Printed Highly-Porous 3D LiFePO4 Electrodes by Low Temperature Direct Writing Process

    Science.gov (United States)

    Cheng, Xingxing; Li, Bohan; Chen, Zhangwei; Mi, Shengli; Lao, Changshi

    2017-01-01

    LiFePO4 (LFP) is a promising cathode material for lithium-ion batteries. In this study, low temperature direct writing (LTDW)-based 3D printing was used to fabricate three-dimensional (3D) LFP electrodes for the first time. LFP inks were deposited into a low temperature chamber and solidified to maintain the shape and mechanical integrity of the printed features. The printed LFP electrodes were then freeze-dried to remove the solvents so that highly-porous architectures in the electrodes were obtained. LFP inks capable of freezing at low temperature was developed by adding 1,4 dioxane as a freezing agent. The rheological behavior of the prepared LFP inks was measured and appropriate compositions and ratios were selected. A LTDW machine was developed to print the electrodes. The printing parameters were optimized and the printing accuracy was characterized. Results showed that LTDW can effectively maintain the shape and mechanical integrity during the printing process. The microstructure, pore size and distribution of the printed LFP electrodes was characterized. In comparison with conventional room temperature direct ink writing process, improved pore volume and porosity can be obtained using the LTDW process. The electrochemical performance of LTDW-fabricated LFP electrodes and conventional roller-coated electrodes were conducted and compared. Results showed that the porous structure that existed in the printed electrodes can greatly improve the rate performance of LFP electrodes. PMID:28796182

  10. Fabrication and Characterization of 3D-Printed Highly-Porous 3D LiFePO4 Electrodes by Low Temperature Direct Writing Process

    Directory of Open Access Journals (Sweden)

    Changyong Liu

    2017-08-01

    Full Text Available LiFePO4 (LFP is a promising cathode material for lithium-ion batteries. In this study, low temperature direct writing (LTDW-based 3D printing was used to fabricate three-dimensional (3D LFP electrodes for the first time. LFP inks were deposited into a low temperature chamber and solidified to maintain the shape and mechanical integrity of the printed features. The printed LFP electrodes were then freeze-dried to remove the solvents so that highly-porous architectures in the electrodes were obtained. LFP inks capable of freezing at low temperature was developed by adding 1,4 dioxane as a freezing agent. The rheological behavior of the prepared LFP inks was measured and appropriate compositions and ratios were selected. A LTDW machine was developed to print the electrodes. The printing parameters were optimized and the printing accuracy was characterized. Results showed that LTDW can effectively maintain the shape and mechanical integrity during the printing process. The microstructure, pore size and distribution of the printed LFP electrodes was characterized. In comparison with conventional room temperature direct ink writing process, improved pore volume and porosity can be obtained using the LTDW process. The electrochemical performance of LTDW-fabricated LFP electrodes and conventional roller-coated electrodes were conducted and compared. Results showed that the porous structure that existed in the printed electrodes can greatly improve the rate performance of LFP electrodes.

  11. Organosilane-functionalization of nanostructured indium tin oxide films.

    Science.gov (United States)

    Pruna, R; Palacio, F; Martínez, M; Blázquez, O; Hernández, S; Garrido, B; López, M

    2016-12-06

    Fabrication and organosilane-functionalization and characterization of nanostructured ITO electrodes are reported. Nanostructured ITO electrodes were obtained by electron beam evaporation, and a subsequent annealing treatment was selectively performed to modify their crystalline state. An increase in geometrical surface area in comparison with thin-film electrodes area was observed by atomic force microscopy, implying higher electroactive surface area for nanostructured ITO electrodes and thus higher detection levels. To investigate the increase in detectability, chemical organosilane-functionalization of nanostructured ITO electrodes was performed. The formation of 3-glycidoxypropyltrimethoxysilane (GOPTS) layers was detected by X-ray photoelectron spectroscopy. As an indirect method to confirm the presence of organosilane molecules on the ITO substrates, cyclic voltammetry and electrochemical impedance spectroscopy (EIS) were also carried out. Cyclic voltammograms of functionalized ITO electrodes presented lower reduction-oxidation peak currents compared with non-functionalized ITO electrodes. These results demonstrate the presence of the epoxysilane coating on the ITO surface. EIS showed that organosilane-functionalized electrodes present higher polarization resistance, acting as an electronic barrier for the electron transfer between the conductive solution and the ITO electrode. The results of these electrochemical measurements, together with the significant difference in the X-ray spectra between bare ITO and organosilane-functionalized ITO substrates, may point to a new exploitable oxide-based nanostructured material for biosensing applications. As a first step towards sensing, rapid functionalization of such substrates and their application to electrochemical analysis is tested in this work. Interestingly, oxide-based materials are highly integrable with the silicon chip technology, which would permit the easy adaptation of such sensors into lab

  12. Directly grown nanostructured electrodes for high volumetric energy density binder-free hybrid supercapacitors: a case study of CNTs//Li4Ti5O12.

    Science.gov (United States)

    Zuo, Wenhua; Wang, Chong; Li, Yuanyuan; Liu, Jinping

    2015-01-14

    Hybrid supercapacitor (HSC), which typically consists of a Li-ion battery electrode and an electric double-layer supercapacitor electrode, has been extensively investigated for large-scale applications such as hybrid electric vehicles, etc. Its application potential for thin-film downsized energy storage systems that always prefer high volumetric energy/power densities, however, has not yet been explored. Herein, as a case study, we develop an entirely binder-free HSC by using multiwalled carbon nanotube (MWCNT) network film as the cathode and Li(4)Ti(5)O(12) (LTO) nanowire array as the anode and study the volumetric energy storage capability. Both the electrode materials are grown directly on carbon cloth current collector, ensuring robust mechanical/electrical contacts and flexibility. Our 3 V HSC device exhibits maximum volumetric energy density of ~4.38 mWh cm(-3), much superior to those of previous supercapacitors based on thin-film electrodes fabricated directly on carbon cloth and even comparable to the commercial thin-film lithium battery. It also has volumetric power densities comparable to that of the commercial 5.5 V/100 mF supercapacitor (can be operated within 3 s) and has excellent cycling stability (~92% retention after 3000 cycles). The concept of utilizing binder-free electrodes to construct HSC for thin-film energy storage may be readily extended to other HSC electrode systems.

  13. Planar self-aligned imprint lithography for coplanar plasmonic nanostructures fabrication

    KAUST Repository

    Wan, Weiwei

    2014-03-01

    Nanoimprint lithography (NIL) is a cost-efficient nanopatterning technology because of its promising advantages of high throughput and high resolution. However, accurate multilevel overlay capability of NIL required for integrated circuit manufacturing remains a challenge due to the high cost of achieving mechanical alignment precision. Although self-aligned imprint lithography was developed to avoid the need of alignment for the vertical layered structures, it has limited usage in the manufacture of the coplanar structures, such as integrated plasmonic devices. In this paper, we develop a new process of planar self-alignment imprint lithography (P-SAIL) to fabricate the metallic and dielectric structures on the same plane. P-SAIL transfers the multilevel imprint processes to a single-imprint process which offers higher efficiency and less cost than existing manufacturing methods. Such concept is demonstrated in an example of fabricating planar plasmonic structures consisting of different materials. © 2014 Springer-Verlag Berlin Heidelberg.

  14. Studies on electrochemical glucose sensing, antimicrobial activity and cytotoxicity of fabricated copper nanoparticle immobilized chitin nanostructure.

    Science.gov (United States)

    Solairaj, Dhanasekaran; Rameshthangam, Palanivel; Muthukumaran, Palanisamy; Wilson, Jeyaraj

    2017-08-01

    In this study, copper nanoparticle immobilized chitin nanocomposite (CNP/CuNP) was synthesized and used for the development of non-enzymatic electrochemical sensor. The CNP/CuNP was characterized by X-ray diffraction (XRD), fourier transform infra red (FTIR) spectroscopy and high resolution transmission electron microscopy (HRTEM) analysis. The glucose sensing property of CNP/CuNP was investigated by cyclic voltammetry (CV) and chronoamperometry (CA). As a result of the synergistic effect of CNP and CuNP, the modified electrode displayed effective electro-oxidation of glucose in 0.1M NaOH solution. At 0.45V potential the modified electrode showed response towards glucose in the linear range of 1-1000μM with a lowest detection limit of 0.776μM with better selectivity and stability. In addition, the antimicrobial activity of CNP/CuNP was evaluated against bacterial and fungal strains. CNP/CuNP displayed enhanced antimicrobial activity when compared to CNP and CuNP alone. Similarly, cytotoxicity of CNP/CuNP was tested against Artemia salina, which showed no toxic effect in the tested concentration. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Nanostructured Iron and Manganese Oxide Electrode Materials for Lithium Batteries: Influence of Chemical and Physical Properties on Electrochemistry

    Science.gov (United States)

    Durham, Jessica L.

    The widespread use of portable electronics and growing interest in electric and hybrid vehicles has generated a mass market for batteries with increased energy densities and enhanced electrochemical performance. In order to address a variety of applications, commercially fabricated secondary lithium-ion batteries employ transition metal oxide based electrodes, the most prominent of which include lithium nickel manganese cobalt oxide (LiNixMn yCo1-x-yO2), lithium iron phosphate (LiFePO4), and lithium manganese oxide (LiMn 2O4). Transition metal oxides are of particular interest as cathode materials due to their robust framework for lithium intercalation, potential for high energy density, and utilization of earth-abundant elements (i.e. iron and manganese) leading to decreased toxicity and cost-effective battery production on industrial scales. Specifically, this research focuses on MgFe2O4, AgxMn8O16, and AgFeO 2 transition metal oxides for use as electrode materials in lithium-based batteries. The electrode materials are prepared via co-precipitation, reflux, and hydrothermal methods and characterized by several techniques (XRD, SEM, BET, TGA, DSC, XPS, Raman, etc.). The low-temperature syntheses allowed for precise manipulation of structural, compositional, and/or functional properties of MgFe2O4, AgxMn8 O16, and AgFeO2 which have been shown to influence electrochemical behavior. In addition, advanced in situ and ex situ characterization techniques are employed to study the lithiation/de-lithiation process and establish valid redox mechanisms. With respect to both chemical and physical properties, the influence of MgFe2O4 particle size and morphology on electrochemical behavior was established using ex situ X-ray absorption spectroscopy (XAS) and transmission electron microscopy (TEM) imaging. Based on composition, tunneled AgxMn8O16 nanorods, prepared with distinct Ag+ contents and crystallite sizes, display dramatic differences in ion-transport kinetics due to

  16. Deep Ultraviolet Copper(I) Thiocyanate (CuSCN) Photodetectors Based on Coplanar Nanogap Electrodes Fabricated via Adhesion Lithography

    KAUST Repository

    Wyatt-Moon, Gwenhivir

    2017-11-28

    Adhesion lithography (a-Lith) is a versatile fabrication technique used to produce asymmetric coplanar electrodes separated by a <15 nm nanogap. Here, we use a-Lith to fabricate deep ultraviolet (DUV) photodetectors by combining coplanar asymmetric nanogap electrode architectures (Au/Al) with solution-processable wide-band-gap (3.5–3.9 eV) p-type semiconductor copper(I) thiocyanate (CuSCN). Because of the device’s unique architecture, the detectors exhibit high responsivity (≈79 A W–1) and photosensitivity (≈720) when illuminated with a DUV-range (λpeak = 280 nm) light-emitting diode at 220 μW cm–2. Interestingly, the photosensitivity of the photodetectors remains fairly high (≈7) even at illuminating intensities down to 0.2 μW cm–2. The scalability of the a-Lith process combined with the unique properties of CuSCN paves the way to new forms of inexpensive, yet high-performance, photodetectors that can be manufactured on arbitrary substrate materials including plastic.

  17. Layer by layer assembly of ultrathin V₂O₅ anchored MWCNTs and graphene on textile fabrics for fabrication of high energy density flexible supercapacitor electrodes.

    Science.gov (United States)

    Shakir, Imran; Ali, Zahid; Bae, Jihyun; Park, Jongjin; Kang, Dae Joon

    2014-04-21

    Among transition metal oxides, vanadium oxides have received relatively modest attention for supercapacitor applications. Yet, this material is abundant, relatively inexpensive and offer several oxidation states which can provide a broad range of redox reactions suitable for supercapacitor operation. Electrochemical supercapacitors based on nanostructured vanadium oxide (V₂O₅) suffer from relatively low energy densities as they have low surface area and poor electrical conductivities. To overcome these problems, we developed a layer by layer assembly (LBL) technique in which a graphene layer was alternatively inserted between MWCNT films coated with ultrathin (3 nm) V₂O₅. The insertion of a conductive spacer of graphene between the MWCNT films coated with V₂O₅ not only prevents agglomeration between the MWCNT films but also substantially enhances the specific capacitance by 67%, to as high as ∼2590 F g(-1). Furthermore, the LBL assembled multilayer supercapacitor electrodes exhibited an excellent cycling performance of >97%, capacitance retention over 5000 cycles and a high energy density of 96 W h kg(-1) at a power density of 800 W kg(-1). Our approach clearly offers an exciting opportunity for enhancing the device performance of metal oxide-based electrochemical supercapacitors suitable for next-generation flexible energy storage devices by employing a facile LBL assembly technique.

  18. Fabrication of Polymer Solar Cells Using Aqueous Processing for All Layers Including the Metal Back Electrode

    DEFF Research Database (Denmark)

    Søndergaard, Roar; Helgesen, Martin; Jørgensen, Mikkel

    2011-01-01

    The challenges of printing all layers in polymer solar cells from aqueous solution are met by design of inks for the electron-, hole-, active-, and metallic back electrode-layers. The conversion of each layer to an insoluble state after printing enables multilayer formation from the same solvent ...... (water). The photograph here was taken just before screen printing of the aqueous silver ink.......The challenges of printing all layers in polymer solar cells from aqueous solution are met by design of inks for the electron-, hole-, active-, and metallic back electrode-layers. The conversion of each layer to an insoluble state after printing enables multilayer formation from the same solvent...

  19. Design, fabrication, and characterization of a 2.3 kJ plasma focus of negative inner electrode

    International Nuclear Information System (INIS)

    Mathuthu, M.; Zengeni, T.G.; Gholap, A.V.

    1997-01-01

    The design, fabrication, and characterization of a 2.3 kJ plasma focus device with negative inner electrode are discussed. The purpose of the design was to initiate research in and study of plasma dynamics, nuclear reactions, and neutron emission mechanisms at the university. Also the device will be used to teach and demonstrate plasma phenomena at the postgraduate level and to perform experiments with inverted polarity to examine different operating regimes with nonstandard gases. It is hoped that in the long run the research work will help find a solution to the polarity riddle of plasma focus devices. When the system was operated with spectrographic argon as the filling gas, the best focus was obtained at a pressure range of 0.1 endash 1.25 Torr. With nitrogen as the filling gas, the best focus was obtained at pressures between 0.1 and 1.25 Torr. Air gave the best focus at a pressure range of 0.5 endash 1.5 Torr. The observed good focus action is attributed to the small inner electrode length (this reduces the amount of anode material ablated into the current sheath) and tapering of the inner electrode. Positive z-directed electrons contribute to the temperature and further ionization of the plasma gas during focusing. The performance of the device compares quite well with other known devices. copyright 1997 American Institute of Physics

  20. The fabrication of graphene/polydopamine/nickel foam composite material with excellent electrochemical performance as supercapacitor electrode

    Science.gov (United States)

    Zheng, Yu; Lu, Shixiang; Xu, Wenguo; He, Ge; Cheng, Yuanyuan; Yu, Tianlong; Zhang, Yan

    2018-02-01

    A three dimensional composite electrode consisted of reduced graphene oxide (rGO), polydopamine (PDA) and nickel foam (NF) (rGO/PDA/NF) was fabricated by immersing NF into PDA aqueous solution and then graphene oxide (GO) suspension solution respectively, and followed by annealing treatment. During the procedure, GO was coated on NF with assistance of cohesive effect of the PDA middle film, and the reduction of GO and nitrogen doping occurred simultaneously while annealing. Through XRD analyzing, the composites GO/PDA and rGO/PDA treated in experiment are amorphous. The resulted rGO/PDA/NF composite electrode was directly applied as a supercapacitor electrode and showed excellent electrochemical performance, with a high specific capacitance of 566.9 F g-1 at 1 A g-1, the maximum energy density of 172.7 W h kg-1 and a power density of 27.2 kW kg-1 in 1 mol L-1 Na2SO4 electrolyte.

  1. Facile synthesis of silver nanostructures by using various deposition potential and time: A nonenzymetic sensor for hydrogen peroxide

    Energy Technology Data Exchange (ETDEWEB)

    Amiri, Mandana, E-mail: mandanaamiri@uma.ac.ir [Department of Chemistry, University of Mohaghegh Ardabili, Ardabil (Iran, Islamic Republic of); Nouhi, Sima [Department of Chemistry, University of Mohaghegh Ardabili, Ardabil (Iran, Islamic Republic of); Azizian-Kalandaragh, Yashar [Department of Physics, University of Mohaghegh Ardabili, Ardabil (Iran, Islamic Republic of)

    2015-04-01

    Silver nanostructures have been successfully fabricated by using electrodeposition method onto indiumtinoxide (ITO) substrate. Scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and ultraviolet–visible spectroscopy (UV–Vis) techniques were employed for characterization of silver nanostructures. The results show nanostructures with different morphology and electrochemical properties can be obtained by various deposition potentials and times. Electrochemical behavior of the nanostructures has been studied by using cyclic voltammetry. Silver nanostructures exhibits good electrocatalytic activity towards the reduction of H{sub 2}O{sub 2}. The presented electrode can be employed as sensing element for hydrogen peroxide. - Highlights: • Silver nanostructures (AgNS) have been fabricated using electrodeposition ITO. • AgNS with different morphology and electrochemical properties obtained. • AgNS exhibits good electrocatalytic activity for reduction of H{sub 2}O{sub 2}.

  2. An economic approach to fabricate photo sensor based on nanostructured ZnO thin films

    Science.gov (United States)

    Huse, Nanasaheb; Upadhye, Deepak; Sharma, Ramphal

    2016-05-01

    Nanostructural ZnO Thin Films have been synthesized by simple and economic Chemical Bath Deposition technique onto glass substrate with bath temperature at 60°C for 1 hour. Structural, Optical, Electrical and topographical properties of the prepared Thin Films were investigated by GIXRD, I-V Measurement System, UV-Visible Spectrophotometer and AFM respectively. Calculated lattice parameters are in good agreement with the standard JCPDS card (36-1451) values, exhibits Hexagonal Wurtzite crystal structure. I-V Measurement curve has shown ohmic nature in dark condition and responds to light illumination which reveals Photo sensor properties. After illumination of 60W light, decrease in resistance was observed from 110.9 KΩ to 104.4 KΩ. The change in current and calculated Photo sensitivity was found to be 3.51 µA and 6.3% respectively. Optical band gap was found to be 3.24 eV. AFM images revealed uniform deposition over entire glass substrate with 32.27 nm average roughness of the film.

  3. Piezoelectric paper fabricated via nanostructured barium titanate functionalization of wood cellulose fibers.

    Science.gov (United States)

    Mahadeva, Suresha K; Walus, Konrad; Stoeber, Boris

    2014-05-28

    We have successfully developed hybrid piezoelectric paper through fiber functionalization that involves anchoring nanostructured BaTiO3 into a stable matrix with wood cellulose fibers prior to the process of making paper sheets. This is realized by alternating immersion of wood fibers in a solution of poly(diallyldimethylammonium chloride) PDDA (+), followed by poly(sodium 4-styrenesulfonate) PSS (-), and once again in PDDA (+), resulting in the creation of a positively charged surface on the wood fibers. The treated wood fibers are then immersed in a BaTiO3 suspension, resulting in the attachment of BaTiO3 nanoparticles to the wood fibers due to a strong electrostatic interaction. Zeta potential measurements, X-ray diffraction, and microscopic and spectroscopic analysis imply successful functionalization of wood fibers with BaTiO3 nanoparticles without altering the hydrogen bonding and crystal structure of the wood fibers. The paper has the largest piezoelectric coefficient, d33 = 4.8 ± 0.4 pC N(-1), at the highest nanoparticle loading of 48 wt % BaTiO3. This newly developed piezoelectric hybrid paper is promising as a low-cost substrate to build sensing devices.

  4. Fabrication of Silicon nanostructures by UHV-STM lithography in Self-Assembled Monolayers

    International Nuclear Information System (INIS)

    Sundermann, M.; Brechling, A.; Rott, K.; Meyners, D.; Kleineberg, U.; Heinzmann, U.; Knueller, A.; Eck, W.; Goelzhueuser, A.; Grunze, M.

    2002-01-01

    Our approach utilizes UHV-STM writing in Self-Assembled Monolayers (SAM). SAMs form highly-ordered ultrathin (∼2-3 nm) monomolecular layers on top of pre-activated Si(100) or Si(111) surfaces. After patterning by UHV-STM writing in constant-current mode at different write parameters (gap voltage, electron dose) the modified Self-Assembled Monolayer serves as an etch mask for an anisotropic wet etch transfer (two-step etch process in aqueous solutions of 5 % HF and 1 M KOH), of the write structure into the silicon substrate. The corresponding silicon nano-structures have been analyzed afterwards by AFM or SEM to characterize the pattern accuracy. We have studied the suitability of three different types of SAMs on silicon single-crystals. Alkyl-chain-type SAMs like Octadecylsilane (ODS) monolayer have been formed by immersion of hydroxylated Si(100) in Octadecyltrichlorosilane (CH 3 (CH 27 SiCl 3 ) while SAMs with aromatic spacer groups such as Hydroxybiphenyl (HBP, (C 6 H 6 ) 2 OH) and Ethoxybiphenyl silane (EBP, (C 6 H 6 ) 2 O(CH 2 ) 3 Si(OCH 3 ) 3 ) are formed on Si(111). (Authors)

  5. Selective Adsorption of Nano-bio materials and nanostructure fabrication on Molecular Resists Modified by proton beam irradiation

    International Nuclear Information System (INIS)

    Lee, H. W.; Kim, H. S.; Kim, S. M.

    2008-04-01

    The purpose of this research is the fabrication of nanostructures on silicon substrate using proton beam and selectively adsorption of bio-nano materials on the patterned substrate. Recently, the miniaturization of the integrated devices with fine functional structures was intensively investigated, based on combination of nanotechnology (NT), biotechnology (BT) and information technology (IT). Because of the inherent limitation in optical lithography, large variety of novel patterning technologies were evolved to construct nano-structures onto a substrate. Atomic force microscope-based nanolithography has readily formed sub-50 nm patterns by the local modification of a substrate using a probe with a curvature of 10 nm. The surface property was regarded as one of the most important factors for AFM-based nanolithography as well as for other novel nanolithographies. The molecular thin films such as a self-assembled monolayer or a polymer resist layer have been used as an alternative to modifying the surface property. Although proton or ion beam irradiation has been used as an efficient tool to modify the physical, chemical and electrical properties of a surface, the nano-patterning on the substrate or the molecular film modified with the beam irradiation has hardly been studied at both home and abroad. The selective adsorption of nano-bio materials such as carbon nanotubes and proteins on the patterns would contribute to developing the integrated devices. The polystyrene nanoparticles (400 nm) were arrayed on al silicon surface using nanosphere lithography and the various nanopatterns were fabricated by proton beam irradiation on the polystyrene nanoparticles arrayed silicon surface. We obtained the two different nanopatterns such as polymer nanoring patterns and silicon oxide patterns on the same silicon substrate. The polymer nanoring patterns formed by the crosslinkage of polystyrene when proton beam was irradiated at the triangular void spaces that are enclosed by

  6. Optimization of modified carbon paste electrode with multiwalled carbon nanotube/ionic liquid/cauliflower-like gold nanostructures for simultaneous determination of ascorbic acid, dopamine and uric acid

    Energy Technology Data Exchange (ETDEWEB)

    Afraz, Ahmadreza [Department of Physical Chemistry, Faculty of Chemistry, Bu-Ali Sina University, P.O. Box 65174, Hamedan (Iran, Islamic Republic of); Rafati, Amir Abbas, E-mail: aa_rafati@basu.ac.ir [Department of Physical Chemistry, Faculty of Chemistry, Bu-Ali Sina University, P.O. Box 65174, Hamedan (Iran, Islamic Republic of); Najafi, Mojgan [Department of Materials Engineering, Hamedan University of Technology (HUT), 65169 Hamedan (Iran, Islamic Republic of)

    2014-11-01

    We describe the modification of a carbon paste electrode (CPE) with multiwalled carbon nanotubes (MWCNTs) and an ionic liquid (IL). Electrochemical studies by using a D-optimal mixture design in Design-Expert software revealed an optimized composition of 60% graphite, 14.2% paraffin, 10.8% MWCNT and 15% IL. The optimal modified CPE shows good electrochemical properties that are well matched with model prediction parameters. In the next step, the optimized CPE was modified with gold nanostructures by applying a double-pulse electrochemical technique. The resulting electrode was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and electrochemical impedance spectroscopy. It gives three sharp and well-separated oxidation peaks for ascorbic acid (AA), dopamine (DA), and uric acid (UA). The sensor enables simultaneous determination of AA, DA and UA with linear responses from 0.3 to 285, 0.08 to 200, and 0.1 to 450 μM, respectively, and with 120, 30 and 30 nM detection limits (at an S/N of 3). The method was successfully applied to the determination of AA, DA, and UA in spiked samples of human serum and urine. - Highlights: • New method for simultaneous determination of AA, DA and UA was developed. • MWCNT/ionic liquid/cauliflower-like Au nanostructure was used for CPE modification. • Optimization of electrode composition was done by Design-Expert software. • The pH effect, peak separation mechanism and real samples was thoroughly studied.

  7. Optimization of modified carbon paste electrode with multiwalled carbon nanotube/ionic liquid/cauliflower-like gold nanostructures for simultaneous determination of ascorbic acid, dopamine and uric acid

    International Nuclear Information System (INIS)

    Afraz, Ahmadreza; Rafati, Amir Abbas; Najafi, Mojgan

    2014-01-01

    We describe the modification of a carbon paste electrode (CPE) with multiwalled carbon nanotubes (MWCNTs) and an ionic liquid (IL). Electrochemical studies by using a D-optimal mixture design in Design-Expert software revealed an optimized composition of 60% graphite, 14.2% paraffin, 10.8% MWCNT and 15% IL. The optimal modified CPE shows good electrochemical properties that are well matched with model prediction parameters. In the next step, the optimized CPE was modified with gold nanostructures by applying a double-pulse electrochemical technique. The resulting electrode was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and electrochemical impedance spectroscopy. It gives three sharp and well-separated oxidation peaks for ascorbic acid (AA), dopamine (DA), and uric acid (UA). The sensor enables simultaneous determination of AA, DA and UA with linear responses from 0.3 to 285, 0.08 to 200, and 0.1 to 450 μM, respectively, and with 120, 30 and 30 nM detection limits (at an S/N of 3). The method was successfully applied to the determination of AA, DA, and UA in spiked samples of human serum and urine. - Highlights: • New method for simultaneous determination of AA, DA and UA was developed. • MWCNT/ionic liquid/cauliflower-like Au nanostructure was used for CPE modification. • Optimization of electrode composition was done by Design-Expert software. • The pH effect, peak separation mechanism and real samples was thoroughly studied

  8. Fabrication of a nanosize-Pt-embedded membrane electrode assembly to enhance the utilization of Pt in proton exchange membrane fuel cells.

    Science.gov (United States)

    Choe, Junseok; Kim, Doyoung; Shim, Jinyong; Lee, Inhae; Tak, Yongsug

    2011-08-01

    A procedure to locate the Pt nanostructure inside the hydrophilic channel of a Nafion membrane was developed in order to enhance Pt utilization in PEMFCs. Nanosize Pt-embedded MEA was constructed by Cu electroless plating and subsequent Pt electrodeposition inside the hydrophilic channels of the Nafion membrane. The metallic Pt nanostructure fabricated inside the membrane was employed as an oxygen reduction catalyst for a PEMFC and facilitated effective use of the hydrophilic channels inside the membrane. Compared to the conventional MEA, a Pt-embedded MEA with only 68% Pt loading showed better PEMFC performance.

  9. Nano-structure fabrication for HgCdTe ultra-fast infrared sensors

    Science.gov (United States)

    Wang, Shao-Wei; Yang, Jianrong; Chen, Yifang; Zhen, Honglou; Chen, Xiaoshuang; Lu, Wei

    2009-09-01

    High-speed infrared sensors are necessary for broad applications in optic fibre communications with high data capacity and high security and distance sensing by laser. In this paper, an ultra-fast infrared sensor with 100 nm ballistic channels has been proposed and successfully fabricated by electron beam lithography. The area of photosensitive surface is as large as 100 μm × 100 μm to ensure its high sensitivity. The principle is based on the ballistic transport of electrons in the nano-scale channels. The frequency is expected to be in the range of 10 GHz, one or two orders higher than conventional photovoltaic sensors.

  10. Fabrication of porous boron-doped diamond electrodes by catalytic etching under hydrogen-argon plasma

    Science.gov (United States)

    Shi, Chao; Li, Cuiping; Li, Mingji; Li, Hongji; Dai, Wei; Wu, Yongheng; Yang, Baohe

    2016-01-01

    Porous boron-doped diamond (BDD) was prepared by hydrogen-argon plasma etching using electrodeposited Ni nanoparticles as a catalyst. The etching process and formation mechanism of porous BDD were investigated by changing the etching time from 30 s to 300 s. Pores were produced due to the C atoms around Ni nanoparticles are easy to react with hydrogen plasma and form methane. With the increase of etching time, the pore size increased, the pore density decreased, and the pore depth first increased and then maintained unchanged. The sp2-bonded graphitic carbons existing on the surface of BDD increase with increasing etching time due to the increase of surface area. No preferential etching was observed due to the high energy of argon plasma. The electrochemical behaviors of the pristine and porous BDD electrodes were characterized by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS). The results showed that the porous BDD electrode exhibited high specific capacitance, which is attributed to its high electrical conductivity and large specific surface area. The highest specific capacitance of porous BDD electrode is 9.55 mF cm-2, which is 22 times higher than that of pristine BDD electrode. The specific capacitance retention of the porous BDD electrode reduced to 98.2% of the initial capacitance after 500 cycles and then increased to 120.0% after 10,000 cycles. For the first 500 cycles, the reduction of capacitance can be attributed to the dissolution of Ni nanoparticles that attached on the porous BDD surface or buried in the shallow layer. The capacitance increase after 10,000 cycles is due to the better contact of the electrolytic solution with the residual Ni with the increase of cycle number.

  11. Fabrication of lithium titanate/graphene composites with high rate capability as electrode materials for hybrid electrochemical supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Rong, E-mail: xuerongsmile@qq.com; Yan, Jingwang, E-mail: yanjw@dicp.ac.cn; Jiang, Liang, E-mail: jiangliang@dicp.ac.cn; Yi, Baolian, E-mail: blyi@dicp.ac.cn

    2015-06-15

    A lithium titanate (Li{sub 4}Ti{sub 5}O{sub 12})/graphene composite (LTO/graphene) is fabricated with a one-pot sol–gel method. Graphite oxide is dispersed in an aqueous solution of lithium acetate and tetrabutyl titanate followed by heat treatment in H{sub 2}/Ar. The LTO/graphene composite with reduced aggregation and improved homogeneity is investigated as an anode material for electrochemical capacitors. Electron transport is improved by the conductive graphene network in the insulating Li{sub 4}Ti{sub 5}O{sub 12} particles. The charge transfer resistance at the particle/electrolyte interface is reduced from 83.1 Ω to 55.4 Ω. The specific capacity of LTO/graphene composite is 126 mAh g{sup −1} at 20C. The energy density and power density of a hybrid electrochemical supercapacitor with a LTO/graphene negative electrode and an activated carbon positive electrode are 120.8 Wh kg{sup −1} and 1.5 kW kg{sup −1}, respectively, which is comparable to that of conventional electrochemical double layer capacitors (EDLCs). The LTO/graphene composite fabricated by the one-pot sol–gel method is a promising anode material for hybrid electrochemical supercapacitors. - Highlights: • A Li{sub 4}Ti{sub 5}O{sub 12}/graphene composite was fabricated with a one-pot sol–gel method. • The Li{sub 4}Ti{sub 5}O{sub 12}/graphene composite showed a reduced aggregation and an improved homogeneity. • The Li{sub 4}Ti{sub 5}O{sub 12}/graphene based hybrid supercapacitor exhibited higher energy and power densities.

  12. Fabrication, appraisal, and transdermal permeation of sildenafil citrate-loaded nanostructured lipid carriers versus solid lipid nanoparticles

    Science.gov (United States)

    Elnaggar, Yosra SR; El-Massik, Magda A; Abdallah, Ossama Y

    2011-01-01

    Although sildenafil citrate (SC) is used extensively for erectile dysfunction, oral delivery of SC encounters many obstacles. Furthermore, the physicochemical characteristics of this amphoteric drug are challenging for delivery system formulation and transdermal permeation. This article concerns the assessment of the potential of nanomedicine for improving SC delivery and transdermal permeation. SC-loaded nanostructured lipid carriers (NLCs) and solid lipid nanoparticles (SLNs) were fabricated using a modified high-shear homogenization technique. Nanoparticle optimization steps included particle size analysis, entrapment efficiency (EE) determination, freeze-drying and reconstitution, differential scanning calorimetry, in vitro release, stability study and high-performance liquid chromatography analysis. Transdermal permeation of the nanocarriers compared with SC suspension across human skin was assessed using a modified Franz diffusion cell assembly. Results revealed that SLNs and NLCs could be optimized in the nanometric range (180 and 100 nm, respectively) with excellent EE (96.7% and 97.5%, respectively). Nanoparticles have significantly enhanced in vitro release and transdermal permeation of SC compared with its suspensions. Furthermore, transdermal permeation of SC exhibited higher initial release from both SLN and NLC formulations followed by controlled release, with promising implications for faster onset and longer drug duration. Nanomedicines prepared exhibited excellent physical stability for the study period. Solid nanoparticles optimized in this study successfully improved SC characteristics, paving the way for an efficient topical Viagra® product. PMID:22238508

  13. Effect of dielectric barrier discharge treatment on surface nanostructure and wettability of polylactic acid (PLA) nonwoven fabrics

    Science.gov (United States)

    Ren, Yu; Xu, Lin; Wang, Chunxia; Wang, Xiaona; Ding, Zhirong; Chen, Yuyue

    2017-12-01

    Polylactic acid (PLA) nonwoven fabrics are treated with atmospheric dielectric barrier discharge (DBD) plasma to improve surface wettability. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) show that micro- to nano-scale textures appear on the treated PLA surfaces dependent on the treatment time. X-ray photoelectron spectroscopy (XPS) analysis reveals that the DBD plasma treatments result in decreased carbon contents and increased oxygen contents as well as slightly increased nitrogen contents. The water contact angle decreases sharply with the increase of the DBD plasma treatment time. The super hydrophilic PLA surfaces (the water contact angle reached 0°) are obtained when the treatment time is longer than 90 s. Ninety days after the DBD plasma treatment, the XPS analysis shows that Csbnd O/Csbnd N and Cdbnd O/Osbnd Cdbnd O percentages decline for all treatment groups. However, the water contact angle is kept constant at 0° for the groups treated above 90 s, which could be due to the oxidized nano-structured layer on the DBD plasma treated PLA surfaces.

  14. Plasmonic nanostructures fabricated using nanosphere-lithography, soft-lithography and plasma etching

    Directory of Open Access Journals (Sweden)

    Manuel R. Gonçalves

    2011-08-01

    Full Text Available We present two routes for the fabrication of plasmonic structures based on nanosphere lithography templates. One route makes use of soft-lithography to obtain arrays of epoxy resin hemispheres, which, in a second step, can be coated by metal films. The second uses the hexagonal array of triangular structures, obtained by evaporation of a metal film on top of colloidal crystals, as a mask for reactive ion etching (RIE of the substrate. In this way, the triangular patterns of the mask are transferred to the substrate through etched triangular pillars. Making an epoxy resin cast of the pillars, coated with metal films, allows us to invert the structure and obtain arrays of triangular holes within the metal. Both fabrication methods illustrate the preparation of large arrays of nanocavities within metal films at low cost.Gold films of different thicknesses were evaporated on top of hemispherical structures of epoxy resin with different radii, and the reflectance and transmittance were measured for optical wavelengths. Experimental results show that the reflectivity of coated hemispheres is lower than that of coated polystyrene spheres of the same size, for certain wavelength bands. The spectral position of these bands correlates with the size of the hemispheres. In contrast, etched structures on quartz coated with gold films exhibit low reflectance and transmittance values for all wavelengths measured. Low transmittance and reflectance indicate high absorbance, which can be utilized in experiments requiring light confinement.

  15. Fabrication and hydrophobic characteristics of micro / nanostructures on polydimethylsiloxane surface prepared by picosecond laser

    Science.gov (United States)

    Bin, Wang; Dong, Shiyun; Yan, Shixing; Gang, Xiao; Xie, Zhiwei

    2018-03-01

    Picosecond laser has ultrashort pulse width and ultrastrong peak power, which makes it widely used in the field of micro-nanoscale fabrication. polydimethylsiloxane (PDMS) is a typical silicone elastomer with good hydrophobicity. In order to further improve the hydrophobicity of PDMS, the picosecond laser was used to fabricate a grid-like microstructure on the surface of PDMS, and the relationship between hydrophobicity of PDMS with surface microstructure and laser processing parameters, such as processing times and cell spacing was studied. The results show that: compared with the unprocessed PDMS, the presence of surface microstructure significantly improved the hydrophobicity of PDMS. When the number of processing is constant, the hydrophobicity of PDMS decreases with the increase of cell spacing. However, when the cell spacing is fixed, the hydrophobicity of PDMS first increases and then decreases with the increase of processing times. In particular, when the times of laser processing is 6 and the cell spacing is 50μm, the contact angle of PDMS increased from 113° to 154°, which reached the level of superhydrophobic.

  16. Hydrothermal carbon-based nanostructured hollow spheres as electrode materials for high-power lithium-sulfur batteries.

    Science.gov (United States)

    Brun, Nicolas; Sakaushi, Ken; Yu, Linghui; Giebeler, Lars; Eckert, Jürgen; Titirici, Magdalena M

    2013-04-28

    Carbon hollow spheres were produced using a sustainable approach, i.e. hydrothermal carbonization, using monosaccharides as carbon precursors and silica nanoparticles as hard-templates. Hydrothermal carbonization is an eco-efficient and cost-effective route to synthesize nanostructured carbonaceous materials from abundant biomass-derived molecules. After further thermal treatment under an inert atmosphere and removal of the silica-based core by chemical etching, porous hollow spheres depicting 5-8 nm thin shells were obtained. Subsequently, carbon-sulfur composites were synthesized via a melt diffusion method and used as nanostructured composites for cathodes in lithium-sulfur (Li-S) cells. The morphology of the hollow spheres was controlled and optimized to achieve improved electrochemical properties. Both high specific energies and high specific powers were obtained, due to the unique nanostructure of the hollow spheres. These results revealed that using optimized carbonaceous materials, it is possible to design sustainable Li-S cells showing promising electrochemical properties.

  17. Nano-honeycomb structured transparent electrode for enhanced light extraction from organic light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Xiao-Bo; Qian, Min; Wang, Zhao-Kui, E-mail: zkwang@suda.edu.cn, E-mail: lsliao@suda.edu.cn; Liao, Liang-Sheng, E-mail: zkwang@suda.edu.cn, E-mail: lsliao@suda.edu.cn [Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou, Jiangsu 215123 (China)

    2015-06-01

    A universal nano-sphere lithography method has been developed to fabricate nano-structured transparent electrode, such as indium tin oxide (ITO), for light extraction from organic light-emitting diodes (OLEDs). Perforated SiO{sub 2} film made from a monolayer colloidal crystal of polystyrene spheres and tetraethyl orthosilicate sol-gel is used as a template. Ordered nano-honeycomb pits on the ITO electrode surface are obtained by chemical etching. The proposed method can be utilized to form large-area nano-structured ITO electrode. More than two folds' enhancement in both current efficiency and power efficiency has been achieved in a red phosphorescent OLED which was fabricated on the nano-structured ITO substrate.

  18. Micellar Self-Assembly of Block Copolymers for Fabrication of Nanostructured Membranes

    KAUST Repository

    Marques, Debora S.

    2013-11-01

    This research work examines the process of block copolymer membrane fabrication by self-assembly combined by non-solvent induced phase separation. Self-assembly takes place from the preparation of the primordial solution until the moment of immersion in a non-solvent bath. These mechanisms are driven thermodynamically but are limited by kinetic factors. It is shown in this work how the ordering of the assembly of micelles is improved by the solution parameters such as solvent quality and concentration of block copolymer. Order transitions are detected, yielding changes in the morphology. The evaporation of the solvents after casting is demonstrated to be essential to reach optimum membrane structure. The non-solvent bath stops the phase separation at an optimum evaporation time.

  19. Fabrication of graphene/gold-modified screen-printed electrode for detection of carcinoembryonic antigen

    Energy Technology Data Exchange (ETDEWEB)

    Chan, K.F. [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, UPM Serdang, 43400 Selangor (Malaysia); Lim, H.N., E-mail: janetlimhn@gmail.com [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, UPM Serdang, 43400 Selangor (Malaysia); Shams, N. [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, UPM Serdang, 43400 Selangor (Malaysia); Jayabal, S.; Pandikumar, A.; Huang, N.M. [Low Dimensional Materials Research Centre (LDMRC), Physics Department, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2016-01-01

    Immunosensors based on gold nanoparticles and reduced graphene oxide (AuNPs/rGO)-modified screen-printed electrodes (SPEs) were successfully synthesized using an electrochemical deposition method. The modified SPEs were characterized using a field emission scanning electron microscope (FESEM) and Raman spectroscopy to analyze the morphology and composition of AuNPs and rGO. Both the FESEM and Raman spectroscopy revealed that the AuNPs were successfully anchored on the thin film of rGO deposited on the surface of the SPEs. Characterization with a ferri–ferrocyanide couple [Fe(CN){sub 6}{sup 3−/4−}] showed that the electron transfer kinetic between the analyte and electrode was enhanced after the modification with the AuNPs/rGO composite on the electrode surface, in addition to increasing the effective surface area of the electrode. The modified SPE was immobilized with a sandwich type immunosensor to mimic the ELISA (enzyme-linked immunosorbent assay) immunoassay. The modified SPE that was fortified with the sandwich type immunosensor exhibited double electrochemical responses in the detection of carcinoembryonic antigen (CEA), with linear ranges of 0.5–50 ng/mL and 250–2000 ng/mL and limits of detection of 0.28 ng/mL and 181.5 ng/mL, respectively. - Highlights: • An AuNP/rGO-modified SPE is prepared via an in-situ electrodeposition method. • It is introduced in a sandwich-type immunoassay for the detection of CEA. • The LODs for CEA are 0.28 ng/mL for 0.5–25 ng/mL, and 181.5 ng/mL for 250–2000 ng/mL.

  20. Toward practical all-solid-state lithium-ion batteries with high energy density and safety: Comparative study for electrodes fabricated by dry- and slurry-mixing processes

    Science.gov (United States)

    Nam, Young Jin; Oh, Dae Yang; Jung, Sung Hoo; Jung, Yoon Seok

    2018-01-01

    Owing to their potential for greater safety, higher energy density, and scalable fabrication, bulk-type all-solid-state lithium-ion batteries (ASLBs) employing deformable sulfide superionic conductors are considered highly promising for applications in battery electric vehicles. While fabrication of sheet-type electrodes is imperative from the practical point of view, reports on relevant research are scarce. This might be attributable to issues that complicate the slurry-based fabrication process and/or issues with ionic contacts and percolation. In this work, we systematically investigate the electrochemical performance of conventional dry-mixed electrodes and wet-slurry fabricated electrodes for ASLBs, by varying the different fractions of solid electrolytes and the mass loading. This information calls for a need to develop well-designed electrodes with better ionic contacts and to improve the ionic conductivity of solid electrolytes. As a scalable proof-of-concept to achieve better ionic contacts, a premixing process for active materials and solid electrolytes is demonstrated to significantly improve electrochemical performance. Pouch-type 80 × 60 mm2 all-solid-state LiNi0·6Co0·2Mn0·2O2/graphite full-cells fabricated by the slurry process show high cell-based energy density (184 W h kg-1 and 432 W h L-1). For the first time, their excellent safety is also demonstrated by simple tests (cutting with scissors and heating at 110 °C).

  1. Fabrication of Robust Reference Tips and Reference Electrodes for Kelvin Probe Applications in Changing Atmospheres.

    Science.gov (United States)

    Uebel, M; Vimalanandan, A; Laaboudi, A; Evers, S; Stratmann, M; Diesing, D; Rohwerder, M

    2017-10-17

    The scanning Kelvin probe (SKP) is a versatile method for the measurement of the Volta potential difference between a sample and the SKP-tip (Δψ sample SKP-tip ). Based on suitable calibration, this technique is highly suited for the application in corrosion science due to its ability to serve as a very sensitive noncontact and nondestructive method for determining the electrode potential, even at buried interfaces beneath coatings or on surfaces covered by ultrathin electrolyte layers, which are not accessible by standard reference electrodes. However, the potential of the reference (i.e., the SKP-tip) will be influenced by variations of the surrounding atmosphere, resulting in errors of the electrode potential referred to the sample. The objective of this work is to provide a stable SKP-tip which can be used in different or changing atmosphere, e.g., within a wide range of relative humidity (approximately 0-99%-rh) or varying O 2 partial pressure, without showing a change of its potential (note that the work functions measured in non-UHV atmospheres are electrochemical in nature [Hausbrand et al. J. Electrochem. Soc. 2008, 155 (7), C369-C379], and hence in the following we will refer to the potential of the SKP-tip instead of its work function). In that regard, the SKP-tip is in a first approach modified with self-assembled monolayers (SAMs) in order to create a hydrophobic barrier between the metallic surface and the surrounding atmosphere. The changes in potential upon varying relative humidity (ΔE rh ) of different bare metallic substrates are quantified, and it is shown that these potential differences cannot be minimized by SAMs. On the contrary, the ΔE rh increases for every examined material system modified with SAMs. The major explanation for this observation is the dipole layer at the interface metal|SAM, causing an interfacial adsorption of water molecules even in a preferred orientation of their dipole moments, which leads to a changed work

  2. Fabrication and characterization of transparent conducting titanium-zinc oxide nanostructured thin films

    Science.gov (United States)

    Lu, Zhou; Long, Lu; Zhong, Zhi-you; Hou, Jin; Yang, Chun-yong; Gu, Jin-hua; Long, Hao

    2016-03-01

    Nano transparent conducting titanium-zinc oxide (Ti-ZnO) thin films were prepared on glass substrates by radio frequency (RF) magnetron sputtering technique. The deposited films are characterized by X-ray diffraction (XRD), four-probe meter and UV-visible spectrophotometer. The effects of Ti-doping content on the structural, optical and electrical properties of the films are investigated. The XRD results show that the obtained films are polycrystalline with a hexagonal wurtzite structure and preferentially oriented in the (002) crystallographic direction. The structural and optoelectronic characteristics of the deposited films are subjected to the Ti-doping content. The Ti-ZnO sample fabricated with the Ti-doping content of 3% (weight percentage) possesses the best crystallinity and optoelectronic performance, with the highest degree of preferred (002) orientation of 99.87%, the largest crystallite size of 83.2 nm, the minimum lattice strain of 6.263×10-4, the highest average visible transmittance of 88.8%, the lowest resistivity of 1.18×10-3 Ω·cm and the maximum figure of merit ( FOM) of 7.08×103 Ω-1·cm-1. Furthermore, the optical bandgaps of the films are evaluated by extrapolation method and observed to be an increasing tendency with the increase of the Ti-doping content.

  3. Nanostructural characterization of large-scale porous alumina fabricated via anodizing in arsenic acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Akiya, Shunta; Kikuchi, Tatsuya, E-mail: kiku@eng.hokudai.ac.jp; Natsui, Shungo; Suzuki, Ryosuke O.

    2017-05-01

    Highlights: • Anodic porous alumina was formed in an arsenic acid solution. • Potential difference (voltage) anodizing at 340 V was achieved. • The porous alumina was slightly ordered under the appropriate conditions. • Pore sealing behavior was not observed in boiling distilled water. • The porous alumina exhibits a white photoluminescence emission under UV irradiation. - Abstract: Anodizing of aluminum in an arsenic acid solution is reported for the fabrication of anodic porous alumina. The highest potential difference (voltage) without oxide burning increased as the temperature and the concentration of the arsenic acid solution decreased, and a high anodizing potential difference of 340 V was achieved. An ordered porous alumina with several tens of cells was formed in 0.1–0.5 M arsenic acid solutions at 310–340 V for 20 h. However, the regularity of the porous alumina was not improved via anodizing for 72 h. No pore sealing behavior of the porous alumina was observed upon immersion in boiling distilled water, and it may be due to the formation of an insoluble complex on the oxide surface. The porous alumina consisted of two different layers: a hexagonal alumina layer that contained arsenic from the electrolyte and a pure alumina honeycomb skeleton. The porous alumina exhibited a white photoluminescence emission at approximately 515 nm under UV irradiation at 254 nm.

  4. Fabrication of chronocoulometric DNA sensor based on gold nanoparticles/poly(l-lysine) modified glassy carbon electrode.

    Science.gov (United States)

    Wang, Jie; Zhang, Shaojun; Zhang, Yuzhong

    2010-01-15

    In this work, we fabricated a sensitivity chronocoulometric DNA sensor (CDS) based on gold nanoparticles (AuNPs)/poly(L-lysine) complex film modified glassy carbon electrode. Hexaammineruthenium(III) chloride ([Ru(NH3)6]3+) was used as the electroactive indicator. The assembled process was investigated by cyclic voltammetry (CV) and chronocoulometry (CC). CC is used to monitor the DNA hybridization event by measurement of electrostatic binding [Ru(NH3)6]3+. Under the optimal conditions, the signal of [Ru(NH3)6]3+ was linear with the logarithm of the concentration of the complementary oligonucleotides from 1.0 x 10(-13) to 1.0 x 10(-11) M, and the detection limit is 3.5 x 10(-14) M.

  5. Fabrication and characterization of solid mercury amalgam electrodes for protein analysis

    Czech Academy of Sciences Publication Activity Database

    Jusková, Petra; Ostatná, Veronika; Paleček, Emil; Foret, František

    2010-01-01

    Roč. 82, č. 7 (2010), s. 2690-2695 ISSN 0003-2700 R&D Projects: GA MŠk(CZ) LC06035; GA AV ČR KAN400310651; GA MŠk ME09038; GA ČR GP202/07/P497 Institutional research plan: CEZ:AV0Z40310501; CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : microelectrodes * lithography * electrochemical detection * solid mercury amalgan electrode Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 5.874, year: 2010

  6. PEDOT:PSS Nanofilms Fabricated by a Nonconventional Coating Method for Uses as Transparent Conducting Electrodes in Flexible Electrochromic Devices

    Directory of Open Access Journals (Sweden)

    Kanyanee Sanglee

    2017-01-01

    Full Text Available Nanofilms of a polymer mixer of two ionomers, poly 3,4-ethylenedioxythiophene:poly(styrene sulfonic acid (PEDOT:PSS, were used as conducting materials to develop transparent conducting electrodes. It was firstly found that convective deposition, a versatile and wide-area coating method, could be used for the coating and acid treatment of PEDOT:PSS films. Electrical conductivity of the PEDOT:PSS films was significantly enhanced up to 1814 S/cm by only one-time surface treatment by a mild acid solution (4 M methanesulfonic acid. This is because some PSS chains were removed out from the polymer mixer films without damage on the substrates. UV-vis-NIR spectroscopy, Raman spectroscopy, and cyclic voltammetry were used to characterize the acid-treated transparent conducting films. In this report, obtained transparent conducting PEDOT:PSS films on polyester substrates were used as flexible electrodes for fabrication of flexible electrochromic devices. Poly(3-hexylthiophene (P3HT was used as an active layer, which its color changed reversibly from transparent-light blue to purple with a small applied voltage (±3 V.

  7. Fabrication of 3D rotor-like ZnO nanostructure from 1D ZnO nanorods and their morphology dependent photoluminescence property

    Science.gov (United States)

    Rai, Prabhakar; Jo, Jin-Nyeong; Lee, In-Hwan; Yu, Yeon-Tae

    2010-10-01

    A facile and eco-friendly sonochemical route to fabricate well-defined dentritic (rotor-like) ZnO nanostructures from 1D ZnO nanorods without alloying elements, templates and surfactants has been reported. Phase and structural analysis has been carried out by X-ray diffraction (XRD) and Fourier Transform Infra-Red (FTIR) spectroscopy, showed the formation of hexagonal wurtzite structure of ZnO. Scanning electron microscopic (SEM) study showed the formation of rotor-like ZnO nanostructure having a central core which is surrounded by side branches nanocones. Transmission electron microscopic (TEM) study showed that these nanocones grow along [0001] direction on the six {01-10} planes of central core ZnO nanorods. A plausible formation mechanism of rotor-like ZnO nanostructures was studied by SEM which indicates that the size and morphology of side branches can be controlled by adjusting the concentration of OH - ions and time duration of growth. The photoluminescence (PL) spectrum of the synthesized rotor-like ZnO nanostructures exhibited a weak ultraviolet emission at 400 nm and a strong green emission at 532 nm recorded at room temperature. The influence of morphology on the origin of green emission was discussed in detail. The results suggested a positive relationship among polar plane, oxygen vacancy and green emission.

  8. Hybrid nanostructured microporous carbon-mesoporous carbon doped titanium dioxide/sulfur composite positive electrode materials for rechargeable lithium-sulfur batteries

    Science.gov (United States)

    Zegeye, Tilahun Awoke; Kuo, Chung-Feng Jeffrey; Wotango, Aselefech Sorsa; Pan, Chun-Jern; Chen, Hung-Ming; Haregewoin, Atetegeb Meazah; Cheng, Ju-Hsiang; Su, Wei-Nien; Hwang, Bing-Joe

    2016-08-01

    Herein, we design hybrid nanostructured microporous carbon-mesoporous carbon doped titanium dioxide/sulfur composite (MC-Meso C-doped TiO2/S) as a positive electrode material for lithium-sulfur batteries. The hybrid MC-Meso C-doped TiO2 host material is produced by a low-cost, hydrothermal and annealing process. The resulting conductive material shows dual microporous and mesoporous behavior which enhances the effective trapping of sulfur and polysulfides. The hybrid MC-Meso C-doped TiO2/S composite material possesses rutile TiO2 nanotube structure with successful carbon doping while sulfur is uniformly distributed in the hybrid MC-Meso C-doped TiO2 composite materials after the melt-infusion process. The electrochemical measurement of the hybrid material also shows improved cycle stability and rate performance with high sulfur loading (61.04%). The material delivers an initial discharge capacity of 802 mAh g-1 and maintains it at 578 mAh g-1 with a columbic efficiency greater than 97.1% after 140 cycles at 0.1 C. This improvement is thought to be attributed to the unique hybrid nanostructure of the MC-Meso C-doped TiO2 host and the good dispersion of sulfur in the narrow pores of the MC spheres and the mesoporous C-doped TiO2 support.

  9. Fabrication of metal nanopatterns for organic field effect transistor electrodes by cracking and transfer printing

    Science.gov (United States)

    Wang, Xiaonan; Fu, Tingting; Wang, Zhe

    2018-04-01

    In this paper, we demonstrate a novel method for fabricating metal nanopatterns using cracking to address the limitations of traditional techniques. Parallel crack arrays were created in a polydimethylsiloxane (PDMS) mold using a combination of surface modification and control of strain fields. The elastic PDMS containing the crack arrays was subsequently used as a stamp to prepare nanoscale metal patterns on a substrate by transfer printing. To illustrate the functionality of this technique, we employed the metal patterns as the source and drain contacts of an organic field effect transistor. Using this approach, we fabricated transistors with channel lengths ranging from 70–600 nm. The performance of these devices when the channel length was reduced was studied. The drive current density increases as expected, indicating the creation of operational transistors with recognizable properties.

  10. Fabrication and properties of mechanically grooved silicon solar cells with buried contact Cu electrode

    Science.gov (United States)

    Jang, Pyungwoo; Jung, Chi-Sup; Kim, Kwang-Ho; Kyu, Seomoon

    2011-09-01

    Mechanically grooved silicon solar cells with buried contact copper electrode were attempted. In order to groove a simple mechanical grooving system was home-made, in which synchronous motors in hard disc driver (HDD), audio amplifier, signal generator were used. For the anti-reflection films sputtering condition for SiNx films was optimized. With increasing input power, pressure, index of refraction of the films increased so that a very low etching rate of 0.8 nm/min could be achieved with a condition of Ar and N2 flow rate of 5 SCCM, input power of 300 W and sputtering pressure of 1 × 10-2 torr. Annealing condition for the formation of nickel silicie from electroless plated Ni-P layer was optimized as well as plating condition of copper electrode. However, the conversion efficiency of the BCSC in this study is 3.6% which is unexpectedly small. It seems that the reason for the low efficiency is due to short circuit forming in the lancet of the pyramid.

  11. Self-Assembly of Crystalline Structures of Magnetic Core-Shell Nanoparticles for Fabrication of Nanostructured Materials.

    Science.gov (United States)

    Xue, Xiaozheng; Wang, Jianchao; Furlani, Edward P

    2015-10-14

    A theoretical study is presented of the template-assisted formation of crystalline superstructures of magnetic-dielectric core-shell particles. The templates produce highly localized gradient fields and a corresponding magnetic force that guides the assembly with nanoscale precision in particle placement. The process is studied using two distinct and complementary computational models that predict the dynamics and energy of the particles, respectively. Both mono- and polydisperse colloids are studied, and the analysis demonstrates for the first time that although the particles self-assemble into ordered crystalline superstructures, the particle formation is not unique. There is a Brownian motion-induced degeneracy in the process wherein various distinct, energetically comparable crystalline structures can form for a given template geometry. The models predict the formation of hexagonal close packed (HCP) and face centered cubic (FCC) structures as well as mixed phase structures due to in-plane stacking disorders, which is consistent with experimental observations. The polydisperse particle structures are less uniform than the monodisperse particle structures because of the irregular packing of different-sized particles. A comparison of self-assembly using soft- and hard-magnetic templates is also presented, the former being magnetized in a uniform field. This analysis shows that soft-magnetic templates enable an order-of-magnitude more rapid assembly and much higher spatial resolution in particle placement than their hard-magnetic counterparts. The self-assembly method discussed is versatile and broadly applies to arbitrary template geometries and multilayered and multifunctional mono- and polydisperse core-shell particles that have at least one magnetic component. As such, the method holds potential for the bottom-up fabrication of functional nanostructured materials for a broad range of applications. This work provides unprecedented insight into the assembly

  12. Fabrication process for CMUT arrays with polysilicon electrodes, nanometre precision cavity gaps and through-silicon vias

    Science.gov (United States)

    Due-Hansen, J.; Midtbø, K.; Poppe, E.; Summanwar, A.; Jensen, G. U.; Breivik, L.; Wang, D. T.; Schjølberg-Henriksen, K.

    2012-07-01

    Capacitive micromachined ultrasound transducers (CMUTs) can be used to realize miniature ultrasound probes. Through-silicon vias (TSVs) allow for close integration of the CMUT and read-out electronics. A fabrication process enabling the realization of a CMUT array with TSVs is being developed. The integrated process requires the formation of highly doped polysilicon electrodes with low surface roughness. A process for polysilicon film deposition, doping, CMP, RIE and thermal annealing that resulted in a film with sheet resistance of 4.0 Ω/□ and a surface roughness of 1 nm rms has been developed. The surface roughness of the polysilicon film was found to increase with higher phosphorus concentrations. The surface roughness also increased when oxygen was present in the thermal annealing ambient. The RIE process for etching CMUT cavities in the doped polysilicon gave a mean etch depth of 59.2 ± 3.9 nm and a uniformity across the wafer ranging from 1.0 to 4.7%. The two presented processes are key processes that enable the fabrication of CMUT arrays suitable for applications in for instance intravascular cardiology and gastrointestinal imaging.

  13. Fabrication process for CMUT arrays with polysilicon electrodes, nanometre precision cavity gaps and through-silicon vias

    International Nuclear Information System (INIS)

    Due-Hansen, J; Poppe, E; Summanwar, A; Jensen, G U; Breivik, L; Wang, D T; Schjølberg-Henriksen, K; Midtbø, K

    2012-01-01

    Capacitive micromachined ultrasound transducers (CMUTs) can be used to realize miniature ultrasound probes. Through-silicon vias (TSVs) allow for close integration of the CMUT and read-out electronics. A fabrication process enabling the realization of a CMUT array with TSVs is being developed. The integrated process requires the formation of highly doped polysilicon electrodes with low surface roughness. A process for polysilicon film deposition, doping, CMP, RIE and thermal annealing that resulted in a film with sheet resistance of 4.0 Ω/□ and a surface roughness of 1 nm rms has been developed. The surface roughness of the polysilicon film was found to increase with higher phosphorus concentrations. The surface roughness also increased when oxygen was present in the thermal annealing ambient. The RIE process for etching CMUT cavities in the doped polysilicon gave a mean etch depth of 59.2 ± 3.9 nm and a uniformity across the wafer ranging from 1.0 to 4.7%. The two presented processes are key processes that enable the fabrication of CMUT arrays suitable for applications in for instance intravascular cardiology and gastrointestinal imaging. (paper)

  14. The influence of electrical effects on device performance of organic solar cells with nano-structured electrodes

    DEFF Research Database (Denmark)

    Mirsafaei, Mina; Rubahn, Horst-Günter; Madsen, Morten

    2017-01-01

    in inorganic devices. While this light-trapping concept can be transferred to organic devices, one has to also consider nanostructure-induced electrical effects on the device performance, due to the fundamental difference in the organic semiconducting material properties compared to their inorganic......Integration of light-trapping features and exploitation of metal nanostructure plasmonic effects are promising approaches for enhancing the power conversion efficiency of organic solar cells. These approaches’ effects on the light absorption enhancement have been widely studied, especially...... counterparts. In this contribution, we exemplarily model the electrical properties of organic solar cells with rectangular-grating structures, as compared to planar reference devices. Based on our numeric results, we demonstrate that, beyond an optical absorption enhancement, the device fill factor improves...

  15. Nanostructured gold microelectrodes for extracellular recording

    Energy Technology Data Exchange (ETDEWEB)

    Brueggemann, Dorothea; Wolfrum, Bernhard; Maybeck, Vanessa; Offenhaeusser, Andreas [CNI Center of Nanoelectronic Systems for Information Technology and Institute of Bio- and Nanosystems 2, Forschungszentrum Juelich (Germany)

    2010-07-01

    Electrophysiological activity of electrogenic cells is currently recorded with planar bioelectronic interfaces such as microelectrode arrays (MEAs). In this work, a novel concept of biocompatible nanostructured gold MEAs for extracellular signal recording is presented. MEAs were fabricated using clean room technologies, e.g. photolithography and metallization. Subsequently, they were modified with gold nanopillars of approximately 300 to 400 nm in height and 60 nm width. The nanostructuring process was carried out with a template-assisted approach using nanoporous aluminium oxide. Impedance spectroscopy of the resulting nanostructures showed higher capacitances compared to planar gold. This confirmed the expected increase of the surface area via nanostructuring. We used the nanostructured microelectrodes to record extracellular potentials from heart muscle cells (HL1), which were plated onto the chips. Good coupling between the HL1 cells and the nanostructured electrodes was observed. The resulting signal-to-noise ratio of nanopillar-MEAs was increased by a factor of 2 compared to planar MEAs. In future applications this nanopillar concept can be adopted for distinct interface materials and coupling to cellular and molecular sensing components.

  16. Non-volatile resistive memory device fabricated from CdSe quantum dot embedded in thermally grown In2O3 nanostructure by oblique angle deposition

    Science.gov (United States)

    Kannan, V.; Kim, Hyun-Seok; Park, Hyun-Chang

    2016-11-01

    In this paper we report In2O3/CdSe quantum dot based non-volatile resistive memory device with ON/OFF ratio ∼1000. Indium nanostructures were grown by oblique angle deposition technique in a thermal evaporator. Indium oxide nanostructures had size ranging from 20 nm to 100 nm as observed from TEM and AFM methods. The facile device fabricated with a layer of CdSe quantum dot on indium oxide film exhibited excellent endurance characteristics over 100,000 switching cycles. Retention tests showed good stability for over 4000 s. Memory operating mechanism is proposed based on charge trapping/de-trapping in quantum dots with indium oxide acting as barrier leading to Coulomb blockade. The mechanism is supported by negative differential resistance (NDR) observed exclusively in the ON state.

  17. Hole-mask colloidal nanolithography combined with tilted-angle-rotation evaporation: A versatile method for fabrication of low-cost and large-area complex plasmonic nanostructures and metamaterials.

    Science.gov (United States)

    Zhao, Jun; Frank, Bettina; Neubrech, Frank; Zhang, Chunjie; Braun, Paul V; Giessen, Harald

    2014-01-01

    Many nano-optical applications require a suitable nanofabrication technology. Hole-mask colloidal nanolithography has proven to be a low-cost and large-area alternative for the fabrication of complex plasmonic nanostructures as well as metamaterials. In this paper, we describe the fabrication process step by step. We manufacture a variety of different plasmonic structures ranging from simple nano-antennas over complex chiral structures to stacked composite materials for applications such as sensing. Additionally, we give details on the control of the nanostructure lateral density which allows for the multilayer-fabrication of complex nanostructures. In two accompanying movies, the fabrication strategy is explained and details are being demonstrated in the lab. The movies can be found at the website of Beilstein TV.

  18. Optimization of modified carbon paste electrode with multiwalled carbon nanotube/ionic liquid/cauliflower-like gold nanostructures for simultaneous determination of ascorbic acid, dopamine and uric acid.

    Science.gov (United States)

    Afraz, Ahmadreza; Rafati, Amir Abbas; Najafi, Mojgan

    2014-11-01

    We describe the modification of a carbon paste electrode (CPE) with multiwalled carbon nanotubes (MWCNTs) and an ionic liquid (IL). Electrochemical studies by using a D-optimal mixture design in Design-Expert software revealed an optimized composition of 60% graphite, 14.2% paraffin, 10.8% MWCNT and 15% IL. The optimal modified CPE shows good electrochemical properties that are well matched with model prediction parameters. In the next step, the optimized CPE was modified with gold nanostructures by applying a double-pulse electrochemical technique. The resulting electrode was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and electrochemical impedance spectroscopy. It gives three sharp and well-separated oxidation peaks for ascorbic acid (AA), dopamine (DA), and uric acid (UA). The sensor enables simultaneous determination of AA, DA and UA with linear responses from 0.3 to 285, 0.08 to 200, and 0.1 to 450 μM, respectively, and with 120, 30 and 30 nM detection limits (at an S/N of 3). The method was successfully applied to the determination of AA, DA, and UA in spiked samples of human serum and urine. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Nanostructured CuO thin film electrodes prepared by spray pyrolysis: a simple method for enhancing the electrochemical performance of CuO in lithium cells

    International Nuclear Information System (INIS)

    Morales, Julian; Sanchez, Luis; Martin, Francisco; Ramos-Barrado, Jose R.; Sanchez, Miguel

    2004-01-01

    Nanostructured CuO thin films were prepared by using a spray pyrolysis method, copper acetate as precursor and stainless steel as substrate. The textural and structural properties of the films were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The SEM images revealed thorough coating of the substrate and thickness of 450-1250 nm; the average particle size as determined from the AFM images ranged from 30 to 160 nm. The XRD patterns revealed the formation of CuO alone and the XPS spectra confirmed the presence of Cu 2+ as the main oxidation state on the surface. The films were tested as electrodes in lithium cells and their electrochemical properties evaluated from galvanostatic and step potential electrochemical spectroscopy (SPES) measurements. The discharge STEP curves exhibited various peaks consistent with the processes CuO Cu 2 O Cu and with decomposition of the electrolyte, a reversible process in the light of the AFM images. The best electrode exhibited capacity values of 625 Ah kg -1 over more than 100 cycles. This value, which involves a CuO Cu reversible global reaction, is ca. 50% higher than that reported for bulk CuO. The nanosize of the particles and the good adherence of the active material to the substrate are thought to be the key factors accounting for the enhanced electrochemical activity found

  20. XPS and NRA investigations during the fabrication of gold nanostructured functionalized screen-printed sensors for the detection of metallic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Jasmin, Jean-Philippe [Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement, UMR 8587, CNRS-Université Evry Val d’Essonne-CEA, 1 rue du père Jarlan, 91025 Evry Cedex (France); Miserque, Frédéric [Den-Service de la Corrosion et du Comportement des Matériaux dans leur Environnement (SCCME), CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Dumas, Eddy [Institut Lavoisier de Versailles, UMR 8180, CNRS-Université de Versailles Saint-Quentin-en-Yvelines, 78035 Versailles (France); Vickridge, Ian; Ganem, Jean-Jacques [INSP, UMR 7588, CNRS- Université Pierre et Marie Curie, 4 place Jussieu, boîte courrier 840 75252 Paris, Cedex 05 (France); Cannizzo, Caroline, E-mail: caroline.cannizzo@univ-evry.fr [Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement, UMR 8587, CNRS-Université Evry Val d’Essonne-CEA, 1 rue du père Jarlan, 91025 Evry Cedex (France); Chaussé, Annie [Laboratoire Analyse et Modélisation pour la Biologie et l’Environnement, UMR 8587, CNRS-Université Evry Val d’Essonne-CEA, 1 rue du père Jarlan, 91025 Evry Cedex (France)

    2017-03-01

    Highlights: • Functionalized nanostructured SPEs were made by multi-step diazonium salt chemistry. • Investigation of SPEs surface by XPS and NRA shows monolayer coverage by aminobenzyl groups. • Complete conversion of aminobenzyl groups into diazonium functions was also evidenced. • Covalent grafting of AuNPs onto SPEs lead to an unusual modification of Au-4f core level spectrum. • Ligand and lead signals showed the interest of nanostructurated SPEs for trace metals detection. - Abstract: An all covalent nanostructured lead sensor was built by the successive grafting of gold nanoparticles and carboxylic ligands at the surface of self-adhesive carbon screen-printed electrodes (SPEs). Surface analysis techniques were used in each step in order to investigate the structuration of this sensor. The self-adhesive surfaces were made from the electrochemical grafting of p-phenylenediamine at the surface of the SPEs via diazonium salts chemistry. The quantity of grafted aniline functions, estimated by Nuclear Reaction Analysis (NRA) performed with p-phenylenediamine labelled with {sup 15}N isotope, is in agreement with an almost complete coverage of the electrode surface. The subsequent diazotization of the aniline functions at the surface of the SPEs was performed; X-ray Photoelectron Spectroscopy (XPS) allowed us to consider a quantitative conversion of the aniline functions into diazonium moieties. The spontaneous grafting of gold nanoparticles on the as-obtained reactive surfaces ensures the nanostructuration of the material, and XPS studies showed that the covalent bonding of the gold nanoparticles at the surface of the SPEs induces a change both in the Au-4f (gold nanoparticles) and Cl-2p (carbon ink) core level signals. These unusual observations are explained by an interaction between the carbon ink constituting the substrate and the gold nanoparticles. Heavy and toxic metals are considered of major environmental concern because of their non

  1. Graphene-assisted room-temperature synthesis of 2D nanostructured hybrid electrode materials: dramatic acceleration of the formation rate of 2D metal oxide nanoplates induced by reduced graphene oxide nanosheets.

    Science.gov (United States)

    Sung, Da-Young; Gunjakar, Jayavant L; Kim, Tae Woo; Kim, In Young; Lee, Yu Ri; Hwang, Seong-Ju

    2013-05-27

    A new prompt room temperature synthetic route to 2D nanostructured metal oxide-graphene-hybrid electrode materials can be developed by the application of colloidal reduced graphene oxide (RGO) nanosheets as an efficient reaction accelerator for the synthesis of δ-MnO2 2D nanoplates. Whereas the synthesis of the 2D nanostructured δ-MnO2 at room temperature requires treating divalent manganese compounds with persulfate ions for at least 24 h, the addition of RGO nanosheet causes a dramatic shortening of synthesis time to 1 h, underscoring its effectiveness for the promotion of the formation of 2D nanostructured metal oxide. To the best of our knowledge, this is the first example of the accelerated synthesis of 2D nanostructured hybrid material induced by the RGO nanosheets. The observed acceleration of nanoplate formation upon the addition of RGO nanosheets is attributable to the enhancement of the oxidizing power of persulfate ions, the increase of the solubility of precursor MnCO3, and the promoted crystal growth of δ-MnO2 2D nanoplates. The resulting hybridization between RGO nanosheets and δ-MnO2 nanoplates is quite powerful not only in increasing the surface area of manganese oxide nanoplate but also in enhancing its electrochemical activity. Of prime importance is that the present δ-MnO2 -RGO nanocomposites show much superior electrode performance over most of 2D nanostructured manganate systems including a similar porous assembly of RGO and layered MnO2 nanosheets. This result underscores that the present RGO-assisted solution-based synthesis can provide a prompt and scalable method to produce nanostructured hybrid electrode materials. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. MEMS fabrication and frequency sweep for suspending beam and plate electrode in electrostatic capacitor

    Science.gov (United States)

    Zhu, Jianxiong; Song, Weixing

    2018-01-01

    We report a MEMS fabrication and frequency sweep for a high-order mode suspending beam and plate layer in electrostatic micro-gap semiconductor capacitor. This suspended beam and plate was designed with silicon oxide (SiO2) film which was fabricated using bulk silicon micromachining technology on both side of a silicon substrate. The designed semiconductor capacitors were driven by a bias direct current (DC) and a sweep frequency alternative current (AC) in a room temperature for an electrical response test. Finite element calculating software was used to evaluate the deformation mode around its high-order response frequency. Compared a single capacitor with a high-order response frequency (0.42 MHz) and a 1 × 2 array parallel capacitor, we found that the 1 × 2 array parallel capacitor had a broader high-order response range. And it concluded that a DC bias voltage can be used to modulate a high-order response frequency for both a single and 1 × 2 array parallel capacitors.

  3. Oxygen vacancy mediated enhanced photo-absorption from ZnO(0001) nanostructures fabricated by atom beam sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Solanki, Vanaraj; Joshi, Shalik R.; Mishra, Indrani; Varma, Shikha, E-mail: shikha@iopb.res.in [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005 (India); Kabiraj, D.; Avasthi, D. K. [Inter University Accelerator Center, New Delhi 110067 (India); Mishra, N. C. [Department of Physics, Utkal University, Bhubaneswar 751004 (India)

    2016-08-07

    The nanoscale patterns created on the ZnO(0001) surfaces during atom beam irradiation have been investigated here for their photo absorption response. Preferential sputtering, during irradiation, promotes Zn-rich zones that serve as the nucleation centers for the spontaneous creation of nanostructures. Nanostructured surfaces with bigger (78 nm) nanodots, displaying hexagonal ordering and long ranged periodic behavior, show higher photo absorption and a ∼0.09 eV reduced bandgap. These nanostructures also demonstrate higher concentration of oxygen vacancies which are crucial for these results. The enhanced photo-response, as observed here, has been achieved in the absence of any dopant elements.

  4. XPS and NRA investigations during the fabrication of gold nanostructured functionalized screen-printed sensors for the detection of metallic pollutants

    Science.gov (United States)

    Jasmin, Jean-Philippe; Miserque, Frédéric; Dumas, Eddy; Vickridge, Ian; Ganem, Jean-Jacques; Cannizzo, Caroline; Chaussé, Annie

    2017-03-01

    An all covalent nanostructured lead sensor was built by the successive grafting of gold nanoparticles and carboxylic ligands at the surface of self-adhesive carbon screen-printed electrodes (SPEs). Surface analysis techniques were used in each step in order to investigate the structuration of this sensor. The self-adhesive surfaces were made from the electrochemical grafting of p-phenylenediamine at the surface of the SPEs via diazonium salts chemistry. The quantity of grafted aniline functions, estimated by Nuclear Reaction Analysis (NRA) performed with p-phenylenediamine labelled with 15N isotope, is in agreement with an almost complete coverage of the electrode surface. The subsequent diazotization of the aniline functions at the surface of the SPEs was performed; X-ray Photoelectron Spectroscopy (XPS) allowed us to consider a quantitative conversion of the aniline functions into diazonium moieties. The spontaneous grafting of gold nanoparticles on the as-obtained reactive surfaces ensures the nanostructuration of the material, and XPS studies showed that the covalent bonding of the gold nanoparticles at the surface of the SPEs induces a change both in the Au-4f (gold nanoparticles) and Cl-2p (carbon ink) core level signals. These unusual observations are explained by an interaction between the carbon ink constituting the substrate and the gold nanoparticles. Heavy and toxic metals are considered of major environmental concern because of their non-biodegradability. In a final step, the grafting of the carboxylic ligands at the surface of the SPEs and an accumulation step in the presence of lead(II) cations allowed us to evidence the interest of nanostructured materials as metallic pollutants sensors.

  5. High-performance binder-free supercapacitor electrode by direct growth of cobalt-manganese composite oxide nansostructures on nickel foam

    Science.gov (United States)

    Jiang, Shulan; Shi, Tielin; Long, Hu; Sun, Yongming; Zhou, Wei; Tang, Zirong

    2014-09-01

    A facile approach composed of hydrothermal process and annealing treatment is proposed to directly grow cobalt-manganese composite oxide ((Co,Mn)3O4) nanostructures on three-dimensional (3D) conductive nickel (Ni) foam for a supercapacitor electrode. The as-fabricated porous electrode exhibits excellent rate capability and high specific capacitance of 840.2 F g-1 at the current density of 10 A g-1, and the electrode also shows excellent cycling performance, which retains 102% of its initial discharge capacitance after 7,000 cycles. The fabricated binder-free hierarchical composite electrode with superior electrochemical performance is a promising candidate for high-performance supercapacitors.

  6. PVP assisted hydrothermal fabrication and morphology-controllable fabrication of BiFeO{sub 3} uniform nanostructures with enhanced photocatalytic activities

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xingfu; Mao, Weiwei [Key Laboratory for Organic Electronics & Information Displays (KLOEID), Synergetic Innovation Center for Organic Electronics and Information Displays (SICOEID), Institute of Advanced Materials - IAM, School of Materials Science and Engineering - SMSE, Nanjing University of Posts and Telecommunications - NUPT, Nanjing 210023 (China); School of Science, Advanced Energy Technology Center, Nanjing University of Posts and Telecommunications (NUPT), Nanjing 210023 (China); Zhang, Qiaoxia; Wang, Qi; Zhu, Yiyi; Zhang, Jian; Yang, Tao [Key Laboratory for Organic Electronics & Information Displays (KLOEID), Synergetic Innovation Center for Organic Electronics and Information Displays (SICOEID), Institute of Advanced Materials - IAM, School of Materials Science and Engineering - SMSE, Nanjing University of Posts and Telecommunications - NUPT, Nanjing 210023 (China); Yang, Jianping [School of Science, Advanced Energy Technology Center, Nanjing University of Posts and Telecommunications - NUPT, Nanjing 210023 (China); Li, Xing' ao, E-mail: lxahbmy@126.com [Key Laboratory for Organic Electronics & Information Displays (KLOEID), Synergetic Innovation Center for Organic Electronics and Information Displays (SICOEID), Institute of Advanced Materials - IAM, School of Materials Science and Engineering - SMSE, Nanjing University of Posts and Telecommunications - NUPT, Nanjing 210023 (China); Huang, Wei, E-mail: iamwhuang@njupt.edu.cn [Key Laboratory for Organic Electronics & Information Displays (KLOEID), Synergetic Innovation Center for Organic Electronics and Information Displays (SICOEID), Institute of Advanced Materials - IAM, School of Materials Science and Engineering - SMSE, Nanjing University of Posts and Telecommunications - NUPT, Nanjing 210023 (China); Key Laboratory of Flexible Electronics (KLOFE), Institute of Advanced Materials (IAM), National Synergistic Innovation Center for Advanced Materials - SICAM, Nanjing Tech University - NanjingTech, 30 South Puzhu Road, Nanjing 211816 (China)

    2016-08-25

    Bismuth ferrite (BiFeO{sub 3}) nanostructures with various morphologies (spindles, cubes and plates) have been successfully synthesized via a convenient one-pot hydrothermal method. The results show that three kinds of BiFeO{sub 3} products were obtained in this polyvinylpyrrolidone (PVP)-assisted hydrothermal reaction under different alkaline conditions. The resulting nanostructures were characterized using XRD and SEM. Possible formation mechanism for BiFeO{sub 3} nanostructures was proposed on the basis of our results. The experiments showed that the visible light absorptive capacity of the BiFeO{sub 3} nanostructures was significant influenced on the size and morphology. Notably, the as-prepared BiFeO{sub 3} plates with (104) facets exposed exhibit high efficiency for the degradation of methyl orange (MO) under visible light irradiation, suggesting potential applications in photocatalytic and related areas under visible light. - Highlights: • BiFeO{sub 3} nanostructures were synthesized via a PVP-assisted hydrothermal method. • The effect of the PVP and alkaline concentration was investigated. • The visible light absorptive capacity was significant influenced on the morphology. • The photocatalytic activity of the as-prepared BiFeO{sub 3} plates is the best.

  7. Fabrication and photoelectrocatalytic properties of nanocrystalline monoclinic BiVO4 thin-film electrode.

    Science.gov (United States)

    Zhou, Bin; Qu, Jiuhui; Zhao, Xu; Liu, Huijuan

    2011-01-01

    Monoclinic bismuth vanadate (BiVO4) thin film was fabricated on indium-tin oxide glass from an amorphous heteronuclear complex via dip-coating. After annealation at 400, 500, and 600 degrees C, the thin films were characterized by X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectroscopy, and UV-Vis spectrophotometry. The BiVO4 particles on the ITO glass surface had a monoclinic structure. The UV-Visible diffuse reflection spectra showed the BiVO4 thin film had photoabsorption properties, with a band gap around 2.5 eV. In addition, the thin film showed high visible photocatalytic activities towards 2,4-dichlorophenol and Bisphenol A degradation under visible light irradiation (lambda > 420 nm). Over 90% of the two organic pollutants were removed in 5 hr. A possible degradation mechanism of 2,4-dichlorophenol were also studied.

  8. Fabrication of high-performance metal ion doped iron oxide electrode for supercapacitor applications through a novel platform

    Science.gov (United States)

    Aghazadeh, Mustafa; Karimzadeh, Isa

    2017-10-01

    We provide a novel electrodeposition platform of undoped and Eu3+ doped iron oxide nanoparticles (Eu-IONPs) from an additive-free electrolyte containing Fe(NO3)3, FeCl2 and EuCl3. The prepared IONPs were analyzed using x-ray diffraction, field emission electron microscopy and energy-dispersive x-ray techniques, and the obtained data showed successful electrosynthesis of magnetite nanoparticles (size  ≈  10 nm) doped with about 10 wt% Eu3+ ions. The Eu-IONPs were used as supercapacitor electrode materials, and characterized by cyclic voltammetry and galvanostatic charge–discharge measurements. The as-synthesized Eu-IONPs exhibit remarkable pseudocapacitive activities including high specific capacitances of 212.5 and 153.2 F g‑1 at 0.5 and 2 A g‑1, respectively, and excellent cycling stabilities of 93.9% and 86.5% after 2000 discharging cycles. Furthermore, vibrational sample magnetometer data confirmed better superparamagnetic performance of Eu-IONPs (Ms  =  72.8 emu g‑1, Mr  =  0.24 emu g‑1 and H Ci  =  3.48 G) as compared with pure IONPs (Ms  =  51.92 emu g‑1, Mr  =  0.95 emu g‑1 and H Ci  =  14.62 G) due to exhibiting lower Mr and H Ci values. This novel synthetic platform of metal ion doped iron oxide is potentially a convenient way to fabricate high-performance iron oxide electrodes for energy storage systems.

  9. Fabrication of ZnO nanorods for NO{sub 2} sensor applications: Effect of dimensions and electrode position

    Energy Technology Data Exchange (ETDEWEB)

    Öztürk, Sadullah [Gebze Institute of Technology, Science Faculty, Department of Physics, 41400 Gebze, Kocaeli (Turkey); Kılınç, Necmettin, E-mail: nkilinc@gyte.edu.tr [Gebze Institute of Technology, Science Faculty, Department of Physics, 41400 Gebze, Kocaeli (Turkey); Koc University, Electrical and Electronics Engineering, 34450 Sariyer, Istanbul (Turkey); Öztürk, Zafer Ziya [Gebze Institute of Technology, Science Faculty, Department of Physics, 41400 Gebze, Kocaeli (Turkey); TÜBİTAK-Marmara Research Center, Materials Institute, 41470 Gebze, Kocaeli (Turkey)

    2013-12-25

    Highlights: •ZnO nanorods with various dimensions were prepared by hydrothermal method. •NO{sub 2} gas sensing properties of the nanorods was investigated depending on various parameters. •The highest sensor response was observed for ZnO nanorod with 60 nm in diameter. •The response and recovery times of sensors decreased with increasing temperature. •The all sensors were fully recovered above temperature of 100 °C. -- Abstract: In this study, zinc oxide (ZnO) nanorods were fabricated by using hydrothermal method and resistive type nitrogen dioxide (NO{sub 2}) sensing properties of the nanorods were investigated depending on temperature, NO{sub 2} concentration, electrode position and the dimension of the nanorods. To produce ZnO seed layer, zinc acetate solution was coated on a glass substrate by using spin-coater. ZnO nanorods were grown by changing concentration of solution at 90 °C for 3 h onto seed layer coated substrate. ZnO nanorods were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was observed that the diameters of ZnO nanorods were approximately 30 nm, 60 nm and 120 nm depending on solution concentration. For gas sensing measurements, interdigitated Au electrodes were coated on top or bottom of ZnO nanorods by using thermal evaporator. All samples were tested against to NO{sub 2} in dry air ambient depending on concentration (100 ppb–1 ppm) in the temperature range of 25–200 °C. The highest sensor response was observed for ZnO nanorods that were 60 nm in diameter. The response and recovery times for all sensors decreased with increasing temperature and the sensors were fully recovered above temperature of 100 °C.

  10. Fabrication of three-dimensional suspended, interlayered and hierarchical nanostructures by accuracy-improved electron beam lithography overlay.

    Science.gov (United States)

    Yoon, Gwanho; Kim, Inki; So, Sunae; Mun, Jungho; Kim, Minkyung; Rho, Junsuk

    2017-07-27