Sample records for micro assay devices



    The present invention relates to a device for use in performing assays on standard laboratory solid supports whereon chemical entities are attached. The invention furthermore relates to the use of such a device and a kit comprising such a device. The device according to the present invention is a......, when operatively connected, one or more chambers (21) comprising the chemical entities (41), the inlet(s) (5) and outlet(s) (6) and chambers (21) being in fluid connection. The device further comprise means for providing differing chemical conditions in each chamber (21)....

  2. Micro-Organ Device

    Gonda, Steve R. (Inventor); Chang, Robert C. (Inventor); Starly, Binil (Inventor); Culbertson, Christopher (Inventor); Holtorf, Heidi L. (Inventor); Sun, Wei (Inventor); Leslie, Julia (Inventor)


    A method for fabricating a micro-organ device comprises providing a microscale support having one or more microfluidic channels and one or more micro-chambers for housing a micro-organ and printing a micro-organ on the microscale support using a cell suspension in a syringe controlled by a computer-aided tissue engineering system, wherein the cell suspension comprises cells suspended in a solution containing a material that functions as a three-dimensional scaffold. The printing is performed with the computer-aided tissue engineering system according to a particular pattern. The micro-organ device comprises at least one micro-chamber each housing a micro-organ; and at least one microfluidic channel connected to the micro-chamber, wherein the micro-organ comprises cells arranged in a configuration that includes microscale spacing between portions of the cells to facilitate diffusion exchange between the cells and a medium supplied from the at least one microfluidic channel.

  3. Micro Embossing of Ceramic Green Substrates for Micro Devices

    Shan, X -C; Maw, H P; Lu, C W; Lam, Y C


    Multilayered ceramic substrates with embedded micro patterns are becoming increasingly important, for example, in harsh environment electronics and microfluidic devices. Fabrication of these embedded micro patterns, such as micro channels, cavities and vias, is a challenge. This study focuses on the process of patterning micro features on ceramic green substrates using micro embossing. A ceramic green tape that possessed near-zero shrinkage in the x-y plane was used, six layers of which were laminated as the embossing substrate. The process parameters that impact on the pattern fidelity were investigated and optimized in this study. Micro features with line-width as small as several micrometers were formed on the ceramic green substrates. The dynamic thermo-mechanical analysis indicated that extending the holding time at certain temperature range would harden the green substrates with little effect on improving the embossing fidelity. Ceramic substrates with embossed micro patterns were obtain d after co-firi...

  4. Methods and devices for protein assays

    Chhabra, Swapnil; Cintron, Jose M.; Shediac, Renee


    Methods and devices for protein assays based on Edman degradation in microfluidic channels are disclosed herein. As disclosed, the cleaved amino acid residues may be immobilized in an array format and identified by detectable labels, such as antibodies, which specifically bind given amino acid residues. Alternatively, the antibodies are immobilized in an array format and the cleaved amino acids are labeled identified by being bound by the antibodies in the array.

  5. Pressure-driven microfluidic perfusion culture device for integrated dose-response assays.

    Hattori, Koji; Sugiura, Shinji; Kanamori, Toshiyuki


    Cell-based assays are widely used in the various stages of drug discovery. Advances in microfluidic systems over the past two decades have enabled them to become a powerful tool for cell-based assays to achieve both reliability and high throughput. The interface between the micro-world and macro-world is important in industrial assay processes. Therefore, microfluidic cell-based assays using pressure-driven liquid handling are an ideal platform for integrated assays. The aim of this article is to review recent advancements in microfluidic cell-based assays focusing on a pressure-driven perfusion culture device. Here, we review the development of microfluidic cell-based assay devices and discuss the techniques involved in designing a microfluidic network, device fabrication, liquid and cell manipulation, and detection schemes for pressure-driven perfusion culture devices. Finally, we describe recent progress in semiautomatic and reliable pressure-driven microfluidic cell-based assays.

  6. Micro and smart devices and systems

    Ananthasuresh, G; Pratap, Rudra; Krupanidhi, S


    The book presents cutting-edge research in the emerging fields of micro, nano, and smart devices and systems from experts working in these fields over the last decade. Most of the contributors have built devices or systems or developed processes or algorithms in these areas. The book is a unique collection of chapters from different areas with a common theme and is immensely useful to academic researchers and practitioners in the industry who work in this field.

  7. Hierarchical Design Method for Micro Device

    Zheng Liu


    Full Text Available Traditional mask-beginning design flow of micro device is unintuitive and fussy for designers. A hierarchical design method and involved key technologies for features mapping procedure are presented. With the feature-based design framework, the model of micro device is organized by various features in different designing stages, which can be converted into each other based on the mapping rules. The feature technology is the foundation of the three-level design flow that provides a more efficient design way. In system level, functional features provide the top level of schematic and functional description. After the functional mapping procedure, on the other hand, parametric design features construct the 3D model of micro device in device level, which is based on Hybird Model representation. By means of constraint features, the corresponding revision rules are applied to the rough model to optimize the original structure. As a result, the model reconstruction algorithm makes benefit for the model revision and constraint features mapping process. Moreover, the formulating description of manufacturing features derivation provides the automatic way for model conversion.

  8. Medical Devices; Immunology and Microbiology Devices; Classification of the Assayed Quality Control Material for Clinical Microbiology Assays. Final order.


    The Food and Drug Administration (FDA, Agency, or we) is classifying the assayed quality control material for clinical microbiology assays into class II (special controls). The special controls that will apply to the device are identified in this order and will be part of the codified language for the assayed quality control material for clinical microbiology assays' classification. The Agency is classifying the device into class II (special controls) to provide a reasonable assurance of safety and effectiveness of the device.

  9. Colorimetric micro-assay for accelerated screening of mould inhibitors

    Carol A. Clausen; Vina W. Yang


    Since current standard laboratory methods are time-consuming macro-assays that rely on subjective visual ratings of mould growth, rapid and quantitative laboratory methods are needed to screen potential mould inhibitors for use in and on cellulose-based products. A colorimetric micro-assay has been developed that uses XTT tetrazolium salt to enzymatically assess...

  10. VARTA micro batteries for wireless telecommunication devices

    Ilic, D.; Heydecke, J.; Kilb, M.; Knop, I.; Schulz, G.

    Newly developed nickel-metal hydride (Ni/MH) micro cells that are capable of high rates, meet the requirements of main power sources for modern wireless telecommunication devices, like GSM hand phones, PDAs and others. Besides having the capability to give high continuous and pulse discharge currents, they also ensure the realisation of a device with slim design and low cost. For the back-up of the RTC function, a lithium-ion cell based on the carbon-manganese dioxide system provides high reliability by having a long cycle life and complete tolerance to deep discharge. For MBU (which require higher rates), a Ni/MH cell only 2 mm thick is now being introduced. Other wireless devices, like headsets for comfortable use of mobiles whilst driving, wireless mice and keyboards and the upcoming "Bluetooth" technology will need suitable power sources. Besides the rather high currents, which exclude low-power lithium systems, miniaturisation is limiting the space available for the battery. Some concepts using Ni/MH micro batteries will be discussed in this paper.

  11. Bio-barcode gel assay for microRNA

    Lee, Hyojin; Park, Jeong-Eun; Nam, Jwa-Min


    MicroRNA has been identified as a potential biomarker because expression level of microRNA is correlated with various cancers. Its detection at low concentrations would be highly beneficial for cancer diagnosis. Here, we develop a new type of a DNA-modified gold nanoparticle-based bio-barcode assay that uses a conventional gel electrophoresis platform and potassium cyanide chemistry and show this assay can detect microRNA at aM levels without enzymatic amplification. It is also shown that single-base-mismatched microRNA can be differentiated from perfectly matched microRNA and the multiplexed detection of various combinations of microRNA sequences is possible with this approach. Finally, differently expressed microRNA levels are selectively detected from cancer cells using the bio-barcode gel assay, and the results are compared with conventional polymerase chain reaction-based results. The method and results shown herein pave the way for practical use of a conventional gel electrophoresis for detecting biomolecules of interest even at aM level without polymerase chain reaction amplification.

  12. Micro-Combined Heat and Power Device Test Facility

    Federal Laboratory Consortium — NIST has developed a test facility for micro-combined heat and power (micro-CHP) devices to measure their performance over a range of different operating strategies...

  13. Systems, devices, and methods for agglutination assays using sedimentation

    Schaff, Ulrich Y.; Sommer, Gregory J.; Singh, Anup K.


    Embodiments of the present invention include methods for conducting agglutination assays using sedimentation. Aggregates may be exposed to sedimentation forces and travel through a density medium to a detection area. Microfluidic devices, such as microfluidic disks, are described for conducting the agglutination assays, as are systems for conducting the assays.

  14. Integration of electrochemistry in micro-total analysis systems for biochemical assays: recent developments.

    Xu, Xiaoli; Zhang, Song; Chen, Hui; Kong, Jilie


    Micro-total analysis systems (microTAS) integrate different analytical operations like sample preparation, separation and detection into a single microfabricated device. With the outstanding advantages of low cost, satisfactory analytical efficiency and flexibility in design, highly integrated and miniaturized devices from the concept of microTAS have gained widespread applications, especially in biochemical assays. Electrochemistry is shown to be quite compatible with microanalytical systems for biochemical assays, because of its attractive merits such as simplicity, rapidity, high sensitivity, reduced power consumption, and sample/reagent economy. This review presents recent developments in the integration of electrochemistry in microdevices for biochemical assays. Ingenious microelectrode design and fabrication methods, and versatility of electrochemical techniques are involved. Practical applications of such integrated microsystem in biochemical assays are focused on in situ analysis, point-of-care testing and portable devices. Electrochemical techniques are apparently suited to microsystems, since easy microfabrication of electrochemical elements and a high degree of integration with multi-analytical functions can be achieved at low cost. Such integrated microsystems will play an increasingly important role for analysis of small volume biochemical samples. Work is in progress toward new microdevice design and applications.

  15. A screwing device for handling and assembly of micro screws

    Gegeckaite, Asta; Hansen, Hans Nørgaard; Eriksson, Torbjörn Gerhard


    Nowadays, the application of specially designed handling devices in micro technology is an important topic and a necessity for the industry. Conventional methods for screwing can not be applied directly to micro screws. This is caused by the 3D micro object geometry and dimensions which inducing ...

  16. Micro- and nanoelectronics emerging device challenges and solutions

    Brozek, Tomasz


    Micro- and Nanoelectronics: Emerging Device Challenges and Solutions presents a comprehensive overview of the current state of the art of micro- and nanoelectronics, covering the field from fundamental science and material properties to novel ways of making nanodevices. Containing contributions from experts in both industry and academia, this cutting-edge text:Discusses emerging silicon devices for CMOS technologies, fully depleted device architectures, characteristics, and scalingExplains the specifics of silicon compound devices (SiGe, SiC) and their unique propertiesExplores various options

  17. A Sensitive Chemotaxis Assay Using a Novel Microfluidic Device

    Chen Zhang


    Full Text Available Existing chemotaxis assays do not generate stable chemotactic gradients and thus—over time—functionally measure only nonspecific random motion (chemokinesis. In comparison, microfluidic technology has the capacity to generate a tightly controlled microenvironment that can be stably maintained for extended periods of time and is, therefore, amenable to adaptation for assaying chemotaxis. We describe here a novel microfluidic device for sensitive assay of cellular migration and show its application for evaluating the chemotaxis of smooth muscle cells in a chemokine gradient.

  18. Micro Computer Tomography for medical device and pharmaceutical packaging analysis.

    Hindelang, Florine; Zurbach, Raphael; Roggo, Yves


    Biomedical device and medicine product manufacturing are long processes facing global competition. As technology evolves with time, the level of quality, safety and reliability increases simultaneously. Micro Computer Tomography (Micro CT) is a tool allowing a deep investigation of products: it can contribute to quality improvement. This article presents the numerous applications of Micro CT for medical device and pharmaceutical packaging analysis. The samples investigated confirmed CT suitability for verification of integrity, measurements and defect detections in a non-destructive manner. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Hollow micro string based calorimeter device


    The present invention relates to a micron-scale calorimeter and a calorimetry method utilizing the micron-scale calorimeter. In accordance with the invention, there is provided a micron-scale calorimeter comprising a micro-channel string, being restrained at at least two longitudinally distanced...... positions so as to form a free released double clamped string in-between said two longitudinally distanced positions said micro-channel string comprising a microfluidic channel having a closed cross section and extending in the longitudinal direction of the hollow string, acoustical means adapted...


    Dong Sup Lee; Su Jin Kim; Jun Ho Sohn; In Gul Kim; Sae WoongKim; Dong Wan Sohn; Jong Hyun Kim; Bumkyoo Choi


    We evaluated the biocompatibility of a dimethylpolysiloxane-coated micro-device which had been designed for monitoring real-time bladder volume in previous studies.The extract assay with dimethylpolysiloxane which had been used for coating the micro-device to measure the bladder volume was performed as an in vitro cytotoxicity test.For in vivo biocompatibility testing,the inflammatory responses around the implantation site of the micro-device in subcutaneous tissue of rat were assessed by light microscope with H&E stain and fluorescence microscope with ED1 stain and von Willebrand factor stain.The averages of cell viability in dimethylpolysiloxane group were 84.6% and 82.3% at 24 h and 72 h incubation,respectively.The qualitative evaluations with light and fluorescence microscope revealed that the inflammatory changes peaked during 2 weeks but almost disappeared at 4 weeks after implantation of devices.The quantitative evaluations for granulation layer formation and neovascularization showed that the thickness of the layer in dimethylpolysiloxane group peaked during 2 weeks but it came to be stabilized at 4 weeks as thin as at 2 weeks in control group,and the frequency of neovascularization was higher in dimetbylpolysiloxane group than in control group but it was not increased with time.The dimethylpolysiloxane-coated micro-device is thought be a reliable bio-medical device.

  1. Medical Devices; Immunology and Microbiology Devices; Classification of Trichomonas Vaginalis Nucleic Acid Assay. Final order.


    The Food and Drug Administration (FDA) is classifying a Trichomonas vaginalis nucleic acid assay into class II (special controls). The Agency is classifying the device into class II (special controls) in order to provide a reasonable assurance of safety and effectiveness of the device.

  2. Micro-Fluidic Device for Drug Delivery

    Beebe, David J. (Inventor); MacDonald, Michael J. (Inventor); Eddington, David T. (Inventor); Mensing, Glennys A. (Inventor)


    A microfluidic device is provided for delivering a drug to an individual. The microfluidic device includes a body that defines a reservoir for receiving the drug therein. A valve interconnects the reservoir to an output needle that is insertable into the skin of an individual. A pressure source urges the drug from the reservoir toward the needle. The valve is movable between a closed position preventing the flow of the drug from the reservoir to the output needle and an open position allowing for the flow of the drug from the reservoir to the output needle in response to a predetermined condition in the physiological fluids of the individual.

  3. IMAPS Device Packaging Conference 2017 - Engineered Micro Systems & Devices Track

    Varnavas, Kosta


    NASA field center Marshall Space Flight Center (Huntsville, AL), has invested in advanced wireless sensor technology development. Developments for a wireless microcontroller back-end were primarily focused on the commercial Synapse Wireless family of devices. These devices have many useful features for NASA applications, good characteristics and the ability to be programmed Over-The-Air (OTA). The effort has focused on two widely used sensor types, mechanical strain gauges and thermal sensors. Mechanical strain gauges are used extensively in NASA structural testing and even on vehicle instrumentation systems. Additionally, thermal monitoring with many types of sensors is extensively used. These thermal sensors include thermocouples of all types, resistive temperature devices (RTDs), diodes and other thermal sensor types. The wireless thermal board will accommodate all of these types of sensor inputs to an analog front end. The analog front end on each of the sensors interfaces to the Synapse wireless microcontroller, based on the Atmel Atmega128 device. Once the analog sensor output data is digitized by the onboard analog to digital converter (A/D), the data is available for analysis, computation or transmission. Various hardware features allow custom embedded software to manage battery power to enhance battery life. This technology development fits nicely into using numerous additional sensor front ends, including some of the low-cost printed circuit board capacitive moisture content sensors currently being developed at Auburn University.

  4. Miniaturized analytical instrumentation for electrochemiluminescence assays: a spectrometer and a photodiode-based device.

    Neves, Marta M P S; Bobes-Limenes, Pablo; Pérez-Junquera, Alejandro; González-García, María Begoña; Hernández-Santos, David; Fanjul-Bolado, Pablo


    Herein, a new miniaturized analytical instrumentation for electrochemiluminescence (ECL) assays is presented. A photodiode integrated in an ECL cell combined with a potentiostat/galvanostat, all integrated in a one-piece instrument (μSTAT ECL), was developed. In addition, a complementary micro-spectrometer integrated in a similar ECL cell for luminescence spectra recording is also proposed. Both cells are intended to be used with screen-printed electrodes and all the devices are portable and small sized. Their performance was corroborated with two innovative proofs-of-concept that centered on the luminol transduction chemistry: a first time reported ECL assay based on the enzymatic reaction between an indoxyl substrate and the enzyme alkaline phosphatase, and the electrochemiluminescence resonance energy transfer (ECL-RET) process triggered by the electro-oxidized luminol to the acceptor fluorescein. The photodiode system revealed to be more sensitive than the spectrometer device in collecting the light; however, with the latter, it is possible to discriminate different luminescent species according to their maximum wavelength emission, which is extremely useful for carrying out simple and simultaneous ECL multiplex analyzes. The spectrometer device works as an excellent accessory to couple with the μSTAT ECL instrument, complementing the experiments. Graphical abstract Schematic representation of the ECL-RET: from luminol-H2O2 system to fluorescein, the micro-spectrometer for the light collection and the 3D representation of the ECL-RET reaction.

  5. Tunable photonic devices and modules based on micro-optomechatronics

    Katagiri, Yoshitada


    Photonic devices with ultra-wide and precise controllability for lightwaves are essential for constructing flexible optical networks to serve versatile multimedia applications. However, conventional monolithically fabricated photonic devices suffer from their controllability being limited by the physical characteristics. Micro-optomechatronics based on precise positional control of optical elements is a promising method of meeting the above requirements. This paper presents typical examples, which include repetition- rate tunable optical pulse sources with a micro mechanically controllable cavity length and synchro-scanned tunable disk- shaped optical fiber modules. The operations of these modules were demonstrated to confirm the validity of micro- optomechatronics as the ultimate lightwave control scheme, which will be useful for future optical telecommunications systems.

  6. Micro Data: Wearable Devices Contribute to Improved Chronic Disease Management.

    Bianchi, Andria; Parke, Bob


    Issues involving chronic disease prevention and management (CDPM) are prevalent in today's aging society, and suggestions for improvement are essential to treat this patient demographic effectively. This article addresses the use of wearable devices for the medical community to improve CDPM by relying on the accumulation of micro data. For the patient, we recognize that these devices can be an effective tool to facilitate real-time monitoring of their vital signs and activity levels. With real-time monitoring and earlier responses, individuals can benefit by preventing, delaying or reducing exacerbations of chronic diseases. Use of these devices also has great benefit to the person and has the potential to decrease the individual's emergency room visits, hospital admissions and re-admissions. As patients and their healthcare providers work together to identify cumulative trends in their micro data, transitions in care planning will be enhanced, further contributing to improved chronic disease management.

  7. Devices, systems, and methods for conducting sandwich assays using sedimentation

    Schaff, Ulrich Y; Sommer, Gregory J; Singh, Anup K; Hatch, Anson V


    Embodiments of the present invention are directed toward devices, systems, and method for conducting sandwich assays using sedimentation. In one example, a method includes generating complexes on a plurality of beads in a fluid sample, individual ones of the complexes comprising a capture agent, a target analyte, and a labeling agent. The plurality of beads including the complexes may be transported through a density media, wherein the density media has a density lower than a density of the beads and higher than a density of the fluid sample, and wherein the transporting occurs, at least in part, by sedimentation. Signal may be detected from the labeling agents of the complexes.

  8. Micro-scale and microfluidic devices for neurobiology.

    Taylor, Anne M; Jeon, Noo Li


    The precise spatial and temporal control afforded by microfluidic devices make them uniquely suited as experimental tools for cellular neuroscience. Micro-structures have been developed to direct the placement of cells and small organisms within a device. Microfluidics can precisely define pharmacological microenvironments, mimicking conditions found in vivo with the advantage of defined parameters which are usually difficult to control and manipulate in vivo. These devices are compatible with high-resolution microscopy, are simple to assemble, and are reproducible. In this review we will focus on microfluidic devices that have recently been developed for small, whole organisms such as C. elegans and dissociated cultured neurons. These devices have improved control over the placement of cells or organisms and allowed unprecedented experimental access, enabling novel investigations in neurobiology.

  9. Two component micro injection moulding for moulded interconnect devices

    Islam, Aminul


    Moulded interconnect devices (MIDs) contain huge possibilities for many applications in micro electro-mechanical-systems because of their capability of reducing the number of components, process steps and finally in miniaturization of the product. Among the available MID process chains, two...... and a reasonable adhesion between them. • Selective metallization of the two component plastic part (coating one polymer with metal and leaving the other one uncoated) To overcome these two main issues in MID fabrication for micro applications, the current Ph.D. project explores the technical difficulties...

  10. Micro fabrication of biodegradable polymer drug delivery devices

    Nagstrup, Johan

    The pharmaceutical industry is presently facing several obstacles in developing oral drug delivery systems. This is primarily due to the nature of the discovered drug candidates. The discovered drugs often have poor solubility and low permeability across the gastro intestinal epithelium. Furtherm...... the developed devices. Additionally, it has been shown that it is possible to control the release of drug by adding polymeric coatings........ Furthermore, they are often degraded before they can be absorbed. The result is low bioavailability of the drugs. To overcome these challenges, better drug delivery systems need to be developed. Recently, micro systems have emerged as promising candidates to solve the challenges of poor solubility, low...... permeability and degradation. These systems are for the majority based on traditional materials used in micro technology, such as SU-8, silicon, poly(methyl methacrylate). The next step in developing these new drug delivery systems is to replace classical micro fabrication materials with biodegradable polymers...

  11. Fabrication of Micro -Optical Devices by a Femtosecond Laser

    Kazuyuki; Hirao


    Femtosecond laser is a perfect laser source for materials processing when high accuracy and small structure size are required. Due to the ultra short interaction time and the high peak power, the process is generally characterized by the absence of heat diffusion and, consequently molten layers. Various induced structures have been observed in materials after the femtosecond laser irradiation. Here, we report on fabrication of micro-optical devices by the femtosecond laser. 1) formation of optical waveg...

  12. 3D Printed Micro Free-Flow Electrophoresis Device.

    Anciaux, Sarah K; Geiger, Matthew; Bowser, Michael T


    The cost, time, and restrictions on creative flexibility associated with current fabrication methods present significant challenges in the development and application of microfluidic devices. Additive manufacturing, also referred to as three-dimensional (3D) printing, provides many advantages over existing methods. With 3D printing, devices can be made in a cost-effective manner with the ability to rapidly prototype new designs. We have fabricated a micro free-flow electrophoresis (μFFE) device using a low-cost, consumer-grade 3D printer. Test prints were performed to determine the minimum feature sizes that could be reproducibly produced using 3D printing fabrication. Microfluidic ridges could be fabricated with dimensions as small as 20 μm high × 640 μm wide. Minimum valley dimensions were 30 μm wide × 130 μm wide. An acetone vapor bath was used to smooth acrylonitrile-butadiene-styrene (ABS) surfaces and facilitate bonding of fully enclosed channels. The surfaces of the 3D-printed features were profiled and compared to a similar device fabricated in a glass substrate. Stable stream profiles were obtained in a 3D-printed μFFE device. Separations of fluorescent dyes in the 3D-printed device and its glass counterpart were comparable. A μFFE separation of myoglobin and cytochrome c was also demonstrated on a 3D-printed device. Limits of detection for rhodamine 110 were determined to be 2 and 0.3 nM for the 3D-printed and glass devices, respectively.

  13. Micro and nano devices in passive millimetre wave imaging systems

    Appleby, R.


    The impact of micro and nano technology on millimetre wave imaging from the post war years to the present day is reviewed. In the 1950s whisker contacted diodes in mixers and vacuum tubes were used to realise both radiometers and radars but required considerable skill to realise the performance needed. Development of planar semiconductor devices such as Gunn and Schottky diodes revolutionised mixer performance and provided considerable improvement. The next major breakthrough was high frequency transistors based on gallium arsenide which were initially used at intermediate frequencies but later after further development at millimeter wave frequencies. More recently Monolithic Microwave Integrated circuits(MMICs) offer exceptional performance and the opportunity for innovative design in passive imaging systems. In the future the use of micro and nano technology will continue to drive system performance and we can expect to see integration of antennae, millimetre wave and sub millimetre wave circuits and signal processing.

  14. Isothermal circular-strand-displacement polymerization of DNA and microRNA in digital microfluidic devices.

    Giuffrida, Maria Chiara; Zanoli, Laura Maria; D'Agata, Roberta; Finotti, Alessia; Gambari, Roberto; Spoto, Giuseppe


    Nucleic-acid amplification is a crucial step in nucleic-acid-sequence-detection assays. The use of digital microfluidic devices to miniaturize amplification techniques reduces the required sample volume and the analysis time and offers new possibilities for process automation and integration in a single device. The recently introduced droplet polymerase-chain-reaction (PCR) amplification methods require repeated cycles of two or three temperature-dependent steps during the amplification of the nucleic-acid target sequence. In contrast, low-temperature isothermal-amplification methods have no need for thermal cycling, thus requiring simplified microfluidic-device features. Here, the combined use of digital microfluidics and molecular-beacon (MB)-assisted isothermal circular-strand-displacement polymerization (ICSDP) to detect microRNA-210 sequences is described. MicroRNA-210 has been described as the most consistently and predominantly upregulated hypoxia-inducible factor. The nmol L(-1)-pmol L(-1) detection capabilities of the method were first tested by targeting single-stranded DNA sequences from the genetically modified Roundup Ready soybean. The ability of the droplet-ICSDP method to discriminate between full-matched, single-mismatched, and unrelated sequences was also investigated. The detection of a range of nmol L(-1)-pmol L(-1) microRNA-210 solutions compartmentalized in nanoliter-sized droplets was performed, establishing the ability of the method to detect as little as 10(-18) mol of microRNA target sequences compartmentalized in 20 nL droplets. The suitability of the method for biological samples was tested by detecting microRNA-210 from transfected K562 cells.

  15. Liquid as template for next generation micro devices

    Charmet, Jerome; Haquette, Henri; Laux, Edith; Keppner, Herbert [HES-SO ARC, Institut des Microtechnologies Appliquees, La Chaux de Fonds (Switzerland); Gorodyska, Ganna; Textor, Marcus [ETHZ, BioInterfaceGroup, Zuerich (Switzerland); Durante, Guido Spinola; Portuondo-Campa, Erwin; Knapp, Helmut [CSEM Centre Suisse d' Electronique et de Microtechnique SA, Alpnach (Switzerland); Bitterli, Roland; Noell, Wilfried, E-mail: Jerome.Charmet@he-arc.c [Ecole Polytechnique Federale de Lausanne, Institute of Microengineering, Sensors, Actuators and Microsystems laboratory, Rue Jaquet Droz 1, 2000 Neuchatel (Switzerland)


    Liquids have fascinated generations of scientists and engineers. Since ancient Greece, the perfect natural shape of liquids has been used to create optical systems. Nowadays, the natural shape of liquid is used in the fabrication of microlens arrays that rely on the melting of glass or photoresist to generate high quality lenses. However shrinkage normally associated to the liquid to solid phase transition will affect the initial shape and quality of the liquid structure. In this contribution, a novel fabrication technique that enables the encapsulation and replication of liquid templates without affecting their natural shape is presented. The SOLID (SOlid on LIquid Deposition) process allows for a transparent solid film to be deposited and grown onto a liquid template (droplet, film, line) in a way that the liquid shapes the overgrowing solid layer. The resulting configuration of the SOLID devices is chemically and mechanically stable and is the base of a huge variety of new micro-nano systems in the field of microfluidics, biomedical devices and micro-optics among others. The SOLID process enables in a one step process the encapsulation of liquid microlenses, fluidics channels, drug reservoir or any naturally driven liquid structure. The phenomenon and solid-liquid interface resulting from the SOLID process is new and still unexploited. The solid layer used for the SOLID process chosen in this paper is poly-para-xylylene called Parylene, a transparent biocompatible polymer with excellent mechanical and chemical properties. Moreover, as the solid layer is growing over a liquid template, atomically smooth surfaces channels can be obtained. The polymerization of Parylene does not exert stress and does not change the shape of the liquid; this latter aspect is particularly interesting for manufacturing naturally driven liquid structures. In this paper the authors explore the limits of this new method by testing different designs of SOLID encapsulated structures and

  16. Fabrication of Micro -Optical Devices by a Femtosecond Laser

    Jianrong Qiu; Kazuyuki Hirao


    Femtosecond laser is a perfect laser source for materials processing when high accuracy and small structure size are required. Due to the ultra short interaction time and the high peak power, the process is generally characterized by the absence of heat diffusion and, consequently molten layers. Various induced structures have been observed in materials after the femtosecond laser irradiation. Here, we report on fabrication of micro-optical devices by the femtosecond laser. 1) formation of optical waveguide with internal loss less than 0.5dB/cm in the wavelength region from 1.2 to 1.6 mm, by translating a silica glass perpendicular to the axis of the focused femtosecond laser beam; 2) nano-scale valence state manipulation of active ions inside transparent materials; 3) space-selective precipitation and control of metal nanoparticles inside transparent materials; The mechanisms and applications of the femtosecond laser induced phenomena were also discussed.

  17. From micro- to nanostructured implantable device for local anesthetic delivery.

    Zorzetto, Laura; Brambilla, Paola; Marcello, Elena; Bloise, Nora; De Gregori, Manuela; Cobianchi, Lorenzo; Peloso, Andrea; Allegri, Massimo; Visai, Livia; Petrini, Paola


    Local anesthetics block the transmission of painful stimuli to the brain by acting on ion channels of nociceptor fibers, and find application in the management of acute and chronic pain. Despite the key role they play in modern medicine, their cardio and neurotoxicity (together with their short half-life) stress the need for developing implantable devices for tailored local drug release, with the aim of counterbalancing their side effects and prolonging their pharmacological activity. This review discusses the evolution of the physical forms of local anesthetic delivery systems during the past decades. Depending on the use of different biocompatible materials (degradable polyesters, thermosensitive hydrogels, and liposomes and hydrogels from natural polymers) and manufacturing processes, these systems can be classified as films or micro- or nanostructured devices. We analyze and summarize the production techniques according to this classification, focusing on their relative advantages and disadvantages. The most relevant trend reported in this work highlights the effort of moving from microstructured to nanostructured systems, with the aim of reaching a scale comparable to the biological environment. Improved intracellular penetration compared to microstructured systems, indeed, provides specific drug absorption into the targeted tissue and can lead to an enhancement of its bioavailability and retention time. Nanostructured systems are realized by the modification of existing manufacturing processes (interfacial deposition and nanoprecipitation for degradable polyester particles and high- or low-temperature homogenization for liposomes) or development of novel strategies (electrospun matrices and nanogels). The high surface-to-volume ratio that characterizes nanostructured devices often leads to a burst drug release. This drawback needs to be addressed to fully exploit the advantage of the interaction between the target tissues and the drug: possible strategies

  18. Towards molecular gas flows in micro propulsion devices

    Groll, Rodion; Rath, Hans J.

    Developing micro propulsion devices like cold gas thrusters the geometry has to be optimized for the varying pressure and temperature fields inside the unit. Modelling diluted gas flows in microchannels the influence of the mean free path of molecules has to be respected describing pressure drop and specific momentum of a micro-propulsion unit. With the molecule mass factor the density is given used for a five-equation-system modelling the momentum and heat diffusion inside a channel flow for higher Knudsen numbers. The five equations are transport equation for the three mean velocity components, the velocity standard deviation and the molecule collision rate. The present model does not base on the definition of a Dirichlet boundary condition. The momentum boundary condition is given by a shear stress function depending on the collision rate and the standard deviation square of the molecule velocity. With this new wall stress modelling method the slip velocity results from the computation of the transported parameters. The present model is validated computing Poiseuille and Couette flows with different Knudsen numbers. Showing the advantages of the present model the simulation results are compared with simulation results of the wall-distance depending diffusivity model of Lockerby and Reese and BGK results of a Lattice-Boltzmann simulation.

  19. A Cell Lysis and Protein Purification - Single Molecule Assay Devices for Evaluation of Genetically Engineered Proteins

    Nakyama, Tetsuya; Tabata, Kazuhito; Noji, Hiroyuki; Yokokawa, Ryuji

    We have developed two devices applicable to evaluate genetically engineered proteins in single molecule assay: on-chip cell lysis device, and protein purification - assay device. A motor protein, F1-ATPase expressed in E.coli, was focused in this report as a target protein. Cell lysis was simply performed by applying pulse voltage between Au electrodes patterned by photolithography, and its efficiency was determined by absorptiometry. The subsequent processes, purification and assay of extracted proteins, were demonstrated in order to detect F1-ATPase and to evaluate its activity. The specific bonding between his-tag in F1-ATPase and Ni-NTA coated on a glass surface was utilized for the purification process. After immobilization of F1-ATPase, avidin-coated microspheres and adenosine tri-phosphate (ATP) solution were infused sequentially to assay the protein. Microsphere rotation was realized by activity of F1-ATPase corresponding to ATP hydrolysis. Results show that the cell lysis device, at the optimum condition, extracts enough amount of protein for single molecule assay. Once cell lysate was injected to the purification - assay device, proteins were diffused in the lateral direction in a Y-shape microchannel. The gradient of protein concentratioin provides an optimal concentration for the assay i.e. the highest density of rotating beads. Density of rotating beads is also affected by the initial concentration of protein injected to the device. The optimum concentration was achieved by our cell lysis device not by the conventional method by ultrasonic wave. Rotation speed was analyzed for several microspheres assayed in the purification - assay device, and the results were compatible to that of conventional assay in which F1-ATPase was purified in bulk scale. In conclusion, we have demonstrated on-chip cell lysis and assay appropriate for the sequential analysis without any pretreatment. On-chip devices replacing conventional bioanalytical methods will be

  20. Capillary electrophoresis methods for microRNAs assays: A review

    Ban, Eunmi; Song, Eun Joo, E-mail:


    Highlights: • A review of CE analysis of miRNAs. • Summary of developments and applications of CE systems in miRNA studies. • Applications and development of microchip-based CE for rapid analysis of miRNA. - Abstract: MicroRNAs (miRNAs) are short noncoding RNAs that conduct important roles in many cellular processes such as development, proliferation, differentiation, and apoptosis. In particular, circulating miRNAs have been proposed as biomarkers for cancer, diabetes, cardiovascular disease, and other illnesses. Therefore, determination of miRNA expression levels in various biofluids is important for the investigation of biological processes in health and disease and for discovering their potential as new biomarkers and drug targets. Capillary electrophoresis (CE) is emerging as a useful analytical tool for analyzing miRNA because of its simple sample preparation steps and efficient resolution of a diverse size range of compounds. In particular, CE with laser-induced fluorescence detection is a promising and relatively rapidly developing tool with the potential to provide high sensitivity and specificity in the analysis of miRNAs. This paper covers a short overview of the recent developments and applications of CE systems in miRNA studies in biological and biomedical areas.

  1. Micro-arrayed human embryonic stem cells-derived cardiomyocytes for in vitro functional assay.

    Elena Serena

    Full Text Available INTRODUCTION: The heart is one of the least regenerative organs in the body and any major insult can result in a significant loss of heart cells. The development of an in vitro-based cardiac tissue could be of paramount importance for many aspects of the cardiology research. In this context, we developed an in vitro assay based on human cardiomyocytes (hCMs and ad hoc micro-technologies, suitable for several applications: from pharmacological analysis to physio-phatological studies on transplantable hCMs. We focused on the development of an assay able to analyze not only hCMs viability, but also their functionality. METHODS: hCMs were cultured onto a poly-acrylamide hydrogel with tunable tissue-like mechanical properties and organized through micropatterning in a 20×20 array. Arrayed hCMs were characterized by immunofluorescence, GAP-FRAP analyses and live and dead assay. Their functionality was evaluated monitoring the excitation-contraction coupling. RESULTS: Micropatterned hCMs maintained the expression of the major cardiac markers (cTnT, cTnI, Cx43, Nkx2.5, α-actinin and functional properties. The spontaneous contraction frequency was (0.83±0.2 Hz, while exogenous electrical stimulation lead to an increase up to 2 Hz. As proof of concept that our device can be used for screening the effects of pathological conditions, hCMs were exposed to increasing levels of H(2O(2. Remarkably, hCMs viability was not compromised with exposure to 0.1 mM H(2O(2, but hCMs contractility was dramatically suppressed. As proof of concept, we also developed a microfluidic platform to selectively treat areas of the cell array, in the perspective of performing multi-parametric assay. CONCLUSIONS: Such system could be a useful tool for testing the effects of multiple conditions on an in vitro cell model representative of human heart physiology, thus potentially helping the processes of therapy and drug development.

  2. Medical Devices; Immunology and Microbiology Devices; Classification of Gastrointestinal Microorganism Multiplex Nucleic Acid-Based Assay. Final order.


    The Food and Drug Administration (FDA) is classifying a gastrointestinal microorganism multiplex nucleic acid-based assay into class II (special controls). The Agency is classifying the device into class II (special controls) in order to provide a reasonable assurance of safety and effectiveness of the device.

  3. A micro-scale hot-surface device based on non-radiative carrier recombination

    Kovalgin, Alexeij Y.; Holleman, J.; Iordache, G.


    This work employs the idea of making micro-scale hot-surface devices (e.g. sensors, flow meters, micro reactors, etc) based on generation of heat due to nonradiative recombination of carriers in a thin (13 nm) poly silicon surface layer. An important part of the device is a nano-scale (10-100 nm)

  4. A simple agar plate method, using micro-algae, for herbicide bio-assay or detection.

    Wright, S J


    A simple, inexpensive method is described for the bio-assay of herbicides using micro-algae growing on agar plates. A result is obtainable in 2 days and the method is suitable for biodetection of herbicide residues, or toxicity studies on soil or aquatic pollutants.

  5. Methods and Devices for Micro-Isolation, Extraction, and/or Analysis of Microscale Components

    Kartalov, Emil P. (Inventor); Shibata, Darryl (Inventor); Taylor, Clive (Inventor); Wade, Lawrence A. (Inventor)


    Provided herein are devices and methods for the micro-isolation of biological cellular material. A micro-isolation apparatus described can comprise a photomask that protects regions of interest against DNA-destroying illumination. The micro-isolation apparatus can further comprise photosensitive material defining access wells following illumination and subsequent developing of the photosensitive material. The micro-isolation apparatus can further comprise a chambered microfluidic device comprising channels providing access to wells defined in photosensitive material. The micro-isolation apparatus can comprise a chambered microfluidic device without access wells defined in photosensitive material where valves control the flow of gases or liquids through the channels of the microfluidic device. Also included are methods for selectively isolating cellular material using the apparatuses described herein, as are methods for biochemical analysis of individual regions of interest of cellular material using the devices described herein. Further included are methods of making masking arrays useful for the methods described herein.

  6. From micro- to nanostructured implantable device for local anesthetic delivery

    Zorzetto L


    Full Text Available Laura Zorzetto,1 Paola Brambilla,1 Elena Marcello,1 Nora Bloise,2 Manuela De Gregori,3 Lorenzo Cobianchi,4,5 Andrea Peloso,4,5 Massimo Allegri,6 Livia Visai,2,7 Paola Petrini1 1Department of Chemistry, Materials and Chemical Engineering ‘G. Natta’, Politecnico di Milano, Milan, 2Department of Molecular Medicine, Centre for Health Technologies (CHT, INSTM UdR of Pavia, University of Pavia, 3Pain Therapy Service, IRCCS Foundation Policlinico San Matteo Pavia, Pavia, 4General Surgery Department, IRCCS Foundation Policlinico San Matteo, Pavia, 5Departments of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Pavia, 6Department of Surgical Sciences, University of Parma, Parma, 7Department of Occupational Medicine, Toxicology and Environmental Risks, S. Maugeri Foundation, IRCCS, Lab of Nanotechnology, Pavia, Italy Abstract: Local anesthetics block the transmission of painful stimuli to the brain by acting on ion channels of nociceptor fibers, and find application in the management of acute and chronic pain. Despite the key role they play in modern medicine, their cardio and neurotoxicity (together with their short half-life stress the need for developing implantable devices for tailored local drug release, with the aim of counterbalancing their side effects and prolonging their pharmacological activity. This review discusses the evolution of the physical forms of local anesthetic delivery systems during the past decades. Depending on the use of different biocompatible materials (degradable polyesters, thermosensitive hydrogels, and liposomes and hydrogels from natural polymers and manufacturing processes, these systems can be classified as films or micro- or nanostructured devices. We analyze and summarize the production techniques according to this classification, focusing on their relative advantages and disadvantages. The most relevant trend reported in this work highlights the effort of moving from microstructured

  7. Molecular assays for the detection of microRNAs in prostate cancer

    Becker Michael M


    Full Text Available Abstract Background MicroRNAs (miRNAs are small non-coding RNAs (about 21 to 24 nucleotides in length that effectively reduce the translation of their target mRNAs. Several studies have shown miRNAs to be differentially expressed in prostate cancer, many of which are found in fragile regions of chromosomes. Expression profiles of miRNAs can provide information to separate malignancies based upon stage, progression and prognosis. Here we describe research prototype assays that detect a number of miRNA sequences with high analytical sensitivity and specificity, including miR-21, miR-182, miR-221 and miR-222, which were identified through expression profiling experiments with prostate cancer specimens. The miRNAs were isolated, amplified and quantified using magnetic bead-based target capture and a modified form of Transcription-Mediated Amplification (TMA. Results Analytical sensitivity and specificity were demonstrated in model system experiments using synthetic mature microRNAs or in vitro miRNA hairpin precursor transcripts. Research prototype assays for miR-21, miR-182, miR-221 and miR-222 provided analytical sensitivities ranging from 50 to 500 copies of target per reaction in sample transport medium. Specific capture and detection of mature miR-221 from complex samples was demonstrated in total RNA isolated from human prostate cancer cell lines and xenografts. Conclusion Research prototype real-time TMA assays for microRNAs provide accurate and reproducible quantitation using 10 nanograms of input total RNA. These assays can also be used directly with tissue specimens, without the need for a preanalytic RNA isolation step, and thus provide a high-throughput method of microRNA profiling in clinical specimens.

  8. Diagnostic Accuracy of microEEG: A Miniature, Wireless EEG Device

    Grant, Arthur C.; Samah G Abdel-Baki; Omurtag, Ahmet; Sinert, Richard; Chari, Geetha; Malhotra, Schweta; Weedon, Jeremy; Andre A Fenton; Zehtabchi, Shahriar


    Measuring the diagnostic accuracy (DA) of an EEG device is unconventional and complicated by imperfect interrater reliability. We sought to compare the DA of a miniature, wireless, battery-powered EEG device (“microEEG”) to a reference EEG machine in emergency department (ED) patients with altered mental status (AMS). 225 ED patients with AMS underwent 3 EEGs. EEG1 (Nicolet Monitor, “reference”) and EEG2 (microEEG) were recorded simultaneously with EEG cup electrodes using a signal splitter. ...

  9. A novel, micro, rapid and direct assay to assess total antioxidant capacity of solid foods.

    Condezo-Hoyos, Luis; Abderrahim, Fatima; Arriba, Silvia M; Carmen González, M


    A novel, micro, rapid and direct procedure to measure the total antioxidant capacity of solid foods using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) (mR-QUENCHER-DPPH) was developed and validated. The mR-QUENCHER-DPPH assay was performed in semi-aqueous medium (methanol-Tris buffer) using very small sample amounts (below 3.6 µg), as estimated by a Bradford reagent-based chemical predictor, and it was completed in 10 min at room temperature. The total antioxidant capacity (TAC) of solid foods was expressed as scavenging capacity index (SCI, mmol DPPH scavenged per kg sample), a theoretical and stoichiometric parameter deduced in this study. SCI values measured by mR-QUENCHER-DPPH assay for cereals cous-cous (7.20±0.35), amaranth (7.99±0.35) and buckwheat (194.2±6.72); Goji fruit (91.27±3.98); lotus root (2402±168); and spices turmeric (3767±355), ginger (2493±283), and cinnamon (10461±2133) were further validated using Folin-Ciocalteau assay. Bland-Altman analysis showed that there were not statistically significant differences in TAC values as measured by both assays. In the same way, TAC values measured by mR-QUENCHER-DPPH were correlated with free (r=0.8088, P=0.0151), bound (r=0.9668, P<0.0001) and total (r=0.9067, P=0.0019) reducing capacity of extracts from solid foods as assessed by Folin-Ciocalteau assay. The mR-QUENCHER-DPPH assay allows to measure TAC values using micro-gram amounts in solid food samples with a wide content range of antioxidants (low, high and very high), and omitting the time-consuming dilution cellulose-step commonly employed in the traditional QUENCHER procedures.

  10. Automation of plasma protein binding assay using rapid equilibrium dialysis device and Tecan workstation.

    Ye, Zhengqi; Zetterberg, Craig; Gao, Hong


    Binding of drug molecules to plasma proteins is an important parameter in assessing drug ADME properties. Plasma protein binding (PPB) assays are routinely performed during drug discovery and development. A fully automated PPB assay was developed using rapid equilibrium dialysis (RED) device and Tecan workstation coupled to an automated incubator. The PPB assay was carried out in unsealed RED plates which allowed the assay to be fully automated. The plasma pH was maintained at 7.4 during the 6-h dialysis under 2% CO2 condition. The samples were extracted with acetonitrile and analyzed by liquid chromatography tandem mass spectrometry. The percent bound results of 10 commercial drugs in plasma protein binding were very similar between the automated and manual assays, and were comparable to literature values. The automated assay increases laboratory productivity and is applicable to high-throughput screening of drug protein binding in drug discovery.

  11. Optimization of a micro-neutralisation assay and its application in antigenic characterisation of influenza viruses.

    Lin, Yipu; Gu, Yan; Wharton, Stephen A; Whittaker, Lynne; Gregory, Victoria; Li, Xiaoyan; Metin, Simon; Cattle, Nicholas; Daniels, Rodney S; Hay, Alan J; McCauley, John W


    The identification of antigenic variants and the selection of influenza viruses for vaccine production are based largely on antigenic characterisation of the haemagglutinin (HA) of circulating viruses using the haemagglutination inhibition (HI) assay. However, additional to evolution related to escape from host immunity, variants emerging as a result of propagation in different cell substrates can complicate interpretation of HI results. The objective was to develop further a micro-neutralisation (MN) assay to complement the HI assay in antigenic characterisation of influenza viruses to assess the emergence of new antigenic variants and reinforce the selection of vaccine viruses. A 96-well-plate plaque reduction MN assay based on measurement of the Infected Cell Population (ICP) using a simple imaging technique. Improvements to the plaque reduction MN assay included selection of the most suitable cell line according to virus type or subtype, and optimisation of experimental design and data quantitation. Comparisons of the results of MN and HI assays showed the importance of complementary data in determining the true antigenic relationships among recent human influenza A(H1N1)pdm09, A(H3N2) and type B viruses. Our study demonstrates that the improved MN assay has certain advantages over the HI assay: it is not significantly influenced by the cell-selected amino acid substitutions in the neuraminidase (NA) of A(H3N2) viruses, and it is particularly useful for antigenic characterisation of viruses which either grow to low HA titre and/or undergo an abortive infection resulting in an inability to form plaques in cultured cells. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  12. Reduce microRNA RT-qPCR Assay Costs by More Than 10-fold Without Compromising Results

    Goldrick, Marianna; Busk, Peter Kamp; Lepovitz, Lance


    This white paper describes a detailed protocol for carrying out qPCR-based microRNA analysis for only ~$0.39 per assay, a cost-savings of >90% compared to commonly used alternative methods.......This white paper describes a detailed protocol for carrying out qPCR-based microRNA analysis for only ~$0.39 per assay, a cost-savings of >90% compared to commonly used alternative methods....

  13. Self-Assembly in Micro- and Nanofluidic Devices: A Review of Recent Efforts

    Hwa Seng Khoo


    Full Text Available Self-assembly in micro- and nanofluidic devices has been the focus of much attention in recent years. This is not only due to their advantages of self-assembling with fine temporal and spatial control in addition to continuous processing that is not easily accessible in conventional batch procedures, but they have evolved to become indispensable tools to localize and assimilate micro- and nanocomponents into numerous applications, such as bioelectronics, drug delivery, photonics, novel microelectronic architectures, building blocks for tissue engineering and metamaterials, and nanomedicine. This review aims to focus on the most recent advancements and characteristic investigations on the self-assembly of micro- and nanoscopic objects in micro- and nanofluidic devices. Emphasis is placed on the salient aspects of this technology in terms of the types of micro- and nanomaterials being assembled, the principles and methodologies, as well as their novel applications.

  14. Two-phase flow in micro and nanofluidic devices

    Shui, Lingling


    This thesis provides experimental data and theoretical analysis on two-phase flow in devices with different layouts of micrometer or nanometer-size channels. A full flow diagram is presented for oil and water flow in head-on microfluidic devices. Morphologically different flow regimes (dripping, jet

  15. Micro and Nanofluidic devices: For Single cell and DNA analysis

    Mokkapati, V.R.S.S.


    Research in the field of Micro/nanofluidics has been extensively carried out for the last few years. With the available technological advancements today many complex systems can be fabricated in a more efficient and simpler way. Conventional methods in a laboratory consumes a lot of time, chemicals

  16. 75 FR 59611 - Microbiology Devices; Reclassification of Herpes Simplex Virus Types 1 and 2 Serological Assays...


    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 866 Microbiology Devices; Reclassification of Herpes Simplex Virus Types 1 and 2 Serological Assays; Confirmation of Effective Date AGENCY: Food and...

  17. Topology optimization of flexible micro-fluidic devices

    Kreissl, Sebastian; Pingen, Georg; Evgrafov, Anton;


    A multi-objective topology optimization formulation for the design of dynamically tunable fluidic devices is presented. The flow is manipulated via external and internal mechanical actuation, leading to elastic deformations of flow channels. The design objectives characterize the performance...

  18. Micro- and nano-scale optoelectronic devices using vanadium dioxide

    Joushaghani, Arash

    Miniaturization has the potential to reduce the size, cost, and power requirements of active optical devices. However, implementing (sub)wavelength-scale electro-optic switches with high efficiency, low insertion loss, and high extinction ratios remains challenging due to their small active volumes. Here, we use the insulator-metal phase transition of vanadium dioxide (VO2), which exhibits a large and reversible change in the refractive index across the phase transition to demonstrate compact, broadband, and efficient switches and photodetectors with record-setting characteristics. We begin by analyzing the electrical and optical properties of VO2 thin films across the phase transition and discuss the fabrication processes that yield micron- and nano-scale VO2 devices. We then demonstrate a surface plasmon thermo-optic switch, which achieves an extinction ratio of 10 dB in a 5 um long device, a record for plasmonic devices. The switch operates over a 100 nm optical bandwidth, and exhibits a thermally limited switching time of 40 mus. We investigate the current and voltage induced switching of VO2 in nano-gap junctions and show optical switching times as short as 20 ns. The two terminal VO2 junctions are incorporated in a silicon photonics platform to yield silicon-VO2 hybrid waveguide devices with a record extinction ratio of 12 dB in a 1 mum long device. In photodetector mode, the devices exhibit a nonlinear responsivity greater than 12 A/W for optical powers less than 1 muW. This device is the smallest electrically controlled and integrated switch and photodetector capable of achieving extinction ratios > 10 dB/mum. We finally investigate the ultra-fast thermal heating in gold nano-apertures and demonstrate that electron heating can change the gold lattice temperature by 300 K in tens of picoseconds. These nano-apertures can be hybridized with VO2 to demonstrate high extinction and ultrafast optical switches.

  19. Polymeric Micro- and Nanofabricatced Devices for Oral Drug Delivery

    Fox, Cade Brylee

    While oral drug administration is by far the most preferred route, it is accompanied by many barriers that limit drug uptake such as the low pH of the stomach, metabolic and proteolytic enzymes, and limited permeability of the intestinal epithelium. As a result, many drugs ranging from small molecules to biological therapeutics have limited oral bioavailability, precluding them from oral administration. To address this issue, microfabrication has been applied to create planar, asymmetric devices capable of binding to the lining of the gastrointestinal tract and releasing drug at high concentrations, thereby increasing oral drug uptake. While the efficacy of these devices has been validated in vitro and in vivo, modifying their surfaces with nanoscale features has potential to refine their properties for enhanced drug delivery. This dissertation first presents an approach to fabricate polymeric microdevices coated with nanowires in a rapid, high throughput manner. The nanowires demonstrate rapid drug localization onto the surface of these devices via capillary action and increased adhesion to epithelial tissue, suggesting that this fabrication technique can be used to create devices with enhanced properties for oral drug delivery. Also presented are microdevices sealed with nanostraw membranes. The nanostraw membranes provide sustained drug release by limiting drug efflux from the devices, prevent drug degradation by limiting influx of outside biomolecules, and enhance device bioadhesion by penetrating into the mucus layer of the intestinal lining. Finally, an approach that dramatically increases the capacity and efficiency of drug loading into microdevices over previous methods is presented. A picoliter-volume printer is used to print drug directly into device reservoirs in an automated fashion. The technologies presented here expand the capabilities of microdevices for oral drug delivery by incorporating nanoscale structures that enhance device bioadhesion

  20. [An implantable micro-device using wireless power transmission for measuring aortic aneurysm sac pressure].

    Guo, Xudong; Ge, Bin; Wang, Wenxing


    In order to detect endoleaks after endovascular aneurysm repair (EVAR), we developed an implantable micro-device based on wireless power transmission to measure aortic aneurysm sac pressure. The implantable micro-device is composed of a miniature wireless pressure sensor, an energy transmitting coil, a data recorder and a data processing platform. Power transmission without interconnecting wires is performed by a transmitting coil and a receiving coil. The coupling efficiency of wireless power transmission depends on the coupling coefficient between the transmitting coil and the receiving coil. With theoretical analysis and experimental study, we optimized the geometry of the receiving coil to increase the coupling coefficient. In order to keep efficiency balance and satisfy the maximizing conditions, we designed a closed loop power transmission circuit, including a receiving voltage feedback module based on wireless communication. The closed loop improved the stability and reliability of transmission energy. The prototype of the micro-device has been developed and the experiment has been performed. The experiments showed that the micro-device was feasible and valid. For normal operation, the distance between the transmitting coil and the receiving coil is smaller than 8cm. Besides, the distance between the micro-device and the data recorder is within 50cm.

  1. Microfluidic device based on a micro-hydrocyclone for particle-liquid separation.

    Bhardwaj, P; Bagdi, P; Sen, A K


    This paper presents theoretical analysis, design, simulation, fabrication and test of a microfluidic device ('Micro-hydrocyclone') for separation of micron and submicron size solid particles from liquid in a particle liquid mixture. A theoretical analysis of the micro-hydrocyclone is performed to understand the physics and develop suitable design models. The structure of the proposed device is designed based on the Bradley model, as it offers lower cut-size thus making it suitable for microfluidics applications. The operational parameters are derived from the dimensional group model. The particle separation process inside the micro-hydrocyclone is simulated by solving fluid flows using Navier-Stokes equations and particle dynamics using a Lagrangian approach in a Eulerian fluid. The influence of inlet velocity and density on separation efficiency is investigated. The device is fabricated with SU-8 photoresist on a PMMA substrate using a combination of photolithography and micro-milling. Experiments are performed to demonstrate particle-liquid separation using polystyrene microbeads suspended in PBS as the feed sample. The influence of inlet velocity and particle size on particle separation efficiency is measured and compared with that obtained from simulations and a good match was found. The proposed device can be easily integrated with micro-environments thus it is suitable for lab-on-chip and microsystems development. The device may have applications in chemical analysis, materials research, point-of-care, blood sample preparation and other biomedical applications.

  2. Latex immunoagglutination assay for bovine viral diarrhea virus utilizing forward light scattering in a microfluidic device

    Heinze, Brian C.; Song, Jae-Young; Han, Jin-Hee; Yoon, Jeong-Yeol


    We have investigated the utilization of particle agglutination assays using forward light scattering measurements in a microfluidic device towards detecting viral particles. The model viral target was bovine viral diarrhea virus (BVDV). Highly carboxylated polystyrene microspheres (510 nm) were coated with anti-BVDV monoclonal antibodies. This solution was in turn used to detect live modified BVDV. This assay was first performed in a two well slide for proof of concept and then in a simple y-channel microfluidic device with optical fibers arranged in a close proximity setup. Particle immunoagglutination was detected through static light scattering measurements taken at 45° to incident light. In the microfluidic device, modified live BVDV was detected with a detection limit of 0.5 TCID 50 mL -1.

  3. A micro-immuno supported liquid membrane assay (mu-ISLMA).

    Tudorache, Madalina; Emnéus, Jenny


    A chemiluminescent (CL) based micro-immuno supported liquid membrane assay (mu-ISLMA) has been developed that enables clean up, enrichment and detection of simazine in a single miniaturised cartridge system. The mu-ISLM cartridge contains a supported liquid membrane (SLM) sandwiched between a donor and an acceptor plate (channel volumes 1.65 microL), the latter being covered by a thin layer of gold on to which anti-simazine antibodies were covalently immobilised via a self assembled monolayer (SAM) of either dithiobis(11-aminoundecane, hydrochloride) (DTAU) or beta-mercaptoethylamine (beta-MEA). The mu-ISLMA based on DTAU was characterised by both a high apparent extraction efficiency (E(app) = 136%) and high apparent enrichment factor (E(e)(app) = 544), which resulted in a very high sensitivity for simazine (LOD = 0.1 ng L(-1)). The paper discusses the influence of the different SAMs and three different anti-simazine-antibody preparations (polyclonal, affinity purified polyclonal and monoclonal) on the extraction parameters and assay sensitivity. The influence of the sample matrix (e.g. mineral water, orange juice and milk) on the simazine mu-ISLMA was also investigated.

  4. Enzyme-Linked Immunosorbent Assay Using Vertical Micro Reactor Stack for the Detection of Biomolecules

    Matsui, Katsuhiro; Morimoto, Syohei; Asano, Toshifumi; Ukita, Yoshiaki; Kato, Dai-Ichiro; Takeo, Masahiro; Utsumi, Yuichi; Negoro, Seiji

    Microreactors and micro total analysis system (μTAS) are recognized as powerful tools for genomics, proteomics, clinical diagnostics, and environmental testing. In this paper, we describe enzyme linked immunosorvent assay (ELISA) using a new microreactor with a vertical fluid flow operation. This microreactor is composed of two reaction vessels stacked on the vertical lines through PMMA fluid filters (φ3mm). The fluid filters constructed by deep X-ray lithography possess 2,100 pores (φ 40 μm), and have valve functions, which maintain liquid layer in each reaction vessel. In addition, the liquid can be selectively transferred by air pressure from upper vessel to lower, and vice versa. As a model of ELISA using the microreactor, we planed to detect mouse immunoglobulin (IgG). We bound the goat anti-IgG antibody to the surface of the PMMA filters, and assayed the IgG by ELISA using anti-IgG antibody/ peroxidase conjugate. We found that the mouse IgG (100 ng/ml) was quantitatively detected within 45 min of analytical period, which was ca. 1/3 of the period required for the conventional method using micro titer plate.

  5. Characterisation of a micro-plasma device sensor using electrical measurements and emission spectroscopy

    Mariotti, D


    This thesis reports on research undertaken on the characterisation of a micro-plasma device to be used for gas analysis by mean of plasma emission spectroscopy. The work covers aspects related to the micro-plasma electrical and optical emission parameters, and their importance for the utilisation of the micro-plasma device in gas analysis. Experimental results have been used to analyse the fundamental micro-plasma processes and to develop a model, which could provide additional information. This dissertation contains a general literature review of topics related to plasma physics, plasma emission spectroscopy, gas analysis (chemical analysis and artificial olfaction) and other micro-plasma applications. Experimental work focuses on two main areas: electrical measurements and emission measurements. Firstly, electrical measurements are taken and interpretations are given. Where necessary, new theoretical treatments are suggested in order to describe better the physical phenomena. Plasma emission has been considered under different working conditions. This allowed the characterisation of the micro-plasma emission and also a better understanding of the micro-plasma processes. On the basis of the experimental data obtained and other assumptions a model has been developed. A computer simulation based on this model provided additional useful information on the micro- plasma behaviour. The first fundamental implication of this new research is the peculiar behaviour of the micro-plasma. This micro-plasma exhibited deviations from Paschen law and strong dependency on cathode material, which contributed to the formation of a low current stable regime. These results have been followed by physical interpretations and theoretical descriptions. The second implication is the establishment of the boundaries and of the influencing parameters for plasma emission spectroscopy as an analytical tool in this particular micro-plasma. From the applied perspective this study has shown that

  6. Nano/micro-scale magnetophoretic devices for biomedical applications

    Lim, Byeonghwa; Vavassori, Paolo; Sooryakumar, R.; Kim, CheolGi


    In recent years there have been tremendous advances in the versatility of magnetic shuttle technology using nano/micro-scale magnets for digital magnetophoresis. While the technology has been used for a wide variety of single-cell manipulation tasks such as selection, capture, transport, encapsulation, transfection, or lysing of magnetically labeled and unlabeled cells, it has also expanded to include parallel actuation and study of multiple bio-entities. The use of nano/micro-patterned magnetic structures that enable remote control of the applied forces has greatly facilitated integration of the technology with microfluidics, thereby fostering applications in the biomedical arena. The basic design and fabrication of various scaled magnets for remote manipulation of individual and multiple beads/cells, and their associated energies and forces that underlie the broad functionalities of this approach, are presented. One of the most useful features enabled by such advanced integrated engineering is the capacity to remotely tune the magnetic field gradient and energy landscape, permitting such multipurpose shuttles to be implemented within lab-on-chip platforms for a wide range of applications at the intersection of cellular biology and biotechnology.

  7. Technical use of compact micro-onde devices

    Sortais, P.; Lamy, T.; Medard, J.; Angot, J. [Laboratoire de Physique Subatomique et de Cosmologie de Grenoble - UJF-CNRS/IN2P3 - INPG, 53, rue des Martyrs, 38026 Grenoble Cedex (France); Sudraud, P.; Salord, O.; Homri, S. [Orsay Physics S.A., 95 avenue des Monts Aureliens, F-13710 Fuveau (France)


    Due to the very small size of a COMIC (Compact MIcrowave and Coaxial) device [P. Sortais, T. Lamy, J. Medard, J. Angot, L. Latrasse, and T. Thuillier, Rev. Sci. Instrum. 81, 02B31 (2010)] it is possible to install such plasma or ion source inside very different technical environments. New applications of such a device are presented, mainly for industrial applications. We have now designed ion sources for highly focused ion beam devices, ion beam machining ion guns, or thin film deposition machines. We will mainly present new capabilities opened by the use of a multi-beam system for thin film deposition based on sputtering by medium energy ion beams. With the new concept of multi-beam sputtering (MBS), it is possible to open new possibilities concerning the ion beam sputtering (IBS) technology, especially for large size deposition of high uniformity thin films. By the use of multi-spots of evaporation, each one corresponding to an independent tuning of an individual COMIC ion source, it will be very easy to co-evaporate different components.

  8. Efficient Si photovoltaic devices with integrated micro/nano holes

    Cansizoglu, Hilal; Gao, Yang; Kaya, Ahmet; Ghandiparsi, Soroush; Polat, Kazim G.; Wang, Yichuan; Zhang, Runzhou; Reggad, Hind; Mayet, Ahmed; Ponizovskaya Devine, Ekaterina; Islam, M. Saif


    Efficient light harvesting in a thin layer of crystalline Si can be realized by implementing nanoscale pillars and holes to the device structure. The major drawback of the pillars and holes based photovoltaic devices is high surface to volume ratio, contributing to an increase in surface recombination rate of the photo-generated carriers. The common techniques used in pillars/holes fabrication such as dry etching make the surface even worse by bombarding it with high energy ions. Therefore, such damaged surfaces of high aspect ratio structures need to be effectively passivated. In this study, we demonstrate a hole based thin crystalline Si photovoltaic device with enhanced open circuit voltage and short circuit current after a successful surface passivation process through a wet oxidation. In addition, the effect of passivation layer fabricated by rapid thermal oxide growth on photo response is investigated. A successful fabrication of thin crystalline Si solar cells can lead to the applications of ultra-thin, highly efficient, flexible and wearable energy sources.

  9. 3-D Micro and Nano Technologies for Improvements in Electrochemical Power Devices

    Sunshine Holmberg


    Full Text Available This review focuses on recent advances in micro- and nano-fabrication techniques and their applications to electrochemical power devices, specifically microfabricated Lithium-ion batteries, enzymatic and microbial fuel cells (biofuel cells, and dye-sensitized solar cells (DSSCs. Although the maturity of these three technologies ranges from market ready (batteries to fundamental research (biofuel cells to applied research (DSSCs, advances in MEMS (Micro-Electro-Mechanical Systems and NEMS (Nano-Electro-Mechanical Systems techniques, particularly modifications in surface area and surface chemistry, and novel genetic and molecular engineering techniques, significantly improve the electrochemical activity of these technologies across the board. For each of these three categories of power-MEMS devices the review covers: (1 The technical challenges facing the performance and fabrication of electrochemical power devices; (2 Current MEMS and NEMS techniques used to improve efficiency; and (3 Future outlook and suggested improvements of MEMS and NEMS for implementation in electrochemical power devices.

  10. Single-pipetting microfluidic assay device for rapid detection of Salmonella from poultry package.

    Fronczek, Christopher F; You, David J; Yoon, Jeong-Yeol


    A direct, sensitive, near-real-time, handheld optical immunoassay device was developed to detect Salmonella typhimurium in the naturally occurring liquid from fresh poultry packages (hereafter "chicken matrix"), with just single pipetting of sample (i.e., no filtration, culturing and/or isolation, thus reducing the assay time and the error associated with them). Carboxylated, polystyrene microparticles were covalently conjugated with anti-Salmonella, and the immunoagglutination due to the presence of Salmonella was detected by reading the Mie scatter signals from the microfluidic channels using a handheld device. The presence of chicken matrix did not affect the light scatter signal, since the optical parameters (particle size d, wavelength of incident light λ and scatter angle θ) were optimized to minimize the effect of sample matrix (animal tissues and blood proteins, etc.). The sample was loaded into a microfluidic chip that was split into two channels, one pre-loaded with vacuum-dried, antibody-conjugated particles and the other with vacuum-dried, bovine serum albumin-conjugated particles. This eliminated the need for a separate negative control, effectively minimizing chip-to-chip and sample-to-sample variations. Particles and the sample were diffused in-channel through chemical agitation by Tween 80, also vacuum-dried within the microchannels. Sequential mixing of the sample to the reagents under a strict laminar flow condition synergistically improved the reproducibility and linearity of the assay. In addition, dried particles were shown to successfully detect lower Salmonella concentrations for up to 8 weeks. The handheld device contains simplified circuitry eliminating unnecessary adjustment stages, providing a stable signal, thus maximizing sensitivity. Total assay time was 10 min, and the detection limit 10 CFU mL(-1) was observed in all matrices, demonstrating the suitability of this device for field assays.

  11. Three-dimensional paper-based microfluidic device for assays of protein and glucose in urine.

    Sechi, Deidre; Greer, Brady; Johnson, Jesse; Hashemi, Nastaran


    The first step in curing a disease is being able to detect the disease effectively. Paper-based microfluidic devices are biodegradable and can make diagnosing diseases cost-effective and easy in almost all environments. We created a three-dimesnional (3D) paper device using wax printing fabrication technique and basic principles of origami. This design allows for a versatile fabrication technique over previously reported patterning of SU-8 photoresist on chromatography paper by employing a readily available wax printer. The design also utilizes multiple colorimetric assays that can accommodate one or more analytes including urine, blood, and saliva. In this case to demonstrate the functionality of the 3D paper-based microfluidic system, a urinalysis of protein and glucose assays is conducted. The amounts of glucose and protein introduced to the device are found to be proportional to the color change of each assay. This color change was quantified by use of Adobe Photoshop. Urine samples from participants with no pre-existing health conditions and one person with diabetes were collected and compared against synthetic urine samples with predetermined glucose and protein levels. Utilizing this method, we were able to confirm that both protein and glucose levels were in fact within healthy ranges for healthy participants. For the participant with diabetes, glucose was found to be above the healthy range while the protein level was in the healthy range.

  12. 78 FR 3319 - Amendments to Existing Validated End User Authorizations: Advanced Micro Devices China, Inc., Lam...


    ... Authorizations: Advanced Micro Devices China, Inc., Lam Research Corporation, SK hynix Semiconductor (China) Ltd., and SK hynix Semiconductor (Wuxi) Ltd. in the People's Republic of China; Clarification of Scope of... Semiconductor (China) Ltd. and SK hynix Semiconductor (Wuxi) Ltd. Finally, BIS amends Supplement No. 7 to...

  13. Implementation of adaptive coded aperture imaging using a digital micro-mirror device for defocus deblurring

    Chiranjan, Ashill


    Full Text Available between aperture shapes with a traditional camera quickly and efficiently is impractical. This paper aims towards developing an adaptive coded aperture imaging system utilizing a digital micro-mirror device (DMD) as a programmable aperture that is able...

  14. Observing the Sun with micro-interferometric devices: a didactic experiment

    Defrère, D.; Absil, O.; Hanot, C.; Riaud, P.; Magette, A.; Marion, L.; Wertz, O.; Finet, F.; Steenackers, M.; Habraken, S.; Surdej, A.; Surdej, J.


    Measuring the angular diameter of celestial bodies has long been the main purpose of stellar interferometry and was its historical motivation. Nowadays, stellar interferometry is widely used for various other scientific purposes that require very high angular resolution measurements. In terms of angular spatial scales probed, observing distant stars located 10 to 100~pc away with a large hectometric interferometer is equivalent to observing our Sun with a micrometric baseline. Based on this idea, we have manufactured a set of micro-interferometric devices and tested them on the sky. The micro-interferometers consist of a chrome layer deposited on a glass plate that has been drilled by laser lithography to produce micron-sized holes with configurations corresponding to proposed interferometer projects such as CARLINA, ELSA, KEOPS, and OVLA. In this paper, we describe these interferometric devices and present interferometric observations of the Sun made in the framework of Astrophysics lectures being taught at the Liège University. By means of a simple photographic camera placed behind a micro-interferometric device, we observed the Sun and derived its angular size. This experiment provides a very didactic way to easily obtain fringe patterns similar to those that will be obtained with future large imaging arrays. A program written in C also allows to reproduce the various point spread functions and fringe patterns observed with the micro-interferometric devices for different types of sources, including the Sun.

  15. Multi-layer micro/nanofluid devices with bio-nanovalves

    Li, Hao; Ocola, Leonidas E.; Auciello, Orlando H.; Firestone, Millicent A.


    A user-friendly multi-layer micro/nanofluidic flow device and micro/nano fabrication process are provided for numerous uses. The multi-layer micro/nanofluidic flow device can comprise: a substrate, such as indium tin oxide coated glass (ITO glass); a conductive layer of ferroelectric material, preferably comprising a PZT layer of lead zirconate titanate (PZT) positioned on the substrate; electrodes connected to the conductive layer; a nanofluidics layer positioned on the conductive layer and defining nanochannels; a microfluidics layer positioned upon the nanofluidics layer and defining microchannels; and biomolecular nanovalves providing bio-nanovalves which are moveable from a closed position to an open position to control fluid flow at a nanoscale.

  16. Comparison of Two MicroRNA Quantification Methods for Assaying MicroRNA Expression Proifles in Wheat (Triticum aestivum L.)

    HAN Ran; YAN Yan; ZHOU Peng; ZHAO Hui-xian


    Two microRNA (miRNA) quantification methods, namely, poly(A) reverse transcription (RT)-quantitative real-time polymerase chain reaction (qPCR) and stem-loop RT-qPCR, have been developed for quantifying miRNA expression. In the present study, ifve miRNAs, including miR166, miR167, miR168, miR159, and miR396, with different sequence frequencies, were selected as targets to compare their expression proifles in ifve wheat tissues by applying the two methods and deep sequencing. The study aimed to determine a simple, reliable and high-throughput method for detecting miRNA expressions in wheat tissues. Results showed that the miRNA expression proifles determined by poly(A) RT-qPCR were more consistent with those obtained by deep sequencing. Further analysis indicated that the correlation coefifcients of the data obtained by poly(A) RT-qPCR and deep sequencing (0.739, P 0.01) were higher than those obtained by stem-loop RT-qPCR and deep sequencing (0.535, P 0.01). The protocol used for poly(A) RT-qPCR is simpler than that for stem-loop RT-qPCR. Thus, poly(A) RT-qPCR was a more suitable high-throughput assay for detecting miRNA expression proifles. To the best of our knowledge, this study was the ifrst to compare these two miRNA quantiifcation methods. We also provided useful information for quantifying miRNA in wheat or other plant species.

  17. MEMS Micro-Translation Device with Improved Linear Travel Capability

    Abushagur, Mustafa A. G. (Inventor); Ferguson, Cynthia K. (Inventor); Nordin, Gregory P. (Inventor); English, Jennifer M. (Inventor)


    A microscopic translation device for a microelectromechanical system includes a pair of linear stator assemblies disposed in spaced relation to define an elongate channel. Each assembly is formed by a plurality of stators arranged in a row along the channel. A shuttle member is disposed between the stator assemblies for translating movement along the channel. The shuttle member includes a plurality of rotors extending outwardly from opposite sides. The shuttle is grounded through the stator assemblies and includes a mounting area for an object to be translated. Electrical lines are individually connected to alternate stators of a plurality of groups of the stators. A current supply sequentially supplies current through the electrical lines to the alternate stators so as to effect charging of the stators in a predetermined sequence. This produces a tangential capacitive force that causes translation of the shuttle.

  18. All-inkjet-printed flexible ZnO micro photodetector for a wearable UV monitoring device

    Tran, Van-Thai; Wei, Yuefan; Yang, Hongyi; Zhan, Zhaoyao; Du, Hejun


    Fabrication of small-sized patterns of inorganic semiconductor onto flexible substrates is a major concern when manufacturing wearable devices for measuring either biometric or environmental parameters. In this study, micro-sized flexible ZnO UV photodetectors have been thoroughly prepared by a facile inkjet printing technology and followed with heat treatments. A simple ink recipe of zinc acetate precursor solution was investigated. It is found that the substrate temperature during zinc precursor ink depositing has significant effects on ZnO pattern shape, film morphology, and crystallization. The device fabricated from the additive manufacturing approach has good bendability, Ohmic contact, short response time as low as 0.3 s, and high on/off ratio of 3525. We observed the sensor’s dependence of response/decay time by the illuminating UV light intensity. The whole process is based on additive manufacturing which has many benefits such as rapid prototyping, saving material, being environmentally friendly, and being capable of creating high-resolution patterns. In addition, this method can be applied to flexible substrates, which makes the device more applicable for applications requiring flexibility such as wearable devices. The proposed all-inkjet-printing approach for a micro-sized ZnO UV photodetector would significantly simplify the fabrication process of micro-sized inorganic semiconductor-based devices. A potential application is real-time monitoring of UV light exposure to warn users about unsafe direct sunlight to implement suitable avoidance solutions.

  19. Preparation of micro gold devices on poly(dimethylsiloxane) chips with region-selective electroless plating.

    Hao, Zhenxia; Chen, Hengwu; Ma, Dan


    A novel protocol for fabrication of micro gold devices on poly(dimethylsiloxane) (PDMS) substrates was developed on the basis of region-selective electroless plating. The layout of a micro gold device was first photochemically patterned onto the PDMS surface through a UV induced poly(acrylic acid) (PAA) grafting process. The carboxylic moieties on the grafted PAA served as the scaffold for a series of wet chemical reactions that led to the immobilization of gold nanoparticles in the UV-exposed region, where electroless plating then occurred under the catalysis of the nanoparticles. Gold devices fabricated with such a protocol could tolerate the Scotch tape test and survive in a repeated bending-straightening test. They also showed good stability in acidic and alkaline solutions, possessed almost the same electrochemical properties as a standard gold disk electrode, and allowed thiol-compounds to form a perfect self-assembled monolayer on their surfaces. The fabricated micro gold electrode was demonstrated to be suitable as the integrated amperometric detection element in a full PDMS micro electrophoresis chip.

  20. Micro-fabricated Silicon Devices for Advanced Thermal Management and Integration of Particle Tracking Detectors

    Romagnoli, Giulia; Gambaro, Carla

    Since their first studies targeting the cooling of high-power computing chips, micro-channel devices are proven to provide a very efficient cooling system. In the last years micro-channel cooling has been successfully applied to the cooling of particle detectors at CERN. Thanks to their high thermal efficiency, they can guarantee a good heat sink for the cooling of silicon trackers, fundamental for the reduction of the radiation damage caused by the beam interactions. The radiation damage on the silicon detector is increasing with temperature and furthermore the detectors are producing heat that should be dissipated in the supporting structure. Micro-channels guarantee a distributed and uniform thermal exchange, thanks to the high flexibility of the micro-fabrication process that allows a large variety of channel designs. The thin nature of the micro-channels etched inside silicon wafers, is fulfilling the physics requirement of minimization of the material crossed by the particle beam. Furthermore micro-chan...

  1. Statistical inference for the within-device precision of quantitative measurements in assay validation.

    Liu, Jen-Pei; Lu, Li-Tien; Liao, C T


    Intermediate precision is one of the most important characteristics for evaluation of precision in assay validation. The current methods for evaluation of within-device precision recommended by the Clinical Laboratory Standard Institute (CLSI) guideline EP5-A2 are based on the point estimator. On the other hand, in addition to point estimators, confidence intervals can provide a range for the within-device precision with a probability statement. Therefore, we suggest a confidence interval approach for assessment of the within-device precision. Furthermore, under the two-stage nested random-effects model recommended by the approved CLSI guideline EP5-A2, in addition to the current Satterthwaite's approximation and the modified large sample (MLS) methods, we apply the technique of generalized pivotal quantities (GPQ) to derive the confidence interval for the within-device precision. The data from the approved CLSI guideline EP5-A2 illustrate the applications of the confidence interval approach and comparison of results between the three methods. Results of a simulation study on the coverage probability and expected length of the three methods are reported. The proposed method of the GPQ-based confidence intervals is also extended to consider the between-laboratories variation for precision assessment.

  2. Performance improvement of electrochromic display devices employing micro-size precipitates of tungsten oxide

    Cheng, Chin-Pao; Kuo, Yi; Chou, Chuan-Pu; Cheng, Chun-Hu [National Taiwan Normal University, Department of Mechatronic Technology, Taipei (China); Teng, Tun Ping [National Taiwan Normal University, Department of Industrial Education, Taipei (China)


    In this paper, we studied the effect of micro-size WO{sub 3} precipitates on the electrochromic characteristics based on aging test. The electrochromic mechanism can be effectively investigated by a solid-state TaN/WO{sub 3}/ITO capacitor. The experimental results reveal that WO{sub 3} electrochromic devices with optimized aging time of 4 days exhibit a higher optical contrast and longer retention time, which is mainly attributed to the formation of micro-size WO{sub 3} precipitates during aging process. The performance improvement using micro-size WO{sub 3} precipitates has the potential in future large-area window or energy efficient display applications. (orig.)

  3. Controlled aniline polymerization strategies for polyaniline micro- and nano self-assembling into practical electronic devices.

    Yunus, Sami; Attout, Anne; Bertrand, Patrick


    Electroless polymerization of aniline on platinum is investigated for polyaniline micro- and nanostructuring into practical electronic devices. This type of reaction is adapted to estimate its usefulness in a lithographic process. For practical electronic device fabrication, electroless polymerization of aniline can be used to electrically bridge initially independent platinum electrodes. As this application requires a polyaniline bridge to form over a nonconductive material before an electrical contact is obtained, polyaniline growth using chemical oxidative reaction is investigated on substrates presenting surface-tension contrast patterns.

  4. Medical devices; immunology and microbiology devices; classification of multiplex nucleic acid assay for identification of microorganisms and resistance markers from positive blood cultures. Final order.


    The Food and Drug Administration (FDA) is classifying multiplex nucleic acid assay for identification of microorganisms and resistance markers from positive blood cultures into class II (special controls). The special controls that will apply to this device are identified in this order and will be part of the codified language for the multiplex nucleic acid assay for identification of microorganisms and resistance markers from positive blood cultures. The Agency is classifying the device into class II (special controls) in order to provide a reasonable assurance of safety and effectiveness of the device.

  5. Development and Application of a Diaphragm Micro-Pump with Piezoelectric Device

    Ma, H K; Wu, H Y; Lin, C Y; Gao, J J; Kou, M C


    In this study, a new type of thin, compact, and light weighed diaphragm micro-pump has been successfully developed to actuate the liquid by the vibration of a diaphragm. The micro-diaphragm pump with two valves is fabricated in an aluminum case by using highly accurate CNC machine, and the cross-section dimension is 5mm x 8mm. Both valves and diaphragm are manufactured from PDMS. The amplitude of vibration by a piezoelectric device produces an oscillating flow which may change the chamber volume by changing the curvature of a diaphragm. Several experimental set-ups for performance test in a single micro-diaphragm pump, isothermal flow open system, and a closed liquid cooling system is designed and implemented. The performance of one-side actuating micro-diaphragm pump is affected by the design of check valves, diaphragm, piezoelectric device, chamber volume, input voltage and frequency. The measured maximum flow rate of present design is 72 ml/min at zero total pump head in the range of operation frequency 70...

  6. Photonic microsystems micro and nanotechnology applied to optical devices and systems

    Solgaard, Olav


    ""Photonic Microsystems: Micro and Nanotechnology Applied to Optical Devices and Systems"", describes MEMS technology and demonstrates how MEMS allow miniaturization, parallel fabrication, and efficient packaging of optics, as well as integration of optics and electronics. It shows how the characteristics of MEMS enable practical implementations of a variety of applications, including projection displays, fiber switches, interferometers, spectrometers. The book describes the phenomenon of Photonic crystals (nanophotonics) and demonstrates how Photonic crystals enable synthesis of materials wit

  7. Calibration-free assays on standard real-time PCR devices

    Debski, Pawel R.; Gewartowski, Kamil; Bajer, Seweryn; Garstecki, Piotr


    Quantitative Polymerase Chain Reaction (qPCR) is one of central techniques in molecular biology and important tool in medical diagnostics. While being a golden standard qPCR techniques depend on reference measurements and are susceptible to large errors caused by even small changes of reaction efficiency or conditions that are typically not marked by decreased precision. Digital PCR (dPCR) technologies should alleviate the need for calibration by providing absolute quantitation using binary (yes/no) signals from partitions provided that the basic assumption of amplification a single target molecule into a positive signal is met. Still, the access to digital techniques is limited because they require new instruments. We show an analog-digital method that can be executed on standard (real-time) qPCR devices. It benefits from real-time readout, providing calibration-free assessment. The method combines advantages of qPCR and dPCR and bypasses their drawbacks. The protocols provide for small simplified partitioning that can be fitted within standard well plate format. We demonstrate that with the use of synergistic assay design standard qPCR devices are capable of absolute quantitation when normal qPCR protocols fail to provide accurate estimates. We list practical recipes how to design assays for required parameters, and how to analyze signals to estimate concentration.

  8. Biofilm removal by medical device cleaners: comparison of two bioreactor detection assays.

    Hadi, R; Vickery, K; Deva, A; Charlton, T


    Currently there are no standards for testing efficacy of medical device cleaners. With fears of prion transmission, residual protein on medical devices needs to be minimised. A bioreactor model was used to grow Pseudomonas aeruginosa biofilm on polytetrafluoroethylene coupons. The biofilm was subjected to various cleaners and residual biofilm was detected either by Crystal Violet assay (CrV) or a commercially available protein assay (PA) following hydrolysis of the biofilm. Percentage reduction of biofilm was compared with untreated controls in three independent tests. There was no significant difference in percentage biofilm reduction irrespective of whether the CrV or PA was used to detect residual biofilm. Processing of coupons attached to the bioreactor rod and position of coupon within the rod had no significant effect on cleaning efficiency or detection of residual biofilm. Both within-run and between-run variation was very low for good cleaners such as 10g/L NaOH, Zen, and 3M Rapid Multi-Enzyme Cleaner (RMEC) 70500 but was higher for poor cleaners such as Tween 20 which removed less than 20% of the biofilm. Confocal microscopy and electron microscopy provided visual confirmation of the assay results. We propose that this method is suitable as a test method for evaluating the efficacy of surgical instrument cleaners in removing biofilm, as both within-run and between-run variation was low, detection of residual biofilm can be done using either CrV or PA, and the apparatus is easy to use, cheap and readily available.

  9. A Wirelessly Powered Micro-Spectrometer for Neural Probe-Pin Device

    Choi, Sang H.; Kim, Min Hyuck; Song, Kyo D.; Yoon, Hargsoon; Lee, Uhn


    Treatment of neurological anomalies, places stringent demands on device functionality and size. A micro-spectrometer has been developed for use as an implantable neural probe to monitor neuro-chemistry in synapses. The microspectrometer, based on a NASA-invented miniature Fresnel grating, is capable of differentiating the emission spectra from various brain tissues. The micro-spectrometer meets the size requirements, and is able to probe the neuro-chemistry and suppression voltage typically associated with a neural anomaly. This neural probe-pin device (PPD) is equipped with wireless power technology (WPT) enabling operation in a continuous manner without requiring an implanted battery. The implanted neural PPD, together with a neural electronics interface and WPT, allow real-time measurement and control/feedback for remediation of neural anomalies. The design and performance of the combined PPD/WPT device for monitoring dopamine in a rat brain will be presented to demonstrate the current level of development. Future work on this device will involve the addition of an embedded expert system capable of performing semi-autonomous management of neural functions through a routine of sensing, processing, and control.

  10. Thermoelastic stress analysis of multilayered films in a micro-thermoelectric cooling device

    Yu-Mei Yang; Xing-Zhe Wang; Wen-Jie Zhang


    This paper presents an analytical solution for the thermoelastic stress in a typical in-plane's thin-film microthermoelectric cooling device under different operating conditions.The distributions of the permissible temperature fields in multilayered thin-films are analytically obtained,and the characteristics,including maximum temperature difference and maximum refrigerating output of the thermoelectric device,are discussed for two operating conditions.Analytical expressions of the thermoelastic stresses in the layered thermoelectric thin-films induced by the temperature difference are formulated based on the theory of multilayer system.The results demonstrate that,the geometric dimension is a significant factor which remarkably affects the thermoelastic stresses.The stress distributions in layers of semiconductor thermoelements,insulating and supporting membrane show distinctly different features.The present work may profitably guide the optimization design of highefficiency micro-thermoelectric cooling devices.

  11. A Novel Bearing Lubricating Device Based on the Piezoelectric Micro-Jet

    Kai Li


    Full Text Available A novel bearing lubricating device, which is embedded in gyroscope’s bearing system and based on the theory of the piezoelectric micro-jet, was designed for this study. The embedded structure of a bearing lubricating system can make effective use of the limited space of bearing systems without increasing the whole mass of the system. The drop-on-demand (DOD lubrication can be realized by the piezoelectric micro-jet system to implement the long acting lubrication of the bearing system. A mathematical model of inlet boundary conditions was established to carry on the numerical simulation based on CFD. The motion states of the droplets with different voltage excitations were analyzed via numerical simulations, and the injection performances of the piezoelectric micro-jet lubricating device were tested in accordance with past experiments. The influences of different parameters of voltage excitation on injection performance were obtained, and the methods of adjusting the injection performance to meet different requirements are given according to the analyses of the results. The mathematical model and numerical simulation method were confirmed by comparing the results of past simulations and experiments.

  12. From Extended Nanofluidics to an Autonomous Solar-Light-Driven Micro Fuel-Cell Device.

    Pihosh, Yuriy; Uemura, Jin; Turkevych, Ivan; Mawatari, Kazuma; Kazoe, Yutaka; Smirnova, Adelina; Kitamori, Takehiko


    Autonomous micro/nano mechanical, chemical, and biomedical sensors require persistent power sources scaled to their size. Realization of autonomous micro-power sources is a challenging task, as it requires combination of wireless energy supply, conversion, storage, and delivery to the sensor. Herein, we realized a solar-light-driven power source that consists of a micro fuel cell (μFC) and a photocatalytic micro fuel generator (μFG) integrated on a single microfluidic chip. The μFG produces hydrogen by photocatalytic water splitting under solar light. The hydrogen fuel is then consumed by the μFC to generate electricity. Importantly, the by-product water returns back to the photocatalytic μFG via recirculation loop without losses. Both devices rely on novel phenomena in extended-nano-fluidic channels that ensure ultra-fast proton transport. As a proof of concept, we demonstrate that μFG/μFC source achieves remarkable energy density of ca. 17.2 mWh cm(-2) at room temperature. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Naked-eye quantitative aptamer-based assay on paper device.

    Zhang, Yun; Gao, Dong; Fan, Jinlong; Nie, Jinfang; Le, Shangwang; Zhu, Wenyuan; Yang, Jiani; Li, Jianping


    This work initially describes the design of low-cost, naked-eye quantitative aptamer-based assays by using microfluidic paper-based analytical device (μPAD). Two new detection motifs are proposed for quantitative μPAD measurement without using external electronic readers, which depend on the length of colored region in a strip-like μPAD and the number of colorless detection microzones in a multi-zone μPAD. The length measuring method is based on selective color change of paper from colorless to blue-black via formation of iodine-starch complex. The counting method is conducted on the basis of oxidation-reduction reaction between hydrogen peroxide and potassium permanganate. Their utility is well demonstrated with sensitive, specific detection of adenosine as a model analyte with the naked eye in buffer samples and undiluted human serum. These equipment-free quantitative methods proposed thus hold great potential for the development of more aptamer-based assays that are simple, cost-efficient, portable, and user-friendly for various point-of-care applications particularly in resource-constrained environments.

  14. A Microfluidic Device with Integrated Sonication and Immunoprecipitation for Sensitive Epigenetic Assays.

    Cao, Zhenning; Lu, Chang


    Epigenetic studies increasingly require analysis of a small number of cells that are of one specific type and derived from patients or animals. In this report, we demonstrate a simple microfluidic device that integrates sonication and immunoprecipitation (IP) for epigenetic assays, such as chromatin immunoprecipitation (ChIP) and methylated DNA immunoprecipitation (MeDIP). By incorporating an ultrasonic transducer with a microfluidic chamber, we implemented microscale sonication for both shearing chromatin/DNA and mixing/washing of IP beads. Such integration allowed highly sensitive tests starting with 100 cross-linked cells for ChIP or 500 pg of genomic DNA for MeDIP (compared to 10(6)-10(7) cells for ChIP and 1-10 μg of DNA for MeDIP in conventional assays). The entire on-chip process of sonication and IP took only 1 h. Our tool will be useful for highly sensitive epigenetic studies based on a small quantity of sample.

  15. Thermal management of power sources for mobile electronic devices based on micro-SOFC

    Murayama, S.; Iguchi, F.; Shimizu, M.; Yugami, H.


    Small power sources based on micro-SOFC for mobile electronic devices required two conditions, i,e, thermally compatibility and thermally self-sustain, because of high operating temperature over 300 oC. Moreover, high energy efficiency was also required. It meant that this system should be designed considering thermal management. In this study, we developed micro-SOFC packages which have three functions, thermal insulation, thermal recovery, and self-heating. Heat conduction analysis based on finite element method, and thermochemical calculation revealed that vacuum thermal insulation was effective for size reduction and gas-liquid heat exchanger could reduce the temperature of outer surface. We fabricated the package with three functions for proof of concept and evaluated. As a result, it was suggested that developed package could satisfy both two requirements with high efficiency.

  16. Sensitive biomolecule detection in lateral flow assay with a portable temperature-humidity control device.

    Choi, Jane Ru; Hu, Jie; Feng, Shangsheng; Wan Abas, Wan Abu Bakar; Pingguan-Murphy, Belinda; Xu, Feng


    Lateral flow assays (LFAs) have currently attracted broad interest for point-of-care (POC) diagnostics, but their application has been restricted by poor quantification and limited sensitivity. While the former has been currently solved to some extent by the development of handheld or smartphone-based readers, the latter has not been addressed fully, particularly the potential influences of environmental conditions (e.g., temperature and relative humidity (RH)), which have not yet received serious attention. The present study reports the use of a portable temperature-humidity control device to provide an optimum environmental requirement for sensitivity improvement in LFAs, followed by quantification by using a smartphone. We found that a RH beyond 60% with temperatures of 55-60°C and 37-40°C produced optimum nucleic acid hybridization and antigen-antibody interaction in LFAs, respectively representing a 10-fold and 3-fold signal enhancement over ambient conditions (25°C, 60% RH). We envision that in the future the portable device could be coupled with a fully integrated paper-based sample-to-answer biosensor for sensitive detection of various target analytes in POC settings.

  17. Passive micro-assembly of modular, hot embossed, polymer microfluidic devices using exact constraint design

    You, Byoung Hee; Chen, Pin-Chuan; Park, Daniel S.; Park, Sunggook; Nikitopoulos, Dimitris E.; Soper, Steven A.; Murphy, Michael C.


    Low-cost microfluidic platforms have the potential to change accepted practices in many fields, including biology and medicine, in the near future. Micro-assembly of molded polymer microfluidic devices is one approach to cost-effective mass production of modular, microfluidic instruments. Polymer, passive alignment structures were used to precisely assemble molded polymer components to prevent infinitesimal motions and minimize the misalignment between assembled components and devices. The motion and constraint of the assemblies were analyzed using screw theory to identify combinations of passive alignment structures that would provide exact constraint of all degrees of freedom of the two mating parts without over-constraint. One option identified by kinematic analysis was a set of three v-groove and hemisphere-tipped pin joints, which are well known from precision engineering and suitable for microfabrication. To validate the passive alignment scheme, brass mold inserts containing alignment structures were micro-milled and used to hot emboss components in polycarbonate (PC). Dimensional and location variations of prototype alignment structures were measured to quantify the difference between the as-designed and actual dimensions and the locations of the alignment structures. The dimensional variation was 0.2-3% less than the designed dimensions and the location variation was 0.7% less. The alignment accuracy of an assembly was characterized by measuring the mismatch and vertical variation between molded alignment standards embossed on each pair of mating plates. With molded, polymer alignment structures the mean mismatch and mean vertical variation were as low as 13 ± 3 µm in the lateral plane along the x- and y-axes and -6 ± 15 µm with respect to the nominal value of 107 µm. This micro-assembly technology is applicable to the integration of all microsystems including the interconnection of microfluidic devices, the assembly of hybrid microsystems and the

  18. Sub-Rayleigh ghost imaging via sparsity constraints based on a digital micro-mirror device

    Chen, Jie; Gong, Wenlin, E-mail:; Han, Shensheng, E-mail:


    In a diffraction-limited system, the imaging resolution limit is given by Rayleigh criterion. When both the image's sparsity and the point spread function determined by the optical system's Rayleigh diffraction limit are taken as popular a priori, sub-Rayleigh ghost imaging, which is backed up by numerical simulation and experiments, is achieved by modulating the thermal light with a digital micro-mirror device (DMD). The differences between this approach and former ghost imaging without considering the optical system's point spread function are also discussed.

  19. Shaping perfect optical vortex with amplitude modulated using a digital micro-mirror device

    Zhang, Chonglei; Min, Changjun; Yuan, X.-C.


    We propose a technique to generate of perfect optical vortex (POV) via Fourier transformation of Bessel-Gauss (BG) beams through encoding of the amplitude of the optical field with binary amplitude digital micro-mirrors device (DMD). Furthermore, we confirm the correct phase patterns of the POV with the method of Mach-Zehnder interferometer. Our approach to generate the POV has the advantages that rapidly switch among the different modes, wide spectral regions and high energy tolerance. Since the POV possess propagation properties that not shape-invariant, we therefore suppose that our proposed approach will find potential applications in optical microscopy, optical fabrication, and optical communication.

  20. An overview of micro-optical components and system technology: bulk, planar, and thin-film for laser initiated devices

    Lizotte, Todd


    There are a number of attractive micro optical elements or combinations of elements that are currently used or could be employed in optically initiated ordnance systems. When taking a broad-spectrum examination of optically initiated devices, the required key parameters become obviously straightforward for micro optics. Plainly stated, micro optics need to be simple, inexpensive, reliable, robust and compatible within their operational environment. This presentation focuses on the variety of optical elements and components available in the market place today that could be used to realize micro-optical beam shaping and delivery systems for optically initiated devices. A number of micro optical elements will be presented with specific bulk, planar optical and thin film optical devices, such as diffractive optics, micro prisms, axicons, waveguides, micro lenses, beam splitters and gratings. Further descriptions will be presented on the subject of coupling light from a laser beam into a multimode optical fiber. The use of micro optics for collimation of the laser source and conditioning of the laser beam to achieve the highest efficiency and matching the optical fiber NA will be explained. An emphasis on making these optical assemblies compact and rugged will be highlighted.

  1. Multi-Functional Micro Projection Device as Screen Substitute for Low Power Consumption Computing

    Zeev Zalevsky


    Full Text Available One of the major power consuming components in a computer is its display unit. On average the screen consumes ten times more power than the DSP processor itself. Thus, reducing the power consumption should be one of the most important tasks in the development of low power consumption computing systems. In this paper we present one possible solution involving micro projection device based upon lasers and a digital light processing (DLP matrix which is a matrix of electrically controllable mirrors capable of translating electrical signal to a time varying projected image. It can serve to substitute a screen and consume ten times less power than a conventional screen. The described device is a multifunctional highly efficient customized DLP light engine being capable of serving as an image projector and simultaneously to support range and topography estimation measurements.

  2. Micro- and nanoscale devices for the investigation of epigenetics and chromatin dynamics

    Aguilar, Carlos A.; Craighead, Harold G.


    Deoxyribonucleic acid (DNA) is the blueprint on which life is based and transmitted, but the way in which chromatin -- a dynamic complex of nucleic acids and proteins -- is packaged and behaves in the cellular nucleus has only begun to be investigated. Epigenetic modifications sit 'on top of' the genome and affect how DNA is compacted into chromatin and transcribed into ribonucleic acid (RNA). The packaging and modifications around the genome have been shown to exert significant influence on cellular behaviour and, in turn, human development and disease. However, conventional techniques for studying epigenetic or conformational modifications of chromosomes have inherent limitations and, therefore, new methods based on micro- and nanoscale devices have been sought. Here, we review the development of these devices and explore their use in the study of DNA modifications, chromatin modifications and higher-order chromatin structures.

  3. Basic Research of Vibration Energy Harvesting Micro Device using Vinylidene Fluoride / Trifluoroethylene Copolymer Thin Film

    Takiguchi, T.; Sasaki, T.; Nakajima, T.; Yamaura, S.; Sekiguchi, T.; Shoji, S.


    Basic research of MEMS based micro devices for vibration energy harvesting using vinylidene fluoride / trifluoroethylene (VDF/TrFE) copolymer thin film was investigated. The VDF/TrFE copolymer thin film was formed by spin coating. Thickness of VDF/TrFE copolymer thin film was ranged from 375 nm to 2793 nm. Impedance of VDF/TrFE copolymer thin film was measured by LCR meter. Thin film in each thickness was fully poled by voltage based on C-V characteristics result. Generated power of the devices under applied vibration was observed by an oscilloscope. When the film thickness is 2793 nm, the generated power was about 0.815 μJ.

  4. Note: Suppression of kHz-frequency switching noise in digital micro-mirror devices.

    Hueck, Klaus; Mazurenko, Anton; Luick, Niclas; Lompe, Thomas; Moritz, Henning


    High resolution digital micro-mirror devices (DMDs) make it possible to produce nearly arbitrary light fields with high accuracy, reproducibility, and low optical aberrations. However, using these devices to trap and manipulate ultracold atomic systems for, e.g., quantum simulation is often complicated by the presence of kHz-frequency switching noise. Here we demonstrate a simple hardware extension that solves this problem and makes it possible to produce truly static light fields. This modification leads to a 47 fold increase in the time that we can hold ultracold (6)Li atoms in a dipole potential created with the DMD. Finally, we provide reliable and user friendly APIs written in Matlab and Python to control the DMD.

  5. Development of FDTD simulation tool for designing micro-nanostructured based optical devices

    Shrestha, Anil; Mizuno, Genki; Oduor, Patrick; Islam, Saif; Dutta, Achyut K.; Dhar, Nibir K.


    The use of Graphics Processing Unit (GPU) for computational work has revolutionized how complex electromagnetic problems are solved. Complex problems which required supercomputers in the past for analysis can now be tackled and solved using personal computers by channeling the computational work towards GPUs instead of the traditional computer Central Processing Unit (CPU). Finite-Difference Time-Domain (FDTD) analysis, which is a computationally expensive method of solving electromagnetic problems is highly parallel in nature and can be readily executed in a GPU. We have developed an algorithm for three dimensional FDTD analysis of optical devices with micro and nano-structures using Compute Unified Device Architecture (CUDA). The developed algorithm exploits the benefits of multiple cores of GPU chips and boosts the speed of simulation without sacrificing its accuracy. We achieved a 25-fold speed up of simulation using CUDA compared to MATLAB code in CPU.

  6. Note: Suppression of kHz-frequency switching noise in digital micro-mirror devices

    Hueck, Klaus; Mazurenko, Anton; Luick, Niclas; Lompe, Thomas; Moritz, Henning


    High resolution digital micro-mirror devices (DMDs) make it possible to produce nearly arbitrary light fields with high accuracy, reproducibility, and low optical aberrations. However, using these devices to trap and manipulate ultracold atomic systems for, e.g., quantum simulation is often complicated by the presence of kHz-frequency switching noise. Here we demonstrate a simple hardware extension that solves this problem and makes it possible to produce truly static light fields. This modification leads to a 47 fold increase in the time that we can hold ultracold 6Li atoms in a dipole potential created with the DMD. Finally, we provide reliable and user friendly APIs written in Matlab and Python to control the DMD.

  7. Suppression of kHz-Frequency Switching Noise in Digital Micro-Mirror Devices

    Hueck, Klaus; Luick, Niclas; Lompe, Thomas; Moritz, Henning


    High resolution digital micro-mirror devices (DMD) make it possible to produce nearly arbitrary light fields with high accuracy, reproducibility and low optical aberrations. However, using these devices to trap and manipulate ultracold atomic systems for e.g. quantum simulation is often complicated by the presence of kHz-frequency switching noise. Here we demonstrate a simple hardware extension that solves this problem and makes it possible to produce truly static light fields. This modification leads to a 47 fold increase in the time that we can hold ultracold $^6$Li atoms in a dipole potential created with the DMD. Finally, we provide reliable and user friendly APIs written in Matlab and Python to control the DMD.

  8. Development of a polymer-based easy-to-fabricate micro-free-flow electrophoresis device

    Akagi, Takanori; Kubota, Ryosuke; Kobayashi, Masashi; Ichiki, Takanori


    Since 1990s, micro-free-flow electrophoresis (µFFE) devices have been developed to allow for smaller sample volume and reagent consumption. To solve several technical problems involving the generation of electrolysis gas on the electrodes, most of the µFFE devices reported in the past were fabricated using elaborate micromachining process on silicon or glass substrates. However, high-cost micromachining processes were required and these were not suitable for mass production. In this paper, we report a polymer-based easy-to-fabricate µFFE device using a poly(methyl methacrylate-co-styrene), P(MMA-co-S), substrate and tetra-PEG gel for preventing the invasion of electrolysis gas into the separation chamber. In the separation experiment using a mixture of rhodamine B and sulforhodamine B, the resolution increased linearly with the increase of the applied voltages up to 50 V, whereas a deviation from the linear relation was observed above 50 V, which is possibly the Joule heating. These results indicate that this device could be applicable to separation of biological samples.

  9. Preliminary experience with the MicroMed DeBakey pediatric ventricular assist device.

    Fraser, Charles D; Carberry, Kathleen E; Owens, W Richard; Arrington, Karol A; Morales, David L S; Heinle, Jeffery S; McKenzie, E Dean


    Mechanical circulatory support for both acute and chronic heart failure is a widely applied therapeutic option in the adult population with a variety of devices clinically available. Technology in this field has advanced sufficiently such that long-term support or "destination therapy" has become a generally accepted reality. Similar progress has not occurred in the field of device support for heart failure in children. While the number of potential patients is significantly lower in the pediatric population, the clinical relevance and poignancy of individual need are nonetheless real. Until recently, children with heart failure have been largely disadvantaged in comparison to their adult counterparts. The DeBakey VAD Child (MicroMed Technology, Inc, Houston, TX) represents a hopeful initial step in the direction of reducing the technological gap between adults and children. While the clinical experience with this device is limited at present, preliminary results are encouraging. This report will provide an overview of the DeBakey VAD Child, including device specifications, indications for clinical use, surgical and postoperative considerations, and updated clinical experience.

  10. Expanding the available assays: adapting and validating In-Cell Westerns in microfluidic devices for cell-based assays.

    Paguirigan, Amy L; Puccinelli, John P; Su, Xiaojing; Beebe, David J


    Microfluidic methods for cellular studies can significantly reduce costs due to reduced reagent and biological specimen requirements compared with many traditional culture techniques. However, current types of readouts are limited and this lack of suitable readouts for microfluidic cultures has significantly hindered the application of microfluidics for cell-based assays. The In-Cell Western (ICW) technique uses quantitative immunocytochemistry and a laser scanner to provide an in situ measure of protein quantities in cells grown in microfluidic channels of arbitrary geometries. The use of ICWs in microfluidic channels was validated by a detailed comparison with current macroscale methods and shown to have excellent correlation. Transforming growth factor-β-induced epithelial-to-mesenchymal transition of an epithelial cell line was used as an example for further validation of the technique as a readout for soluble-factor-based assays performed in high-throughput microfluidic channels. The use of passive pumping for sample delivery and laser scanning for analysis opens the door to high-throughput quantitative microfluidic cell-based assays that integrate seamlessly with existing high-throughput infrastructure.

  11. Fabricated micro-nano devices for in vivo and in vitro biomedical applications.

    Barkam, Swetha; Saraf, Shashank; Seal, Sudipta


    In recent years, the innovative use of microelectromechanical systems (MEMSs) and nanoelectromechanical systems (NEMSs) in biomedical applications has opened wide opportunities for precise and accurate human diagnostics and therapeutics. The introduction of nanotechnology in biomedical applications has facilitated the exact control and regulation of biological environments. This ability is derived from the small size of the devices and their multifunctional capabilities to operate at specific sites for selected durations of time. Researchers have developed wide varieties of unique and multifunctional MEMS/NEMS devices with micro and nano features for biomedical applications (BioMEMS/NEMS) using the state of the art microfabrication techniques and biocompatible materials. However, the integration of devices with the biological milieu is still a fundamental issue to be addressed. Devices often fail to operate due to loss of functionality, or generate adverse toxic effects inside the body. The in vitro and in vivo performance of implantable BioMEMS such as biosensors, smart stents, drug delivery systems, and actuation systems are researched extensively to understand the interaction of the BioMEMS devices with physiological environments. BioMEMS developed for drug delivery applications include microneedles, microreservoirs, and micropumps to achieve targeted drug delivery. The biocompatibility of BioMEMS is further enhanced through the application of tissue and smart surface engineering. This involves the application of nanotechnology, which includes the modification of surfaces with polymers or the self-assembly of monolayers of molecules. Thereby, the adverse effects of biofouling can be reduced and the performance of devices can be improved in in vivo and in vitro conditions.

  12. Multifunctional semiconductor micro-Hall devices for magnetic, electric, and photo-detection

    Gilbertson, A. M.; Cohen, L. F. [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BZ (United Kingdom); Sadeghi, Hatef; Lambert, C. J. [Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom); Panchal, V.; Kazakova, O. [National Physical Laboratory, Teddington TW11 0LW (United Kingdom); Solin, S. A. [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BZ (United Kingdom); Department of Physics and Institute for Materials Science and Engineering, Washington University in St. Louis, St. Louis, Missouri 63130 (United States)


    We report the real-space voltage response of InSb/AlInSb micro-Hall devices to local photo-excitation, electric, and magnetic fields at room temperature using scanning probe microscopy. We show that the ultrafast generation of localised photocarriers results in conductance perturbations analogous to those produced by local electric fields. Experimental results are in good agreement with tight-binding transport calculations in the diffusive regime. The magnetic, photo, and charge sensitivity of a 2 μm wide probe are evaluated at a 10 μA bias current in the Johnson noise limit (valid at measurement frequencies > 10 kHz) to be, respectively, 500 nT/√Hz; 20 pW/√Hz (λ = 635 nm) comparable to commercial photoconductive detectors; and 0.05 e/√Hz comparable to that of single electron transistors. These results demonstrate the remarkably versatile sensing attributes of simple semiconductor micro-Hall devices that can be applied to a host of imaging and sensing applications.

  13. Optical scanning holography based on compressive sensing using a digital micro-mirror device

    A-qian, Sun; Ding-fu, Zhou; Sheng, Yuan; You-jun, Hu; Peng, Zhang; Jian-ming, Yue; xin, Zhou


    Optical scanning holography (OSH) is a distinct digital holography technique, which uses a single two-dimensional (2D) scanning process to record the hologram of a three-dimensional (3D) object. Usually, these 2D scanning processes are in the form of mechanical scanning, and the quality of recorded hologram may be affected due to the limitation of mechanical scanning accuracy and unavoidable vibration of stepper motor's start-stop. In this paper, we propose a new framework, which replaces the 2D mechanical scanning mirrors with a Digital Micro-mirror Device (DMD) to modulate the scanning light field, and we call it OSH based on Compressive Sensing (CS) using a digital micro-mirror device (CS-OSH). CS-OSH can reconstruct the hologram of an object through the use of compressive sensing theory, and then restore the image of object itself. Numerical simulation results confirm this new type OSH can get a reconstructed image with favorable visual quality even under the condition of a low sample rate.

  14. Design and validation of an ambulatory system for the measurement of the microcirculation in the capillaries: microHematron device.

    Toumi, Dareen; Gehin, Claudine; Dittmar, Andre; McAdams, Eric


    The non-invasive Hematron sensor is an active sensor used in studying skin blood flow (SBF) by measuring thermal conductivity of living tissues. Up to now, the Hematron device was composed of the Hematron probe and a heavy analog conditioning electronics. This paper presents the design, realization and validation of an ambulatory device (microHematron) associated with the original Hematron probe. The electronic architecture is based on a Programmable System on Chip (PSoC), which contributes in reducing the number of discrete components, and consequently, the electronic conditioning circuit of Hematron. The microHematron device can be worn on the wrist of the patient thanks to its size (4x3x1cm3) compared to the non-ambulatory conditioning electronics sized 20x30x20cm3. In addition, data can be stored in a microSD card or transmitted using a ZigBee module. The validation of the microHematron device was performed using the analog conditioning electronics as a reference. Experiments were performed first on a physical model reproducing microcirculation in order to characterize the linearity of the thermal conductivity as a function of water flow. Then, two experiments were hold in-vivo conditions highlighting the performances of this new device. In a first experiment, effects of mental calculation on effective tissue perfusion were measured and in a second one, effects of an anti-cellulite cream on micro-vascularisation and skin temperature were studied.

  15. In-channel printing-device opening assay for micropatterning multiple cells and gene analysis.

    Zhou, Hao; Zhao, Liang; Zhang, Xueji


    Herein we report an easy but versatile method for patterning different cells on a single substrate by using a microfluidic approach that allows not only spatial and temporal control of multiple microenvironments but also retrieval of specific treated cells to profile their expressed genetic information at around 10-cell resolution. By taking advantages of increased surface area of gold nanoparticles on a poly(dimethylsiloxane) (PDMS) coated substrate, cell adhesive-promotive protein, human fibronectin (hFN) can be significantly accumulated on designed regions where cells can recognize the protein and spread out. Moreover, the whole device can be easily opened by hand without any loss of patterned cells which could be retrieved by mouth-pipet. Consequently, we demonstrate the possibility of analyzing the difference of gene expression patterns between wild type MCF-7 cell and MCF/Adr (drug-resistant cell line) from less than 400 cells in total for a single comprehensive assay, including parallel experiments, controls, and multiple dose treatments. Certain genes, especially the P-glycoprotein coding gene (ABCB1), show high expression level in resistant cells compared with the wild type, suggesting a possible pathway that may contribute to the antidrug mechanism.

  16. Quantitative assay of element mass inventories in single cell biological systems with micro-PIXE

    Ogrinc, Nina [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); LOTRIČ Metrology, Selca 163, SI-4227 Selca (Slovenia); Pelicon, Primož, E-mail: [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Vavpetič, Primož; Kelemen, Mitja; Grlj, Nataša; Jeromel, Luka [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Tomić, Sergej [Medical Faculty of the Military Medical Academy, University of Defense, Crnotravska 17, Belgrade (Serbia); Čolić, Miodrag [Medical Faculty of the Military Medical Academy, University of Defense, Crnotravska 17, Belgrade (Serbia); Medical Faculty, University of Niš, Boulevard of Dr. Zoran Djindjić 81, 18000 Niš (Serbia); Beran, Alfred [Dipartimento di Oceanografia Biologica, Istituto Nazionale di Oceanografia e Geofisica Sperimentale, Via Auguste Piccard 54, 34151 Trieste (Italy)


    Elemental concentrations in micro-PIXE (Particle Induced X-ray Emission) maps of elements in biological tissue slices have been determined using auxiliary information on the sample matrix composition from EBS (Elastic Backscattering Spectroscopy) and STIM (Scanning Transmission Ion Microscopy). The thin sample approximation may be used for evaluating micro-PIXE data in cases, where X-ray absorption in the sample can be neglected and the mass of elements in a selected area can be estimated. The resulting sensitivity amounts to an impressive 10{sup −12} g of the selected elements. Two cases are presented as examples. In the first, we determined the total mass of gold nanoparticles internalized by human monocyte-derived dendritic cells (MDDC). In the second, an inventory of the mass of elements in the micro-particulate material adsorbed at the wall of the lorica of the microzooplankton species Tintinnopsis radix has been created.

  17. 78 FR 24425 - Assay Migration Studies for In Vitro Diagnostic Devices; Guidance for Industry and Food and Drug...


    ... study approach in support of the change. The FDA believes that the assay migration study paradigm... new system (previously not approved or licensed). The paradigm is suitable in cases when sufficient...'s current thinking on ``migration studies'' for in vitro diagnostic device. It does not create or...

  18. Rapid, single-molecule assays in nano/micro-fluidic chips with arrays of closely spaced parallel channels fabricated by femtosecond laser machining.

    Canfield, Brian K; King, Jason K; Robinson, William N; Hofmeister, William H; Davis, Lloyd M


    Cost-effective pharmaceutical drug discovery depends on increasing assay throughput while reducing reagent needs. To this end, we are developing an ultrasensitive, fluorescence-based platform that incorporates a nano/micro-fluidic chip with an array of closely spaced channels for parallelized optical readout of single-molecule assays. Here we describe the use of direct femtosecond laser machining to fabricate several hundred closely spaced channels on the surfaces of fused silica substrates. The channels are sealed by bonding to a microscope cover slip spin-coated with a thin film of poly(dimethylsiloxane). Single-molecule detection experiments are conducted using a custom-built, wide-field microscope. The array of channels is epi-illuminated by a line-generating red diode laser, resulting in a line focus just a few microns thick across a 500 micron field of view. A dilute aqueous solution of fluorescently labeled biomolecules is loaded into the device and fluorescence is detected with an electron-multiplying CCD camera, allowing acquisition rates up to 7 kHz for each microchannel. Matched digital filtering based on experimental parameters is used to perform an initial, rapid assessment of detected fluorescence. More detailed analysis is obtained through fluorescence correlation spectroscopy. Simulated fluorescence data is shown to agree well with experimental values.

  19. Micro-/nanoscale multi-field coupling in nonlinear photonic devices

    Yang, Qing; Wang, Yubo; Tang, Mingwei; Xu, Pengfei; Xu, Yingke; Liu, Xu


    The coupling of mechanics/electronics/photonics may improve the performance of nanophotonic devices not only in the linear region but also in the nonlinear region. This review letter mainly presents the recent advances on multi-field coupling in nonlinear photonic devices. The nonlinear piezoelectric effect and piezo-phototronic effects in quantum wells and fibers show that large second-order nonlinear susceptibilities can be achieved, and second harmonic generation and electro-optic modulation can be enhanced and modulated. Strain engineering can tune the lattice structures and induce second order susceptibilities in central symmetry semiconductors. By combining the absorption-based photoacoustic effect and intensity-dependent photobleaching effect, subdiffraction imaging can be achieved. This review will also discuss possible future applications of these novel effects and the perspective of their research. The review can help us develop a deeper knowledge of the substance of photon-electron-phonon interaction in a micro-/nano- system. Moreover, it can benefit the design of nonlinear optical sensors and imaging devices with a faster response rate, higher efficiency, more sensitivity and higher spatial resolution which could be applied in environmental detection, bio-sensors, medical imaging and so on.

  20. Current state of micro-robots/devices as substitutes for screening colonoscopy: assessment based on technology readiness levels.

    Tapia-Siles, Silvia C; Coleman, Stuart; Cuschieri, Alfred


    Previous reports have described several candidates, which have the potential to replace colonoscopy, but to date, there is still no device capable of fully replacing flexible colonoscopy in the management of colonic disorders and for mass adult population screening for asymptomatic colorectal cancer. NASA developed the TRL methodology to describe and define the stages of development before use and marketing of any device. The definitions of the TRLS used in the present review are those formulated by "The US Department of Defense Technology Readiness Assessment Guidance" but adapted to micro-robots for colonoscopy. All the devices included are reported in scientific literature. They were identified by a systematic search in Web of Science, PubMed and IEEE Xplore amongst other sources. Devices that clearly lack the potential for full replacement of flexible colonoscopy were excluded. The technological salient features of all the devices included for assessment are described briefly, with particular focus on device propulsion. The devices are classified according to the TRL criteria based on the reported information. An analysis is next undertaken of the characteristics and salient features of the devices included in the review: wireless/tethered devices, data storage-transmission and navigation, additional functionality, residual technology challenges and clinical and socio-economical needs. Few devices currently possess the required functionality and performance to replace the conventional colonoscopy. The requirements, including functionalities which favour the development of a micro-robot platform to replace colonoscopy, are highlighted.

  1. A spontaneous and passive waste-management device (PWMD) for a micro direct methanol fuel cell

    Chuang, Yun-Ju; Chieng, Ching-Chang; Pan, Chin; Luo, Shih-Jin; Tseng, Fan-Gang


    This paper introduces a passive waste-management device (PWMD) for a micro direct methanol fuel cell to exhale CO2 gas and to gather and transport water and methanol residue during operation. It passively employs condensation, temperature gradient, surface tension gradient and droplet coalescence to accumulate liquid, separate liquid and gas, and transport droplets without the need of external power. CO2 gas can be breathed out through hydrophobic micro holes with the assistance of buoyancy force while water/methanol vapor is condensing into droplets, coalescing with smaller droplets and is transported toward a cooler and more hydrophilic waste tank through wettability gradient. The wettability gradient is prepared by diffusion-controlled silanization with a gradient from 117° to 28° and is radial toward the outer boundary, which can drive droplets down to 1 µl with a speed of up to 20 mm s-1. With the assistance of coalescence along with the wettability gradient, the condensed water droplets can reach a double speed of 40 mm s-1. The maximum water removal rate of the PWMD can approach 6.134 µl s-1 cm-2, which is at least one order of magnitude higher than the demand of a standard µDMFC with power generation ability of 100 mW cm-2.

  2. High-throughput micro plate vanillin assay for determination of tannin in sorghum grain

    Sorghum tannins are phenolic compounds that offer health promoting antioxidant properties. The conventional HCl-vanillin assay for determining tannin content is a time-consuming method for screening large sample sets as seen in association mapping panels or breeder nursery samples. The objective of ...

  3. Magnetic nanoparticles for high-sensitivity detection on nucleic acids via superconducting-quantum-interference-device-based immunomagnetic reduction assay

    Yang, S. Y.; Chieh, J. J.; Wang, W. C.; Yu, C. Y.; Hing, N. S.; Horng, H. E.; Hong, Chin-Yih; Yang, H. C.; Chang, C. F.; Lin, H. Y.


    In this work, we investigate the feasibility of detecting quantitatively DNA molecules utilizing the technology named after the immunomagnetic reduction (IMR) assay. Magnetic nanoparticles dispersed in a phosphate buffer saline solution were bio-functionalized with probing single-strand DNA. A superconducting quantum interference device (SQUID) ac magnetosusceptometer was employed to detect IMR signals related to the concentration of the target DNA. The results reveal that use of IMR assay had merits such as a high convenience level, e.g. wash-free processes and high sensitivity, down to pM, for DNA detection.

  4. Micro-scale piezoelectric vibration energy harvesting: From fixed-frequency to adaptable-frequency devices

    Miller, Lindsay Margaret

    Wireless sensor networks (WSNs) have the potential to transform engineering infrastructure, manufacturing, and building controls by allowing condition monitoring, asset tracking, demand response, and other intelligent feedback systems. A wireless sensor node consists of a power supply, sensor(s), power conditioning circuitry, radio transmitter and/or receiver, and a micro controller. Such sensor nodes are used for collecting and communicating data regarding the state of a machine, system, or process. The increasing demand for better ways to power wireless devices and increase operation time on a single battery charge drives an interest in energy harvesting research. Today, wireless sensor nodes are typically powered by a standard single-charge battery, which becomes depleted within a relatively short timeframe depending on the application. This introduces tremendous labor costs associated with battery replacement, especially when there are thousands of nodes in a network, the nodes are remotely located, or widely-distributed. Piezoelectric vibration energy harvesting presents a potential solution to the problems associated with too-short battery life and high maintenance requirements, especially in industrial environments where vibrations are ubiquitous. Energy harvester designs typically use the harvester to trickle charge a rechargeable energy storage device rather than directly powering the electronics with the harvested energy. This allows a buffer between the energy harvester supply and the load where energy can be stored in a "tank". Therefore, the harvester does not need to produce the full required power at every instant to successfully power the node. In general, there are tens of microwatts of power available to be harvested from ambient vibrations using micro scale devices and tens of milliwatts available from ambient vibrations using meso scale devices. Given that the power requirements of wireless sensor nodes range from several microwatts to about one

  5. Analysis and Selection of Features for Gesture Recognition Based on a Micro Wearable Device

    Yinghui Zhou


    Full Text Available More and More researchers concerned about designing a health supporting system for elders that is light weight, no disturbing to user, and low computing complexity. In the paper, we introduced a micro wearable device based on a tri-axis accelerometer, which can detect acceleration change of human body based on the position of the device being set. Considering the flexibility of human finger, we put it on a finger to detect the finger gestures. 12 kinds of one-stroke finger gestures are defined according to the sensing characteristic of the accelerometer. Feature is a paramount factor in the recognition task. In the paper, gestures features both in time domain and frequency domain are described since features decide the recognition accuracy directly. Feature generation method and selection process is analyzed in detail to get the optimal feature subset from the candidate feature set. Experiment results indicate the feature subset can get satisfactory classification results of 90.08% accuracy using 12 features considering the recognition accuracy and dimension of feature set.

  6. Application of micro- and nano-electromechanical devices to drug delivery.

    Staples, Mark; Daniel, Karen; Cima, Michael J; Langer, Robert


    Micro- and nano-electromechanical systems (MEMS and NEMS)-based drug delivery devices have become commercially-feasible due to converging technologies and regulatory accommodation. The FDA Office of Combination Products coordinates review of innovative medical therapies that join elements from multiple established categories: drugs, devices, and biologics. Combination products constructed using MEMS or NEMS technology offer revolutionary opportunities to address unmet medical needs related to dosing. These products have the potential to completely control drug release, meeting requirements for on-demand pulsatile or adjustable continuous administration for extended periods. MEMS or NEMS technologies, materials science, data management, and biological science have all significantly developed in recent years, providing a multidisciplinary foundation for developing integrated therapeutic systems. If small-scale biosensor and drug reservoir units are combined and implanted, a wireless integrated system can regulate drug release, receive sensor feedback, and transmit updates. For example, an "artificial pancreas" implementation of an integrated therapeutic system would improve diabetes management. The tools of microfabrication technology, information science, and systems biology are being combined to design increasingly sophisticated drug delivery systems that promise to significantly improve medical care.

  7. Circulating microRNA Biomarkers as Liquid Biopsy for Cancer Patients: Pros and Cons of Current Assays.

    Ono, Shigeshi; Lam, Stella; Nagahara, Makoto; Hoon, Dave S B


    An increasing number of studies have focused on circulating microRNAs (cmiRNA) in cancer patients' blood for their potential as minimally-invasive biomarkers. Studies have reported the utility of assessing specific miRNAs in blood as diagnostic/prognostic biomarkers; however, the methodologies are not validated or standardized across laboratories. Unfortunately, there is often minimum limited overlap in techniques between results reported even in similar type studies on the same cancer. This hampers interpretation and reliability of cmiRNA as potential cancer biomarkers. Blood collection and processing, cmiRNA extractions, quality and quantity control of assays, defined patient population assessment, reproducibility, and reference standards all affect the cmiRNA assay results. To date, there is no reported definitive method to assess cmiRNAs. Therefore, appropriate and reliable methodologies are highly necessary in order for cmiRNAs to be used in regulated clinical diagnostic laboratories. In this review, we summarize the developments made over the past decade towards cmiRNA detection and discuss the pros and cons of the assays.

  8. Syringe micro vibrator (SMV a new device being introduced in dentistry to alleviate pain and anxiety of intraoral injections, and a comparative study with a similar device

    Shahidi Bonjar Amir Hashem


    Full Text Available Abstract Background Neurologically, it is proven that stimulation of larger diameter fibers - e.g. using appropriate coldness, warmth, rubbing, pressure or vibration- can close the neural "gate" so that the central perception of itch and pain is reduced. This fact is based upon "Gate-control" theory of Melzack and Wall. Presentation of the hypothesis Syringe Micro Vibrator is a new design being introduced for the first time in the field of Dentistry. This device is a promising breakthrough in pain and anxiety management and may deliver solution for clinicians plagued with patient pain phobia. It has an off-set rotating micro vibration creator with ultra high frequency and ultra low altitude that can be easily placed on any standard dental syringe and some disposable syringes. This device was registered as an invention in dentistry and received Iran National Patent number of 63765. Testing the hypothesis By creating micro vibration, this device would be effective in reducing the pain and anxiety confronted with most types of intraoral injections as palatal, mandibular block, intraligamental and local infiltration. From the aspect of the patient pain management, this device contributes both physiologically (based on Gate Control Theory of pain and psychologically (based on the device function as will be explained by dentist to the patient as a modern pain reducing technology. From the aspect of clinician, SMV motor provides vibrations with ultra high frequency to alleviate pain, but since it has ultra low vibration altitude, it has no adverse effect on the clinician dexterity and accuracy during injection and it does not interfere with pin point localization of injection site. Implications of the hypothesis Upon mounting on a conventional dental anesthesia injection syringe, SMV is switched on and the clinician then uses normal injection technique to administer the anesthetic. This device is not only a useful accessory device for ordinary patients

  9. Microfludic device for creating ionic strength gradients over DNA microarrays for efficient DNA melting studies and assay development

    Petersen, Jesper; Poulsen, Lena; Birgens, Henrik


    is to use a thermal gradient and information from melting curves, for instance to score genotypes. However, application of temperature gradients normally requires complicated equipment, and the size of the arrays that can be investigated is restricted due to heat dissipation. Here we present a simple...... microfluidic device that creates a gradient comprising zones of defined ionic strength over a glass slide, in which each zone corresponds to a subarray. Using this device, we demonstrated that ionic strength gradients function in a similar fashion as corresponding thermal gradients in assay development. More...

  10. A tunable microflow focusing device utilizing controllable moving walls and its applications for formation of micro-droplets in liquids

    Lee, Chun-Hong; Hsiung, Suz-Kai; Lee, Gwo-Bin


    This study reports a new microfluidic device capable of fine-tuned sample-flow focusing and generation of micro-droplets in liquids by controlling moving wall structures. Two microfluidic components including an 'active microchannel width controller' and a 'micro chopper' can be used to fine-tune the width of the hydrodynamically pre-focused stream and subsequently generate micro-droplets. In this study, a basic concept of a 'controllable moving wall' structure was addressed and applied as the active microchannel width controller and the micro chopper to generate the proposed function. Pneumatic side chambers were placed next to a main flow channel to construct the controllable moving wall structures. The deformation of the controllable moving wall structure can be generated by the pressurized air injected into the pneumatic side chambers. The proposed chip device was fabricated utilizing polymer material such as PDMS (polydimethylsiloxane) to provide the flexibility of the controllable moving wall deformation. The microfluidic chip device with dimensions of 2.5 cm in width and 3.0 cm in length can be fabricated using a simple fabrication process. Experimental data showed that the deformation of the controllable moving wall structure can be adjusted by applying different air pressures, so that the width of the main flow channel can be controlled accordingly. By utilizing the proposed mechanism, the pre-focused dispersed phase stream could be actively focused into a narrower stream, and well-controlled micro-droplets with smaller diameters could be generated. The stream width can be reduced from 30 µm to 9 µm and micro-droplets with a diameter of 76 µm could be generated by utilizing the proposed device. In addition, to generate micro-droplets within smaller diameters, uniform size distribution of the micro-droplets can be obtained. According to the experimental results, development of the microfluidic device could be promising for a variety of applications such

  11. A novel microRNA assay with optical detection and enzyme-free DNA circuits

    Liao, Yuhui; Zhou, Xiaoming


    MicroRNAs (miRNAs) participate in the significant processes of life course, can be used as quantificational biomarkers for cellular level researches and related diseases. Conventional methods of miRNAs' quantitative detection are obsessed with low sensitivity, time and labour consuming. Otherwise, the emerging miRNAs detection approaches are mostly exposed to the expensive equipment demands and the professional operation, remains at the stage of laboratory and concept demonstration phase. Herein, we designed a novel miRNAs detection platform that based on enzyme-free DNA circuits and electrochemical luminescence (ECL). MicroRNA21 was chosen as the ideal analyte of this platform. The whole process consists of enzyme-free DNA circuits and ECL signal giving-out steps, achieves advantages of operating in constant temperature condition, without the participation of the enzyme, preferable sensitivity and specificity. Through this approach, the sensitivity achieved at 10pM. It is indicated that this miRNAs detection platform possesses potentials to be an innovation of miRNA detection technologies in routine tests. Benefits of the high penetration of ECL in well-equipped medical establishment, this approach could greatly lessen the obstacles in process of popularization and possess excellent prospects of practical application.

  12. A low temperature Co-fired ceramic-based dielectrophoretic device for manipulating micro and nanostructure materials.

    Seon, Ji-Yun; Yoon, Young Joon; Choi, Jaekyoung; Kim, Hyo Tae; Kim, Chang-Yeoul; Kim, Jong-Hee; Baik, Hong Koo


    A dielectophoretic (DEP) device fabricated by a conventional low temperature co-fired ceramic (LTCC) process, for manipulating micro and nanostructure materials, such as spherical polystyrene microspheres, titanium dioxide (TiO2) nanotubes, and silver (Ag) nanowires, is described. To generate a non-uniform electric field, a castellated electrode configuration was applied to the LTCC-based DEP device using a screen printing method. The actual motions of the micro and nanostructure materials under both a positive and a negative DEP force were observed in detail and the findings compared with numerical simulation data for the electric field distribution. The performance of the LTCC-based DEP device for separating and trapping was evaluated and potential applications are discussed.

  13. A wafer-level vacuum package using glass-reflowed silicon through-wafer interconnection for nano/micro devices.

    Jin, Joo-Young; Yoo, Seung-Hyun; Yoo, Byung-Wook; Kim, Yong-Kweon


    We propose a vacuum wafer-level packaging (WLP) process using glass-reflowed silicon via for nano/micro devices (NMDs). A through-wafer interconnection (TWIn) substrate with silicon vias and reflowed glass is introduced to accomplish a vertical feed-through of device. NMDs are fabricated in the single crystal silicon (SCS) layer which is formed on the TWIn substrate by Au eutectic bonding including Cr adhesion layer. The WLPof the devices is achieved with the capping glass wafer anodically bonded to the SCS layer. In order to demonstrate the successful hermetic packaging, we fabricated the micro-Pirani gauge in the SCS layer, and packaged it in the wafer-level. The vacuum level inside the packaging was measured to be 3.1 Torr with +/- 0.12 Torr uncertainty, and the packaging leakage was not detected during 24 hour after the packaging.

  14. Device and method for enhanced collection and assay of chemicals with high surface area ceramic

    Addleman, Raymond S.; Li, Xiaohong Shari; Chouyyok, Wilaiwan; Cinson, Anthony D.; Bays, John T.; Wallace, Krys


    A method and device for enhanced capture of target analytes is disclosed. This invention relates to collection of chemicals for separations and analysis. More specifically, this invention relates to a solid phase microextraction (SPME) device having better capability for chemical collection and analysis. This includes better physical stability, capacity for chemical collection, flexible surface chemistry and high affinity for target analyte.

  15. High-throughput Assays for MicroRNA Target Genes%MicroRNA靶基因的高通量鉴定方法

    陈灵锋; 张均平; 王明席


    MicroRNAs(miRNAs)are a class of endogenous non-coding RNAs involved in the regulation of gene expression at the post-transcriptional level. miRNAs play pivotal roles in cell growth, development and disease pathogenesis. Therefore, to identify and validate miRNAs target genes regulated is essential to understand the functions of miRNAs in disease. miRNAs bind the complementary sequences of target mRN As to mediate translational repression or target degradation and gene silencing, both computer-aided predication and biological experimental screening can be used for target identification. The former may produce a large number of miRNA target genes with higher false positive genes to be further excluded by the biological experiments. The latter approaches can be further greatly facilitated with high-throughput multiple target screening assays, such as microarray, proteome analysis, or RNA ligase mediated rapid amplification of cDNA ends. The applications involving these assays were summarized and compared, together with the discussion on the further development of related technologies.%MicroRNAs (miRNAs)是一类内源性非编码小RNA,可在转录后水平调节基因的表达,在细胞生长、发育、疾病发生等过程中发挥着重要作用.明确miRNAs所调控的靶基因对阐明miRNAs的功能及在各种生命过程和疾病发生机制的角色非常关键.目前,鉴定miRNAs的靶基因的方法主要计算机预测方法和生物学实验方法.前者对miRNA靶基因的寻找作出巨大贡献,但常存在很多假阳性,必须通过生物学实验方法加以验证.后者涉及单靶基因鉴定技术和高通量多靶基因鉴定技术,高通量技术又包括基因芯片分析技术、蛋白质组学分析技术、RNA连接酶介导的cDNA末端扩增技术和生物化学法等.本文主要对这些高通量技术的应用、优劣进行归纳,并对其改进方向予以讨论.

  16. The development of microbatteries based on three-dimensional architectures for autonomous micro devices

    Min, Hong-Seok


    The goal of fabricating three-dimensional (3D) microbatteries is to improve upon the performance of 2D microbatteries or thin-film batteries by reconfiguring existing materials in a more advanced architecture. 3D battery architectures offer a new approach for miniaturized power sources. These batteries are designed to have a small areal foot print and yet provide sufficient power and energy density to operate autonomous MEMS devices. The more convenient approaches for fabricating such batteries are based on micromachining techniques such as electrodeposition of high aspect ratio metal rods in an array configuration. Three types of three-dimensional microbatteries were fabricated and characterized: Ni-Zn, zinc-air, and Ag-Zn. These different types of microbatteries use different chemistries but all have the common feature of an out-of-plane array of micro-post electrodes. A 3D Ni-Zn microbattery was fabricated and demonstrated proper charge-discharge behavior for the first few cycles. The development of 3D zinc-air microbattery showed high discharge capability under various discharge conditions. Furthermore, performance of 3D zinc-air microbattery was demonstrated by successfully powering an electronic device. During discharge, the 3D zinc-air microbattery exhibited an electrode reaction which formed hollow ZnO electrodes by the Kirkendall effect. This electrode reaction strongly supports the functionality of the 3D microbattery. The fabrication of the Ag-Zn microbattery was accomplished by Ag electrode formation, separator coating, and Zn sedimentation. Due to imperfections in the separator coating, the 3D Ag-Zn microbattery had electrical shorts.

  17. Combination of micro-dialysis and infrared spectroscopy: a multianalyte assay for accurate biofluid analysis and patient monitoring

    Vahlsing, Thorsten; Delbeck, Sven; Budde, Janpeter; Ihrig, Dieter; Heise, H. Michael


    Micro-dialysis can be used for continuously harvesting body fluids, while a multi-component analysis of the dialysates by infrared spectrometry offers splendid opportunities for monitoring substrates and metabolites such as glucose, lactate and others small enough to penetrate the semi-permeable dialysis membranes. However, a drawback of this process are variable recovery rates, which can be observed especially for subcutaneously implanted catheters in human subjects. Isotonic perfusates were investigated with acetate and mannitol as recovery markers for the dialysis of human serum at 37°C to mimic in vivo patient monitoring. The latter non-ionic substance has been suggested for application when other ionic substances such as bicarbonate or pH are also to be determined. Simultaneously for acetate and mannitol, the depletion of the marker substances from the perfusates using different micro-dialysis devices was investigated under various flow-rates. Relationships between relative dialysate marker concentrations and glucose recovery rates were determined based on multivariate calibrations. For quantification, classical least squares with reference spectra for modelling the serum dialysates was used, rendering a basis for reliable blood glucose and lactate measurements.

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

    Tania Limongi; Luca Tirinato; Francesca Pagliari; Andrea Giugni; Marco Allione; Gerardo Perozziello; Patrizio Candeloro; Enzo Di Fabrizio


    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.

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

    Tania Limongi; Luca Tirinato; Francesca Pagliari; Andrea Giugni; Marco Allione; Gerardo Perozziello; Patrizio Candeloro; Enzo Di Fabrizio


    Nanotechnology allows the realization of new materials and devices with basic structural unit in the range of1–100 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.

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

    Limongi, Tania


    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.

  1. Electrochemical sensors and devices for heavy metals assay in water: the French groups' contribution

    Pujol, Luca; Evrard, David; Groenen-Serrano, Karine; Freyssinier, Mathilde; Ruffien-Cizsak, Audrey; Gros, Pierre


    A great challenge in the area of heavy metal trace detection is the development of electrochemical techniques and devices which are user-friendly, robust, selective, with low detection limits and allowing fast analyses...

  2. "Optical communication with brain cells by means of an implanted duplex micro-device with optogenetics and Ca(2+) fluoroimaging".

    Kobayashi, Takuma; Haruta, Makito; Sasagawa, Kiyotaka; Matsumata, Miho; Eizumi, Kawori; Kitsumoto, Chikara; Motoyama, Mayumi; Maezawa, Yasuyo; Ohta, Yasumi; Noda, Toshihiko; Tokuda, Takashi; Ishikawa, Yasuyuki; Ohta, Jun


    To better understand the brain function based on neural activity, a minimally invasive analysis technology in a freely moving animal is necessary. Such technology would provide new knowledge in neuroscience and contribute to regenerative medical techniques and prosthetics care. An application that combines optogenetics for voluntarily stimulating nerves, imaging to visualize neural activity, and a wearable micro-instrument for implantation into the brain could meet the abovementioned demand. To this end, a micro-device that can be applied to the brain less invasively and a system for controlling the device has been newly developed in this study. Since the novel implantable device has dual LEDs and a CMOS image sensor, photostimulation and fluorescence imaging can be performed simultaneously. The device enables bidirectional communication with the brain by means of light. In the present study, the device was evaluated in an in vitro experiment using a new on-chip 3D neuroculture with an extracellular matrix gel and an in vivo experiment involving regenerative medical transplantation and gene delivery to the brain by using both photosensitive channel and fluorescent Ca(2+) indicator. The device succeeded in activating cells locally by selective photostimulation, and the physiological Ca(2+) dynamics of neural cells were visualized simultaneously by fluorescence imaging.

  3. Applying Taguchi methods for solvent-assisted PMMA bonding technique for static and dynamic micro-TAS devices.

    Hsu, Yi-Chu; Chen, Tang-Yuan


    This work examines numerous significant process parameters in the solvent-assistant Polymethyl methacrylate (PMMA) bonding scheme and presents two Micro-total-analysis System (micro-TAS) devices generated by adopting the optimal bonding parameters. The process parameters considered were heating temperature, applied loading, duration and solution. The effects of selected process parameters on bonding dimensions loss and strength, and subsequent optimal setting of the parameters were accomplished using Taguchi's scheme. Additionally, two micro-TAS devices were realized using a static paraffin microvalve and a dynamic diffuser micropump. The PMMA chips were carved using a CO2 laser that patterned device microchannels and microchambers. The operation principles, fabrication processes and experimental performance of the devices are discussed. This bonding technique has numerous benefits, including high bonding strength (240 kgf/cm2) and low dimension loss (2-6%). For comparison, this work also demonstrates that the normal stress of this technology is 2-15 times greater than that of other bonding technologies, including hot embossing, anodic bonding, direct bonding and thermal fusion bonding.

  4. Microfludic device for creating ionic strength gradients over DNA microarrays for efficient DNA melting studies and assay development.

    Jesper Petersen

    Full Text Available The development of DNA microarray assays is hampered by two important aspects: processing of the microarrays is done under a single stringency condition, and characteristics such as melting temperature are difficult to predict for immobilized probes. A technical solution to these limitations is to use a thermal gradient and information from melting curves, for instance to score genotypes. However, application of temperature gradients normally requires complicated equipment, and the size of the arrays that can be investigated is restricted due to heat dissipation. Here we present a simple microfluidic device that creates a gradient comprising zones of defined ionic strength over a glass slide, in which each zone corresponds to a subarray. Using this device, we demonstrated that ionic strength gradients function in a similar fashion as corresponding thermal gradients in assay development. More specifically, we noted that (i the two stringency modulators generated melting curves that could be compared, (ii both led to increased assay robustness, and (iii both were associated with difficulties in genotyping the same mutation. These findings demonstrate that ionic strength stringency buffers can be used instead of thermal gradients. Given the flexibility of design of ionic gradients, these can be created over all types of arrays, and encompass an attractive alternative to temperature gradients, avoiding curtailment of the size or spacing of subarrays on slides associated with temperature gradients.

  5. Endotoxin Detection in Pharmaceuticals and Medical Devices with Kinetic-QCL, a Kinetic-Quantitative Chromogenic Limulus Amebocyte Lysate Assay.

    Berzofsky, Ronald N.


    The observation that endotoxin caused gelation in extracts of Limulus amebocytes has been expanded to the development of an in vitro kinetic, quantitative chromogenic LAL assay (Kinetic-QCL) for the detection of endotoxin in aqueous fluids. Within the last 15 years, the use of Limulus amebocyte lysate to detect and control the presence of pyrogenic substances in pharmaceuticals and medical devices has gained wide international acceptance. Both the United States and European Pharmacopoeias contain descriptions of and requirements for the LAL Bacterial Endotoxin Test. Both pharmacopoeias have begun to remove the rabbit pyrogen test requirement in a majority of drug monographs and have substituted endotoxin limits to be determined by LAL. The use of LAL has proved invaluable in controlling the level of endotoxin in finished product. The endotoxin contribution of raw materials and packaging material can be monitored as well. In-process testing at critical production steps can identify additional sources of endotoxin contamination, and depyrogenation processes can be validated by quantitating the degradation of endotoxin challenges. The speed, reproducibility, sensitivity, and economics of the Kinetic-QCL assay, in conjunction with the ppropriate equipment and software, over both the in vivo rabbit pyrogen test and the more traditional LAL gel-clot assay allow a more in-depth approach to the control of endotoxin in pharmaceuticals and medical devices.

  6. Differential Diagnosis of Malaria on Truelab Uno®, a Portable, Real-Time, MicroPCR Device for Point-Of-Care Applications.

    Nair, Chandrasekhar Bhaskaran; Manjula, Jagannath; Subramani, Pradeep Annamalai; Nagendrappa, Prakash B; Manoj, Mulakkapurath Narayanan; Malpani, Sukriti; Pullela, Phani Kumar; Subbarao, Pillarisetti Venkata; Ramamoorthy, Siva; Ghosh, Susanta K


    Sensitive and specific detection of malarial parasites is crucial in controlling the significant malaria burden in the developing world. Also important is being able to identify life threatening Plasmodium falciparum malaria quickly and accurately to reduce malaria related mortality. Existing methods such as microscopy and rapid diagnostic tests (RDTs) have major shortcomings. Here, we describe a new real-time PCR-based diagnostic test device at point-of-care service for resource-limited settings. Truenat® Malaria, a chip-based microPCR test, was developed by bigtec Labs, Bangalore, India, for differential identification of Plasmodium falciparum and Plasmodium vivax parasites. The Truenat Malaria tests runs on bigtec's Truelab Uno® microPCR device, a handheld, battery operated, and easy-to-use real-time microPCR device. The performance of Truenat® Malaria was evaluated versus the WHO nested PCR protocol. The Truenat® Malaria was further evaluated in a triple-blinded study design using a sample panel of 281 specimens created from the clinical samples characterized by expert microscopy and a rapid diagnostic test kit by the National Institute of Malaria Research (NIMR). A comparative evaluation was done on the Truelab Uno® and a commercial real-time PCR system. The limit of detection of the Truenat Malaria assay was found to be test was found to have sensitivity and specificity of 100% each, compared to the WHO nested PCR protocol based on the evaluation of 100 samples. The sensitivity using expert microscopy as the reference standard was determined to be around 99.3% (95% CI: 95.5-99.9) at the species level. Mixed infections were identified more accurately by Truenat Malaria (32 samples identified as mixed) versus expert microscopy and RDTs which detected 4 and 5 mixed samples, respectively. The Truenat® Malaria microPCR test is a valuable diagnostic tool and implementation should be considered not only for malaria diagnosis but also for active surveillance

  7. Use of PLL-g-PEG in micro-fluidic devices for localizing selective and specific protein binding.

    Marie, Rodolphe; Beech, Jason P; Vörös, Janos; Tegenfeldt, Jonas O; Höök, Fredrik


    By utilizing flow-controlled PLL-g-PEG and PLL-g-PEGbiotin modification of predefined regions of a poly(dimethylsiloxane) (PDMS) micro-fluidic device, with an intentionally chosen large (approximately 1 cm2) internal surface area, we report rapid (10 min), highly localized (6 x 10(-6) cm2), and specific surface-based protein capture from a sample volume (100 microL) containing a low amount of protein (160 attomol in pure buffer and 400 attomol in serum). The design criteria for this surface modification were achieved using QCM-D (quartz crystal microbalance with energy dissipation monitoring) of serum protein adsorption onto PLL-g-PEG-modified oxidized PDMS. Equally good, or almost as good, results were obtained for oxidized SU-8, Topas, and poly(methyl metacrylate) (PMMA), demonstrating the generic potential of PLL-g-PEG for surface modification in various micro-fluidic applications.

  8. A spheroid toxicity assay using magnetic 3D bioprinting and real-time mobile device-based imaging.

    Tseng, Hubert; Gage, Jacob A; Shen, Tsaiwei; Haisler, William L; Neeley, Shane K; Shiao, Sue; Chen, Jianbo; Desai, Pujan K; Liao, Angela; Hebel, Chris; Raphael, Robert M; Becker, Jeanne L; Souza, Glauco R


    An ongoing challenge in biomedical research is the search for simple, yet robust assays using 3D cell cultures for toxicity screening. This study addresses that challenge with a novel spheroid assay, wherein spheroids, formed by magnetic 3D bioprinting, contract immediately as cells rearrange and compact the spheroid in relation to viability and cytoskeletal organization. Thus, spheroid size can be used as a simple metric for toxicity. The goal of this study was to validate spheroid contraction as a cytotoxic endpoint using 3T3 fibroblasts in response to 5 toxic compounds (all-trans retinoic acid, dexamethasone, doxorubicin, 5'-fluorouracil, forskolin), sodium dodecyl sulfate (+control), and penicillin-G (-control). Real-time imaging was performed with a mobile device to increase throughput and efficiency. All compounds but penicillin-G significantly slowed contraction in a dose-dependent manner (Z' = 0.88). Cells in 3D were more resistant to toxicity than cells in 2D, whose toxicity was measured by the MTT assay. Fluorescent staining and gene expression profiling of spheroids confirmed these findings. The results of this study validate spheroid contraction within this assay as an easy, biologically relevant endpoint for high-throughput compound screening in representative 3D environments.

  9. Wet-lab tested microRNA assays for qPCR studies with SYBR® Green and DNA primers in pig tissues.

    Mentzel, Caroline M J; Skovgaard, Kerstin; Córdoba, Sarai; Herrera Uribe, Juber; Busk, Peter K; Cirera, Susanna


    MicroRNAs are key post-transcriptional regulators of gene expression that are involved in several biological processes including those that mediate disease pathophysiology. Hence, quantifying microRNA expression levels can provide important and novel insights into disease biology. In recent years, the pig has emerged as an excellent large animal model for studying human diseases and conditions (e.g. obesity) due to similarities in organ size, gastro-intestinal tract, metabolism, immune response, genetics and the availability of relevant tissues that are not normally easily available in humans. We have previously developed two useful tools in the field of microRNA quantitative real time PCR (qPCR): 1) a very specific, sensitive and simple qPCR method based on DNA primers, MiR-specific qPCR; and 2) the free primer-design software miRprimer. The present study integrates in a publicly accessible database all available information on validated porcine microRNA qPCR assays that have utilized these tools. Due to the high phylogenetic conservation in microRNA sequence between pig, humans and other domestic species this database is a very valuable resource for the broader scientist community who are working on microRNAs and want to use readily tested qPCR assays in a simple and cost-effective manner.

  10. A facile and specific assay for quantifying microRNA by an optimized RT-qPCR approach.

    Qian Mei

    Full Text Available BACKGROUND: The spatiotemporal expression patterns of microRNAs (miRNAs are important to the verification of their predicted function. RT-qPCR is the accepted technique for the quantification of miRNA expression; however, stem-loop RT-PCR and poly(T-adapter assay, the two most frequently used methods, are not very convenient in practice and have poor specificity, respectively. RESULTS: We have developed an optimal approach that integrates these two methods and allows specific and rapid detection of tiny amounts of sample RNA and reduces costs relative to other techniques. miRNAs of the same sample are polyuridylated and reverse transcribed into cDNAs using a universal poly(A-stem-loop RT primer and then used as templates for SYBR® Green real-time PCR. The technique has a dynamic range of eight orders of magnitude with a sensitivity of up to 0.2 fM miRNA or as little as 10 pg of total RNA. Virtually no cross-reaction is observed among the closely-related miRNA family members and with miRNAs that have only a single nucleotide difference in this highly specific assay. The spatial constraint of the stem-loop structure of the modified RT primer allowed detection of miRNAs directly from cell lysates without laborious total RNA isolation, and the poly(U tail made it possible to use multiplex RT reactions of mRNA and miRNAs in the same run. CONCLUSIONS: The cost-effective RT-qPCR of miRNAs with poly(A-stem-loop RT primer is simple to perform and highly specific, which is especially important for samples that are precious and/or difficult to obtain.

  11. A simple micro-extraction plate assay for automated LC-MS/MS analysis of human serum 25-hydroxyvitamin D levels.

    Geib, Timon; Meier, Florian; Schorr, Pascal; Lammert, Frank; Stokes, Caroline S; Volmer, Dietrich A


    This short application note describes a simple and automated assay for determination of 25-hydroxyvitamin D (25(OH)D) levels in very small volumes of human serum. It utilizes commercial 96-well micro-extraction plates with commercial 25(OH)D isotope calibration and quality control kits. Separation was achieved using a pentafluorophenyl liquid chromatography column followed by multiple reaction monitoring-based quantification on an electrospray triple quadrupole mass spectrometer. Emphasis was placed on providing a simple assay that can be rapidly established in non-specialized laboratories within days, without the need for laborious and time consuming sample preparation steps, advanced calibration or data acquisition routines. The analytical figures of merit obtained from this assay compared well to established assays. To demonstrate the applicability, the assay was applied to analysis of serum samples from patients with chronic liver diseases and compared to results from a routine clinical immunoassay.

  12. Electrochemical sensors and devices for heavy metals assay in water: the French groups' contribution

    Luca ePUJOL


    Full Text Available A great challenge in the area of heavy metal trace detection is the development of electrochemical techniques and devices which are user-friendly, robust, selective, with low detection limits and allowing fast analyses. This review presents the major contribution of the French scientific academic community in the field of electrochemical sensors and electroanalytical methods within the last 20 years. From the well-known polarography to the up-to-date generation of functionalized interfaces, the different strategies dedicated to analytical performances improvement are exposed: stripping voltammetry, solid mercury-free electrode, ion selective sensor, carbon based materials, chemically modified electrodes, nano-structured surfaces. The paper particularly emphasizes their advantages and limits face to the last Water Frame Directive devoted to the Environmental Quality Standards for heavy metals. Recent trends on trace metal speciation as well as on automatic on line monitoring devices are also evoked.

  13. Micro-structure Engineering of InGaN/GaN Quantum Wells for High Brightness Light Emitting Devices

    Shen, Chao


    With experimental realization of micro-structures, the feasibility of achieving high brightness, low efficiency droop blue LED was implemented based on InGaN/GaN micro-LED-pillar design. A significantly high current density of 492 A/cm2 in a 20 μm diameter (D) micro-LED-pillar was achieved, compared to that of a 200 μm diameter LED (20 A/cm2), both at 10 V bias voltage. In addition, an increase in sustained quantum efficiency from 70.2% to 83.7% at high injection current density (200 A/cm2) was observed in micro-LED-pillars in conjunction with size reduction from 80 μm to 20 μm. A correlation between the strain relief and the electrical performance improvement was established for micro-LED-pillars with D < 50 μm, apart from current spreading effect. The degree of strain relief and its distribution were further studied in micro-LED-pillars with D ranging from 1 μm to 15 μm. Significant wavenumbers down-shifts for E2 and A1 Raman peaks, together with the blue shifted PL peak emission, were observed in as-prepared pillars, reflecting the degree of strain relief. A sharp transition from strained to relaxed epitaxy region was discernible from the competing E2 phonon peaks at 572 cm-1 and 568 cm-1, which were attributed to strain residue and strain relief, respectively. A uniform strain relief at the center of micro-pillars was achieved, i.e. merging of the competing phonon peaks, after Rapid Thermal Annealing (RTA) at 950℃ for 20 seconds, 4 phenomenon of which was observed for the first time. The transition from maximum strain relief to a uniform strain relief was found along the narrow circumference (< 2.5 μm) of the pillars from the line-map of Raman spectroscopy. The extent of strain relief is also examined considering the height (L) of micro-LED-pillars fabricated using FIB micro-machining technique. The significant strain relief of up to 70% (from -1.4 GPa to -0.37 GPa), with a 71 meV PL peak blue shift, suggested that micro-LED-pillar with D < 3 μm and

  14. A parallel and quantitative cell migration assay using a novel multi-well-based device.

    Quan, Qianghua; Zhang, Shuwen; Wang, Xudong; Ouyang, Qi; Wang, Yugang; Yang, Gen; Luo, Chunxiong


    Cell migration assays for different chemical environments are important for both scientists and clinicians searching for new therapeutics. In this study, we developed a multi-well-based microfluidic chip that has multiple units for different conditions. In each unit, cells can be patterned and then released to observe their migration. Automatic image analysis and model-based data processing were developed to describe the integrated cell migration assay precisely and quickly. As a demonstration, the migration behaviors of two types of cells in eight chemical conditions were studied. The results showed that supplementation with transforming growth factor-β(TGF-β) significantly promoted the migration of MCF-7 and MCF-10 A cells compared to several growth factors, such as Epidermal Growth Factor(EGF) and basic fibroblast growth factor(bFGF), as well as a control sample. Cells can migrate particularly fast with two or more mixed supplementary factors, such as TGF-β + bFGF + EGF, which indicated a synergy effect. Thus, this chip could be used to quantitatively observe cancer cell migration and demonstrated great potential for use in quantitative migration studies and chemical screening.

  15. Micro/nanofabricated solid-state thermoelectric generator devices for integrated high voltage power sources

    Fleurial, J. P.; Snyder, G. J.; Patel, J.; Huang, C. K.; Ryan, M. A.; Averback, R.; Chen, G.; Hill, C.


    The Jet Propulsion Laboratory has been actively pursuing the development of thermoelectric micro/nanodevices that can be fabricated using a combination of electrochemical deposition and integrated circuit processing techniques.

  16. Micro/nanofabricated solid-state thermoelectric generator devices for integrated high voltage power sources

    Fleurial, J. P.; Snyder, G. J.; Patel, J.; Huang, C. K.; Ryan, M. A.; Averback, R.; Chen, G.; Hill, C.


    The Jet Propulsion Laboratory has been actively pursuing the development of thermoelectric micro/nanodevices that can be fabricated using a combination of electrochemical deposition and integrated circuit processing techniques.

  17. An automated packed protein G micro-pipette tip assay for rapid quantification of polyclonal antibodies in ovine serum.

    Chhatre, Sunil; Francis, Richard; Bracewell, Daniel G; Titchener-Hooker, Nigel J


    The demands on the biopharmaceutical sector to expedite process development have instigated the deployment of micro-biochemical engineering techniques to acquire manufacturing insight with extremely small sample volumes. In conjunction with automated liquid handlers, this permits the simultaneous evaluation of multiple operating conditions and reduces manual intervention. For these benefits to be sustained, novel ways are now required to accelerate analysis and so prevent this becoming a throughput bottleneck. For example, although Protein G HPLC is used to quantify antibody titres in bioprocess feedstocks, it can be time-consuming owing to the serial nature of its application. Although commercial options are available that can process many samples simultaneously, these require separate, potentially expensive instruments. A more integrated approach is desirable wherein the assay is implemented directly on a robot. This article describes a high-throughput alternative to antibody HPLC analysis which uses an eight-channel liquid handler to control pipette tips packed with 40 μL of Protein G affinity matrix. The linearity, range, limit of detection, specificity and precision of the method were established, with results showing that antibody was detected reliably and specifically between 0.10 and 1.00 mg/mL. Subsequently, the technique was used to quantify the antibody titre in ovine serum, which is used as feed material by BTG PLC for manufacturing FDA-approved polyclonal bio-therapeutics. The mean concentration determined by the tips was comparable to that found by HPLC, but the tip method delivered its results in less than 40% of the time and with the potential for further, substantial time-savings possible by using higher capacity robots.

  18. Staphylococcal enterotoxin B-specific electrochemiluminescence and lateral flow device assays cross-react with staphylococcal enterotoxin D.

    Tallent, Sandra M; Hait, Jennifer; Bennett, Reginald W


    Guam school children and faculty members experienced symptoms of vomiting, nausea, abdominal cramps, and diarrhea shortly after eating breakfast prepared by contracted caterers. The first illness was reported within an hour after breakfast, affecting 295 students and two faculty members. Local hospitals treated 130 people, and 61 were admitted for further treatment. Reported symptoms were consistent with staphylococcal food poisoning. Initial food testing using a lateral flow device and electrochemiluminescence method incorrectly implicated staphylococcal enterotoxin B as the causative agent, prompting partial activation of Guam's Emergency Response Center. Traditional ELISAs proved that the food poisoning agent was staphylococcal enterotoxin D. More specific and sensitive assays would have alleviated the issues and confusion that surrounded the reporting and investigation of this outbreak.

  19. 用于微机电系统的叉形微铰链%Micro Fork Hinge for MEMS Devices


    Flexible beams are often used for rotation in MEMS (Micro Electro Mechanical Systems) devices to avoid the friction problems associated with hinge. However, the rotation angle of flexible beam is very limited and not enough for many applications. In this paper, we introduce a quasi hinge structure named as Fork Hinge, which has a larger equivalent rotation angle (e.g.10 times lager) and is more stable than the flexible hinge, while keeping its interesting properties. We develop an analytical model and simulate the Fork hinge behavior with FEM analysis. We find a good correlation with Fork Hinges fabricated using a SOI (Silicon on Insulator) wafer and DRIE (Deep Reactive Ion Etching).

  20. Tracer gas dispersion in ducts-study of a new compact device using arrays of sonic micro jets

    Silva, A.R. [Instituto Nacional de Engenharia e Tecnologia Industrial (INETI), Lisboa (Portugal); Afonso, C.F. [Faculdade de Engenharia, Universidade do Porto Departmento de Mecanica e Gestao Industrial, Porto (Portugal)


    One of the most feasible ways to measure duct airflows is by tracer gas techniques, especially for complex situations when the duct lengths are short as well as their access, which makes extremely difficult or impossible other methods to be implemented. One problem associated with the implementation of tracer gas technique when the ducts lengths are short is due to the impossibility of achieving complete mixing of the tracer with airflow and its sampling. In this work, the development of a new device for the injection of tracer gas in ducts is discussed as well as a new tracer-sampling device. The developed injection device has a compact tubular shape, with magnetic fixation to be easy to apply in duct walls. An array of sonic micro jets in counter current direction, with the possibility of angular movement according to its main axle ensures a complete mixing of the tracer in very short distances. The tracer-sampling device, with a very effective integration function, feeds the sampling system for analysis. Both devices were tested in a wind tunnel of approximately 21 m total length. The tests distances between injection and integration device considered were: X/Dh = 22; X/Dh = 4; X/Dh 2; and X/Dh = 1. For very short distances of X/Dh = 2 and X/Dh = 1, semi-empirical expressions were needed. A good reproducibility of airflow rate values was obtained. These preliminary tests showed that the practical implementation of tracer gas techniques in HVAC systems for measuring airflow rates with a very short mixing distance is possible with the devices developed. (author)

  1. Lab-on-a-brain: Implantable micro-optical fluidic devices for neural cell analysis in vivo

    Takehara, Hiroaki; Nagaoka, Akira; Noguchi, Jun; Akagi, Takanori; Kasai, Haruo; Ichiki, Takanori


    The high-resolution imaging of neural cells in vivo has brought about great progress in neuroscience research. Here, we report a novel experimental platform, where the intact brain of a living mouse can be studied with the aid of a surgically implanted micro-optical fluidic device; acting as an interface between neurons and the outer world. The newly developed device provides the functions required for the long-term and high-resolution observation of the fine structures of neurons by two-photon laser scanning microscopy and the microfluidic delivery of chemicals or drugs directly into the brain. A proof-of-concept experiment of single-synapse stimulation by two-photon uncaging of caged glutamate and observation of dendritic spine shrinkage over subsequent days demonstrated a promising use for the present technology.

  2. EDTA-treated cotton-thread microfluidic device used for one-step whole blood plasma separation and assay.

    Ulum, Mokhamad Fakhrul; Maylina, Leni; Noviana, Deni; Wicaksono, Dedy Hermawan Bagus


    This study aims to observe the wicking and separation characteristics of blood plasma in a cotton thread matrix functioning as a microfluidic thread-based analytical device (μTAD). We investigated several cotton thread treatment methods using ethylenediaminetetraacetic acid (EDTA) anticoagulant solution for wicking whole blood samples and separating its plasma. The blood of healthy Indonesian thin tailed sheep was used in this study to understand the properties of horizontal wicking and separation on the EDTA-treated μTAD. The wicking distance and blood cell separation from its plasma was observed for 120 s and documented using a digital phone camera. The results show that untreated cotton-threads stopped the blood wicking process on the μTAD. On the other hand, the deposition of EDTA anticoagulant followed by its drying on the thread at room temperature for 10 s provides the longest blood wicking with gradual blood plasma separation. Furthermore, the best results in terms of the longest wicking and the clearest on-thread separation boundary between blood cells and its plasma were obtained using the μTAD treated with EDTA deposition followed by 60 min drying at refrigerated temperature (2-8 °C). The separation length of blood plasma in the μTADs treated with dried-EDTA at both room and refrigerated temperatures was not statistically different (P > 0.05). This separation occurs through the synergy of three factors, cotton fiber, EDTA anticoagulant and blood platelets, which induce the formation of a fibrin-filter via a partial coagulation process in the EDTA-treated μTAD. An albumin assay was employed to demonstrate the efficiency of this plasma separation method during a one-step assay on the μTAD. Albumin in blood is an important biomarker for kidney and heart disease. The μTAD has a slightly better limit of detection (LOD) than conventional blood analysis, with an LOD of 114 mg L(-1) compared to 133 mg L(-1), respectively. However, the μTAD performed

  3. Impact of assay selection and study design on the outcome of cytotoxicity testing of medical devices: the case of multi-purpose vision care solutions.

    Lehmann, David M; Richardson, Mary E


    Medical device biocompatibility testing usually includes a cytotoxicity component. Assay selection and protocol design often depend on a specific testing standard rather than on the characteristics of the medical device. To better understand the impact of assay selection on study outcome of unstructured medical devices, we evaluated contact lens multi-purpose solutions (MPS) in the agar diffusion, direct contact and two elution cytotoxicity assays. To simulate the conditions of use, MPS were evaluated alone and in combination with contact lenses. All MPS passed the agar diffusion assay (n=3) and extracts prepared from contact lenses soaked in MPS passed the USP elution assay (n=3). Both the duration of contact and MPS concentration impacted the outcome of a modified elution assay. When tested at 25% strength for 48 h, all MPS evaluated were non-cytotoxic (n>3). Test article movement and mechanical damage were significant issues with the direct contact assay. Movement was effectively controlled by manipulating contact lens orientation while using 0.8 mL culture medium. All MPS passed the USP direct contact cytotoxicity test when evaluated using this optimized methodology (n=3). These data are consistent with MPS results in ocular irritation studies in rabbits (n=3).

  4. Quality Control Method for a Micro-Nano-Channel Microfabricated Device

    Grattoni, Alessandro; Ferrari, Mauro; Li, Xuewu


    A variety of silicon-fabricated devices is used in medical applications such as drug and cell delivery, and DNA and protein separation and analysis. When a fluidic device inlet is connected to a compressed gas reservoir, and the outlet is at a lower pressure, a gas flow occurs through the membrane toward the outside. The method relies on the measurement of the gas pressure over the elapsed time inside the upstream and downstream environments. By knowing the volume of the upstream reservoir, the gas flow rate through the membrane over the pressure drop can be calculated. This quality control method consists of measuring the gas flow through a device and comparing the results with a standard curve, which can be obtained by testing standard devices. Standard devices can be selected through a variety of techniques, both destructive and nondestructive, such as SEM, AFM, and standard particle filtration.

  5. Rapid prototyping of microfluidic devices with integrated wrinkled gold micro-/nano textured electrodes for electrochemical analysis.

    Gabardo, C M; Adams-McGavin, R C; Vanderfleet, O M; Soleymani, L


    Fully-integrated electro-fluidic systems with micro-/nano-scale features have a wide range of applications in lab-on-a-chip systems used for biosensing, biological sample processing, and environmental monitoring. Rapid prototyping of application-specific electro-fluidic systems is envisioned to facilitate the testing, validation, and market translation of several lab-on-a-chip systems. Towards this goal, we developed a rapid prototyping process for creating wrinkled micro-/nano-textured electrodes on shrink memory polymers, fabricating microfluidics using molds patterned by a craft-cutter, and bonding electrical and fluidic circuitries using a PDMS partial curing method optimized for creating void-free bonds at the side walls and surfaces of tall (>5 μm) micro-/nano-textured wrinkled electrodes. The resulting electro-fluidic devices, featuring closely spaced high topography electrodes for electrochemical analysis, can withstand flow-rates and burst pressures larger than 25 mL min(-1) and 125 kPa, respectively. In addition, the fully-integrated electrochemical flow-cell developed here demonstrates excellent electrochemical behaviour, with negligible scan to scan variation for over 100 cyclic voltammetry scans, and expected redox signatures measured under various voltage scan rates and fluidic flow rates.

  6. Eat-by-light: fiber-optic and micro-optic devices for food safety and quality assessment

    Mignani, A. G.; Ciaccheri, L.; Cucci, C.; Mencaglia, A. A.; Cimato, A.; Attilio, C.; Thienpont, H.; Ottevaere, H.; Paolesse, R.; Mastroianni, M.; Monti, D.; Buonocore, G.; Del Nobile, A.; Mentana, A.; Dall'Asta, C.; Faccini, A.; Galaverna, G.; Dossena, A.


    A selection of fiber-optic and micro-optic devices is presented designed and tested for monitoring the quality and safety of typical foods, namely the extra virgin olive oil, the beer, and the milk. Scattered colorimetry is used for the authentication of various types of extra virgin olive oil and beer, while a fiber-optic-based device for UV-VIS-NIR absorption spectroscopy is exploited in order to obtain the hyperspectral optical signature of olive oil. This is done not only for authentication purposes, but also so as to correlate the spectral data with the content of fatty acids that are important nutritional factors. A micro-optic sensor for the detection of olive oil aroma is presented. It is capable of distinguishing different ageing levels of extra virgin olive oil. It shows effective potential for acting as a smart cap of bottled olive oil in order to achieve a non-destructive olfactory perception of oil ageing. Lastly, a compact portable fluorometer is experimented for the rapid monitoring of the carcinogenic M1 aflatoxin in milk.

  7. Eat-by-light fiber-optic and micro-optic devices for food quality and safety assessment

    Mignani, A. G.; Ciaccheri, L.; Cucci, C.; Mencaglia, A. A.; Cimato, A.; Attilio, C.; Thienpont, H.; Ottevaere, H.; Paolesse, R.; Mastroianni, M.; Monti, D.; Buonocore, G.; Del Nobile, A.; Mentana, A.; Grimaldi, M. F.; Dall'Asta, C.; Faccini, A.; Galaverna, G.; Dossena, A.


    A selection is presented of fiber-optic and micro-optic devices that have been designed and tested for guaranteeing the quality and safety of typical foods, such as extra virgin olive oil, beer, and milk. Scattered colorimetry is used to authenticate various types of extra virgin olive oil and beer, while a fiber-optic-based device for UV-VIS-NIR absorption spectroscopy is exploited in order to obtain the hyperspectral optical signature of olive oil. This is done not only for authentication purposes, but also so as to correlate the spectral data with the content of fatty acids, which are important nutritional factors. A micro-optic sensor for the detection of olive oil aroma that is capable of distinguishing different ageing levels of extra virgin olive oil is also presented. It shows effective potential for acting as a smart cap of bottled olive oil in order to achieve a non-destructive olfactory perception of oil ageing. Lastly, a compact portable fluorometer for the rapid monitoring of the carcinogenic M1 aflatoxin in milk, is experimented.

  8. Laser direct writing of micro- and nano-scale medical devices.

    Gittard, Shaun D; Narayan, Roger J


    Laser-based direct writing of materials has undergone significant development in recent years. The ability to modify a variety of materials at small length scales and using short production times provides laser direct writing with unique capabilities for fabrication of medical devices. In many laser-based rapid prototyping methods, microscale and submicroscale structuring of materials is controlled by computer-generated models. Various laser-based direct write methods, including selective laser sintering/melting, laser machining, matrix-assisted pulsed-laser evaporation direct write, stereolithography and two-photon polymerization, are described. Their use in fabrication of microstructured and nanostructured medical devices is discussed. Laser direct writing may be used for processing a wide variety of advanced medical devices, including patient-specific prostheses, drug delivery devices, biosensors, stents and tissue-engineering scaffolds.

  9. Micro/nanostructured surface modification using femtosecond laser pulses on minimally invasive electrosurgical devices.

    Lin, Chia-Cheng; Lin, Hao-Jan; Lin, Yun-Ho; Sugiatno, Erwan; Ruslin, Muhammad; Su, Chen-Yao; Ou, Keng-Liang; Cheng, Han-Yi


    The purpose of the present study was to examine thermal damage and a sticking problem in the tissue after the use of a minimally invasive electrosurgical device with a nanostructured surface treatment that uses a femtosecond laser pulse (FLP) technique. To safely use an electrosurgical device in clinical surgery, it is important to decrease thermal damage to surrounding tissues. The surface characteristics and morphology of the FLP layer were evaluated using optical microscopy, scanning electron microscopy, and transmission electron microscopy; element analysis was performed using energy-dispersive X-ray spectroscopy, grazing incidence X-ray diffraction, and X-ray photoelectron spectroscopy. In the animal model, monopolar electrosurgical devices were used to create lesions in the legs of 30 adult rats. Animals were sacrificed for investigations at 0, 3, 7, 14, and 28 days postoperatively. Results indicated that the thermal damage and sticking situations were reduced significantly when a minimally invasive electrosurgical instrument with an FLP layer was used. Temperatures decreased while film thickness increased. Thermographic data revealed that surgical temperatures in an animal model were significantly lower in the FLP electrosurgical device compared with that in the untreated one. Furthermore, the FLP device created a relatively small area of thermal damage. As already mentioned, the biomedical nanostructured layer reduced thermal damage and promoted the antisticking property with the use of a minimally invasive electrosurgical device. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2016.

  10. Design, fabrication, and characterization of electroless Ni–P alloy films for micro heating devices

    Liu, Bernard Haochih, E-mail: [Department of Materials Science and Engineering, National Cheng Kung University, Taiwan (China); Promotion Center for Global Materials Research, National Cheng Kung University, Taiwan (China); Research Center for Energy Technology and Strategy, National Cheng Kung University, Taiwan (China); Liao, Fang-Yi; Chen, Jian-Hong [Department of Materials Science and Engineering, National Cheng Kung University, Taiwan (China)


    In this work electroless nickel–phosphorous coatings were used as the micro heaters for scanning thermal microscopy. The deposition of Ni–P alloys not only simplified the microelectromechanical system fabrication steps but also provided flexibility in the tuning of the resistance of the heating elements. Ni–P films were plated on patterned silicon substrates and silicon with a silicon nitride film. The pre-deposition reactive ion etch (RIE) treatment caused a change in surface roughness that enhanced the adhesion of Ni–P coatings. Optimization of RIE parameters and pH values could achieve selective deposition of Ni–P, thus helped the lift-off of a serpentine circuit pattern. The chemical composition and microstructure of Ni–P films affect the electrical properties of micro heaters. Energy-dispersive X-ray spectroscopy identified the Ni–P composition and confirmed its insignificant level of oxidation. The high-temperature X-ray diffraction indicated that the as-deposited film was crystalline Ni, which later transformed into Ni{sub 3}P at higher temperature. The resistivity of Ni–P films was tailored between 10{sup −5} and 10{sup −7} Ω m via a post-deposition annealing, which also obtained a stable temperature coefficient of resistance. Consequently, the performance of micro heaters could be designed with a high degree of flexibility. - Highlights: • We developed a process to fabricate micro heater by Ni–P electroless plating. • Reactive ion etch caused oscillating surface roughness and affected Ni–P adhesion. • Ni{sub 3}P phase precipitates during annealing and reduces resistivity of Ni–P alloys. • Resistivity of Ni–P is tunable from 10{sup −5} to 10{sup −7} Ω m by plating and annealing.

  11. Distance-Based Tear Lactoferrin Assay on Microfluidic Paper Device Using Interfacial Interactions on Surface-Modified Cellulose.

    Yamada, Kentaro; Henares, Terence G; Suzuki, Koji; Citterio, Daniel


    "Distance-based" detection motifs on microfluidic paper-based analytical devices (μPADs) allow quantitative analysis without using signal readout instruments in a similar manner to classical analogue thermometers. To realize a cost-effective and calibration-free distance-based assay of lactoferrin in human tear fluid on a μPAD not relying on antibodies or enzymes, we investigated the fluidic mobilities of the target protein and Tb(3+) cations used as the fluorescent detection reagent on surface-modified cellulosic filter papers. Chromatographic elution experiments in a tear-like sample matrix containing electrolytes and proteins revealed a collapse of attractive electrostatic interactions between lactoferrin or Tb(3+) and the cellulosic substrate, which was overcome by the modification of the paper surface with the sulfated polysaccharide ι-carrageenan. The resulting μPAD based on the fluorescence emission distance successfully analyzed 0-4 mg mL(-1) of lactoferrin in complex human tear matrix with a lower limit of detection of 0.1 mg mL(-1) by simple visual inspection. Assay results of 18 human tear samples including ocular disease patients and healthy volunteers showed good correlation to the reference ELISA method with a slope of 0.997 and a regression coefficient of 0.948. The distance-based quantitative signal and the good batch-to-batch fabrication reproducibility relying on printing methods enable quantitative analysis by simply reading out "concentration scale marks" printed on the μPAD without performing any calibration and using any signal readout instrument.

  12. Generation of emulsion droplets and micro-bubbles in microfluidic devices

    Zhang, Jiaming


    Droplet-based microfluidic devices have become a preferred versatile platform for various fields in physics, chemistry and biology to manipulate small amounts of liquid samples. In addition to microdroplets, microbubbles are also needed for various pro- cesses in the food, healthcare and cosmetic industries. Polydimethylsiloxane (PDMS) soft lithography, the mainstay for fabricating microfluidic devices, usually requires the usage of expensive apparatus and a complex manufacturing procedure. In ad- dition, current methods have the limited capabilities for fabrication of microfluidic devices within three dimensional (3D) structures. Novel methods for fabrication of droplet-based microfluidic devices for the generation microdroplets and microbubbles are therefore of great interest in current research. In this thesis, we have developed several simple, rapid and low-cost methods for fabrication of microfluidic devices, especially for generation of microdroplets and mi- crobubbles. We first report an inexpensive full-glass microfluidic devices with as- sembly of glass capillaries, for generating monodisperse multiple emulsions. Different types of devices have been designed and tested and the experimental results demon- strated the robust capability of preparing monodisperse single, double, triple and multi-component emulsions. Second, we propose a similar full-glass device for generation of microbubbles, but with assembly of a much smaller nozzle of a glass capillary. Highly monodisperse microbubbles with diameter range from 3.5 to 60 microns have been successfully produced, at rates up to 40 kHz. A simple scaling law based on the capillary number and liquid-to-gas flow rate ratio, successfully predicts the bubble size. Recently, the emergent 3D printing technology provides an attractive fabrication technique, due to its simplicity and low cost. A handful of studies have already demonstrated droplet production through 3D-printed microfluidic devices. However, two

  13. Protein Detection Using the Multiplexed Proximity Extension Assay (PEA from Plasma and Vaginal Fluid Applied to the Indicating FTA Elute Micro Card™

    Malin Berggrund


    Full Text Available The indicating FTA elute micro card™ has been developed to collect and stabilize the nucleic acid in biological samples and is widely used in human and veterinary medicine and other disciplines. This card is not recommended for protein analyses, since surface treatment may denature proteins. We studied the ability to analyse proteins in human plasma and vaginal fluid as applied to the indicating FTA elute micro card™ using the sensitive proximity extension assay (PEA. Among 92 proteins in the Proseek Multiplex Oncology Iv2 panel, 87 were above the limit of detection (LOD in liquid plasma and 56 among 92 above LOD in plasma applied to FTA cards. Washing and protein elution protocols were compared to identify an optimal method. Liquid-based cytology samples showed a lower number of proteins above LOD than FTA cards with vaginal fluid samples applied. Our results demonstrate that samples applied to the indicating FTA elute micro card™ are amendable to protein analyses, given that a sensitive protein detection assay is used. The results imply that biological samples applied to FTA cards can be used for DNA, RNA and protein detection.

  14. Deployable and Conformal Planar Micro-Devices: Design and Model Validation

    Jinda Zhuang


    Full Text Available We report a design concept for a deployable planar microdevice and the modeling and experimental validation of its mechanical behavior. The device consists of foldable membranes that are suspended between flexible stems and actuated by push-pull wires. Such a deployable device can be introduced into a region of interest in its compact “collapsed” state and then deployed to conformally cover a large two-dimensional surface area for minimally invasive biomedical operations and other engineering applications. We develop and experimentally validate theoretical models based on the energy minimization approach to examine the conformality and figures of merit of the device. The experimental results obtained using model contact surfaces agree well with the prediction and quantitatively highlight the importance of the membrane bending modulus in controlling surface conformality. The present study establishes an early foundation for the mechanical design of this and related deployable planar microdevice concepts.

  15. Magnetic Shape Memory Alloys as smart materials for micro-positioning devices

    A. Hubert


    Full Text Available In the field of microrobotics, actuators based on smart materials are predominant because of very good precision, integration capabilities and high compactness. This paper presents the main characteristics of Magnetic Shape Memory Alloys as new candidates for the design of micromechatronic devices. The thermo-magneto-mechanical energy conversion process is first presented followed by the adequate modeling procedure required to design actuators. Finally, some actuators prototypes realized at the Femto-ST institute are presented, including a push-pull bidirectional actuator. Some results on the control and performances of these devices conclude the paper.

  16. Encapsulated, High-Performance, Stretchable Array of Stacked Planar Micro-Supercapacitors as Waterproof Wearable Energy Storage Devices.

    Kim, Hyoungjun; Yoon, Jangyeol; Lee, Geumbee; Paik, Seung-Ho; Choi, Gukgwon; Kim, Daeil; Kim, Beop-Min; Zi, Goangseup; Ha, Jeong Sook


    We report the fabrication of an encapsulated, high-performance, stretchable array of stacked planar micro-supercapacitors (MSCs) as a wearable energy storage device for waterproof applications. A pair of planar all-solid-state MSCs with spray-coated multiwalled carbon nanotube electrodes and a drop-cast UV-patternable ion-gel electrolyte was fabricated on a polyethylene terephthalate film using serial connection to increase the operation voltage of the MSC. Additionally, multiple MSCs could be vertically stacked with parallel connections to increase both the total capacitance and the areal capacitance owing to the use of a solid-state patterned electrolyte. The overall device of five parallel-connected stacked MSCs, a microlight-emitting diode (μ-LED), and a switch was encapsulated in thin Ecoflex film so that the capacitance remained at 82% of its initial value even after 4 d in water; the μ-LED was lit without noticeable decrease in brightness under deformation including bending and stretching. Furthermore, an Ecoflex encapsulated oximeter wound around a finger was operated using the stored energy of the MSC array attached to the hand (even in water) to give information on arterial pulse rate and oxygen saturation in the blood. This study suggests potential applications of our encapsulated MSC array in wearable energy storage devices especially in water.

  17. Device for rapid and agile measurement of diffusivity in micro- and nanochannels.

    Grattoni, Alessandro; Gill, Jaskaran; Zabre, Erika; Fine, Daniel; Hussain, Fazle; Ferrari, Mauro


    The lack of a viable theory for describing diffusivity when fluids are confined at the micro- and nanoscale [Ladero et al. Chem. Eng. Sci.2007, 62, 666-678; Deen AIChE J.1987, 33, 1409-1425] has necessitated accurate measurement of diffusivity (D) [Jin and Chen Chromatographia2000, 52, 17-21; Nie et al. Science1994, 266, 1018-1021; Durand et al. Anal. Chem.2009, 81, 5407-5412], crucial for a host of micro- and nanofluidic technologies [Grattoni et al. Curr. Pharm. Biotechnol.2010, 11, 343-365]. We demonstrate a rapid and agile method for the direct measurement of diffusivity in a system possessing 10(4) to 10(5) precisely fabricated channels with characteristic sizes (β) ranging from micro- to nanometers. Custom chambers allowed us to measure the diffusivity in a closed unperturbed system using UV/vis spectroscopy. D was measured for rhodamine B (RhoB) in aqueous solution in channels of 200 and 1 μm, as well as 13 and 5.7 nm. The observed logarithmic scaling of diffusivity with β, in close agreement with prior experiments, but far from theoretical prediction, surprisingly highlights that diffusivity is significantly altered even at the microscale. Accurate measurement of D by reducing the size of the source reservoir by 3 orders of magnitude (from 150 μL to 910 nL) proves that a substantial reduction in measurement time (from 7 days to 40 min) can be achieved. Our design thus is ready for rapid translation into a standard analytical tool--useful for multiple applications. © 2011 American Chemical Society

  18. A Method and Device for 3D Recognition of Cutting Edge Micro Geometry

    Bartosz Palubicki


    Full Text Available A very useful method was successfully applied in the investigation of tools for machining wood and wood based composites. It allows scanning of the cutting edge micro geometry in three dimensions and reproducing it in a virtual space as a 3D surface. The application of the method opens new possibilities of studying tool wear by scanning, including the calculation of volume loss and other analysis of tool wedge geometry along and perpendicularly to the cutting edge. Effectiveness of the method and scanner were successfully verified by a reference ESEM (Environmental Scanning Electron Microscopy method.

  19. Spectrum study of top-emitting organic light-emitting devices with micro-cavity structure

    Liu Xiang; Wei Fuxiang; Liu Hui


    Blue and white top-emitting organic light-emitting devices OLEDs with cavity effect have been fabricated.TBADN:3%DSAPh and Alq3:DCJTB/TBADN:TBPe/Alq3:C545 were used as emitting materials of microcavity OLEDs.On a patterned glass substrate,silver was deposited as reflective anode,and copper phthalocyanine (CuPc)layer as HIL and 4'-bis[N-(1-Naphthyl)-N-phenyl-amino]biphenyl(NPB)layer as HTL were made.Al/Ag thin films were made as semi-transparent cathode with a transmittance of about 30%.By changing the thickness of indium tin oxide ITO,deep blue with Commission Internationale de L'Eclairage chromaticity coordinates(CIEx,y)of(0.141,0.049)was obtained on TBADN:3%DSAPh devices,and different color(red,blue and green)was obrained on Alq3:DCJTB/TBADN:TBPe/Alq3:C545 devices,full width at half maxima(FWHM)was only 17 nm.The spectral intensity and FWHM of emission in cavity devices have also been studied.

  20. Technical and clinical analysis of microEEG: a miniature wireless EEG device designed to record high-quality EEG in the emergency department

    Omurtag, Ahmet; Baki, Samah G Abdel; Chari, Geetha; Cracco, Roger Q; Zehtabchi, Shahriar; Fenton, André A.; Grant, Arthur C


    Background We describe and characterize the performance of microEEG compared to that of a commercially available and widely used clinical EEG machine. microEEG is a portable, battery-operated, wireless EEG device, developed by Bio-Signal Group to overcome the obstacles to routine use of EEG in emergency departments (EDs). Methods The microEEG was used to obtain EEGs from healthy volunteers in the EEG laboratory and ED. The standard system was used to obtain EEGs from healthy volunteers in the...

  1. Fabrication of three-dimensional micro-nanofiber structures by a novel solution blow spinning device

    Feng Liang


    Full Text Available The fabrication of three-dimensional scaffolds has attracted more attention in tissue engineering. The purpose of this study is to explore a new method for the fabrication of three-dimensional micro-nanofiber structures by combining solution blow spinning and rotating collector. In this study, we successfully fabricated fibers with a minimum diameter of 200 nm and a three-dimensional structure with a maximum porosity of 89.9%. At the same time, the influence of various parameters such as the solvent volatility, the shape of the collector, the feed rate of the solution and the applied gas pressure were studied. It is found that solvent volatility has large effect on the formation of the three-dimensional shape of the structure. The shape of the collector affects the porosity and fiber distribution of the three-dimensional structure. The fiber diameter and fiber uniformity can be controlled by adjusting the solution feed rate and the applied gas pressure. It is feasible to fabricate high-quality three-dimensional micro-nanofiber structure by this new method, which has great potential in tissue engineering.

  2. Geometric Modulation of Electro-Osmosis of the Second Kind in Micro-Nanochannel Interface Devices

    Yossifon, Gilad; Leibowitz, Neta; Green, Yoav; Schiffbauer, Jarrod; Park, Sinwook


    The charge-selective ionic transport through the nanochannel induces a concentration polarization effect. At sufficiently high currents, the depleted region develops an extended space charge layer adjacent to the micro-nanochannel interface. As the applied voltage exceeds a critical threshold, the loss of mechanical stability in this space-charge region leads to the formation of fast fluid vortices which undergo a complex wavelength-selection process. Both microchannel dimensions and interfacial geometry have been shown to affect the onset and subsequent development of the vortex flow field. Here we present results concerning suppression and control of the onset of instability as well as demonstrating competition between different vortex mechanisms. These effects modulate the interfacial mass transport and, hence, ionic current, through the interface and produce observable patterns. These results are of both fundamental and practical interest, with implications regarding early transitions from limiting to over-limiting currents and colloid-hydrodynamic interactions. The practical applications of such effects range from bio-molecular concentration, separation, and detection to micro-purification and on-chip electro-dialysis.

  3. Beam steering and deflecting device using step-based micro-blazed grating

    Yang, Junbo; Su, Xianyu; Xu, Ping; Gu, Zheng


    The rapidly evolving demands of optical communications and optical switching systems have created a new market for high capacity all-optical beam steering and deflecting techniques. One technology potentially capable of realizing such systems uses the multistep micro-blazed grating optical beam deflectors based on binary and multiple-phase modulation methods. The micro-optical element has been fabricated by introducing very large scale integration (VLSI), stepping photolithography and reactive ion etching (RIE), which can realize beam steering, deflecting, splitting, and switching in free space, and its diffraction properties are determined by the blazed-grating parameters, such as the number of steps, grating depth, grating period, as well as blazed profile. The theoretical analysis and primarily experimental result show that this phase-type element has the advantages of high diffractive efficiency, low cross talk, small feature size, and high reliability due to nonmechanical beam steering without any moving parts. Hence it is ideally suited to applications in optical communication and optical interconnection network.

  4. Development and validation of a microRNA based diagnostic assay for primary tumor site classification of liver core biopsies

    Perell, Katharina; Vincent, Martin; Vainer, Ben;


    negatively affect the accuracy and usability of molecular classifiers. We have developed and validated a microRNA-based classifier, which predicts the primary tumor site of liver biopsies, containing a limited number of tumor cells. Concurrently we explored the influence of surrounding normal tissue...... for normal liver tissue contamination. Performance was estimated by cross-validation, followed by independent validation on 55 liver core biopsies with a tumor content as low as 10%. A microRNA classifier developed, using the statistical contamination model, showed an overall classification accuracy of 74...... on classification. MicroRNA profiling was performed using quantitative Real-Time PCR on formalin-fixed paraffin-embedded samples. 278 primary tumors and liver metastases, representing nine primary tumor classes, as well as normal liver samples were used as a training set. A statistical model was applied to adjust...

  5. A high-throughput three-dimensional cell migration assay for toxicity screening with mobile device-based macroscopic image analysis

    Timm, David M.; Chen, Jianbo; Sing, David; Gage, Jacob A.; Haisler, William L.; Neeley, Shane K.; Raphael, Robert M.; Dehghani, Mehdi; Rosenblatt, Kevin P.; Killian, T. C.; Tseng, Hubert; Souza, Glauco R.


    There is a growing demand for in vitro assays for toxicity screening in three-dimensional (3D) environments. In this study, 3D cell culture using magnetic levitation was used to create an assay in which cells were patterned into 3D rings that close over time. The rate of closure was determined from time-lapse images taken with a mobile device and related to drug concentration. Rings of human embryonic kidney cells (HEK293) and tracheal smooth muscle cells (SMCs) were tested with ibuprofen and sodium dodecyl sulfate (SDS). Ring closure correlated with the viability and migration of cells in two dimensions (2D). Images taken using a mobile device were similar in analysis to images taken with a microscope. Ring closure may serve as a promising label-free and quantitative assay for high-throughput in vivo toxicity in 3D cultures.

  6. A handheld high-sensitivity micro-NMR CMOS platform with B-field stabilization for multi-type biological/chemical assays


    We report a micro-nuclear magnetic resonance (NMR) system compatible with multi-type biological/chemical lab-on-a-chip assays. Unified in a handheld scale (dimension: 14 x 6 x 11 cm³, weight: 1.4 kg), the system is capable to detect<100 pM of Enterococcus faecalis derived DNA from a 2.5 μL sample. The key components are a portable magnet (0.46 T, 1.25 kg) for nucleus magnetization, a system PCB for I/O interface, an FPGA for system control, a current driver for trimming the magnetic (B) fi...

  7. Silicon Carbide Micro-devices for Combustion Gas Sensing under Harsh Conditions

    Ruby Ghosh; Reza Loloee; Roger Tobin


    A sensor based on the wide bandgap semiconductor, silicon carbide (SiC), has been developed for the detection of combustion products in power plant environments. The sensor is a catalytic gate field effect device, Pt/SiO{sub 2}/SiC that can detect hydrogen-containing species in chemically reactive, high temperature (600 C) environments. We demonstrate that the device can be used as a hydrogen monitor in syngas applications of common interferants as well as sulfur and water vapor. These measurements were made in the Catalyst Screening Unit at NETL, Morgantown under atmospheric conditions. The sensor response to hydrogen gas at 350 C is 240 mV/decade, this is significantly higher than the device response to room temperature gas or that predicted from vacuum chamber studies. The enhanced catalytic activity of the platinum sensing film under energy plant operating conditions was investigated via AFM, x-ray diffraction, TEM and x-ray photoelectron spectroscopy. Our characterization indicated that exposure to high temperature gases significantly modifies the morphology of the Pt catalytic film and the Pt/SiO{sub 2} interfacial region, which we tentatively attribute to the enhanced hydrogen sensitivity of the sensing film. A model for the hydrogen/oxygen response of the SiC device under atmospheric conditions was developed. It is based on two independent phenomena: a chemically induced shift in the metal-semiconductor work function difference and the passivation/creation of charged states at the SiO{sub 2}-SiC interface. The optimum operating set point for the SiC sensor with respect to response time and long term reliability was determined to be close to mid-gap. Ultrahigh vacuum (UHV) techniques were used to investigate the effects of sulfur contamination on the Pt gate. Exposure to hydrogen sulfide, even in the presence of hydrogen or oxygen at partial pressures of 20-600 times greater than the H2S level, rapidly coated the gate with a monolayer of sulfur. Although

  8. Numerical And Experimental Analysis Of Fracture Of Athrombogenic Coatings Deposited On Ventricular Assist Device In Micro-Shear Test

    Kopernik M.


    Full Text Available The Polish left ventricular assist device (LVAD – RELIGA_EXT will be made of thermoplastic polycarbonate-urethane (Bionate II with deposited athrombogenic nano-coatings: gold (Au and titanium nitride (TiN. Referring to the physical model, the two-scale model of LVAD developed in the previous works in the authors’ finite element code is composed of a macro-model of blood chamber and a micro-model of wall: TiN, Au and Bionate II. The numerical analysis of stress and strain states confirmed the possibility of fracture based on localization of zones of the biggest values of triaxiality factor. The introduction of Au interlayer between TiN and polymer improved the toughness of the connection, and increased the compressive residual stress in the coating what resulted in reduction of stress and strain close to the boundary between substrate and coating.

  9. Accuracy and Electromagnetic Safety Evaluation of a Portable Electromagnetic Localization System for Micro Invasive Medical Devices in Vivo

    LI Hong-wei; YAN Guo-zheng; JIANG Ping-ping


    Aiming at localizing the telemetric capsule for detecting gastrointestinal physiological parameters in vivo accurately, a portable alternating current ( AC ) electromagnetic localization system is designed. To verify the feasibility of the method, the model and construction of the localization system are detailed. And static and dynamic accuracy of the localization system are tested by experiments. Next, we compare the simulating results of the electromagnetic radiation aroused by the localization system with the electromagnetic safety standards of human (ICNIRP guidelines and IEEE standard C95. 1 - 1991).Finally, in terms of the results of the static and dynamic experiments, conclusions are drawn that the accuracy of portable positioning system is high (less than 10 mm)enough to satisfy the localization need of the micro invasive medical devices in vivo, and there is no harm of electromagnetic radiation to human.


    Ruby N. Ghosh; Peter Tobias; Roger G. Tobin


    A sensor based on the wide bandgap semiconductor, silicon carbide (SiC), has been developed for the detection of combustion products in power plant environments. The sensor is a catalytic gate field effect device that can detect hydrogen containing species in chemically reactive, high temperature environments. Robust metallization and electrical contacting techniques have been developed for device operation at elevated temperatures. To characterize the time response of the sensor responses in the millisecond range, a conceptually new apparatus has been built. Software has been developed to cope with the requirements of fast sensor control and data recording. In addition user friendly software has been developed to facilitate use of the SiC sensors for industrial process control applications.

  11. Lab-on-a-chip devices and micro-total analysis systems a practical guide

    Svendsen, Winnie


    This book covers all the steps in order to fabricate a lab-on-a-chip device starting from the idea, the design, simulation, fabrication and final evaluation. Additionally, it includes basic theory on microfluidics essential to understand how fluids behave at such reduced scale. Examples of successful histories of lab-on-a-chip systems that made an impact in fields like biomedicine and life sciences are also provided.

  12. Laser direct writing of micro- and nano-scale medical devices

    Gittard, Shaun D; Narayan, Roger J.


    Laser-based direct writing of materials has undergone significant development in recent years. The ability to modify a variety of materials at small length scales and using short production times provides laser direct writing with unique capabilities for fabrication of medical devices. In many laser-based rapid prototyping methods, microscale and submicroscale structuring of materials is controlled by computer-generated models. Various laser-based direct write methods, including selective las...


    G. Trapashko


    Development of microelectronics requires solution of the problem ensuring unity of linear measurements in a submicron range. The problem can be solved on the condition that calibration of measuring devices shall be made in accordance with reference samples that is a short length scale.While making calibration of measuring equipment with the help of a reference measure it is important to investigate components of the method accuracy and their influence on measuring results. The paper considers...

  14. Micro-and Nano-Optomechanical Devices for Sensors, Oscillators, and Photonics


    top device layer which is released from the underlying substrate, and can be fabricated using conventional lithography and plasma etching...observation of Qi=1.1x104. Switching platforms to stressed silicon nitride or crystalline silicon should enable material quality factors of Qi=105– that has been fabricated in silicon nitride (SiN), and integrated into an apparatus for delivering cold caesium atoms into the near field of the


    Ruby N. Ghosh; Peter Tobias; Roger G. Tobin


    A sensor based on the wide bandgap semiconductor, silicon carbide (SiC), has been developed for the detection of combustion products in power plant environments. The sensor is a catalytic gate field effect device that can detect hydrogen containing species in chemically reactive, high temperature environments. For these capacitive sensors we have determined that the optimum sensor operating point in terms of sensor lifetime and response time is at midgap. Detailed measurements of the oxide leakage current as a function of temperature were performed to investigate the high temperature reliability of the devices. In addition, robust metallization and electrical contacting techniques have been developed for device operation at elevated temperatures. To characterize the time response of the sensor responses in the millisecond range, a conceptually new apparatus has been built. Using laser induced fluorescence imaging techniques we have shown that the gas underneath the sensor can be completely exchanged with a time constant under 1 millisecond. Ultrahigh vacuum studies of the surface chemistry of the platinum gate have shown that sensor deactivation by adsorbed sulfur is a possible problem. Investigations on the chemical removal of sulfur by catalytic oxidation or reduction are continuing.

  16. Two-phase pressure drop across a hydrofoil-based micro pin device using R-123

    Kosar, Ali [Mechatronics Engineering Program, Sabanci University, Orhanli, Tuzla, 34956 Istanbul (Turkey)


    The two-phase pressure drop in a hydrofoil-based micro pin fin heat sink has been investigated using R-123 as the working fluid. Two-phase frictional multipliers have been obtained over mass fluxes from 976 to 2349 kg/m{sup 2} s and liquid and gas superficial velocities from 0.38 to 1.89 m/s and from 0.19 to 24 m/s, respectively. It has been found that the two-phase frictional multiplier is strongly dependent on flow pattern. The theoretical prediction using Martinelli parameter based on the laminar fluid and laminar gas flow represented the experimental data fairly well for the spray-annular flow. For the bubbly and wavy-intermittent flow, however, large deviations from the experimental data were recorded. The Martinelli parameter was successfully used to determine the flow patterns, which were bubbly, wavy-intermittent, and spray-annular flow in the current study. (author)

  17. Millisecond analysis of double stranded DNA with fluorescent intercalator by micro-thermocontrol-device.

    Arata, Hideyuki F; Gillot, Frederic; Collard, Dominique; Fujita, Hiroyuki


    Study of interaction between DNA and intercalator at molecular level is important to understand the mechanisms of DNA replication and repair. A micro-fabricated local heating thermodevice was adapted to perform denaturation experiments of DNA with fluorescent intercalator on millisecond time scale. Response time of complete unzipping of double stranded DNA, 16 microm in length, was measured to be around 5 min by commercial thermocycler. Response time of quenching of double stranded DNA with fluorescent intercalator SYBR Green was measured to be 10 ms. Thus, quenching properties owing to strand unzipping and denaturation at base pair level were distinguished. This method has provided easy access to measure this parameter and may be a powerful methodology in analyzing biomolecules on millisecond time scale.

  18. Micro and nanophotonics for semiconductor infrared detectors towards an ultimate uncooled device

    Jakšic, Zoran


    The advent of microelectromechanic system (MEMS) technologies and nanotechnologies has resulted in a multitude of structures and devices with ultra compact dimensions and with vastly enhanced or even completely novel properties. In the field of photonics it resulted in the appearance of new paradigms, including photonic crystals that exhibit photonic bandgap and represent an optical analog of semiconductors and metamaterials that have subwavelength features and may have almost arbitrary values of effective refractive index, including those below zero. In addition to that, a whole new field of

  19. Silicon Carbide Micro-devices for Combustion Gas Sensing under Harsh Conditions

    Ruby N. Ghosh; Reza Loloee; Roger G. Tobin; Yung Ho Kahng


    A sensor based on the wide bandgap semiconductor, silicon carbide (SiC), has been developed for the detection of combustion products in power plant environments. The sensor is a catalytic gate field effect device that can detect hydrogen-containing species in chemically reactive, high temperature environments. For fast and stable sensor response measurements, a gate activation process is required. Activation of all sensors took place by switching back and forth between oxidizing (1.0% oxygen in nitrogen) and reducing (10% hydrogen in nitrogen) gases for several hours at a sensor temperature {ge}620 C. All 52 devices on the sensor chip were activated simultaneously by flooding the entire chip with gas. The effects of activation on surface morphology and structure of Pt gates before and after activation were investigated. The optical images obtained from Pt gates demonstrated a clear transition from a smooth and shiny surface to a grainy and cloudy surface morphology. XRD scans collected from Pt gates suggest the presence of an amorphous layer and species other than Pt (111) after activation. The reliability of the gate insulator of our metal-oxide-SiC sensors for long-term device operation at 630 C was studied. We find that the dielectric is stable against breakdown due to electron injection from the substrate with gate leakage current densities as low at 5nA/cm{sup 2} at 630 C. We also designed and constructed a new nano-reactor capable of high gas flow rates at elevated pressure. Our reactor, which is a miniature version of an industrial reactor, is designed to heat the flowing gas up to 700 C. Measurements in ultrahigh vacuum demonstrated that hydrogen sulfide readily deposits sulfur on the gate surface, even at the very high hydrogen/hydrogen sulfide ratios (10{sup 3}-10{sup 5}) expected in applications. Once deposited, the sulfur adversely affects sensor response, and could not be removed by exposure to hydrogen at the temperatures and pressures accessible in

  20. Preliminary performance assessment of biotoxin detection for UWS applications using a MicroChemLab device.

    VanderNoot, Victoria A.; Haroldsen, Brent L.; Renzi, Ronald F.; Shokair, Isaac R.


    In a multiyear research agreement with Tenix Investments Pty. Ltd., Sandia has been developing field deployable technologies for detection of biotoxins in water supply systems. The unattended water sensor or UWS employs microfluidic chip based gel electrophoresis for monitoring biological analytes in a small integrated sensor platform. This instrument collects, prepares, and analyzes water samples in an automated manner. Sample analysis is done using the {mu}ChemLab{trademark} analysis module. This report uses analysis results of two datasets collected using the UWS to estimate performance of the device. The first dataset is made up of samples containing ricin at varying concentrations and is used for assessing instrument response and detection probability. The second dataset is comprised of analyses of water samples collected at a water utility which are used to assess the false positive probability. The analyses of the two sets are used to estimate the Receiver Operating Characteristic or ROC curves for the device at one set of operational and detection algorithm parameters. For these parameters and based on a statistical estimate, the ricin probability of detection is about 0.9 at a concentration of 5 nM for a false positive probability of 1 x 10{sup -6}.

  1. Synechococcus as a "singing" bacterium: biology inspired by micro-engineered acoustic streaming devices

    Ehlers, Kurt


    Certain cyanobacteria, such as open ocean strains of Synechococcus, are able to swim at speeds up to 25 diameters per second, without flagella or visible changes in shape. The means by which Synechococcus generates thrust for self-propulsion is unknown. The only mechanism that has not been ruled out employs tangential waves of surface deformations. In Ehlers et al, the average swimming velocity for this mechanism was estimated using the methods inaugurated by Taylor and Lighthill in the 1950's and revisited in differential geometric language by Shapere and Wilczek in 1989. In this article we propose an entirely different physical principle self propulsion based on acoustic streaming (AS). Micro-pumps in silicon chips, based on AS, have been constructed by engineers since the 1990's, but to the best of our knowledge acoustic streaming as a means of microorganisms locomotion has not been proposed before. Our hypothesis is supported by two recent discoveries: (1) In Samuel, et al, deep-freeze electron microscopy...

  2. High-throughput micro-plate HCL-vanillin assay for screening tannin content in sorghum grain

    Sorghum contains tannin which is a phenolic compound that offers health promoting antioxidant capacity. The HCl-vanillin assay is a common and time consuming method for determining tannin content, but is not efficient for screening large sample sets as seen in association mapping panels or breeding ...

  3. Sol-Gel Deposition of Iridium Oxide for Biomedical Micro-Devices

    Cuong M. Nguyen


    Full Text Available Flexible iridium oxide (IrOx-based micro-electrodes were fabricated on flexible polyimide substrates using a sol-gel deposition process for utilization as integrated pseudo-reference electrodes for bio-electrochemical sensing applications. The fabrication method yields reliable miniature on-probe IrOx electrodes with long lifetime, high stability and repeatability. Such sensors can be used for long-term measurements. Various dimensions of sol-gel iridium oxide electrodes including 1 mm × 1 mm, 500 µm × 500 µm, and 100 µm × 100 µm were fabricated. Sensor longevity and pH dependence were investigated by immersing the electrodes in hydrochloric acid, fetal bovine serum (FBS, and sodium hydroxide solutions for 30 days. Less pH dependent responses, compared to IrOx electrodes fabricated by electrochemical deposition processes, were measured at 58.8 ± 0.4 mV/pH, 53.8 ± 1.3 mV/pH and 48 ± 0.6 mV/pH, respectively. The on-probe IrOx pseudo-reference electrodes were utilized for dopamine sensing. The baseline responses of the sensors were higher than the one using an external Ag/AgCl reference electrode. Using IrOx reference electrodes integrated on the same probe with working electrodes eliminated the use of cytotoxic Ag/AgCl reference electrode without loss in sensitivity. This enables employing such sensors in long-term recording of concentrations of neurotransmitters in central nervous systems of animals and humans.

  4. An integrated enzyme-linked immunosorbent assay system with an organic light-emitting diode and a charge-coupled device for fluorescence detection.

    Nakajima, Hizuru; Okuma, Yukiko; Morioka, Kazuhiro; Miyake, Mayo; Hemmi, Akihide; Tobita, Tatsuya; Yahiro, Masayuki; Yokoyama, Daisuke; Adachi, Chihaya; Soh, Nobuaki; Nakano, Koji; Xue, Shuhua; Zeng, Hulie; Uchiyama, Katsumi; Imato, Toshihiko


    A fluorescence detection system for a microfluidic device using an organic light-emitting diode (OLED) as the excitation light source and a charge-coupled device (CCD) as the photo detector was developed. The OLED was fabricated on a glass plate by photolithography and a vacuum deposition technique. The OLED produced a green luminescence with a peak emission at 512 nm and a half bandwidth of 55 nm. The maximum external quantum efficiency of the OLED was 7.2%. The emission intensity of the OLED at 10 mA/cm(2) was 13 μW (1.7 mW/cm(2)). The fluorescence detection system consisted of the OLED device, two band-pass filters, a five microchannel poly(dimethylsiloxane) (PDMS) microfluidic device and a linear CCD. The fluorescence detection system was successfully used in a flow-based enzyme-linked immunosorbent assay on a PDMS microfluidic device for the rapid determination of immunoglobulin A (IgA), a marker for human stress. The detection limit (S/N=3) for IgA was 16.5 ng/mL, and the sensitivity was sufficient for evaluating stress. Compared with the conventional 96-well microtiter plate assay, the analysis time and the amounts of reagent and sample solutions could all be reduced.

  5. Simulation of self-organized waveguides for self-aligned coupling between micro- and nano-scale devices

    Yoshimura, Tetsuzo


    We propose an optical coupling technique based on the reflective self-organized lightwave network (R-SOLNET), where optical devices with different core sizes are connected, for nano-scale-waveguide-based optical interconnects. Growth of R-SOLNET between a 3-μm-wide waveguide and a 600-nm-wide waveguide, on the core edge of which a luminescent target has been deposited, is simulated by the finite-difference time-domain method. The two waveguides are placed with gap distances ranging from 16 to 64 μm in a photopolymer with a refractive index that increases upon exposure to a write beam and luminescence. When a 400 nm wavelength write beam is introduced from the micro-scale waveguide, 470 nm luminescence is generated from the target. In the area where the write beam and the luminescence overlap, the refractive index increases rapidly. The write beam and the luminescence thus attract each other to merge into one through the self-focusing, forming a self-aligned coupling waveguide of R-SOLNET with a coupling loss of 1.5-1.8 dB, even when a lateral misalignment of 600 nm exists between them. This indicates that the R-SOLNET can be used as an optical solder to connect a micro-scale waveguide to a nano-scale waveguide. The optimum writing time required to attain the minimum coupling loss increases with increasing lateral misalignment. The dependence of the optimum writing time on the misalignment is reduced with increasing gap distance, and it almost vanishes when the distance is 64 μm, enabling unmonitored optical solder formation. R-SOLNET utilizing the two-photon photochemistry is briefly described as the next-generation SOLNET.

  6. Technical and clinical analysis of microEEG: a miniature wireless EEG device designed to record high-quality EEG in the emergency department.

    Omurtag, Ahmet; Baki, Samah G Abdel; Chari, Geetha; Cracco, Roger Q; Zehtabchi, Shahriar; Fenton, André A; Grant, Arthur C


    We describe and characterize the performance of microEEG compared to that of a commercially available and widely used clinical EEG machine. microEEG is a portable, battery-operated, wireless EEG device, developed by Bio-Signal Group to overcome the obstacles to routine use of EEG in emergency departments (EDs). The microEEG was used to obtain EEGs from healthy volunteers in the EEG laboratory and ED. The standard system was used to obtain EEGs from healthy volunteers in the EEG laboratory, and studies recorded from patients in the ED or ICU were also used for comparison. In one experiment, a signal splitter was used to record simultaneous microEEG and standard EEG from the same electrodes. EEG signal analysis techniques indicated good agreement between microEEG and the standard system in 66 EEGs recorded in the EEG laboratory and the ED. In the simultaneous recording the microEEG and standard system signals differed only in a smaller amount of 60 Hz noise in the microEEG signal. In a blinded review by a board-certified clinical neurophysiologist, differences in technical quality or interpretability were insignificant between standard recordings in the EEG laboratory and microEEG recordings from standard or electrode cap electrodes in the ED or EEG laboratory. The microEEG data recording characteristics such as analog-to-digital conversion resolution (16 bits), input impedance (>100MΩ), and common-mode rejection ratio (85 dB) are similar to those of commercially available systems, although the microEEG is many times smaller (88 g and 9.4 × 4.4 × 3.8 cm). Our results suggest that the technical qualities of microEEG are non-inferior to a standard commercially available EEG recording device. EEG in the ED is an unmet medical need due to space and time constraints, high levels of ambient electrical noise, and the cost of 24/7 EEG technologist availability. This study suggests that using microEEG with an electrode cap that can be applied easily and quickly can


    G. Trapashko


    Full Text Available Development of microelectronics requires solution of the problem ensuring unity of linear measurements in a submicron range. The problem can be solved on the condition that calibration of measuring devices shall be made in accordance with reference samples that is a short length scale.While making calibration of measuring equipment with the help of a reference measure it is important to investigate components of the method accuracy and their influence on measuring results. The paper considers methodical errors which are specific for methods of optical and atomic force microscopy. Calibration results of an optical measuring microscope are given in the paper. The paper reveals that an additive error depends on parameters of a material and the form of measured elements for an optical measuring microscope. The methodical error of atomic force microscopes is predicated on the probe point shape. The paper considers a short length scale used for calibration of optical and atomic force microscopes. Recommendations for users of the measuring equipment are formulated in the paper.

  8. Review—Micro and Nano-Engineering Enabled New Generation of Thermoelectric Generator Devices and Applications

    Rojas, Jhonathan P.


    As we are advancing our world to smart living, a critical challenge is increasingly pressing - increased energy demand. While we need mega power supplies for running data centers and other emerging applications, we also need instant small- scale power supply for trillions of electronics that we are using and will use in the age of Internet of Things (IoT) and Internet of Everything (IoE). Such power supplies must meet some parallel demands: sufficient energy supply in reliable, safe and affordable manner. In that regard, thermoelectric generators emerge as important renewable energy source with great potential to take advantage of the widely-abundant and normally-wasted thermal energy. Thanks to the advancements of nano-engineered materials, thermoelectric generators\\' (TEG) performance and feasibility are gradually improving. However, still innovative engineering solutions are scarce to sufficiently take the TEG performance and functionalities beyond the status-quo. Opportunities exist to integrate them with emerging fields and technologies such as wearable electronics, bio-integrated systems, cybernetics and others. This review will mainly focus on unorthodox but effective engineering solutions to notch up the overall performance of TEGs and broadening their application base. First, nanotechnology\\'s influence in TEGs\\' development will be introduced, followed by a discussion on how the introduction of mechanically reconfigurable devices can shape up the emerging spectrum of novel TEG technologies. (C) The Author(s) 2017. Published by ECS.

  9. Risk assessment of PCDD/Fs levels in human tissues related to major food items based on chemical analyses and micro-EROD assay.

    Tsang, H L; Wu, S C; Wong, C K C; Leung, C K M; Tao, S; Wong, M H


    Nine groups of food items (freshwater fish, marine fish, pork, chicken, chicken eggs, leafy, non-leafy vegetables, rice and flour) and three types of human samples (human milk, maternal serum and cord serum) were collected for the analysis of PCDD/Fs. Results of chemical analysis revealed PCDD/Fs concentrations (pg g(-1) fat) in the following ascending order: pork (0.289 pg g(-1) fat), grass carp (Ctenopharyngodon idellus) (freshwater fish) (0.407), golden thread (Nemipterus virgatus) (marine fish) (0.511), chicken (0.529), mandarin fish (Siniperca kneri) (marine fish) (0.535), chicken egg (0.552), and snubnose pompano (Trachinotus blochii) (marine fish) (1.219). The results of micro-EROD assay showed relatively higher PCDD/Fs levels in fish (2.65 pg g(-1) fat) when compared with pork (0.47), eggs (0.33), chicken (0.13), flour (0.07), vegetables (0.05 pg g(-1) wet wt) and rice (0.05). The estimated average daily intake of PCDD/Fs of 3.51 pg EROD-TEQ/kg bw/day was within the range of WHO Tolerable Daily Intake (1-4 pg WHO-TEQ/kg bw/day) and was higher than the Provisional Tolerable Daily Intake (PMTL) (70 pg for dioxins and dioxin-like PCBs) recommended by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) [Joint FAO/WHO Expert Committee on Food Additives (JECFA), Summary and conclusions of the fifty-seventh meeting, JECFA, 2001.]. Nevertheless, the current findings were significantly lower than the TDI (14 pg WHO-TEQ/kg/bw/day) recommended by the Scientific Committee on Food of the Europe Commission [European Scientific Committee on Food (EU SCF), Opinions on the SCF on the risk assessment of dioxins and dioxin-like PCBs in food, 2000.]. However, it should be noted that micro-EROD assay overestimates the PCDD/Fs levels by 2 to 7 folds which may also amplify the PCDD/Fs levels accordingly. Although the levels of PCDD/Fs obtained from micro-EROD assay were much higher than those obtained by chemical analysis by 2 to 7 folds, it provides a cost-effective and

  10. Micro-fluidic (Lab-on the- Chip) PCR Array Cartridge for Biological Screening in a Hand Held Device: FInal Report for CRADA no 264. PNNL-T2-258-RU with CombiMatrix Corp

    Rainina, Evguenia I.


    The worldwide emergence of both new and old diseases resulting from human expansion and also human and materials mobility has and will continue to place stress on both medical and clinical diagnostics. The classical approach to bioagents detection involves the use of differential metabolic assays to determine species type in the case of most bacteria, or the use of cell culture and electron microscopy to diagnose viruses and some bacteria that are intracellular parasites. The long-term goal in bioagent detection is to develop a hand-held instrument featuring disposable cartridges which contain all the necessary reagents, reaction chambers, waste chambers, and micro-fluidics to extract, concentrate, amplify, and analyze nucleic acids. This GIPP project began development of a sensory platform using nucleic-acid based probes. Although research was not completed, initial findings indicated that an advanced sensing device could theoretically be built on a DNA/RNA-based technology platform.

  11. Fabrication of a Paper-Based Microfluidic Device to Readily Determine Nitrite Ion Concentration by Simple Colorimetric Assay

    Wang, Bo; Lin, Zhiqiang; Wang, Min


    Paper-based microfluidic devices (µPAD) are a burgeoning platform of microfluidic analysis technology. The method described herein is for use in undergraduate and high school chemistry laboratories. A simple and convenient µPAD was fabricated by easy patterning of filter paper using a permanent marker pen. The usefulness of the device was…

  12. Micro-electromechanical Systems for Probing Novel Strain Physics and Innovative Strain Devices in 2D Materials

    Christopher, Jason; Vutukuru, Mounika; Bishop, David; Swan, Anna; Goldberg, Bennett

    Straining 2D materials can dramatically change electrical, thermal and optical properties and can even cause unconventional behavior such as generating pseudo-magnetic fields. However attempts at probing these effects have been hindered by the difficulty involved with precisely straining these materials. Here we present micro-electromechanical systems (MEMS) as an ideal platform for straining 2D materials because they are readily compatible with existing electronics and their size makes them compatible with 2D materials. Additionally the MEMS platform does more than facilitate experimentation; by freeing us to think of strain as dynamical it makes a whole new class of devices practical for next generation technology. To demonstrate the power of this platform we have for the first time measured the strain response of the Raman and photoluminescence spectra of suspended MoS2, and measured the friction force between MoS2 and the MEMS structure. This talk will touch on the basics of designing MEMS structures for straining 2D materials, how to transfer 2D materials onto MEMS without break either, proof of concept experimental results, and next steps in developing the MEMS platform. This work is supported by NSF DMR Grant 1411008, and author J. Christopher thanks the NDSEG program for its support.

  13. “Optical communication with brain cells by means of an implanted duplex micro-device with optogenetics and Ca2+ fluoroimaging”

    Kobayashi, Takuma; Haruta, Makito; Sasagawa, Kiyotaka; Matsumata, Miho; Eizumi, Kawori; Kitsumoto, Chikara; Motoyama, Mayumi; Maezawa, Yasuyo; Ohta, Yasumi; Noda, Toshihiko; Tokuda, Takashi; Ishikawa, Yasuyuki; Ohta, Jun


    To better understand the brain function based on neural activity, a minimally invasive analysis technology in a freely moving animal is necessary. Such technology would provide new knowledge in neuroscience and contribute to regenerative medical techniques and prosthetics care. An application that combines optogenetics for voluntarily stimulating nerves, imaging to visualize neural activity, and a wearable micro-instrument for implantation into the brain could meet the abovementioned demand. To this end, a micro-device that can be applied to the brain less invasively and a system for controlling the device has been newly developed in this study. Since the novel implantable device has dual LEDs and a CMOS image sensor, photostimulation and fluorescence imaging can be performed simultaneously. The device enables bidirectional communication with the brain by means of light. In the present study, the device was evaluated in an in vitro experiment using a new on-chip 3D neuroculture with an extracellular matrix gel and an in vivo experiment involving regenerative medical transplantation and gene delivery to the brain by using both photosensitive channel and fluorescent Ca2+ indicator. The device succeeded in activating cells locally by selective photostimulation, and the physiological Ca2+ dynamics of neural cells were visualized simultaneously by fluorescence imaging.

  14. Modulation of surface trap induced resistive switching by electrode annealing in individual PbS micro/nanowire-based devices for resistance random access memory.

    Zheng, Jianping; Cheng, Baochang; Wu, Fuzhang; Su, Xiaohui; Xiao, Yanhe; Guo, Rui; Lei, Shuijin


    Bipolar resistive switching (RS) devices are commonly believed as a promising candidate for next generation nonvolatile resistance random access memory (RRAM). Here, two-terminal devices based on individual PbS micro/nanowires with Ag electrodes are constructed, whose electrical transport depends strongly on the abundant surface and bulk trap states in micro/nanostructures. The surface trap states can be filled/emptied effectively at negative/positive bias voltage, respectively, and the corresponding rise/fall of the Fermi level induces a variation in a degenerate/nondegenerate state, resulting in low/high resistance. Moreover, the filling/emptying of trap states can be utilized as RRAM. After annealing, the surface trap state can almost be eliminated completely; while most of the bulk trap states can still remain. In the devices unannealed and annealed at both ends, therefore, the symmetrical back-to-back Fowler-Nordheim tunneling with large ON/OFF resistance ratio and Poole-Frenkel emission with poor hysteresis can be observed under cyclic sweep voltage, respectively. However, a typical bipolar RS behavior can be observed effectively in the devices annealed at one end. The acquirement of bipolar RS and nonvolatile RRAM by the modulation of electrode annealing demonstrates the abundant trap states in micro/nanomaterials will be advantageous to the development of new type electronic components.

  15. Label-Free Nanoplasmonic-Based Short Noncoding RNA Sensing at Attomolar Concentrations Allows for Quantitative and Highly Specific Assay of MicroRNA-10b in Biological Fluids and Circulating Exosomes

    Joshi, Gayatri K.; Deitz-McElyea, Samantha; Liyanage, Thakshila; Lawrence, Katie; Mali, Sonali; Sardar, Rajesh; Korc, Murray


    MicroRNAs are short noncoding RNAs consisting of 18–25 nucleotides that target specific mRNA moieties for translational repression or degradation, thereby modulating numerous biological processes. Although microRNAs have the ability to behave like oncogenes or tumor suppressors in a cell-autonomous manner, their exact roles following release into the circulation are only now being unraveled and it is important to establish sensitive assays to measure their levels in different compartments in ...

  16. Serum Levels of MicroRNA-206 and Novel Mini-STR Assays for Carrier Detection in Duchenne Muscular Dystrophy

    Anaya-Segura, Mónica Alejandra; Rangel-Villalobos, Héctor; Martínez-Cortés, Gabriela; Gómez-Díaz, Benjamín; Coral-Vázquez, Ramón Mauricio; Zamora-González, Edgar Oswaldo; García, Silvia; López-Hernández, Luz Berenice


    Duchenne Muscular Dystrophy (DMD) is an X-linked neuromuscular disorder in which the detection of female carriers is of the utmost importance for genetic counseling. Haplotyping with polymorphic markers and quantitation of creatine kinase levels (CK) allow tracking of the at-risk haplotype and evidence muscle damage, respectively. Such approaches are useful for carrier detection in cases of unknown mutations. The lack of informative markers and the inaccuracy of CK affect carrier detection. Therefore, herein we designed novel mini-STR (Short Tandem Repeats) assays to amplify 10 loci within the DMD gene and estimated allele frequencies and the polymorphism information content among other parameters in 337 unrelated individuals from three Mexican populations. In addition, we tested the utility of the assays for carrier detection in three families. Moreover, given that serum levels of miR-206 discern between DMD patients and controls with a high area under the curve (AUC), the potential applicability for carrier detection was assessed. The serum levels of miR-206 of non-carriers (n = 24) and carriers (n = 23) were compared by relative quantitation using real-time PCR (p < 0.05), which resulted in an AUC = 0.80 in the Receiver Operating Characteristic curve analysis. In conclusion, miR-206 has potential as a “liquid biopsy” for carrier detection and genetic counseling in DMD. PMID:27529242

  17. Serum Levels of MicroRNA-206 and Novel Mini-STR Assays for Carrier Detection in Duchenne Muscular Dystrophy

    Mónica Alejandra Anaya-Segura


    Full Text Available Duchenne Muscular Dystrophy (DMD is an X-linked neuromuscular disorder in which the detection of female carriers is of the utmost importance for genetic counseling. Haplotyping with polymorphic markers and quantitation of creatine kinase levels (CK allow tracking of the at-risk haplotype and evidence muscle damage, respectively. Such approaches are useful for carrier detection in cases of unknown mutations. The lack of informative markers and the inaccuracy of CK affect carrier detection. Therefore, herein we designed novel mini-STR (Short Tandem Repeats assays to amplify 10 loci within the DMD gene and estimated allele frequencies and the polymorphism information content among other parameters in 337 unrelated individuals from three Mexican populations. In addition, we tested the utility of the assays for carrier detection in three families. Moreover, given that serum levels of miR-206 discern between DMD patients and controls with a high area under the curve (AUC, the potential applicability for carrier detection was assessed. The serum levels of miR-206 of non-carriers (n = 24 and carriers (n = 23 were compared by relative quantitation using real-time PCR (p < 0.05, which resulted in an AUC = 0.80 in the Receiver Operating Characteristic curve analysis. In conclusion, miR-206 has potential as a “liquid biopsy” for carrier detection and genetic counseling in DMD.

  18. Assessment by Ames test and comet assay of toxicity potential of polymer used to develop field-capable rapid-detection device to analyze environmental samples

    Hebert, Amanda; Bishop, Michelle; Bhattacharyya, Dhiman; Gleason, Karen; Torosian, Stephen


    There is need for devices that decrease detection time of food-borne pathogens from days to real-time. In this study, a rapid-detection device is being developed and assessed for potential cytotoxicity. The device is comprised of melt-spun polypropylene coupons coated via oxidative chemical vapor deposition (oCVD) with 3,4-Ethylenedioxythiophene (EDOT), for conductivity and 3-Thiopheneethanol (3TE), allowing antibody attachment. The Ames test and comet assay have been used in this study to examine the toxicity potentials of EDOT, 3TE, and polymerized EDOT-co-3TE. For this study, Salmonella typhimurium strain TA1535 was used to assess the mutagenic potential of EDOT, 3TE and the copolymer. The average mutagenic potential of EDOT, 3TE and copolymer was calculated to be 0.86, 0.56, and 0.92, respectively. For mutagenic potential, on a scale from 0 to 1, close to 1 indicates low potential for toxicity, whereas a value of 0 indicates a high potential for toxicity. The comet assay is a single-cell gel electrophoresis technique that is widely used for this purpose. This assay measures toxicity based on the area or intensity of the comet-like shape that DNA fragments produce when DNA damage has occurred. Three cell lines were assessed; FRhK-4, BHK-21, and Vero cells. After averaging the results of all three strains, the tail intensity of the copolymer was 8.8 % and tail moment was 3.0, and is most similar to the untreated control, with average tail intensity of 5.7 % and tail moment of 1.7. The assays conducted in this study provide evidence that the copolymer is non-toxic to humans.

  19. Improved RT-PCR Assay to Quantitate the Pri-, Pre-, and Mature microRNAs with Higher Efficiency and Accuracy.

    Tong, Li; Xue, Huihui; Xiong, Li; Xiao, Junhua; Zhou, Yuxun


    Understanding of the functional significance of microRNAs (miRNAs) requires efficient and accurate detection method. In this study, we developed an improved miRNAs quantification system based on quantitative real-time polymerase chain reaction (qRT-PCR). This method showed higher efficiency and accuracy to survey the expression of primary miRNAs (pri-miRNAs), precursor miRNAs (pre-miRNAs), and mature miRNAs. Instead of relative quantification method, we quantified the pri-miRNAs and pre-miRNAs with absolute qRT-PCR based on SYBR Green I fluorescence. This improvement corrected for the inaccuracy caused by the differences in amplicon length and PCR efficiency. We also used SYBR Green method to quantify mature miRNAs based on the stem-loop qRT-PCR method. We extended the pairing part of the stem-loop reverse transcript (RT) primer from 6 to 11 bp, which greatly increased the efficiency of reverse transcription PCR (RT-PCR). The performance of the improved RT primer was tested using synthetic mature miRNAs and tissue RNA samples. Results showed that the improved RT primer demonstrated dynamic range of seven orders of magnitude and sensitivity of detection of hundreds of copies of miRNA molecules.

  20. Discovery of a Small-Molecule Inhibitor of Protein-MicroRNA Interaction Using Binding Assay with a Site-Specifically Labeled Lin28.

    Lim, Donghyun; Byun, Wan Gi; Koo, Ja Young; Park, Hankum; Park, Seung Bum


    MicroRNAs (miRNAs) regulate gene expression by targeting protein-coding transcripts that are involved in various cellular processes. Thus, miRNA biogenesis has been recognized as a novel therapeutic target. Especially, the let-7 miRNA family is well-known for its tumor suppressor functions and is downregulated in many cancer cells. Lin28 protein binds to let-7 miRNA precursors to inhibit their maturation. Herein, we developed a FRET-based, high-throughput screening system to identify small-molecule inhibitors of the Lin28-let-7 interaction. We employed unnatural amino acid mutagenesis and bioorthogonal chemistry for the site-specific fluorescent labeling of Lin28, which ensures the robustness and reliability of the FRET-based protein-miRNA binding assay. Using this direct binding assay, we identified an inhibitor of the oncogenic Lin28-let-7 interaction. The inhibitor enhanced the production of let-7 miRNAs in Lin28-expressing cancer cells and reduced the level of let-7 target oncogene products.

  1. An optimized micro-assay of myosin Ⅱ ATPase activity based on the molybdenum blue method and its application in screening natural product inhibitors

    CHEN Hong-Lin; ZHAO Jing; ZHANG Guan-Jun; KOU Jun-Ping; YU Bo-Yang


    Myosin Ⅱ plays multiple roles in physiological and pathological functions through its ATPase activity.The present study was designed to optimize a micro-assay of myosin Ⅱ ATPase activity based on molybdenum blue method,using a known myosin Ⅱ ATPase inhibitor,blebbistatin.Several parameters were observed in the enzymatic reaction procedure,including the concentrations of the substrate (ATP) and calcium chloride,pH,and the reaction and incubation times.The proportion of coloration agent was also investigated.The sensitivity of this assay was compared with the malachite green method and bioluminescence method.Additionally,20 natural compounds were studied for myosin Ⅱ ATPase inhibitory activity using the optimized method.Our results showed that ATP at the concentration of 5 mmol·L-1 and ammonium molybdate:stannous chloride at the ratio of 15 ∶ 1 could greatly improve the sensitivity of this method.The IC50 of blebbistatin obtained by this method was consistent with literature.Compound 8 was screened with inhibitory activity on myosin Ⅱ ATPase.The optimized method showed similar accuracy,lower detecting limit,and wider linear range,which could be a promising approach to screening myosin Ⅱ ATPase inhibitors in vitro.

  2. Fabrication of a micro through-hole array by gas-blowing a PDMS-treated polyamide screen for a flexible drag-reducing skin-like device

    Li, Yong; Zhou, Kai; Zhao, Xiang; Kong, Quancun


    We propose a method for fabricating a flexible skin-like device for generating and trapping micro bubbles with the aim of reducing underwater drag. This low-cost, efficient, high-pressure gas-blow method is used to fabricate a micro through-hole array in a flexible polydimethylsiloxane (PDMS) gel-based skin. The key parameters in the gas-blowing method are investigated, such as the viscosity of PDMS and the blowing pressure in order to optimize the quality of through-hole layer. Deviation of the linear dimensions of the obtained micro holes was less than 4.5%. In addition, multiphase computational fluid dynamics models were built to analyze the drag-reduction performance of bell-shaped holes made by this method. Compared with cylindrical through holes produced by molding, the drag-reduction effect of bell-shaped holes increased as much as 34%.

  3. Development of Magnetically Excited Flexural Plate Wave Devices for Implementation as Physical, Chemical, and Acoustic Sensors, and as Integrated Micro-Pumps for Sensored Systems

    Schubert, W. K.; Mitchell, M. A.; Graf, D. C.; Shul, R. J.


    The magnetically excited flexural plate wave (mag-FPW) device has great promise as a versatile sensor platform. FPW's can have better sensitivity at lower operating frequencies than surface acoustic wave (SAW) devices. Lower operating frequency simplifies the control electronics and makes integration of sensor with electronics easier. Magnetic rather than piezoelectric excitation of the FPW greatly simplifies the device structure and processing by eliminating the need for piezoelectric thin films, also simplifying integration issues. The versatile mag-FPW resonator structure can potentially be configured to fulfill a number of critical functions in an autonomous sensored system. As a physical sensor, the device can be extremely sensitive to temperature, fluid flow, strain, acceleration and vibration. By coating the membrane with self-assembled monolayers (SAMs), or polymer films with selective absorption properties (originally developed for SAW sensors), the mass sensitivity of the FPW allows it to be used as biological or chemical sensors. Yet another critical need in autonomous sensor systems is the ability to pump fluid. FPW structures can be configured as micro-pumps. This report describes work done to develop mag-FPW devices as physical, chemical, and acoustic sensors, and as micro-pumps for both liquid and gas-phase analytes to enable new integrated sensing platform.

  4. Detecting exposure to environmental organic toxins in individual cells: towards development of a micro-fabricated device

    Holman, Hoi-Ying N.; Zhang, Miqin; Goth-Goldstein, Regine; Martin, Michael C.; Russell, Marion; McKinney, Wayne R.; Ferrari, Mauro; Hunter-Cevera, Jennie C.


    A new method is being developed to quickly screen for the human exposure potential to polycyclic aromatic hydrocarbons (PAHs) and organochlorines (OCs). The development involves two key elements: identifying suitable signals that represent intracellular changes that are specific to PAH and OC exposure, and constructing a device to guide the biological cell growth so that signals from individual cells are consistent and reproducible. We are completing the identification of suitable signals by using synchrotron radiation-based (SR) Fourier-transform infrared (FTIR) spectromicroscopy in the mid-infrared region (4000-400 cm-1). Distinct changes have been observed in the IR spectra after treatment of human cells in culture medium with PAHs and OCs. The potential use of this method for detecting exposure to PAHs and OCs has been tested and compared to a reverse transcription polymerase chain reaction (RT-PCR) assay that quantifies increased expression of the CYP1A1 gene in response to exposu re to PAHs or OCs.

  5. The Hopper: A Wearable Robotic Device Testbed for Micro-Gravity Bone-Loading Proof-of-Concept

    Beck, C. E.; Rovekamp, R. N.; Neuhaus, P. D.


    Wearable robotic systems are showing increased potential for addressing crew countermeasures needs. Wearable robots offer a compactness, programmability, and eccentric loading capability not present in more conventional exercise equipment. Correspondingly, advancements in the man to machine interface has progressed, allowing for higher loads to be applied directly to the person in new and novel ways. Recently, the X1 exoskeleton, a lower extremity wearable robot originally designed for mobility assistance and rehabilitation, underwent human subject testing to assess its potential as a knee dynamometer. This was of interest to NASA physiologists because currently strength is not assessed in flight due to hardware limitations, and thus there is a poor understanding of the time course of in-flight changes to muscle strength. The study concluded that the X1 compared well with the Biodex, the "gold standard" in terrestrial dynamometry, with coefficients of variation less than 6.0%. In a following study, the X1 powered ankle was evaluated for its efficacy in exercising calf muscles. Current on-orbit countermeasures equipment does not adequately protect the calf from atrophy. The results of this study were also positive (targeted muscle activity demonstrated via comparing pre- and post-exercise magnetic resonance imaging T2 measurements), again showing the efficacy of wearable robotic devices for addressing the countermeasure needs of our astronauts. Based on these successes and lessons learned, the Grasshopper was co-developed between IHMC (Florida Institute for Human and Machine Cognition) and NASA. The Grasshopper, or the Hopper for short, is a wearable robotic device designed to address muscle and bone density loss for astronauts spending extended periods of time in micro-gravity. The Grasshopper connects to the user's torso like a hiking backpack, over the shoulders and around the waist. At the feet are footplates that strap to the user. There are two actuators, one

  6. Blood collection tubes as medical devices: The potential to affect assays and proposed verification and validation processes for the clinical laboratory.

    Bowen, Raffick A R; Adcock, Dorothy M


    Blood collection tubes (BCTs) are an often under-recognized variable in the preanalytical phase of clinical laboratory testing. Unfortunately, even the best-designed and manufactured BCTs may not work well in all clinical settings. Clinical laboratories, in collaboration with healthcare providers, should carefully evaluate BCTs prior to putting them into clinical use to determine their limitations and ensure that patients are not placed at risk because of inaccuracies due to poor tube performance. Selection of the best BCTs can be achieved through comparing advertising materials, reviewing the literature, observing the device at a scientific meeting, receiving a demonstration, evaluating the device under simulated conditions, or testing the device with patient samples. Although many publications have discussed method validations, few detail how to perform experiments for tube verification and validation. This article highlights the most common and impactful variables related to BCTs and discusses the validation studies that a typical clinical laboratory should perform when selecting BCTs. We also present a brief review of how in vitro diagnostic devices, particularly BCTs, are regulated in the United States, the European Union, and Canada. The verification and validation of BCTs will help to avoid the economic and human costs associated with incorrect test results, including poor patient care, unnecessary testing, and delays in test results. We urge laboratorians, tube manufacturers, diagnostic companies, and other researchers to take all the necessary steps to protect against the adverse effects of BCT components and their additives on clinical assays.

  7. Miniaturization of environmental chemical assays in flowing systems: The lab-on-a-valve approach vis-à-vis lab-on-a-chip microfluidic devices

    Miró, Manuel; Hansen, Elo Harald


    The analytical capabilities of the microminiaturised lab-on-a-valve (LOV) module integrated into a microsequential injection (muSI) fluidic system in terms of analytical chemical performance, microfluidic handling and on-line sample processing are compared to those of the micro total analysis...... systems (muTAS), also termed lab-on-a-chip (LOC). This paper illustrates, via selected representative examples, the potentials of the LOV scheme vis-à-vis LOC microdevices for environmental assays. By means of user-friendly programmable flow and exploitation of the interplay between the thermodynamics...... and the kinetics of the chemical reactions at will, LOV allows accommodation of reactions which, at least at the present stage, are not feasible by application of microfluidic LOC systems. Thus, in LOV one may take advantage of kinetic discriminations schemes, where even subtle differences in reactions...

  8. Phenotypic and genotypic screening of human-originated lactobacilli for vitamin B12 production potential: process validation by micro-assay and UFLC.

    Bhushan, Bharat; Tomar, S K; Mandal, Surajit


    Vitamin B12 (B12) production is a strain specific, rare and hidden functional attribute of lactobacilli and a cogent protocol for selection of such isolates from the herd of lactobacilli is required. The present study included isolation of lactobacilli from human samples (milk and fecal), screening them by a polyphasic (three-phase) methodology for probable B12 production potential and validating the screening protocol by exploring selected strains for in vitro vitamin production (two-phase fermentation) and quantification [micro-assay and ultra fast liquid chromatography (UFLC)]. Fifty-nine Lactobacillus strains were recovered from tested biological samples. Contrary to screening inapplicabilities of first [growth potential (GP) in B12-free medium] and second phases (GP in B12-free and cobalt chloride-supplemented conditions), third phase (cbiK gene detection on genomic DNA) alone was revealed as a validated strategy for selection of two probable B12-producing lactobacilli. Microbiological assay confirmed production and bioavailability of produced vitamin, while UFLC testing validated the results by precisely quantifying the cyanocobalamin (industrially produced bio-available form of B12) in cell extracts of both possible B12 producers [BHM10 (10.91 ± 1.55 μg/l) and BCF20 (23.90 ± 1.73 μg/l)] and positive standard [Lactobacillus reuteri DSM20016 (20.03 ± 4.17 μg/l)]. Moreover, this study generates a novel report for genomic detection, partial amplification and sequencing of cbiK gene in Lactobacillus plantarum species (both BHM10 and BCF20). In conclusion, contrary to first two phases, cbiK gene detection strategy successfully selects B12-producing strains from a group of human-originated lactobacilli and can be used in the future for similar screening studies.

  9. Terbium complex to quantum dot Förster resonance energy transfer for homogeneous and multiplexed microRNA assay (Conference Presentation)

    Qiu, Xue; Hildebrandt, Niko


    The importance of microRNA (miRNA) dysregulation in the development and progression of diseases has made these short-length nucleic acids to next generation biomarkers. Tb-to-QD Förster resonance energy transfer (FRET) has several unique advantages over organic dye-based FRET systems for biomolecular sensing. Large Förster distances (6-11 nm) offer much high FRET efficiencies, exceptionally long Tb excited-state lifetimes (ms) enable time-gated detection void of autofluorecence background, and the narrow, symmetric, and tunable emission bands of QDs provide unrivaled potential for multiplexing. Here we report a rapid and homogeneous method to sensitively detect three different miRNAs (hsa-miR-20a-5p, hsa-miR-20b-5p, and hsa-miR-21-5p) from a single 150 µL sample based on multiplexed FRET between a luminescent Lumi4-Tb complex and three different QDs. The biosensing approach exploits both base pairing and stacking. Careful design and optimization of sequence lengths and orientations of the QD and Tb-DNA conjugates was performed to provide maximum selectivity and sensitivity for all three miRNA biomarkers. The assays work at room temperature and were designed for their application on a KRYPTOR diagnostic plate reader system.Only 30 min of sample incubation and 7.5 s of measurement are required to obtain ca. 1 nM (subpicomol) detection limits. We also demonstrate precise multiplexed measurements of these miRNAs at different and varying concentrations and the feasibility of adapting the technology to point-of-care testing (POCT) in buffer containing 10% serum. Our assay does not only demonstrate an important milestone for the integration of quantum dots to multiplexed clinical diagnostics but also a unique rapid miRNA detection technology that is complimentary to the rather complicated high-throughput and high-sensitivity approaches that are established today.

  10. Physical properties of ultrafast deposited micro- and nanothickness amorphous hydrogenated carbon films for medical devices and prostheses.

    Zaharia, T; Sullivan, I L; Saied, S O; Bosch, R C; Bijker, M D


    Hydrogenated amorphous carbon films with diamond-like structures have been formed on different substrates at very low energies and temperatures by a plasma-enhanced chemical vapour deposition (PECVD) process employing acetylene as the precursor gas. The plasma source was of a cascaded arc type with argon as the carrier gas. The films grown at very high deposition rates were found to have a practical thickness limit of approximately 1.5 microm, above which delamination from the substrate occurred. Deposition on silicon (100), glass, and plastic substrates has been studied and the films characterized in terms of sp3 content, roughness, hardness, adhesion, and optical properties. Deposition rates of up to 20 nm/s have been achieved at substrate temperatures below 100 degrees C. A typical sp3 content of 60-75 per cent in the films was determined by X-ray-generated Auger electron spectroscopy (XAES). The hardness, reduced modulus, and adhesion of the films were measured using a MicroMaterials NanoTest indenter/scratch tester. Hardness was found to vary from 4 to 13 GPa depending on the admixed acetylene flow and substrate temperature. The adhesion of the film to the substrate was significantly influenced by the substrate temperature and whether an in situ d.c. cleaning was employed prior to the deposition process. The hydrogen content in the film was measured by a combination of the Fourier transformation infrared (FTIR) spectroscopy and Rutherford backscattering (RBS) techniques. From the results it is concluded that the films formed by the process described here are ideal for the coating of long-term implantable medical devices, such as prostheses, stents, invasive probes, catheters, biosensors, etc. The properties reported in this publication are comparable with good-quality films deposited by other PECVD methods. The advantages of these films are the low ion energy and temperature of deposition, ensuring that no damage is done to sensitive substrates, very high

  11. A Portable Smart-Phone Readout Device for the Detection of Mercury Contamination Based on an Aptamer-Assay Nanosensor.

    Xiao, Wei; Xiao, Meng; Fu, Qiangqiang; Yu, Shiting; Shen, Haicong; Bian, Hongfen; Tang, Yong


    The detection of environmental mercury (Hg) contamination requires complex and expensive instruments and professional technicians. We present a simple, sensitive, and portable Hg(2+) detection system based on a smartphone and colorimetric aptamer nanosensor. A smartphone equipped with a light meter app was used to detect, record, and process signals from a smartphone-based microwell reader (MR S-phone), which is composed of a simple light source and a miniaturized assay platform. The colorimetric readout of the aptamer nanosensor is based on a specific interaction between the selected aptamer and Hg(2+), which leads to a color change in the reaction solution due to an aggregation of gold nanoparticles (AuNPs). The MR S-phone-based AuNPs-aptamer colorimetric sensor system could reliably detect Hg(2+) in both tap water and Pearl River water samples and produced a linear colorimetric readout of Hg(2+) concentration in the range of 1 ng/mL-32 ng/mL with a correlation of 0.991, and a limit of detection (LOD) of 0.28 ng/mL for Hg(2+). The detection could be quickly completed in only 20 min. Our novel mercury detection assay is simple, rapid, and sensitive, and it provides new strategies for the on-site detection of mercury contamination in any environment.

  12. A Portable Smart-Phone Readout Device for the Detection of Mercury Contamination Based on an Aptamer-Assay Nanosensor

    Wei Xiao


    Full Text Available The detection of environmental mercury (Hg contamination requires complex and expensive instruments and professional technicians. We present a simple, sensitive, and portable Hg2+ detection system based on a smartphone and colorimetric aptamer nanosensor. A smartphone equipped with a light meter app was used to detect, record, and process signals from a smartphone-based microwell reader (MR S-phone, which is composed of a simple light source and a miniaturized assay platform. The colorimetric readout of the aptamer nanosensor is based on a specific interaction between the selected aptamer and Hg2+, which leads to a color change in the reaction solution due to an aggregation of gold nanoparticles (AuNPs. The MR S-phone-based AuNPs-aptamer colorimetric sensor system could reliably detect Hg2+ in both tap water and Pearl River water samples and produced a linear colorimetric readout of Hg2+ concentration in the range of 1 ng/mL–32 ng/mL with a correlation of 0.991, and a limit of detection (LOD of 0.28 ng/mL for Hg2+. The detection could be quickly completed in only 20 min. Our novel mercury detection assay is simple, rapid, and sensitive, and it provides new strategies for the on-site detection of mercury contamination in any environment.

  13. Optimization of fixed-permeabilized cell monolayers for high throughput micro-neutralizing antibody assays: application to the zebrafish/viral hemorrhagic septicemia virus (vhsv) model.

    Chinchilla, Blanca; Encinas, Paloma; Estepa, Amparo; Coll, Julio; Gomez-Casado, Eduardo


    A new high throughput centrifugation-free method to estimate viral neutralizing antibody levels in low volumes and large numbers of plasma blood samples is described. Cell monolayers were, (i) plated on poly-d-Lys coated 96-wells, (ii) infected with viruses previously incubated with fish plasma containing antibodies, (iii) fixed with formaldehyde to increase cell recovery and avoid centrifugation steps, (iv) permeabilized with Saponin, (v) immunostained in the presence of Saponin by using a monoclonal antibody (MAb) to viral protein, (vi) digested with trypsin to detach cells from the monolayer, in the absence of Saponin to reduce damage of intracellular MAb-antigen complexes, and (vii) gated by flow cytometry using automatic 96-well batch analysis. The method was applied to the determination of plasma neutralizing antibodies from zebrafish (Danio rerio) surviving infections with viral hemorrhagic septicemia virus (VHSV) (an important rhabdovirus of salmonids). This semi-automatic, rapid and practical assay detected anti-VHSV neutralizing antibodies in the plasma (∼3 μl per fish) of 95.1% of the zebrafish surviving VHSV infections. The fixed-permeabilized monolayer (FIXPERM) micro-neutralization method might help to analyze sera/plasma from small fish under standarized high throughput conditions.

  14. The application of a new microfluidic device for the simultaneous identification and quantitation of midazolam metabolites obtained from a single micro-litre of chimeric mice blood.

    Gallagher, Richard; Dillon, Leonard; Grimsley, Aidan; Murphy, Jim; Samuelsson, Kristin; Douce, David


    Improvements in the design of low-flow highly sensitive chromatographic ion source interfaces allow the detection and characterisation of drugs and metabolites from smaller sample volumes. This in turn improves the ethical treatment of animals by reducing both the number of animals needed and the blood sampling volumes required. A new microfluidic device combining an ultra-high pressure liquid chromatography (UHPLC) analytical column with a nano-flow electrospray source is described. All microfluidic, gas and electrical connections are automatically engaged when the ceramic microfluidic device is inserted into the source enclosure. The system was used in conjunction with a hybrid quadrupole-time-of-flight mass spectrometer. The improved sensitivity of the system is highlighted in its application in the quantification and qualification of midazolam and its metabolites detected in whole blood from chimeric and wild-type mice. Metabolite identification and full pharmacokinetic profiles were obtained from a single micro-litre of whole blood at each sampling time and significant pharmacokinetic differences were observed between the two types of mice. Improvements in the enhanced ionisation efficiency from the microfluidic device in conjunction with nanoUHPLC/MS was sufficiently sensitive for the identification and quantification of midazolam metabolites from a single micro-litre of whole blood. Detection of metabolites not previously recorded from the chimeric mouse in vivo model was made. Copyright © 2014 John Wiley & Sons, Ltd.

  15. Label-Free and Enzyme-Free Homogeneous Electrochemical Biosensing Strategy Based on Hybridization Chain Reaction: A Facile, Sensitive, and Highly Specific MicroRNA Assay.

    Hou, Ting; Li, Wei; Liu, Xiaojuan; Li, Feng


    Homogenous electrochemical biosensing strategies have attracted substantial attention, because of their advantages of being immobilization-free and having rapid response and improved recognition efficiency, compared to heterogeneous biosensors; however, the high cost of labeling and the strict reaction conditions of tool enzymes associated with current homogeneous electrochemical methods limit their potential applications. To address these issues, herein we reported, for the first time, a simple label-free and enzyme-free homogeneous electrochemical strategy based on hybridization chain reaction (HCR) for sensitive and highly specific detection of microRNA (miRNA). The target miRNA triggers the HCR of two species of metastable DNA hairpin probes, resulting in the formation of multiple G-quadruplex-incorporated long duplex DNA chains. Thus, with the electrochemical indicator Methylene Blue (MB) selectively intercalated into the duplex DNA chain and the multiple G-quadruplexes, a significant electrochemical signal drop is observed, which is dependent on the concentration of the target miRNA. Thus, using this "signal-off" mode, a simple, label-free and enzyme-free homogeneous electrochemical strategy for sensitive miRNA assay is readily realized. This strategy also exhibits excellent selectivity to distinguish even single-base mismatched miRNA. Furthermore, this method also exhibits additional advantages of simplicity and low cost, since both expensive labeling and sophisticated probe immobilization processes are avoided. Therefore, the as-proposed label-free and enzyme-free homogeneous electrochemical strategy may become an alternative method for simple, sensitive, and selective miRNA detection, and it has great potential to be applied in miRNA-related clinical diagnostics and biochemical research.

  16. Design and Development of Micro-Power Generating Device for Biomedical Applications of Lab-on-a-Disc.

    Karunan Joseph

    Full Text Available The development of micro-power generators for centrifugal microfluidic discs enhances the platform as a green point-of-care diagnostic system and eliminates the need for attaching external peripherals to the disc. In this work, we present micro-power generators that harvest energy from the disc's rotational movement to power biomedical applications on the disc. To implement these ideas, we developed two types of micro-power generators using piezoelectric films and an electromagnetic induction system. The piezoelectric-based generator takes advantage of the film's vibration during the disc's rotational motion, whereas the electromagnetic induction-based generator operates on the principle of current generation in stacks of coil exposed to varying magnetic flux. We have successfully demonstrated that at the spinning speed of 800 revolutions per minute (RPM the piezoelectric film-based generator is able to produce up to 24 microwatts using 6 sets of films and the magnetic induction-based generator is capable of producing up to 125 milliwatts using 6 stacks of coil. As a proof of concept, a custom made localized heating system was constructed to test the capability of the magnetic induction-based generator. The heating system was able to achieve a temperature of 58.62 °C at 2200 RPM. This development of lab-on-a-disc micro power generators preserves the portability standards and enhances the future biomedical applications of centrifugal microfluidic platforms.

  17. Label-Free Nanoplasmonic-Based Short Noncoding RNA Sensing at Attomolar Concentrations Allows for Quantitative and Highly Specific Assay of MicroRNA-10b in Biological Fluids and Circulating Exosomes.

    Joshi, Gayatri K; Deitz-McElyea, Samantha; Liyanage, Thakshila; Lawrence, Katie; Mali, Sonali; Sardar, Rajesh; Korc, Murray


    MicroRNAs are short noncoding RNAs consisting of 18-25 nucleotides that target specific mRNA moieties for translational repression or degradation, thereby modulating numerous biological processes. Although microRNAs have the ability to behave like oncogenes or tumor suppressors in a cell-autonomous manner, their exact roles following release into the circulation are only now being unraveled and it is important to establish sensitive assays to measure their levels in different compartments in the circulation. Here, an ultrasensitive localized surface plasmon resonance (LSPR)-based microRNA sensor with single nucleotide specificity was developed using chemically synthesized gold nanoprisms attached onto a solid substrate with unprecedented long-term stability and reversibility. The sensor was used to specifically detect microRNA-10b at the attomolar (10(-18) M) concentration in pancreatic cancer cell lines, derived tissue culture media, human plasma, and media and plasma exosomes. In addition, for the first time, our label-free and nondestructive sensing technique was used to quantify microRNA-10b in highly purified exosomes isolated from patients with pancreatic cancer or chronic pancreatitis, and from normal controls. We show that microRNA-10b levels were significantly higher in plasma-derived exosomes from pancreatic ductal adenocarcinoma patients when compared with patients with chronic pancreatitis or normal controls. Our findings suggest that this unique technique can be used to design novel diagnostic strategies for pancreatic and other cancers based on the direct quantitative measurement of plasma and exosome microRNAs, and can be readily extended to other diseases with identifiable microRNA signatures.

  18. Evaluation of the absorption of methotrexate on cells and its cytotoxicity assay by using an integrated microfluidic device coupled to a mass spectrometer.

    Gao, Dan; Li, Haifang; Wang, Niejun; Lin, Jin-Ming


    An integrated microfluidic device was developed for high-throughput drug screening with an online electrospray ionization quadrupole time-of-flight mass spectrometer (ESI-Q-TOF MS). The multiple gradient generator followed by an array of microscale cell culture chambers and on-chip solid-phase extraction (SPE) columns for sample pretreatment prior to mass analysis was integrated in the device which was fabricated in one single step. By using the combination system, the process for characterization of drug absorption and evaluation of cytotoxicity could be simultaneously realized. To validate the feasibility, the absorption of methotrexate and its effects on HepG2 and Caco-2 cells were investigated. With the increasing concentration of drugs, the percentage of apoptotic cells appeared in a dose-dependent fashion. By comparison with the results obtained from ESI-Q-TOF MS analysis and cytotoxicity assay, we found that higher intracellular drug concentration resulted in increased cell cytotoxicity. The technique presented herein provides an easy protocol to screen drugs rapidly with low drug consumption, high throughput, and high sensitivity.

  19. Computational Flow Dynamic Simulation of Micro Flow Field Characteristics Drainage Device Used in the Process of Oil-Water Separation

    Guangya Jin


    Full Text Available Aqueous crude oil often contains large amounts of produced water and heavy sediment, which seriously threats the safety of crude oil storage and transportation. Therefore, the proper design of crude oil tank drainage device is prerequisite for efficient purification of aqueous crude oil. In this work, the composition and physicochemical properties of crude oil samples were tested under the actual conditions encountered. Based on these data, an appropriate crude oil tank drainage device was developed using the principle of floating ball and multiphase flow. In addition, the flow field characteristics in the device were simulated and the contours and streamtraces of velocity magnitude at different nine moments were obtained. Meanwhile, the improvement of flow field characteristics after the addition of grids in crude oil tank drainage device was validated. These findings provide insights into the development of effective selection methods and serve as important references for oil-water separation process.

  20. NATO Advanced Research Workshop on Advanced Materials and Technologies for Micro/Nano-Devices, Sensors and Actuators

    Gusev, Evgeni; Dideikin, Arthur


    The main goal of this book is to review recent progress and current status of MEMS/NEMS technologies and devices. Several important areas are discussed: history of research in the field, device physics, examples of sucessful applications, sensors, materials and processing aspects. The authors who have contributed to the book represent a diverse group of leading scientists from academic, industrial and governmental labs worldwide who bring a broad array of backgrounds such as device physics, technologists, electrical and mechanical engineering, surface chemistry and materials science). The contributions to this book are accessible to both expert scientists and engineers who need to keep up with leading edge research, and newcomers to the field who wish to learn more about the exciting basic and applied research issues relevant to micromechanical devices and technologies.

  1. Improved DNA extraction efficiency from low level cell numbers using a silica monolith based micro fluidic device.

    Kashkary, Loay; Kemp, Cordula; Shaw, Kirsty J; Greenway, Gillian M; Haswell, Stephen J


    The evaluation of a micro fluidic system with an integrated silica monolith for performing DNA extraction from limited biological samples has been carried out. Low DNA target concentrations usually require the addition of carrier RNA to ensure desired extraction efficiencies. Here, we demonstrate a micro fluidic extraction system with increasingly efficient extraction performances for biological samples containing extracted DNA showed successful amplification via the polymerase chain reaction demonstrating both the effectiveness of the proposed system at removing potential inhibitors and yielding good quality DNA. The work presented here beneficially identifies reduced sample volumes/concentrations as suitable for processing with respect to downstream analysis by enabling pre-concentration of the biological sample, particularly important when dealing with clinical or forensic specimens.

  2. An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides

    Wang Ziming, E-mail: [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); College of Environment and Resources, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Zhao Xin; Xu Xu; Wu Lijie; Su Rui; Zhao Yajing; Jiang Chengfei; Zhang Hanqi [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Ma Qiang [Chinese Academy of Inspection and Quarantine, Beijing 100123 (China); Lu Chunmei [College of Technology Center, Jilin Entry-Exit Inspection and Quarantine Bureau, Changchun 130062 (China); Dong Deming [College of Environment and Resources, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)


    Highlights: Black-Right-Pointing-Pointer An absorbing microwave {mu}-SPE device packed with activated carbon was used. Black-Right-Pointing-Pointer Absorbing microwave {mu}-SPE device was made and used to enrich the analytes. Black-Right-Pointing-Pointer Absorbing microwave {mu}-SPE device was made and used to heat samples directly. Black-Right-Pointing-Pointer MAE-{mu}-SPE was applied to the extraction of OPPs with non-polar solvent only. - Abstract: A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction ({mu}-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave {mu}-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in {mu}-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave {mu}-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60 Degree-Sign C for 10 min. The extracts obtained by MAE-{mu}-SPE were directly analyzed by GC-MS without any clean-up process. The recoveries were in the range of 93.5-104.6%, and the relative standard deviations were lower than 8.7%.

  3. 数字全息显微术应用于微器件的测量研究%Digital Holographic Microscopy Applied to Measurement of Micro Devices

    王红军; 李方方


    The method of digital holographic microscopy measurement is applied for measuring micro device to realize tiny deformation or displacement measurement ,which then is used for feedback regulation to achieve the effect of real-time monitoring .Basic theories of digital micro-holography are first described ,and a digital micro-holography measurement system without pre-amplification is established to measure tiny object such as MEMS micro devices . Based on Fresnel approximation algorithm of numerical reconstruction ,the program of digital holography reconstruction is compiled . Combined with spectral filtering method ,the zero order term and twin image ,which seriously affect the quality of hologram , are eliminated ,then a desired reconstruction image is made . At last the reproduction of three-dimensional contour ,with 160 nm groove depth and 430 μm grating pitch ,is obtained .%利用数字全息显微测量的方法进行微器件测量,以实现微小形变或者微小位移的测量,继而进行反馈调节,实现实时监测。在学习数字全息的基本理论的基础上,建立无预放大数字全息显微测量系统,对MEMS微器件进行测量。基于菲涅耳近似的再现算法编写了数字全息再现的程序,用频谱滤波的方法对全息图中对图像质量有严重影响的零级项、孪生像进行了有效的抑制,从而使成像质量得到提高,最终获得了其再现三维轮廓,刻槽深度为160 nm ,栅距为430μm 。

  4. 微型波力发电装置的捕浪器研究%Research on Wave-capturing Device of the Floating Micro-type Device for Wave-activated Power Generation

    李驰; 苏毅; 姬龙; 郭显成


    Based on the floating micro-type device for wave activated power generation,the float of wave-capturing device is studied. According to the Froude-krylov assumption,the wave forces on several commonly used float are calculated,and it is con-cluded that the vertical cylindrical float can absorb the wave energy most effectively. Based on the principle that when the device and float come about resonance,the float can absorb the maximum energy the basic parameters of vertical cylindrical float has been designed for further research and use.%针对漂浮式微型波力发电装置,根据弗汝德·克雷洛夫假定法对几种常用形状浮子所受波浪力的大小进行了计算,得出垂直圆柱形浮子吸收波浪能效果最佳的结论;运用装置和浮子共振时吸收能量最大的原理,对垂直圆柱形浮子的基本参数进行了研究,为漂浮式微型波力发电装置捕浪器浮子的设计打下了基础。

  5. Evaluation of pancreatic cancer cell migration with multiple parameters in vitro by using an optical real-time cell mobility assay device.

    Yamauchi, Akira; Yamamura, Masahiro; Katase, Naoki; Itadani, Masumi; Okada, Naoko; Kobiki, Kayoko; Nakamura, Masafumi; Yamaguchi, Yoshiyuki; Kuribayashi, Futoshi


    Migration of cancer cell correlates with distant metastasis and local invasion, which are good targets for cancer treatment. An optically accessible device "TAXIScan" was developed, which provides considerably more information regarding the cellular dynamics and less quantity of samples than do the existing methods. Here, we report the establishment of a system to analyze the nature of pancreatic cancer cells using TAXIScan and we evaluated lysophosphatidic acid (LPA)-elicited pancreatic cell migration. Pancreatic cancer cell lines, BxPC3, PANC-1, AsPC1, and MIAPaCa-2, were analyzed for adhesion as well as migration towards LPA by TAXIScan using parameters such as velocity and directionality or for the number of migrated cells by the Boyden chamber methods. To confirm that the migration was initiated by LPA, the expression of LPA receptors and activation of intracellular signal transductions were examined by quantitative reverse transcriptase polymerase reaction and western blotting. Scaffold coating was necessary for the adhesion of pancreatic cancer cells, and collagen I and Matrigel were found to be good scaffolds. BxPC3 and PANC-1 cells clearly migrated towards the concentration gradient formed by injecting 1 μL LPA, which was abrogated by pre-treatment with LPA inhibitor, Ki16425 (IC50 for the directionality ≈ 1.86 μM). The LPA dependent migration was further confirmed by mRNA and protein expression of LPA receptors as well as phosphorylation of signaling molecules. LPA1 mRNA was highest among the 6 receptors, and LPA1, LPA2 and LPA3 proteins were detected in BxPC3 and PANC-1 cells. Phosphorylation of Akt (Thr308 and Ser473) and p42/44MAPK in BxPC3 and PANC-1 cells was observed after LPA stimulation, which was clearly inhibited by pre-treatment with a compound Ki16425. We established a novel pancreatic cancer cell migration assay system using TAXIScan. This assay device provides multiple information on migrating cells simultaneously, such as their

  6. Application of passive sampling devices for screening of micro-pollutants in marine aquaculture using LC-MS/MS.

    Martínez Bueno, María Jesús; Hernando, María Dolores; Agüera, Ana; Fernández-Alba, Amadeo R


    Knowledge on the presence of micro-pollutants, in particular emerging contaminants, such as pharmaceuticals, biocides or some pesticides, in semi-enclosed coastal areas, where fish farms are installed, is very limited. This article shows data on the presence of micro-pollutants over 1 year monitoring campaign carried out in a fish farm placed on the Mediterranean Sea. With this work, the results of the development of an analytical procedure which, makes use of passive sampling techniques (with polar organic chemical integrative samplers, POCIS, pharmaceutical configuration) and of the LC-QLIT-MS system, are presented. The development of the analytical procedure entail laboratory-based calibration with the samplers POCIS, for calculating uptake rates and sampling rates of compounds representative of a wide range of polarity (4.56>or=logK(ow)>or=-0.12). The uptake of the target compounds in the sampler POCIS, follows a linear pattern for most compounds, and sampling rates varied from 0.001 to 0.319l/d. The calibration experiments have shown that POCIS pharmaceutical configuration could be used for sampling other non-target compounds, such as pesticides and biocides with a logK(ow)monitoring campaign, among the selected compounds, metronidazole, erythromycin, simazine, atrazine, diuron, terbutryn, irgarol, trimethoprim, carbaryl, flumequine, TCMTB and diphenyl sulphone (DPS) were detected. Most of target compounds found were at average concentrations which ranged from 0.01 to 75 ng/l. Irgarol, simazine, diuron, atrazine and DPS were the micro-pollutants most frequently detected over the period of the monitoring programme carried out.

  7. Stochastic modeling of filtrate alkalinity in water filtration devices: Transport through micro/nano porous clay based ceramic materials

    Clay and plant materials such as wood are the raw materials used in manufacture of ceramic water filtration devices around the world. A step by step manufacturing procedure which includes initial mixing, molding and sintering is used. The manufactured ceramic filters have numerous pores which help i...

  8. Fiscal 2000 achievement report on the venture business assisting type regional consortium - Minor business creation base type. Development of touch panel display operated by micro-Peltier device; 2000 nendo chiiki consortium kenkyu kaihatsu jigyo seika hokokusho. Micro Peltier soshi ni yoru shokkaku display no kaihatsu



    The project aims to develop a small, light, and inexpensive touch panel display that enables visually handicapped people to transmit information by use of their manual sensation. Information from computers or the like is exhibited on the display in arrays of hillocks and dents. For improvement on display resolution and for cost reduction, efforts are made (1) to employ micro-Peltier devices for the simplification of the hillock-dent display mechanism and for the realization of a high resolution tactile display and (2) to establish a technology for manufacturing low-cost micro-Peltier devices. In the tactile display to be developed, the hillocks and dents are formed using gas-filled tiny balloons. The balloons are 2-dimensionally arranged, with the gas therein to be expanded and contracted via micro-Peltier devices. Difference between hillock-dent arrays and changes therein with the passage of time provide information. The gas in the balloons is inflated and contracted through the operation of micro-Peltier devices. In concrete terms, efforts were made to develop (1) a prototype hillock-dent display, (2) a technology for manufacturing high-performance low-cost micro-Peltier devices, and (3) a software program for computers to drive tactile displays. (NEDO)

  9. Fabrication of micro- and nanometre-scale polymer structures in liquid crystal devices for next generation photonics applications

    Tartan, Chloe C.; Salter, Patrick S.; Booth, Martin J.; Morris, Stephen M.; Elston, Steve J.


    Direct Laser Writing (DLW) by two-photon photopolymerization (TPP) enables the fabrication of micron-scale polymeric structures in soft matter systems. The technique has implications in a broad range of optics and photonics; in particular fast-switching liquid crystal (LC) modes for the development of next generation display technologies. In this paper, we report two different methodologies using our TPP-based fabrication technique. Two explicit examples are provided of voltage-dependent LC director profiles that are inherently unstable, but which appear to be promising candidates for fast-switching photonics applications. In the first instance, 1 μm-thick periodic walls of polymer network are written into a planar aligned (parallel rubbed) nematic pi-cell device containing a nematic LC-monomer mixture. The structures are fabricated when the device is electrically driven into a fast-switching nematic LC state and aberrations induced by the device substrates are corrected for by virtue of the adaptive optics elements included within the DLW setup. Optical polarizing microscopy images taken post-fabrication reveal that polymer walls oriented perpendicular to the rubbing direction promote the stability of the so-called optically compensated bend mode upon removal of the externally applied field. In the second case, polymer walls are written in a nematic LC-optically adhesive glue mixture. A polymer- LCs-polymer-slices or `POLICRYPS' template is formed by immersing the device in acetone post-fabrication to remove any remaining non-crosslinked material. Injecting the resultant series of polymer microchannels ( 1 μm-thick) with a short-pitch, chiral nematic LC mixture leads to the spontaneous alignment of a fast-switching chiral nematic mode, where the helical axis lies parallel to the glass substrates. Optimal contrast between the bright and dark states of the uniform lying helix alignment is achieved when the structures are spaced at the order of the device thickness

  10. A rapid, micro-scale preliminary screening method for active components in Galangal with protective effect against hydrogen peroxide induced cell apoptosis through "thin layer chromatography" and "tetrazolium-based colorimetric assay" array correspondence.

    Cheng, Yuan; Li, Yuanting; Li, Jin; Deng, Yifeng


    A new method has been established for rapid preliminary screening active ingredients in natural products through thin layer chromatography (TLC) array responding with tetrazolium-based colorimetric assay (MTT assay) along with post LC-MS in micro-scale. The extract of the natural product was first separated by TLC. The separated spots obtained from TLC were visualized in situ with vanillin-ethanolic sulfuric acid agent to define the array correspondence between TLC spots and 384-cell culture plate for MTT cell viability assay. The TLC spots from the replicate TLC plates were then eluted and transferred into the wells of 384-cell culture plates according to the array respondence. The TLC spots with significant antioxidant activities were further screened by MTT assay, and subsequently traced and identified by LC-MS based on the TLC-MTT assay array correspondence. This new method was successfully applied to screen active ingredients in a Chinese medicine known as Galangal. Two major inhibitors for the decline of PC12 cell survival (Galangin, m/z 269.1, and 5-hydroxy-7-(4'-hydroxy-3'-methoxyphenyl)-1-phenyl-3-heptanone, m/z 327.2) were effectively screened and identified by this method.

  11. Detection and isolation of circulating exosomes and microvesicles for cancer monitoring and diagnostics using micro-/nano-based devices

    Ko, Jina


    In the last several years, nanoscale vesicles that originate from tumor cells and which can be found circulating in the blood (i.e. exosomes and microvesicles) have been discovered to contain a wealth of proteomic and genetic information to monitor cancer progression, metastasis, and drug efficacy. However, the use of exosomes and microvesicles as biomarkers to improve patient care has been limited by their small size (30 nm–1 μm) and the extensive sample preparation required for their isolation and measurement. In this Critical Review, we explore the emerging use of micro and nano-technology to isolate and detect exosomes and microvesicles in clinical samples and the application of this technology to the monitoring and diagnosis of cancer. PMID:26378496

  12. 21 CFR 866.3210 - Endotoxin assay.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Endotoxin assay. 866.3210 Section 866.3210 Food... DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3210 Endotoxin assay. (a) Identification. An endotoxin assay is a device that uses serological techniques in whole blood. The device...

  13. A novel approach combining the Calgary Biofilm Device and Phenotype MicroArray for the characterization of the chemical sensitivity of bacterial biofilms.

    Santopolo, L; Marchi, E; Frediani, L; Decorosi, F; Viti, C; Giovannetti, L


    A rapid method for screening the metabolic susceptibility of biofilms to toxic compounds was developed by combining the Calgary Biofilm Device (MBEC device) and Phenotype MicroArray (PM) technology. The method was developed using Pseudomonas alcaliphila 34, a Cr(VI)-hyper-resistant bacterium, as the test organism. P. alcaliphila produced a robust biofilm after incubation for 16 h, reaching the maximum value after incubation for 24 h (9.4 × 10(6) ± 3.3 × 10(6) CFU peg(-1)). In order to detect the metabolic activity of cells in the biofilm, dye E (5×) and menadione sodium bisulphate (100 μM) were selected for redox detection chemistry, because they produced a high colorimetric yield in response to bacterial metabolism (340.4 ± 6.9 Omnilog Arbitrary Units). This combined approach, which avoids the limitations of traditional plate counts, was validated by testing the susceptibility of P. alcaliphila biofilm to 22 toxic compounds. For each compound the concentration level that significantly lowered the metabolic activity of the biofilm was identified. Chemical sensitivity analysis of the planktonic culture was also performed, allowing comparison of the metabolic susceptibility patterns of biofilm and planktonic cultures.

  14. Development of devices and systems of growth of gallium arsenide ingots for micro, nano electronics and photovoltaics

    A. P. Oksanich


    Full Text Available Gallium arsenide is a perspective semiconductor, the need for which is constantly increasing. This is associated with the development of electronic components operating in excess of the high frequency range and development of terrestrial photovoltaics based on gallium arsenide solar cells. Increase in diameter of grown ingots leads to a deterioration in their performance, which is caused by the imperfection of growing technology. The paper presents the results of the development of systems and devices which help to improve existing technology to produce GaAs ingots and wafers with a diameter of 100 mm with the best technical parameters. Developed a system to manage growing GaAs ingot. As a sensor of diameter ingot it uses a weighting method provides a measurement error in the process of growing ± 1,0 mm. The system allows to grow GaAs ingots with an error of ± 2 mm. For the formation of temperature gradients developed thermal unit, which provides a gradient of 51 .. 53 K cm in growing of ingots with diameter of 100 mm. For adjusting the process parameters were developed measuring device of the internal stresses that are generated in the ingot during the growth of the GaAs ingot. Presented in paper technical solutions provided a silicon ingot with a diameter of 100 mm. with mobility, cm2 V-1 s-1 - 2500 ÷ 3500, the charge carrier density, cm-3 - 5x1017 ÷ 5x1018; dislocation density, cm-2 - to 8x104.

  15. Quantification of urinary 5-hydroxyindoleacetic acid by in-house nitrosonaphthol reaction compared with nitrosonaphthol micro column chromatography and enzyme-linked immunosorbent assay

    Joyce Matie Kinoshita da Silva


    Full Text Available The aim of this study was to compare the colorimetric "kit" and enzyme-linked immunosorbent assay (ELISA methods to quantify urinary 5-hydroxyindoleacetic acid through the Goldenberg's technique, exploring the potential of replacing it. 24-hour urine samples were tested by Goldenberg's assay and compared with kits. The agreement was almost perfect for the comparison of Goldenberg's assay with both colorimetric kit, and with ELISA kit, considering ≤ 7.5 mg/24h normal cutoff value. Therefore, both "kits" would be good alternatives to Goldenberg's technique due to practicality and agreement between values.

  16. Achievement report for fiscal 1998 on research and development project for regional consortiums. Regional consortium field (Development of super devices for medical treatment devices using three-dimensional micro processing technology (the second year)); 1998 nendo chiiki consortium bun'ya. Maikuro sanjigen kako gijutsu ni yoru iryo kikiyo super device no kaihatsu (dai 2 nendo)



    It is intended to develop super devices for medical treatment devices using a three-dimensional micro processing technology by developing and combining precision processing technologies accumulated in the Suwa area. Main targets were placed on device size reduction, and a high reliability portable chemical liquid sustaining injector. This paper describes achievements made in fiscal 1998. Micromotors currently used have as low output torque as 1/4 of the target. Enhancement of reduction gear mechanism efficiency and durability is the problem to be solved. Microtubes with an inner diameter of 0.1 mm were produced on a trial basis by using four kinds of materials. The delivery mechanism assured the targeted flow rate successfully by using the direct cum screw system, but reduction in driving torque is desired. Completion of the cartridge system is also in the realm of aim. Joints will be moved closer to commercialization by selecting materials taking into account the chemical resistance and disposition. Micro connectors and cables still have problems for development. The bubble sensor was virtually decided to be of optical type from the points of detection performance requirements. Detectors and peripheral devices will be reduced in dimensions, and their reliability will be enhanced. The flow rate sensor has a problem to be solved in responsiveness to intermittent flows. (NEDO)

  17. A continuous flow micro filtration device for plasma/blood separation using submicron vertical pillar gap structures

    Kang, Tae Goo; Yoon, Yong-Jin; Ji, Hongmiao; Lim, Pei Yi; Chen, Yu


    This work demonstrates a continuous flow plasma/blood separator using a vertical submicron pillar gap structure. The working principle of the proposed separator is based on size exclusion of cells through cross-flow filtration, in which only plasma is allowed to pass through submicron vertical pillars located tangential to the main flow path of the blood sample. The maximum filtration efficiency of 99.9% was recorded with a plasma collection rate of 0.67 µl min-1 for an input blood flow rate of 12.5 µl min-1. The hemolysis phenomenon was observed for an input blood flow rate above 30 µl min-1. Based on the experimental results, we can conclude that the proposed device shows potential for the application of on-chip plasma/blood separation as a part of integrated point-of-care (POC) diagnostics systems.

  18. Wet-lab tested microRNA assays for qPCR studies with SYBR®Green and DNA primers in pig tissues

    Mentzel, Caroline M. Junker; Skovgaard, Kerstin; Córdoba, Sarai


    have previously developed two useful tools in the field of microRNA quantitative real time PCR (qPCR): 1) a very specific, sensitive and simple qPCR method based on DNA primers, MiR-specific qPCR; and 2) the free primer-design software miRprimer. The present study integrates in a publicly accessible...

  19. Effects of Interfaces on Dynamics in Micro-Fluidic Devices: Slip-Boundaries’ Impact on Rotation Characteristics of Polar Liquid Film Motors

    Jiang, Su-Rong; Liu, Zhong-Qiang; Amos Yinnon, Tamar; Kong, Xiang-Mu


    A new approach for exploring effects of interfaces on polar liquids is presented. Their impact on the polar liquid film motor (PLFM) - a novel micro-fluidic device - is studied. We account for the interface’s impact by modeling slip boundary effects on the PLFM’s electro-hydro-dynamical rotations. Our analytical results show as k={l}s/R increases (with {l}s denoting the slip length resulting from the interface’s impact on the film’s properties, k > -1 and R denoting the film’s radius): (a) PLFMs subsequently exhibit rotation characteristics under “negative-”, “no-”, “partial-” and “perfect-” slip boundary conditions; (b) The maximum value of the linear velocity of the steady rotating film increases linearly and its location approaches the film’s border; (c) The decay of the angular velocities’ dependency on the distance from the center of the film slows down, resulting in a macroscopic flow near the boundary. With our calculated rotation speed distributions consistent with the existing experimental ones, research aiming at fitting computed to measured distributions promises identifying the factors affecting {l}s, e.g., solid-fluid potential interactions and surface roughness. The consistency also is advantageous for optimizing PLFM’s applications as micro-washers, centrifuges, mixers in the lab-on-a-chip. Supported by National Natural Science Foundation of China under Grant Nos. 11302118, 11275112, and Natural Science Foundation of Shandong Province under Grant No. ZR2013AQ015

  20. Evaluation of mobile micro-sensing devices for GPS-based personal exposure monitoring of heat and particulate matter - a matter of context

    Ueberham, Maximilian; Schlink, Uwe; Weiland, Ulrike


    The application of mobile micro-sensing devices (MSDs) for human health and personal exposure monitoring (PEM) is an emerging topic of interest in urban air quality research. In the context of climate change, urban population growth and related anthropogenic activities, an increase is expected for the intensity of citizens' exposure to heat and particulate matter (PM). Therefore more focus on the small-scale perspective of spatio-temporal distribution of air quality parameters is important to complement fixed-monitoring site data. Mobile sensors for PEM are useful for both, the investigation of the local distribution of air quality and the personal exposure profiles of individuals moving within their activity spaces. An evaluation of MSDs' accuracy is crucial, before their sophisticated application in measurement campaigns. To detect variations of exposure at small scales, it is even more important to consider the accuracy of Global Positioning System (GPS) devices within different urban structure types (USTs). We present an assessment of the performance of GPS-based MSDs under indoor laboratory conditions and outdoor testing within different USTs. The aim was to evaluate the accuracy of several GPS devices and MSDs for heat and PM 2.5 in relation to reliable standard sensing devices as part of a PhD-project. The performance parameters are summary measures (mean value, standard deviation), correlation (Pearson r), difference measures (mean bias error, mean absolute error, index of agreement) and Bland-Altman plots. The MSDs have been tested in a climate chamber under constant temperature and relative humidity. For temperature MSDs reaction time was tested because of its relevance to detect temperature variations during mobile measurements. For interpretation of the results we considered the MSDs design and technology (e.g. passive vs. active ventilation). GPS-devices have been tested within low/high dense urban residential areas and low/high dense urban green areas

  1. The accuracy of the SenseWear Pro3 and the activPAL3 Micro devices for measurement of energy expenditure.

    Powell, Cormac; Carson, Brian P; Dowd, Kieran P; Donnelly, Alan E


    Activity monitors such as the SenseWear Pro3 (SWP3) and the activPAL3 Micro (aP(3)M) are regularly used by researchers and practitioners to provide estimates of the metabolic cost (METs) of activities in free-living settings. The purpose of this study is to examine the accuracy of the MET predictions from the SWP3 and the aP(3)M compared to the criterion standard MET values from indirect calorimetry. Fifty-six participants (mean age: 39.9 (±11.5), 25M/31F) performed eight activities (four daily living, three ambulatory and one cycling), while simultaneously wearing a SWP3, aP(3)M and the Cosmed K4B(2) (K4B(2)) mobile metabolic unit. Paired samples T-tests were used to examine differences between device predicted METs and criterion METs. Bland-Altman plots were constructed to examine the mean bias and limits of agreement for predicted METs compared to criterion METs. SWP3 predicted MET values were significantly different from the K4B(2) for each activity (p  ⩽  0.004), excluding sweeping (p  =  0.122). aP(3)M predicted MET values were significantly different (p  METs (SWP3), 0.95 METs (aP(3)M)). The greatest mean bias for the SWP3 was for cycling (-3.25 METs), with jogging (-5.16 METs) producing the greatest mean bias for the aP(3)M. All of the activities (excluding SWP3 sweeping) were significantly different from the criterion measure. Although the SWP3 predicted METs are more accurate than their aP(3)M equivalent, the predicted MET values from both devices are significantly different from the criterion measure for the majority of activities.

  2. Metal imaging on surface of micro- and nanoelectronic devices by laser ablation inductively coupled plasma mass spectrometry and possibility to measure at nanometer range.

    Zoriy, Myroslav V; Mayer, Dirk; Becker, J Sabine


    An analytical mass spectrometric method for the elemental analysis of nano-bioelectronic devices involved in bioengineering research was developed and applied for measurements of selected metals (Au, Ti, Pt, Cr, etc.) on interdigitated electrode array chips (IDA-chip). An imaging laser ablation inductively coupled plasma mass spectrometric (LA-ICP-MS) procedure was used to map the elements of interest on the surface of the analyzed sample. The obtained images of metals were in a good agreement and corresponded to the micro- and nanofabricated metal electrode pattern. For the analysis at nanometer resolution scale a NF-LA-ICP-MS (NF-near-field) procedure was applied, which utilize thin Ag needle to enhance laser beam energy and improve spatial resolution of the method. The results show a approximately 100x enhancement of analyte signal, when the needle was positioned in the "near-field region" to the sample surface and the laser shot was performed. In addition, mass spectrometric studies of reproducibly for five separated NF-LA shots in different places of analyzed sample yielded an RSD of the measurement of 16%.

  3. Sustainable Micro-Manufacturing of Micro-Components via Micro Electrical Discharge Machining

    Valeria Marrocco; Giacomo Copani; Irene Fassi; Francesco Modica


    Micro-manufacturing emerged in the last years as a new engineering area with the potential of increasing peoples’ quality of life through the production of innovative micro-devices to be used, for example, in the biomedical, micro-electronics or telecommunication sectors. The possibility to decrease the energy consumption makes the micro-manufacturing extremely appealing in terms of environmental protection. However, despite this common belief that the micro-scale implies a higher sustainabil...

  4. Lab-on-a-disc agglutination assay for protein detection by optomagnetic readout and optical imaging using nano- and micro-sized magnetic beads.

    Uddin, Rokon; Burger, Robert; Donolato, Marco; Fock, Jeppe; Creagh, Michael; Hansen, Mikkel Fougt; Boisen, Anja


    We present a biosensing platform for the detection of proteins based on agglutination of aptamer coated magnetic nano- or microbeads. The assay, from sample to answer, is integrated on an automated, low-cost microfluidic disc platform. This ensures fast and reliable results due to a minimum of manual steps involved. The detection of the target protein was achieved in two ways: (1) optomagnetic readout using magnetic nanobeads (MNBs); (2) optical imaging using magnetic microbeads (MMBs). The optomagnetic readout of agglutination is based on optical measurement of the dynamics of MNB aggregates whereas the imaging method is based on direct visualization and quantification of the average size of MMB aggregates. By enhancing magnetic particle agglutination via application of strong magnetic field pulses, we obtained identical limits of detection of 25pM with the same sample-to-answer time (15min 30s) using the two differently sized beads for the two detection methods. In both cases a sample volume of only 10µl is required. The demonstrated automation, low sample-to-answer time and portability of both detection instruments as well as integration of the assay on a low-cost disc are important steps for the implementation of these as portable tools in an out-of-lab setting.

  5. 多铁性纳米点结构及微纳器件应用%Multiferroic nanodot structures and their applications in micro/nano devices

    高兴森; 曾敏; 刘俊明


    在当前电子技术微型化和高度集成化的趋势下,多铁性纳米材料的研究正逐渐成为一个重要主题。这方面的研究还处在起步阶段,在材料的制备工艺和表征手段方面还面临诸多挑战。文章简要介绍了多铁性纳米点的制备工艺(包括离子刻蚀、自组构、多孔氧化铝模板方法等)和以多功能扫描探针为代表的表征手段,还介绍了纳米点带来的新颖的物理现象及其在微纳器件应用等方面的研究进展。%With the ever increasing development of miniaturization and integration technolo-gies in the microelectronics industry, nanoscale multiferroics have attracted more and more atten-tions. However, there are still several challenges hinter their applications, especially in nanoscale fabrication and characterization methods. We present a brief overview on the current progress in multiferroic nanodots, covering nano-patterning (including self-assembly, focused ion beam lithogra-phy, and anodic aluminium oxide template mask assisted deposition), nanoscale characterization techniques (in particular multifunctional scanning probe microscopy), novel physical properties in-volved in nanodots, as well as related multiferroic nano/micro-device applications.

  6. Colorimetric protein assay techniques.

    Sapan, C V; Lundblad, R L; Price, N C


    There has been an increase in the number of colorimetric assay techniques for the determination of protein concentration over the past 20 years. This has resulted in a perceived increase in sensitivity and accuracy with the advent of new techniques. The present review considers these advances with emphasis on the potential use of such technologies in the assay of biopharmaceuticals. The techniques reviewed include Coomassie Blue G-250 dye binding (the Bradford assay), the Lowry assay, the bicinchoninic acid assay and the biuret assay. It is shown that each assay has advantages and disadvantages relative to sensitivity, ease of performance, acceptance in the literature, accuracy and reproducibility/coefficient of variation/laboratory-to-laboratory variation. A comparison of the use of several assays with the same sample population is presented. It is suggested that the most critical issue in the use of a chromogenic protein assay for the characterization of a biopharmaceutical is the selection of a standard for the calibration of the assay; it is crucial that the standard be representative of the sample. If it is not possible to match the standard with the sample from the perspective of protein composition, then it is preferable to use an assay that is not sensitive to the composition of the protein such as a micro-Kjeldahl technique, quantitative amino acid analysis or the biuret assay. In a complex mixture it might be inappropriate to focus on a general method of protein determination and much more informative to use specific methods relating to the protein(s) of particular interest, using either specific assays or antibody-based methods. The key point is that whatever method is adopted as the 'gold standard' for a given protein, this method needs to be used routinely for calibration.

  7. Lab-on-a-disc agglutination assay for protein detection by optomagnetic readout and optical imaging using nano- and micro-sized magnetic beads

    Uddin, Rokon; Burger, Robert; Donolato, Marco;


    We present a biosensing platform for the detection of proteins based on agglutination of aptamer coated magnetic nano- or microbeads. The assay, from sample to answer, is integrated on an automated, low-cost microfluidic disc platform. This ensures fast and reliable results due to a minimum...... of manual steps involved. The detection of the target protein was achieved in two ways: (1) optomagnetic readout using magnetic nanobeads (MNBs); (2) optical imaging using magnetic microbeads (MMBs). The optomagnetic readout of agglutination is based on optical measurement of the dynamics of MNB aggregates...... whereas the imaging method is based on direct visualization and quantification of the average size of MMB aggregates. By enhancing magnetic particle agglutination via application of strong magnetic field pulses, we obtained identical limits of detection of 25 pM with the same sample-to-answer time (15 min...

  8. Two-stage cyclic enzymatic amplification method for ultrasensitive electrochemical assay of microRNA-21 in the blood serum of gastric cancer patients.

    Li, Bingchen; Liu, Fei; Peng, Yuanyuan; Zhou, Yunlei; Fan, Wenxuan; Yin, Huanshun; Ai, Shiyun; Zhang, Xiansheng


    MicroRNA (miRNA) is riveting nowadays due to its close relevance to human malignancies. Exploiting a fast and convenient biosensor for sensitive and specific detecting miRNA is necessary and it has significant meaning for oncology. In this work, to understand the relationship between miRNA-21 and gastric cancer, we employ T4 RNA ligase 2 to initiate specific ligation reaction depending on the sequence of target RNA, and T7 exonuclease to catalyze the first stage cyclic enzymatic amplification method (CEAM) specifically, which also resting on the target RNA sequence, and the second stage CEAM to further amplify the response resulting from the initial target RNA. Our two-stage CEAM strategy can detect miRNA-21 as low as 0.36fM with remarkable specificity, and most importantly, it can be used to inspect the expression level of miRNA-21 in blood serum of gastric cancer patients. This will offer new perspective for figuring out the pathways of miRNA-21 involving in cancer.

  9. Micro and Nanotechnologies Enhanced Biomolecular Sensing

    Tza-Huei Wang


    Full Text Available This editorial summarizes some of the recent advances of micro and nanotechnology-based tools and devices for biomolecular detection. These include the incorporation of nanomaterials into a sensor surface or directly interfacing with molecular probes to enhance target detection via more rapid and sensitive responses, and the use of self-assembled organic/inorganic nanocomposites that inhibit exceptional spectroscopic properties to enable facile homogenous assays with efficient binding kinetics. Discussions also include some insight into microfluidic principles behind the development of an integrated sample preparation and biosensor platform toward a miniaturized and fully functional system for point of care applications.

  10. Ultrasensitive, simple and solvent-free micro-assay for determining sulphite preservatives (E220-228) in foods by HS-SDME and UV-vis micro-spectrophotometry.

    Gómez-Otero, E; Costas, M; Lavilla, I; Bendicho, C


    A new method based on headspace single-drop microextraction in combination with UV-vis micro-spectrophotometry has been developed for the ultrasensitive determination of banned sulphite preservatives (E220-228) in fruits and vegetables. Sample acidification was used for SO2 generation, which is collected onto a 5,5'-dithiobis-(2-nitrobenzoic acid) microdrop for spectrophotometric measurement. A careful study of this reaction was necessary, including conditions for SO2 generation from different sulphating salts, drop pH, 5,5'-dithiobis-(2-nitrobenzoic acid) concentration and potential interference effects. Variables influencing mass transfer (stirring, sample volume and addition of salt) and microextraction time were also studied. A simple sulphite extraction was carried out, and problems caused by oxidation during the extraction process were addressed. A high enrichment factor (380) allows the determination of low levels of free SO2 in fruits and vegetables (limit of detection 0.06 μg g(-1), limit of quantification 0.2 μg g(-1)) with an adequate precision (repeatability, relative standard deviation 5 %). In addition, the sulphiting process was studied through the monitoring of residual SO2 in a vegetal sample, thus showing the importance of a sensitive tool for SO2 detection at low levels.

  11. Development of paper-based microfluidic analytical device for iron assay using photomask printed with 3D printer for fabrication of hydrophilic and hydrophobic zones on paper by photolithography.

    Asano, Hitoshi; Shiraishi, Yukihide


    This paper describes a paper-based microfluidic analytical device for iron assay using a photomask printed with a 3D printer for fabrication of hydrophilic and hydrophobic zones on the paper by photolithography. Several designed photomasks for patterning paper-based microfluidic analytical devices can be printed with a 3D printer easily, rapidly and inexpensively. A chromatography paper was impregnated with the octadecyltrichlorosilane n-hexane solution and hydrophobized. After the hydrophobic zone of the paper was exposed to the UV light through the photomask, the hydrophilic zone was generated. The smallest functional hydrophilic channel and hydrophobic barrier were ca. 500 μm and ca. 100 μm in width, respectively. The fabrication method has high stability, resolution and precision for hydrophilic channel and hydrophobic barrier. This test paper was applied to the analysis of iron in water samples using a colorimetry with phenanthroline. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. 数字微镜器件热设计计算与试验验证%Thermal Design, Calculation and Verification of Digital Micro-mirror Device

    王飞; 周连生; 方斌; 田伟; 张巍; 隋永新


    为保证数字微镜器件(DMD)的温度水平满足要求,采用计算和试验相结合的方法,对DMD热设计进行了研究。通过设计强迫液体冷却的散热方案,计算DMD各个测温点的温升,得出反射红、绿、蓝光的DMD最大温升分别为14.4℃、11.3℃、10.2℃,通过试验对热设计方案及计算结果进行了验证,试验结果与计算结果最大偏差不超过2.5℃,试验表明,所设计的热设计方案可靠,温升计算正确,为整机热设计和优化提供了理论依据。%To ensure a proper temperature rise of a Digital Micro-mirror Device (DMD), the thermal design of DMD was studied by calculation and experiment. A forced liquid-cooled thermal design was presented, and the temperature rise of each measurement point on DMD was calculated. Calculation results show that the maximum temperature rise of the DMD reflecting red light is 14.4℃, the maximum temperature rise of the DMD reflecting green light is 11.3℃, and the maximum temperature rise of the DMD reflecting blue light is 10.2℃, which have met the working temperature requirements. Thermal design and calculation are also verified through a thermal test and the maximum deviation between thermal calculation and thermal test are not exceeding 2.5℃. The thermal tests verify the reliability of thermal design and the correctness of thermal calculation, and supply a theoretical warrant for thermal design optimizing of DLP digital cinema projector.

  13. Miniaturized Aptamer-Based Assays for Protein Detection

    Alessandro Bosco


    Full Text Available The availability of devices for cancer biomarker detection at early stages of the disease is one of the most critical issues in biomedicine. Towards this goal, to increase the assay sensitivity, device miniaturization strategies empowered by the employment of high affinity protein binders constitute a valuable approach. In this work we propose two different surface-based miniaturized platforms for biomarker detection in body fluids: the first platform is an atomic force microscopy (AFM-based nanoarray, where AFM is used to generate functional nanoscale areas and to detect biorecognition through careful topographic measurements; the second platform consists of a miniaturized electrochemical cell to detect biomarkers through electrochemical impedance spectroscopy (EIS analysis. Both devices rely on robust and highly-specific protein binders as aptamers, and were tested for thrombin detection. An active layer of DNA-aptamer conjugates was immobilized via DNA directed immobilization on complementary single-stranded DNA self-assembled monolayers confined on a nano/micro area of a gold surface. Results obtained with these devices were compared with the output of surface plasmon resonance (SPR assays used as reference. We succeeded in capturing antigens in concentrations as low as a few nM. We put forward ideas to push the sensitivity further to the pM range, assuring low biosample volume (μL range assay conditions.

  14. A thermally self-sustained micro-power plant with integrated micro-solid oxide fuel cells, micro-reformer and functional micro-fluidic carrier

    Scherrer, B.; Evans, A.; Santis-Alvarez, A. J.; Jiang, B.; Martynczuk, J.; Galinski, H.; Nabavi, M.; Prestat, M.; Tölke, R.; Bieberle, A.; Poulikakos, D.; Muralt, P.; Niedermann, P.; Dommann, A.; Maeder, T.; Heeb, P.; Straessle, V.; Muller, C.; Gauckler, L. J.


    Low temperature micro-solid oxide fuel cell (micro-SOFC) systems are an attractive alternative power source for small-size portable electronic devices due to their high energy efficiency and density. Here, we report on a thermally self-sustainable reformer micro-SOFC assembly. The device consists of

  15. A thermally self-sustained micro-power plant with integrated micro-solid oxide fuel cells, micro-reformer and functional micro-fluidic carrier

    Scherrer, B.; Evans, A.; Santis-Alvarez, A. J.; Jiang, B.; Martynczuk, J.; Galinski, H.; Nabavi, M.; Prestat, M.; Tölke, R.; Bieberle, A.; Poulikakos, D.; Muralt, P.; Niedermann, P.; Dommann, A.; Maeder, T.; Heeb, P.; Straessle, V.; Muller, C.; Gauckler, L. J.


    Low temperature micro-solid oxide fuel cell (micro-SOFC) systems are an attractive alternative power source for small-size portable electronic devices due to their high energy efficiency and density. Here, we report on a thermally self-sustainable reformer micro-SOFC assembly. The device consists of

  16. 21 CFR 864.7525 - Heparin assay.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Heparin assay. 864.7525 Section 864.7525 Food and... HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7525 Heparin assay. (a) Identification. A heparin assay is a device used to determine the level of the anticoagulant heparin in the...

  17. MEMS and microfluidics for diagnostics devices.

    Rosen, Y; Gurman, P


    There are conditions in clinical medicine demanding critical therapeutic decisions. These conditions necessitate accuracy, rapidity, accessibility, cost-effectiveness and mobility. New technologies have been developed in order to address these challenges. Microfluidics and Micro Electro-Mechanical Systems are two of such technologies. Microfluidics, a discipline that involves processing fluids at the microscale in etched microchannels, is being used to build lab- on-a-chip systems to run chemical and biological assays. These systems are being transformed into handheld devices designed to be used at remote settings or at the bedside. MEMS are microscale electromechanical elements integrated in lab chip systems or used as individual components. MEMS based sensors represents a highly developed field with successful commercialized products currently being incorporated into vitro,ex vivo and in vivo devices. In the present paper several examples of microfluidic devices and MEMS sensors are introduced together with some current examples of commercialized products. Future challenges and trends will be discussed.

  18. 19. The HUman Micro Nucleus project. International Date Base Comparison for results with the cytokinesis-block micronucleus assay in human lymphocytes. Ⅰ. Effect of laboratory protocol, scoring criteria, and host factors on the frequency of micronuclei


    The first results of an analysis of pooled data from laboratories using the cytokinesis-block micronucleus assay in human lymphocytes and participating in the HUMN (HUman MicroNucleus project) international collaborative study are presented. The effects of laboratory protocol, scoring criteria, and host factors on baseline micronucleus(MN) frequency are evaluated, and a reference range of “normal” values against which future studies may be compared is provided. Primary data from historical records were submitted by 25 laboratories distributed in 16 countries. This resulted in a database of nearly 7000 subjects. Potentially significant differences were present in the methods used by participating laboratories, such as in the type of culture medium, the concentration of Cytochalasin-B, the percentage of fetal calf serum, and in the culture method. Differences in criteria for scoring MN were also evident. The overall median MN frequency in non-exposed(i.e., normal) subjects was 6.5‰ and the interquartile range was between 3‰ and 12‰. An increase in MN frequency with age was evident in all but two laboratories. The effect of gender, although not so evident in all databases, was also present, with females having a 19% higher level of MN (95% C.I.:14-24%). Statistical analyses were performed using random-effects models for correlated data. Our best model, which included exposure to genotoxic factors, host factors, methods, and scoring criteria, explained 75% of the total variance, with the largest contribution attributable to laboratory methods.

  19. Cytotoxicity and mitogenicity assays with real-time and label-free monitoring of human granulosa cells with an impedance-based signal processing technology intergrating micro-electronics and cell biology.

    Oktem, Ozgur; Bildik, Gamze; Senbabaoglu, Filiz; Lack, Nathan A; Akin, Nazli; Yakar, Feridun; Urman, Defne; Guzel, Yilmaz; Balaban, Basak; Iwase, Akira; Urman, Bulent


    A recently developed technology (xCelligence) integrating micro-electronics and cell biology allows real-time, uninterrupted and quantitative analysis of cell proliferation, viability and cytotoxicity by measuring the electrical impedance of the cell population in the wells without using any labeling agent. In this study we investigated if this system is a suitable model to analyze the effects of mitogenic (FSH) and cytotoxic (chemotherapy) agents with different toxicity profiles on human granulosa cells in comparison to conventional methods of assessing cell viability, DNA damage, apoptosis and steroidogenesis. The system generated the real-time growth curves of the cells, and determined their doubling times, mean cell indices and generated dose-response curves after exposure to cytotoxic and mitogenic stimuli. It accurately predicted the gonadotoxicity of the drugs and distinguished less toxic agents (5-FU and paclitaxel) from more toxic ones (cisplatin and cyclophosphamide). This platform can be a useful tool for specific end-point assays in reproductive toxicology. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Application of ATP bioluminescence assay in evaluating cleaning quality of medical devices%应用ATP生物荧光检测法评价医疗器械清洗质量

    李宝珍; 史婧; 李倩


    Objective To explore the application of adenosine triphosphate (ATP )bioluminescence assay in evaluating cleaning quality of medical devices.Methods Manual and machine cleaned medical devices were randomly selected from central sterile supply department of a hospital in 2011 -2013,cleaning quality was detected with ATP biolumi-nescence assay,relative light unit (RLU)value was determined to assess the cleaning quality.Results A total of 460 pieces of cleaned devices were detected in 2011 -2013,404 (87.83%)were qualified.The qualified rates of manual cleaning and machine cleaning were 70.73% and 94.07% respectively,the qualified rates of general surgical devices and lumen devices were 90.71 % and 81 .76% respectively,there were significant differences in qualified rates of different cleaning methods and different categories of medical devices (both P <0.01 ).The qualified rates of manual cleaning in 2011 - 2013 were 32.35%,79.63%,and 94.29% respectively,machine cleaning were 79.45%,98.15%,and 98.08% respectively;differences in qualified rates of manual cleaning and machine cleaning in different years were significant (all P <0.01 ).Conclusion ATP bioluminescence assay can be used for evalua-ting cleaning quality of medical devices.%目的:探讨 ATP 生物荧光检测法在检测医疗器械清洗效果中的应用。方法随机抽取某院2011—2013年消毒供应中心手工清洗和机械清洗后的医疗器械,采用 ATP 生物荧光检测技术进行检测,测定相对光单位值(RLU),评价器械清洗质量。结果2011—2013年共检测清洗后器械460件,404件合格,合格率为87.83%。清洗合格率:手工清洗、机械清洗分别为70.73%、94.07%,普通手术器械、管腔器械分别为90.71%、81.76%;不同清洗方式、不同器械类别的清洗合格率比较,差异均有统计学意义(均 P <0.01)。2011—2013年器械清洗合格率手工清洗分别为32.35%、79.63%、94

  1. Author development of training device for micro-basketball the «Clever ring» as mean of integral psychomotor development of children of 2-5 years old.

    Lakhno E.G.


    Full Text Available A technical device is developed for micro-basketball for integral development of children 1-5 years. In research took part 52 children of age-dependent group of 1-2 years, 56 children of 3-4 years, 56 children, 4-5 years. It is suggested to execute throws in a basket from different distance and under a different corner. Also to give up the balls of different color and size in accordance with a color and size of basket from the set initial position. It is marked that exercises with a ball develop an orientation in space, regulate force and exactness of throw, develop measurement with naked an eye, adroitness, speed of reaction; normalize a volitional sphere emotionally. It is set that application of methods with the use of technical device is instrumental in the increase of indexes of physical preparedness and psychophysiological possibilities of children.

  2. Microcontact printing-based fabrication of digital microfluidic devices.

    Watson, Michael W L; Abdelgawad, Mohamed; Ye, George; Yonson, Neal; Trottier, Justin; Wheeler, Aaron R


    Digital microfluidics is a fluid manipulation technique in which discrete droplets are actuated on patterned arrays of electrodes. Although there is great enthusiasm for the application of this technique to chemical and biological assays, development has been hindered by the requirement of clean room fabrication facilities. Here, we present a new fabrication scheme, relying on microcontact printing (microCP), an inexpensive technique that does not require clean room facilities. In microCP, an elastomeric poly(dimethylsiloxane) stamp is used to deposit patterns of self-assembled monolayers onto a substrate. We report three different microCP-based fabrication techniques: (1) selective etching of gold-on-glass substrates; (2) direct printing of a suspension of palladium colloids; and (3) indirect trapping of gold colloids from suspension. In method 1, etched gold electrodes are used for droplet actuation; in methods 2 and 3, colloid patterns are used to seed electroless deposition of copper. We demonstrate, for the first time, that digital microfluidic devices can be formed by microCP and are capable of the full range of digital microfluidics operations: dispensing, merging, motion, and splitting. Devices formed by the most robust of the new techniques were comparable in performance to devices formed by conventional methods, at a fraction of the fabrication time. These new techniques for digital microfluidics device fabrication have the potential to facilitate expansion of this technology to any research group, even those without access to conventional microfabrication tools and facilities.

  3. Fabrication of a microfluidic paper-based analytical device by silanization of filter cellulose using a paper mask for glucose assay.

    Cai, Longfei; Wang, Yong; Wu, Yunying; Xu, Chunxiu; Zhong, Minghua; Lai, Heyun; Huang, Junsheng


    We developed a novel, low-cost and simple method for the fabrication of microfluidic paper-based analytical devices (μPADs) by silanization of filter cellulose using a paper mask having a specific pattern. The paper mask was penetrated with trimethoxyoctadecylsilane (TMOS) by immersing into TMOS-heptane solution. By heating the filter paper sandwiched between the paper mask and glass slides, TMOS was immobilized onto the filter cellulose via the reaction between cellulose OH and TMOS, while the hydrophilic area was not silanized because it was not in contact with the paper mask penetrated with TMOS. The effects of some factors including TMOS concentration, heating temperature and time on the fabrication of μPADs were studied. This method is free of any expensive equipment and metal masks, and could be performed by untrained personnel. These features are very attractive for the fabrication and applications of μPADs in developing countries or resource-limited settings. A flower-shaped μPAD was fabricated and used to determine glucose in human serum samples. The contents determined by this method agreed well with those determined by a standard method.

  4. 谷氨酸脱羧酶抗体微量平板放射结合检测法的建立与初步应用%Micro-plate radiobinding assay of autoantibody to glutamic acid decarboxylase

    黄干; 金河来; 王霞; 李卉; 张松; 周智广


    Objective The purpose of this study was to develop a high-throughput micro-plate radiobinding assay (RBA) of glutamic acid decarboxylase antibody (GAD-Ab) and to evaluate its clinical application. Methods 35labeled GAD65 antigen was incubated with sera for 24 h on a 96-well plate, and then transferred to the Millipore plate coated with protein A, which was washed with 4℃ PBS buffer, and then counted by a liquid scintillation counter. The GAD-Ab results were expressed by WHO standard unit (U/ml). A total of 224 healthy controls, 162 patients with type 1 diabetes mellitus(T1DM) and 210 patients with newly diagnosed type 2 diabetes (T2DM) were recruited. A total of 119 TI DM and healthy cases with gradually changing GAD-Ab levels were selected to compare the consistency of micro-plate RBA with conventional radioligand assay (RLA). Blood samples were obtained from the peripheral vein and finger tip in 32 healthy controls, 35 T1DM and 24 T2DM patients, and tested with micro-plate RBA and then compared with the conventional RLA to investigate the reliability of finger tip sampling. Linear correlation,student's t-test, variance analysis and receiver operating characteristic (ROC) curve were performed using SPSS 11.5. Results (1) The optimized conditions of micro-plate RBA included 2 μl serum incubated with3 ×104 counts/min 35S-GAD for 24 h under slow vibration, antigen-antibody compounds washed 10 times by 4℃ PBS buffer, and radioactivity counted with Optiphase Supermix scintillation liquid. (2)The intra-batch CV of the micro-plate RBA was 3.8%- 10.2%, and the inter-batch CV was 5.6%- 11.9%. The linearity analysis showed a good correlation when the GAD-Ab in serum samples ranged from 40.3 to 664 U/ml and the detection limit of measurement was 3.6 U/ml. The results from Diabetes Autoantibody Standardization Program (DASP) 2005 showed that the sensitivity and specificity for GAD-Ab were 78% (39 positive among 50 new-onset T1DM) and 98% (2 positive among 100 healthy

  5. Magnetophoretic-based microfluidic device for DNA Concentration.

    Shim, Sangjo; Shim, Jiwook; Taylor, William R; Kosari, Farhad; Vasmatzis, George; Ahlquist, David A; Bashir, Rashid


    Nucleic acids serve as biomarkers of disease and it is highly desirable to develop approaches to extract small number of such genomic extracts from human bodily fluids. Magnetic particles-based nucleic acid extraction is widely used for concentration of small amount of samples and is followed by DNA amplification in specific assays. However, approaches to integrate such magnetic particles based capture with micro and nanofluidic based assays are still lacking. In this report, we demonstrate a magnetophoretic-based approach for target-specific DNA extraction and concentration within a microfluidic device. This device features a large chamber for reducing flow velocity and an array of μ-magnets for enhancing magnetic flux density. With this strategy, the device is able to collect up to 95 % of the magnetic particles from the fluidic flow and to concentrate these magnetic particles in a collection region. Then an enzymatic reaction is used to detach the DNA from the magnetic particles within the microfluidic device, making the DNA available for subsequent analysis. Concentrations of over 1000-fold for 90 bp dsDNA molecules is demonstrated. This strategy can bridge the gap between detection of low concentration analytes from clinical samples and a range of micro and nanofluidic sensors and devices including nanopores, nano-cantilevers, and nanowires.

  6. Micro energy harvesting

    Briand, Danick; Roundy, Shad


    With its inclusion of the fundamentals, systems and applications, this reference provides readers with the basics of micro energy conversion along with expert knowledge on system electronics and real-life microdevices. The authors address different aspects of energy harvesting at the micro scale with a focus on miniaturized and microfabricated devices. Along the way they provide an overview of the field by compiling knowledge on the design, materials development, device realization and aspects of system integration, covering emerging technologies, as well as applications in power management, e

  7. Micro Engineering

    Alting, Leo; Kimura, F.; Hansen, Hans Nørgaard


    The paper addresses the questions of how micro products are designed and how they are manufactured. Definitions of micro products and micro engineering are discussed and the presentation is aimed at describing typical issues, possibilities and tools regarding design of micro products. The implica......The paper addresses the questions of how micro products are designed and how they are manufactured. Definitions of micro products and micro engineering are discussed and the presentation is aimed at describing typical issues, possibilities and tools regarding design of micro products...

  8. Collaborative Exploration with a Micro Aerial Vehicle: A Novel Interaction Method for Controlling a MAV with a Hand-Held Device

    David Pitman


    Full Text Available In order to collaboratively explore an environment with a Micro Aerial Vehicle (MAV, an operator needs a mobile interface, which can support the operator’s divided attention. To this end, we developed the Micro Aerial Vehicle Exploration of an Unknown Environment (MAV-VUE interface, which allows operators with minimal training the ability to remotely explore their environment with a MAV. MAV-VUE employs a concept we term Perceived First-Order (PFO control, which allows an operator to effectively “fly” a MAV with no risk to the vehicle. PFO control utilizes a position feedback control loop to fly the MAV while presenting rate feedback to the operator. A usability study was conducted to evaluate MAV-VUE. This interface was connected remotely to an actual MAV to explore a GPS-simulated urban environment.

  9. Long term response of a Concanavalin-A based fluorescence glucose sensing assay

    Locke, Andrea K.; Cummins, Brian M.; Abraham, Alexander A.; Coté, Gerard L.


    Competitive binding assays comprised of the protein Concanavalin A (ConA) have shown potential for use in continuous glucose monitoring devices. However, its time-dependent, thermal instability can impact the lifetime of these ConA based assays. In an attempt to design sensors with longer in vivo lifetimes, different groups have immobilized the protein to various surfaces. For example, Ballerstadt et al. have shown that immobilizing ConA onto the interior of a micro-dialysis membrane and allowing dextran to be freely suspended within solution allowed for successful in vivo glucose sensing up to 16 days. This work explores the glucose response of an assay comprised of modified ConA and a single fluorescently labeled competing ligand in free solution to increase the in vivo sensing lifetime without immobilization,. The behavior of this assay in the presence of varying glucose concentrations is monitored via fluorescence anisotropy over a 30 day period.

  10. Enzyme assays.

    Reymond, Jean-Louis; Fluxà, Viviana S; Maillard, Noélie


    Enzyme assays are analytical tools to visualize enzyme activities. In recent years a large variety of enzyme assays have been developed to assist the discovery and optimization of industrial enzymes, in particular for "white biotechnology" where selective enzymes are used with great success for economically viable, mild and environmentally benign production processes. The present article highlights the aspects of fluorogenic and chromogenic substrates, sensors, and enzyme fingerprinting, which are our particular areas of interest.

  11. 21 CFR 864.7400 - Hemoglobin A2 assay.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hemoglobin A2 assay. 864.7400 Section 864.7400...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7400 Hemoglobin A2 assay. (a) Identification. A hemoglobin A2 assay is a device used to determine the hemoglobin A2...

  12. 21 CFR 866.3305 - Herpes simplex virus serological assays.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Herpes simplex virus serological assays. 866.3305... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3305 Herpes simplex virus serological assays. (a) Identification. Herpes simplex virus serological assays are devices...

  13. 21 CFR 864.7100 - Red blood cell enzyme assay.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Red blood cell enzyme assay. 864.7100 Section 864...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7100 Red blood cell enzyme assay. (a) Identification. Red blood cell enzyme assay is a device used to measure the activity...

  14. Micro Engineering

    Alting, Leo; Kimura, F.; Hansen, Hans Nørgaard


    The paper addresses the questions of how micro products are designed and how they are manufactured. Definitions of micro products and micro engineering are discussed and the presentation is aimed at describing typical issues, possibilities and tools regarding design of micro products. The implica...

  15. Optical plasma microelectronic devices

    Forati, Ebrahim; Dill, Thyler; Sievenpiper, Dan


    The semiconductor channel in conventional microelectronic devices was successfully replaced with an optically triggered gas plasma channel. The combination of DC and laser-induced gas ionizations controls the conductivity of the channel, enabling us to realize different electronic devices such as transistors, switches, modulators, etc. A special micro-scale metasurface was used to enhance the laser-gas interaction, as well as combining it with DC ionization properly. Optical plasma devices benefit form the advantages of plasma/vacuum electronic devices while preserving most of the integrablity of semiconductor based devices.

  16. Micro Injection Moulding of Polymeric Components

    Trotta, G.; Surace, R.; Modica, F.; Spina, R.; Fassi, I.


    Micro components and micro devices are strongly used in several fields: IT components, biomedical and medical products, automotive industry, telecommunication area and aerospace. A micro component is characterized by small dimensions of the product itself or small dimensions of the functional features. The development of new micro parts is highly dependent on manufacturing systems that can reliably and economically produce micro components in large quantities. In this context, micro-electrical discharge machining (EDM) for mould production and micro-injection moulding of polymer materials are the key technologies for micro manufacturing. This paper will focus on the production and quality evaluation of polymeric micro components manufactured by micro injection moulding. In particular the authors want to investigate the process parameters on the overall quality of the product. The factors affecting micro flow behavior, components weights and dimension definition are experimentally studied basing on DoE approach and then discussed.

  17. Against vaccine assay secrecy.

    Herder, Matthew; Hatchette, Todd F; Halperin, Scott A; Langley, Joanne M


    Increasing the transparency of the evidence base behind health interventions such as pharmaceuticals, biologics, and medical devices, has become a major point of critique, conflict, and policy focus in recent years. Yet the lack of publicly available information regarding the immunogenicity assays upon which many important, widely used vaccines are based has received no attention to date. In this paper we draw attention to this critical public health problem by reporting on our efforts to secure vaccine assay information in respect of 10 vaccines through Canada's access to information law. We argue, under Canadian law, that the public health interest in having access to the methods for these laboratory procedures should override claims by vaccine manufacturers and regulators that this information is proprietary; and, we call upon several actors to take steps to ensure greater transparency with respect to vaccine assays, including regulators, private firms, researchers, research institutions, research funders, and journal editors.

  18. Against vaccine assay secrecy

    Herder, Matthew; Hatchette, Todd F; Halperin, Scott A; Langley, Joanne M


    Increasing the transparency of the evidence base behind health interventions such as pharmaceuticals, biologics, and medical devices, has become a major point of critique, conflict, and policy focus in recent years. Yet the lack of publicly available information regarding the immunogenicity assays upon which many important, widely used vaccines are based has received no attention to date. In this paper we draw attention to this critical public health problem by reporting on our efforts to secure vaccine assay information in respect of 10 vaccines through Canada's access to information law. We argue, under Canadian law, that the public health interest in having access to the methods for these laboratory procedures should override claims by vaccine manufacturers and regulators that this information is proprietary; and, we call upon several actors to take steps to ensure greater transparency with respect to vaccine assays, including regulators, private firms, researchers, research institutions, research funders, and journal editors. PMID:25826194

  19. Modern Analytical Methods Applied to Earth and Planetary Sciences for Micro, Nano and Pico Space Devices and Robots in Landing Site Selection and Surface Investigation

    Vizi, P. G.; Bérczi, Sz.; Horváth, I.; Horváth, A. F.; Vizi, J. Cs.


    Fleet of Nano and Pico Sized Space Devices and Robots (NPSDR) are deployable to realize and accomplish in situ modern analytical methods in wide range of Earth and planetary sciences. Shorter time and bigger field of surfaces and volumes of space.

  20. Micro-Scale Thermoacoustics

    Offner, Avshalom; Ramon, Guy Z.


    Thermoacoustic phenomena - conversion of heat to acoustic oscillations - may be harnessed for construction of reliable, practically maintenance-free engines and heat pumps. Specifically, miniaturization of thermoacoustic devices holds great promise for cooling of micro-electronic components. However, as devices size is pushed down to micro-meter scale it is expected that non-negligible slip effects will exist at the solid-fluid interface. Accordingly, new theoretical models for thermoacoustic engines and heat pumps were derived, accounting for a slip boundary condition. These models are essential for the design process of micro-scale thermoacoustic devices that will operate under ultrasonic frequencies. Stability curves for engines - representing the onset of self-sustained oscillations - were calculated with both no-slip and slip boundary conditions, revealing improvement in the performance of engines with slip at the resonance frequency range applicable for micro-scale devices. Maximum achievable temperature differences curves for thermoacoustic heat pumps were calculated, revealing the negative effect of slip on the ability to pump heat up a temperature gradient. The authors acknowledge the support from the Nancy and Stephen Grand Technion Energy Program (GTEP).

  1. Micro scanning probes

    Niblock, T


    This thesis covers the design methodology, theory, modelling, fabrication and evaluation of a Micro-Scanning-Probe. The device is a thermally actuated bimorph quadrapod fabricated using Micro Electro Mechanical Systems technology. A quadrapod is a structure with four arms, in this case a planar structure with the four arms forming a cross which is dry etched out of a silicon diaphragm. Each arm has a layer of aluminium deposited on it forming a bimorph. Through heating each arm actuation is achieved in the plane of the quadrapod and the direction normal to it. Fabrication of the device has required the development of bulk micromachining techniques to handle post CMOS fabricated wafers and the patterning of thickly sputtered aluminium in bulk micro machined cavities. CMOS fabrication techniques were used to incorporate diodes onto the quadrapod arms for temperature measurement of the arms. Fine tungsten and silicon tips have also been fabricated to allow tunnelling between the tip and the platform at the centr...

  2. Performance of a quantum-dot external-cavity laser based on digital micro-mirror device%基于DMD的外腔量子点激光器性能研究

    成若海; 王海龙; 龚谦; 严进一; 汪洋; 柳庆博; 曹春芳; 岳丽


    In order to obtain more complete test data of quantum-dot external-cavity lasers,the InAs/InP quantum-dot external-cavity lasers using digital micro-mirror device (DMD) are successfully built up and their spectrum characteristics and the tuning range are measured.We also measure its tuning range and the corresponding change in the mode based on DMD quantum external cavity laser dots.The spectrum characteristics of InAs/InP quantum-dot external-cavity laser based on the grating and the DMD are compared theoretically and experimentally,and the differences between the reflection spectrum and angular dispersion are obtained.And a new method based on DMD will be applied to the external-cavity quantum-dot lasers.%为了取得更加完善的外腔量子点激光器(QDL)测试数据,构建了基于数字微镜器件(DMD,digital micro-mirror device)的InAs/InP量子点外腔QDL.测量了其光谱特性以及调谐范围,得到了基于DMD的外腔QDL调谐范围和相应的模式变化.在理论和实验上与基于光栅的外腔QDL性能进行了比较,得到了在角色散和反射光谱中与光栅的区别,实现了将DMD应用于外腔QDL中而获得的一种新方法.

  3. Effects of atmospheric neutrons on advanced micro-electronic devices, standards and applications; Effets des neutrons atmospheriques sur les dispositifs microelectroniques avances, normes et applications

    Leray, J.L. [CEA, 75 - Paris (France); Baggio, J.; Ferlet-Cavrois, V.; Flament, O. [CEA Bruyeres-le-Chatel, 91 (France)


    Since the 1980's, it is known that terrestrial cosmic rays, mainly reported as atmospheric neutrons, can penetrate the natural shielding of buildings, equipments and circuit package and induce soft errors in integrated circuits and breakdown of power devices. The high-energy neutron fluxes of interest, larger than 10 MeV, range between 10 particles/cm{sup 2}/hour at sea level and 10{sup 4} particles/cm{sup 2}/hour at typical airplanes flight altitude of 30000 feet, with modulation due to solar flares. In the 1990's, the phenomenon has pervaded as a consequence of the road-map of electronic devices especially the down-scaling of transistor dimensions, the increase of signal bandwidth and the increase of the size of DRAM and SRAM memory, stand-alone or embedded on processors and system-on-chips. Failure-in-time and soft error rate became unacceptable. Test standards and design solutions have been proposed to maintain reliability of commercial products and improve those used in special high-reliability equipments such as avionic computers. The paper describes the atmospheric neutron flux, the effects in the main classes of devices and specific cases such as neutron induced single event upset observed in CMOS vs. CMOS/SOI and some mitigation issues. In this paper, a model called CCPM (critical cross-point model) is proposed to provide critical graphs of technology node sensitivity along the scaling trend of CMOS. (authors)

  4. Phenomenology and system engineering of micro- and nano-antenna FPA sensors for detection of concealed weapons and improvised explosive devices

    Appleby, R.; Ferguson, S.


    The ability of millimetre wave and terahertz systems to penetrate clothing is well known. The fact that the transmission of clothing and the reflectivity of the body vary as a function of frequency is less so. Several instruments have now been developed to exploit this capability. The choice of operating frequency, however, has often been associated with the maturity and the cost of the enabling technology rather than a sound systems engineering approach. Top level user and systems requirements have been derived to inform the development of design concepts. Emerging micro and nano technology concepts have been reviewed and we have demonstrated how these can be evaluated against these requirements by simulation using OpenFx. Openfx is an open source suite of 3D tools for modeling, animation and visualization which has been modified for use at millimeter waves.

  5. Automated Micro Hall Effect measurements

    Petersen, Dirch Hjorth; Henrichsen, Henrik Hartmann; Lin, Rong


    With increasing complexity of processes and variety of materials used for semiconductor devices, stringent control of the electronic properties is becoming ever more relevant. Collinear micro four-point probe (M4PP) based measurement systems have become high-end metrology methods for characteriza......With increasing complexity of processes and variety of materials used for semiconductor devices, stringent control of the electronic properties is becoming ever more relevant. Collinear micro four-point probe (M4PP) based measurement systems have become high-end metrology methods...... for characterization and monitoring of sheet resistance as well as sheet carrier density and mobility via the Micro Hall Effect (MHE) method....

  6. Micro insert: a prototype full-ring PET device for improving the image resolution of a small-animal PET scanner.

    Wu, Heyu; Pal, Debashish; Song, Tae Yong; O'Sullivan, Joseph A; Tai, Yuan-Chuan


    A full-ring PET insert device should be able to enhance the image resolution of existing small-animal PET scanners. The device consists of 18 high-resolution PET detectors in a cylindric enclosure. Each detector contains a cerium-doped lutetium oxyorthosilicate array (12 x 12 crystals, 0.72 x 1.51 x 3.75 mm each) coupled to a position-sensitive photomultiplier tube via an optical fiber bundle made of 8 x 16 square multiclad fibers. Signals from the insert detectors are connected to the scanner through the electronics of the disabled first ring of detectors, which permits coincidence detection between the 2 systems. Energy resolution of a detector was measured using a (68)Ge point source, and a calibrated (68)Ge point source stepped across the axial field of view (FOV) provided the sensitivity profile of the system. A (22)Na point source imaged at different offsets from the center characterized the in-plane resolution of the insert system. Imaging was then performed with a Derenzo phantom filled with 19.5 MBq of (18)F-fluoride and imaged for 2 h; a 24.3-g mouse injected with 129.5 MBq of (18)F-fluoride and imaged in 5 bed positions at 3.5 h after injection; and a 22.8-g mouse injected with 14.3 MBq of (18)F-FDG and imaged for 2 h with electrocardiogram gating. The energy resolution of a typical detector module at 511 keV is 19.0% +/- 3.1%. The peak sensitivity of the system is approximately 2.67%. The image resolution of the system ranges from 1.0- to 1.8-mm full width at half maximum near the center of the FOV, depending on the type of coincidence events used for image reconstruction. Derenzo phantom and mouse bone images showed significant improvement in transaxial image resolution using the insert device. Mouse heart images demonstrated the gated imaging capability of the device. We have built a prototype full-ring insert device for a small-animal PET scanner to provide higher-resolution PET images within a reduced imaging FOV. Development of additional

  7. Micro-pattern gaseous detectors

    Shekhtman, L I


    Introduced at the end of 1980s micro-pattern gas detectors perform much better than classic wire chambers. They allow to achieve both excellent localization accuracy and high rate capability that make this technology attractive for charged particle tracking at high luminosity colliders. During its evolution micro-pattern gas technology gave raise to many different types of devices such as micro-strip gas chambers, MicroMEGAS, CAT and gas electron multipliers. Essential improvements in the performance of the detectors were achieved especially in what concerned long-term performance: aging and resistance to accidental discharges.

  8. Micro Flow-Through Thermocycler with Simple Meandering Channel with Symmetric Temperature Zones for Disposable PCR-Devices in Microscope Slide Format

    Anett Reichert; Jana Felbel; Mark Kielpinski; Matthias Urban; Benno Steinbrecht; Thomas Henkel


    Chip-based flow-through PCR implements the PCR as a continuous process for nucleic acid analytics. The sample is transported in a winding channel through temperature zones required for denaturation, annealing and extension. Main fields of application are the monitoring of continuous processes for rapid identification of contaminants and quality control as well as high throughput screening of cells or microorganisms. A modular arrangement with five heating zones for flow-through PCR is discussed and evaluated. The special heater arrangement allows the implementation of up to 40 cycles on the footprint of a microscope slide, which is placed on top ofa 5 zones heating plate. Liquid/liquid two phase flow of PCR reaction mixture and mineral oil have been applied to create a segmented flow process scheme. In that way, the developed system may provide flow-through PCR as a unit operation for the droplet based microfluidics platform. The single use of disposable devices is commonly preferred due to the sensitivity of the PCR process to contaminations. All-glass microfluidic chips and disposable chip devices, made from polycarbonate as a replication with identically geometry, have been fabricated and tested. For the fast time, microchannel geometries with nearly circular profile developed by all-glass technology have been transferred to mass fabrication by injection compression molding. Both devices have been successfully applied for the detection of the tumor suppressor gene p53. Although product yield and selectivity of the amplification process do not depend on the chip material, a well defmod, reliable segmented flow regime could only be realized in the all-glass chip.

  9. Towards an integrated device that utilizes adherent cells in a micro-free-flow electrophoresis chip to achieve separation and biosensing.

    Jezierski, Stefan; Klein, Anke S; Benz, Christian; Schaefer, Michael; Nagl, Stefan; Belder, Detlev


    We immobilized adherent human embryonic kidney (HEK) cells--which are able to trace adenosine triphosphate (ATP)--inside a microfluidic free-flow electrophoresis (μFFE) chip in order to develop an integrated device combining separation and biosensing capabilities. HEK 293 cells loaded with fluorescent calcium indicators were used as a model system to enable the spatially and temporally resolved detection of ATP. The local position of a 20 μM ATP stream was successfully visualized by these cells during free-flow electrophoresis, demonstrating the on-line detection capability of this technique towards native, unlabeled compounds.

  10. 微声聚能穿孔装置优化设计及IED安全销毁实验%Optimization design of micro-acoustic shaped charge device and research on its safe destruction of IED

    徐全军; 白帆; 李裕春; 龚自正; 张庆明


    Based on the Held initiation theory, and the fact that shaped charge jet against the charge can produce low velocity explosion, this paper presents a new design of micro-acoustic shaped charge device. The orthogonal analysis methods were applied to optimize the charge structure. The experiments indicate that the noise elimination ability and the anti-detonation ability of the device are fine. The simulator charge boxes were destroyed with low velocity detonation, which helps reduce the explosive harm and allows for destroying IED safely.%根据Held引爆理论,利用聚能射流使炸药只燃烧或发生不完全爆轰的特点,设计了微声聚能穿孔装置,并对装药结构进行了正交优化.实验结果表明,装置的消声能力良好,用于销毁模拟爆炸药盒时,装药仅发生低速爆轰,达到了安全销毁简易爆炸装置的目的.

  11. Evaluation of Brazilian medical devices using agar diffusion cytotoxicity assay Avaliação de dispositivos médicos brasileiros utilizando o ensaio de citotoxicidade pela difusão em ágar

    Mirian N. P. Vidal


    Full Text Available Over the last decades, governmental actions and mechanisms created to protect consumer rights have been linked to a growing effort to guarantee the quality and reliability of products. Samples of condoms (latex, medical devices and blood bags (PVC - polyvinyl chloride have been tested using the agar diffusion assay. This assay evaluates the cytotoxicity induced by biomaterials by measuring the biological reactivity of mammalian cell cultures in contact with these materials. PVC is used in the production of medical devices because of its specific properties, such as flexibility, obtained after the addition of plasticizers (phthalates, which can cause toxicity even at low doses. Latex is a natural elastomer used for surgical gloves and condoms with a formulation that includes dispersion of liquid latex and chemicals, such as antioxidants and a vulcanizing accelerator, both of which are able to induce cytotoxicity. Samples were analyzed by the National Institute of Quality Control in Health - INCQS of the Oswaldo Cruz Foundation (Fiocruz in accordance with the governmental sanitary surveillance actions on respect to the quality control. We observed an increase in the quality of the products in relation to the results of the agar diffusion assay during the period between 2000 and 2007. This situation, together with other actions, reflects in an improvement in the quality of products that can be translated in the health of the population.Durante as últimas décadas, a disseminação de ações governamentais e os mecanismos criados para proteger os direitos dos consumidores se associaram em crescentes esforços para garantir a qualidade e confiabilidade dos produtos. As amostras de preservativos (látex, dispositivos médicos e bolsas de sangue (PVC - cloreto polivinílico foram testadas utilizando o ensaio de difusão em ágar. O teste avalia a citotoxicidade induzida por biomateriais, medindo a reatividade biológica de culturas de células de mam

  12. Poly(N-isopropylacrylamide Hydrogels for Storage and Delivery of Reagents to Paper-Based Analytical Devices

    Haydn T. Mitchell


    Full Text Available The thermally responsive hydrogel N,N'-methylenebisacrylamide-cross-linked poly(N-isopropylacrylamide (PNIPAM was developed and evaluated as a reagent storage and delivery system for microfluidic paper-based analytical devices (microPADs. PNIPAM was shown to successfully deliver multiple solutions to microPADs in specific sequences or simultaneously in laminar-flow configuration and was found to be suitable for delivering four classes of reagents to the devices: Small molecules, enzymes, antibodies and DNA. PNIPAM was also able to successfully deliver a series of standard glucose solutions to microPADs equipped to perform a colorimetric glucose assay. The results of these tests were used to produce an external calibration curve, which in turn was used to determine the concentration of glucose in sample solutions. Finally, PNIPAM was used to store the enzyme horseradish peroxidase for 35 days under ambient conditions with no significant loss of activity. The combination of PNIPAM and microPADs may allow for more complex assays to be performed on paper-based devices, facilitate the preparation of external calibration curves in the field, and extend the shelf life of microPADs by stabilizing reagents in an easy-to-use format.

  13. Micro Vision

    Ohba, Kohtaro; OHARA, Kenichi


    In the field of the micro vision, there are few researches compared with macro environment. However, applying to the study result for macro computer vision technique, you can measure and observe the micro environment. Moreover, based on the effects of micro environment, it is possible to discovery the new theories and new techniques.

  14. Research on Process Compatibility and Device Characteristics of Photoelectric Micro-Power Supply Integrated On-Chip%片上集成光电微能源工艺兼容性及器件特性研究

    肖丽仙; 何永泰; 刘晋豪; 李雷


    根据暂存式光电微能源系统组成器件的制备工艺特点,提出了基于SOI晶片的光电微能源片上集成方案。主要工艺包括绝缘沟槽刻蚀、离子注入、氧化等,具有较好的制备工艺兼容性。另外,根据片上集成方案,对器件特性进行了研究。结果表明,光伏电池的转换效率为9.7%,NMOS管阈值电压、漏极反向击穿电压VT分别为0.98 V和31.97 V,NPN三极管的电流放大倍数、集电极-发射极之间击穿电压约为83 V和12 V。各器件特性满足系统工作要求,集成方案具有较好的可行性。%The on-chip integration scheme of photoelectric Micro-power supply based on SOI wafer is proposed through the analysis of the preparation process of component devices for temporary-storage photoelectric Micro-pow⁃er supply system. The main process includes insulation groove etching,ion implantation,and oxidation and so on. The scheme is of good preparation process compatibility. In addition,analysis of device characteristics is made based on on-chip integration scheme. Experimental results show that the conversion efficiency of photoelectric cell is 9.7%. The threshold voltage and reverse breakdown voltage of drain electrode of NMOS field-effect transistor is 0.98V and 31.97V,respectively. The current magnification of NPN transistor is 83 and breakdown voltage between emitter and collector is 12V. All integrated devices meet the system requirements. The integration scheme is of good feasibility.

  15. Working Principle and Application Analysis of A Micro-power Generation Device%一种微发电装置工作原理与应用分析



    Micro-power generation device referring in this paper is to operate organization by hands or feet, so as to cut the lines of magnetic force or change the coil magnetic flux to generate electricity. This device can change me-chanical kinetic energy into electrical energy. Its power in milliwatts can provide electricity for electronic products. Electronic products are able to be as a power source without battery, so as to avoid a series of problems of using the battery. This device has the advantages of strong reliability, lower cost, and friendly environment. This paper ana-lyzes the structure of the apparatus, the power generation principle, the selection principle, and the analysis of the ap-plication. In this paper, the application of analysis is only for intelligent electrical field. The micro-power generation technology is popular in the market due to its characteristics of environmental protection and energy-saving. Further-more, this paper will detail how to apply it and its specific application characteristics.%本文所指微发电装置是指通过手或脚来操作一个机构,从而切割磁力线或改变线圈磁通量发电,将机械动能转化为电能的一个装置,其发电功率在毫瓦级,其所发电可以为电子产品供电,电子产品则可以不需要采用电池作为电源,避免使用电池存在的一系列问题。该装置使用可靠性较强,节约用户成本,且使用环保。本文分析该装置的结构组成、发电原理、选材原则以及应用分析。本文应用分析仅限于智能电工领域,因该微发电技术具有环保,节能特点而受到市场热捧,如何应用以及他的具体应用特点,本文将详细叙述。

  16. Proposed improvements to a model for characterizing the electrical and thermal energy performance of stirling engine micro-cogeneration devices based upon experimental observations

    Lombardi, K. [CanmetENERGY, 1 Haanel Drive, Ottawa, Ont. (Canada); Ugursal, V.I. [Dalhousie University, Halifax, NS (Canada); Beausoleil-Morrison, I. [Carleton University, 1125 Colonel By Drive, Ottawa, Ont. (Canada)


    Stirling engines (SE) are a market-ready technology suitable for residential cogeneration of heat and electricity to alleviate the increasing demand on central power grids. Advantages of this external combustion engine include high cogeneration efficiency, fuel flexibility, low noise and vibration, and low emissions. To explore and assess the feasibility of using SE based cogeneration systems in the residential sector, there is a need for an accurate and practical simulation model that can be used to conduct sensitivity and what-if analyses. A simulation model for SE based residential scale micro-cogeneration systems was recently developed; however the model is impractical due to its functional form and data requirements. Furthermore, the available experimental data lack adequate diversity to assess the model's suitability. In this paper, first the existing model is briefly presented, followed by a review of the design and implementation of a series of experiments conducted to study the performance and behaviour of the SE system and to develop extensive, and hitherto unavailable, operational data. The empirical observations are contrasted with the functional form of the existing simulation model, and improvements to the structure of the model are proposed based upon these observations. (author)

  17. Slow-Wave Characteristics of a Frame-Rod Structure Based on Micro-Fabricated Technology for THz Vacuum Electron Devices

    Fu, Chengfang; Zhao, Bo; Yang, Yudong; Ju, Yongfeng; Yang, Dingli; Chang, Bo; He, Xiaofeng


    A simple equivalent circuit analysis of the frame-rod slow-wave structure (SWS) on dielectric substrates of a traveling-wave tube (TWT) is developed, using the quasi-TEM approximation approach for the dispersion and coupling impedance characteristics of the structure. Moreover, the obtained complex dispersion equation and coupling impedance are numerically calculated. The calculation results by our theory method agree well with the results obtained by the 3D EM simulation software HFSS. It is shown that the dispersion of the frame-rod circuit is decreased; the phase velocity is reduced and the bandwidth becomes greater, while the coupling impedance decreases after filling the dielectric materials in the frame-rod SWS. In addition, a comparison of slow-wave characteristics of this structure with a rectangular helix counterpart is made. As a planar slow-wave structure, this structure has potential applications in compact TWTs based on the micro-fabrication technology, which could be scaled to millimeter wave, even to THz frequency.

  18. Investigation of noise and contrast sensitivity of an electron multiplying charge-coupled device (EMCCD) based cone beam micro-CT system

    Bysani Krishnakumar, Sumukh; Podgorsak, Alexander R.; Setlur Nagesh, S. V.; Jain, Amit; Rudin, Stephen; Bednarek, Daniel R.; Ionita, Ciprian N.


    A small animal micro-CT system was built using an EMCCD detectors having complex pre-digitization amplification technology, high-resolution, high-sensitivity and low-noise. Noise in CBCT reconstructed images when using predigitization amplification behaves differently than commonly used detectors and warrants a detailed investigation. In this study, noise power and contrast sensitivity were estimated for the newly built system. Noise analysis was performed by scanning a water phantom. Tube voltage was lowered to minimum delivered by the tube (20 kVp and 0.5 mA) and detector gain was varied. Contrast sensitivity was analyzed by using a phantom containing different iodine contrast solutions (20% to 70%) filled in six different tubes. First, we scanned the phantom using various x-ray exposures at 40 kVp while changing the gain to maintain the background air value of the projection images constant. Next, the exposure was varied while the detector gain was maintained constant. Radial NPS plots show that noise power level increases as gain increases. Contrast sensitivity was analyzed by calculating ratio of signal-to-noise ratios (SNR) for increased gain with those of low constant gain at each exposure. The SNR value at low constant gain was always lower than SNR of high detector gain at all x-ray settings and iodine contrast. The largest increase of SNR approached 1.3 for low contrast feature for an iodine concentration of 20%. Despite an increase in noise level as gain increases, the SNR improvement shows that signal level also increases because of the unique on-chip gain of the detector.

  19. 医疗器械溶血性能三种评价方法的比较%Comparison of Three Evaluation Assays of Hemolytic Properties of Medical Devices

    乔春霞; 侯丽; 赵增琳; 王贤美; 范春光; 孙立魁; 于兆琴


    The preclinical safety evaluation of medical devices and materials that wil contact with blood often cal for a direct and/or indirect hemolysis test. This test is frequently performed using the NIH, ASTM and MHLW methods. The three hemolysis assays are wel -recognized tests used international y for routine evaluation of the hemolytic capacity of medical devices/materials. However, the data of the comparative studies that contrast the three methods are general y nonexistent. The hemolysis round robin study was designed by ISO/TC194 group, but the detailed draft protocol would be complete. This article introduced the principle, blood col ection, method and result of the three methods in detail and provided theoretical help for the round robin study.%  与血液接触的医疗器械和材料在临床前的安全性评价中经常要进行直接和/或间接溶血试验。目前使用频率较高的溶血试验方法主要有三种:NIH法、ASTM法和MHLW法。虽然三种方法在国际上常规评价医疗器械/材料溶血性能方面得到广泛认可,但是缺乏对三种方法进行比较研究的数据。目前ISO/TC 194工作组正在组织溶血Round robin(国际比对)试验,但是具体的试验草案还在完善当中。文章从原理、血源、方法和结果判定等方面对此三种方法进行了全面介绍,为Round robin试验提供理论方面的帮助。

  20. Study on Kerr effect-based micro-ring resonator dispersion-compensation devices%基于Kerr效应的微环谐振腔色散补偿器件

    高磊; 王涛


    This paper realizes optical delay and dispersion compensation by using the optical field relationship in micro-ring re-sonators and controls the phase shift changes in the micro-ring by using the Kerr effect.Furthermore,it gives the optimized parameters of the designed device,which can reach a dispersion compensation value of greater than -1 200 ps/nm when the jittering is smaller than ±8 ps and at the same time,the compensation bandwidth of all channels are higher than 20 GHz,sat-isfying the requirements of DWDM systems.The entire structure is small in power consumption (less than 1 .2 mW),fast in response,fully light controllable and small in volume and easy for integration.%利用微环谐振腔中的光场关系实现了光学延时与色散补偿,并利用了Kerr效应来控制微环内相移的改变。文章给出了所设计器件的经过优化后的参数,可以在抖动-1200 ps/nm的色散补偿数值,同时每个信道的色散补偿带宽均>20 GHz,满足DWDM(密集波分复用)系统的要求。整个结构的功耗较小,不超过1.2 mW,响应速度快,完全光控,体积小便于集成。

  1. Angiogenesis Assays.

    Nambiar, Dhanya K; Kujur, Praveen K; Singh, Rana P


    Neoangiogenesis constitutes one of the first steps of tumor progression beyond a critical size of tumor growth, which supplies a dormant mass of cancerous cells with the required nutrient supply and gaseous exchange through blood vessels essentially needed for their sustained and aggressive growth. In order to understand any biological process, it becomes imperative that we use models, which could mimic the actual biological system as closely as possible. Hence, finding the most appropriate model is always a vital part of any experimental design. Angiogenesis research has also been much affected due to lack of simple, reliable, and relevant models which could be easily quantitated. The angiogenesis models have been used extensively for studying the action of various molecules for agonist or antagonistic behaviour and associated mechanisms. Here, we have described two protocols or models which have been popularly utilized for studying angiogenic parameters. Rat aortic ring assay tends to bridge the gap between in vitro and in vivo models. The chorioallantoic membrane (CAM) assay is one of the most utilized in vivo model system for angiogenesis-related studies. The CAM is highly vascularized tissue of the avian embryo and serves as a good model to study the effects of various test compounds on neoangiogenesis.

  2. Micro/nanoscale continuous printing: direct-writing of wavy micro/nano structures via electrospinning

    Fang, Feiyu; Du, Zefeng; Zeng, Jun; Zhu, Ziming; Chen, Xin; Chen, Xindu; Lv, Yuanjun; Wang, Han


    Micro/nanofibers that are created by direct-writing using an electrospinning (ES) technique have aroused much recent attention, owing to their intriguing physical properties and great potential as building blocks for micro/nanoscale devices. In this work, a wavy direct-writing (WDW) process was developed to directly write wavy micro/nanostructures suitable for the fabrication of micro/nanoscale devices. The low voltage WDW technique is anticipated to be useful for a broad range of applications including flexible/stretchable electronics, micro optoelectronics, nano-antennas, microelectromechanical systems (MEMS), and biomedical engineering.

  3. 21 CFR 864.7500 - Whole blood hemoglobin assays.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Whole blood hemoglobin assays. 864.7500 Section... blood hemoglobin assays. (a) Identification. A whole blood hemoglobin assay is a device consisting or... hemoglobin content of whole blood for the detection of anemia. This generic device category does not...

  4. Tunable micro-optics

    Duppé, Claudia


    Presenting state-of-the-art research into the dynamic field of tunable micro-optics, this is the first book to provide a comprehensive survey covering a varied range of topics including novel materials, actuation concepts and new imaging systems in optics. Internationally renowned researchers present a diverse range of chapters on cutting-edge materials, devices and subsystems, including soft matter, artificial muscles, tunable lenses and apertures, photonic crystals, and complete tunable imagers. Special contributions also provide in-depth treatment of micro-optical characterisation, scanners, and the use of natural eye models as inspiration for new concepts in advanced optics. With applications extending from medical diagnosis to fibre telecommunications, Tunable Micro-optics equips readers with a solid understanding of the broader technical context through its interdisciplinary approach to the realisation of new types of optical systems. This is an essential resource for engineers in industry and academia,...

  5. Rapid light transmittance measurements in paper-based microfluidic devices

    Christina Swanson


    Full Text Available We developed methodology and built a portable reader to assess light transmittance in paper-based microfluidic devices in a highly sensitive, user-friendly and field-appropriate manner. By sandwiching the paper assay between micro-light-emitting diodes and micro-photodetectors, the reader quantifies light transmittance through the paper independent of ambient light conditions. To demonstrate the utility of the reader, we created a single-use paper-based microfluidic assay for measurement of alanine aminotransferase, an indicator of liver health in blood. The paper assay and reader system accurately differentiated alanine aminotransferase levels across the human reference range and demonstrated significant differences at clinically relevant cutoff values. Results were provided within 10 min and were automatically generated without complex image analysis. Performance of this point-of-care diagnostic rivals the accuracy of lab-based spectrometer tests at a fraction of the cost, while matching the timeliness of low-cost portable assays, which have historically shown lower accuracy. This combination of features allows flexible deployment of low cost and quantitative diagnostics to resource-poor settings.

  6. 微电子表面贴装关键技术与装备%The Key Technique and Equipment of Micro-electronic Device SMT

    张雍蓉; 刘昊


      In this paper,authors put forw ard that optional drag soldering process and dip soldering process can be finished w ithout special m old. A uthors affirm that by using m old shielded w ave soldering technique the m anufacture double-sided packaging forPC B can be achieved.The production efficiency w ill be significantly im proved and the preparing tim e for stick-up solder glue w ill be shortened.B y reducing production costs itw illm ake com patibility w ith traditionalw ave soldering.It can also be conclude that thru-hole reflow soldering process is benefit for im proving w elding quality and low ering process.A uthor m ake research on the direction of SM T printequipm entw hich tow ards dualtransferboard.The SM T equipm entbecom es faster,high-precision,m ore functions,intelligent, m ore cantilevers,m ore placem entheads and flexible connection.A nd the reflow device is on the w ay to m ulti-channelflow controlling,localforced cooling and tem perature m onitoring forcom ponents%  提出了选择性拖焊工艺,浸焊工艺,在无需制作专门的模具即可完成。确认了采用屏蔽模具波峰焊接工艺,实现双面混装PC B 波峰焊生产,大幅度提高双面混装PC B 生产效率,减少粘贴阻焊胶的准备时间,降低生产成本,达到与传统波峰焊接兼容以及通孔回流焊接工艺,对提升焊接质量、减少工艺流程的优势。研究了SM T 印刷设备的双路输送板发展方向、贴片设备的高速、高精密、多功能、智能化、多悬臂、多贴装头、柔性连接模块化发展方向、以及再流焊设备的多喷嘴气流控制、局部强制冷却、可监测元器件温度的发展方向。

  7. A microfluidic multiplex proteomic immunoassay device for translational research.

    Cao, Jing; Seegmiller, Jesse; Hanson, Naomi Q; Zaun, Christopher; Li, Danni


    Microfluidic technology has the potential to miniaturize and automate complex laboratory procedures. The objective of this study was to assess a microfluidic immunoassay device, Simple Plex, which simultaneously measured IL-1β, TNF-α, IL-6, and IL-10 in serum samples. This assessment is important to understanding the potentials of this microfluidic device as a valuable tool in translational research efforts. We studied the operational characteristics of Simple Plex, and compared to other immunoassay systems including bead-based (i.e., Bio-Plex(®) from Bio-Rad) and planar micro-spot based (i.e., Multi-Array from Meso Scale Discovery) multiplex assays. We determined imprecisions for each of the Simple Plex assays and evaluated the ability of Simple Plex to detect IL-1β, TNF-α, IL-6, and IL-10 in serum samples. Simple Plex assays required 25 µL serum, and 1.5 h to run 16 samples per cartridge per instrument. Assay imprecisions, evaluated by measurement of 6 replicates in duplicate from a serum pool using three different cartridges, were less than 10 % for all 4 cytokine protein biomarkers, comparable to the imprecisions of traditional ELISAs. The Simple Plex assays were able to detect 32, 95, 97, and 100 % [i.e., percentages of the results within the respective analytical measurement ranges (AMRs)] of IL-1β, TNF-α, IL-6, and IL-10, respectively, in 66 serum samples. Simple Plex is a microfluidic multiplex immunoassay device that offers miniaturized, and automated analysis of protein biomarkers. Microfluidic devices such as Simple Plex represent a promising platform to be used in translational research to measure protein biomarkers in real clinical samples.

  8. Fiscal 1999 achievement report on regional consortium research and development project. Regional consortium research field (Development of super-devices for medical equipment by 3-dimensional microstructure machining technology - 3rd year); 1999 nendo micro sanjigen kako gijutsu ni yoru iryo kikiyo super device no kaihatsu seika hokokusho (dai 3 nendo)



    In the development of micromechanisms, a highly efficient micromotor capable of outputting 25g/cm is developed, in which a DC motor, 4mm in diameter and 12.5mm in length, and a deceleration mechanism are combined. A technology is established of manufacturing microtubes 0.1mm in internal diameter of various materials for use with medical equipment. A direct cam screw type discharge mechanism for minute amounts is developed. It is now foreseen that a cartridge (air pressurized) discharge mechanism and a tube pump will be commercialized. A microjoint is developed with a built-in micro check valve for medicine flow channels. A microfilter is developed using a polypropylene hollow yarn membrane. A microsensor is developed, which responds to a 0.01-second change in flow rate at an error rate of {+-}3% or less. A microcomputer control system is test-produced. Newly developed devices are integrated for the test production of a portable device for sustained infusion of medicine, and the product is found to be superior to the existing systems. Also described are the utilization of various micromachining techniques. (NEDO)

  9. Nanocrystalline La1-xSrxCo1-yFe yO3 perovskites fabricated by the micro-emulsion route for high frequency response devices fabrications

    Azhar Khan, Muhammad


    Nanocrystalline La1-xSrxCo1-yFe yO3 (x=0.00-0.60) perovskites were fabricated by a cheap economic route (i.e. micro-emulsion method) and characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). TGA analysis showed ~35% weight loss. The crystallite size determined by XRD and SEM ranged from 30 to 80 nm and ~30 to 50 nm, respectively. The dielectric behavior was evaluated in the range of 1.0×106 Hz to 3.0×10 9 Hz at 298 K, the dielectric parameters resulting appreciably enhanced by co-doping with Sr and Fe. The maximum dielectric parameters (ε′=103.35, ε″=58.92 and tan δ=0.57) were observed for La0.4Sr0.6Co0.4Fe0.6O 3 at 15×106 Hz. Results suggest the potential use of these nanocrystalline perovskites in GHz-operated microwave devices. © 2014 Elsevier Ltd and Techna Group S.r.l.

  10. Real-time PCR based on SYBR-Green I fluorescence: An alternative to the TaqMan assay for a relative quantification of gene rearrangements, gene amplifications and micro gene deletions

    Puisieux Alain


    Full Text Available Abstract Background Real-time PCR is increasingly being adopted for RNA quantification and genetic analysis. At present the most popular real-time PCR assay is based on the hybridisation of a dual-labelled probe to the PCR product, and the development of a signal by loss of fluorescence quenching as PCR degrades the probe. Though this so-called 'TaqMan' approach has proved easy to optimise in practice, the dual-labelled probes are relatively expensive. Results We have designed a new assay based on SYBR-Green I binding that is quick, reliable, easily optimised and compares well with the published assay. Here we demonstrate its general applicability by measuring copy number in three different genetic contexts; the quantification of a gene rearrangement (T-cell receptor excision circles (TREC in peripheral blood mononuclear cells; the detection and quantification of GLI, MYC-C and MYC-N gene amplification in cell lines and cancer biopsies; and detection of deletions in the OPA1 gene in dominant optic atrophy. Conclusion Our assay has important clinical applications, providing accurate diagnostic results in less time, from less biopsy material and at less cost than assays currently employed such as FISH or Southern blotting.

  11. MicroRNA-126 inhibits the proliferation of lung cancer cell line A549

    Xun Yang; Bei-Bei Chen; Ming-Hua Zhang; Xin-Rong Wang


    Objective:To study the role of microRNA-126 in the development of lung cancer.Methods:The biological function of microRNA-126 was detected using EdU assay and CCK-8 assay;the target gene of microRNA-126 was analyzed using real time RT-PCR and Western blot assay.Results: In A549 cell line, overexpression of microRNA-126 inhibits the proliferation rate; VEGF is the target gene of microRNA-126; microRNA-126 exerts its function via regulating VEGF protein level.Conclusions: microRNA-126 inhibits the proliferation in A549 cell line.

  12. Micro Manufacturing

    Hansen, Hans Nørgaard


    . If a micro manufacturing system isn’t designed rationally and correctly, it will be high-cost, unreliable, and not robust. For micro products and systems it is a continuously increasing challenge to create the operational basis for an industrial production. As the products through product development...... processes are made applicable to a large number of customers, the pressure in regard to developing production technologies that make it possible to produce the products at a reasonable price and in large numbers is growing. The micro/nano manufacturing programme at the Department of Manufacturing...

  13. Design, fabrication and test of a pneumatically controlled, renewable, microfluidic bead trapping device for sequential injection analysis applications

    Shao, Guocheng; Lu, Donglai; Fu, Zhifeng; Du, Dan; Ozanich, Richard M.; Wang, Wanjun; Lin, Yuehe


    This paper describes the design, fabrication, and testing of a pneumatically controlled,renewable, microfluidic device for conducting bead-based assays in an automated sequential injection analysis system. The device used a “brick wall”-like pillar array (pillar size: 20 μm length X 50 μm width X 45 μm height) with 5 μm gaps between the pillars serving as the micro filter. The flow channel where bead trapping occurred is 500 μm wide X 75 μm deep. An elastomeric membrane and an air chamber were located underneath the flow channel. By applying pressure to the air chamber, the membrane is deformed and pushed upward against the filter structure. This effectively traps beads larger than 5 μm and creates a “bed” or micro column of beads that can be perfused and washed with liquid samples and reagents. Upon completion of the assay process, the pressure is released and the beads are flushed out from underneath the filter structure to renew the device. Mouse IgG was used as a model analyte to test the feasibility of using the proposed device for immunoassay applications. Resulting microbeads from an on-chip fluorescent immunoassay were individually examined using flow cytometry. The results show that the fluorescence signal intensity distribution is fairly narrow indicating high chemical reaction uniformity among the beads population. Electrochemical onchip assay was also conducted. A detection limit of 0.1 ng/mL1 ppb was achieved and good device reliability and repeatability were demonstrated. The novel microfluidic-based beadstrapping device thus opens up a new pathway to design micro-bead based biosensor immunoassays for clinical and othervarious applications.

  14. Integrated sample-to-detection chip for nucleic acid test assays.

    Prakash, R; Pabbaraju, K; Wong, S; Tellier, R; Kaler, K V I S


    Nucleic acid based diagnostic techniques are routinely used for the detection of infectious agents. Most of these assays rely on nucleic acid extraction platforms for the extraction and purification of nucleic acids and a separate real-time PCR platform for quantitative nucleic acid amplification tests (NATs). Several microfluidic lab on chip (LOC) technologies have been developed, where mechanical and chemical methods are used for the extraction and purification of nucleic acids. Microfluidic technologies have also been effectively utilized for chip based real-time PCR assays. However, there are few examples of microfluidic systems which have successfully integrated these two key processes. In this study, we have implemented an electro-actuation based LOC micro-device that leverages multi-frequency actuation of samples and reagents droplets for chip based nucleic acid extraction and real-time, reverse transcription (RT) PCR (qRT-PCR) amplification from clinical samples. Our prototype micro-device combines chemical lysis with electric field assisted isolation of nucleic acid in a four channel parallel processing scheme. Furthermore, a four channel parallel qRT-PCR amplification and detection assay is integrated to deliver the sample-to-detection NAT chip. The NAT chip combines dielectrophoresis and electrostatic/electrowetting actuation methods with resistive micro-heaters and temperature sensors to perform chip based integrated NATs. The two chip modules have been validated using different panels of clinical samples and their performance compared with standard platforms. This study has established that our integrated NAT chip system has a sensitivity and specificity comparable to that of the standard platforms while providing up to 10 fold reduction in sample/reagent volumes.

  15. Laser micro machining of medical devices.

    Rausch, Y


    Excimer and increasingly ultra-short-pulsed lasers are important tools in the creation of microstructures and nanostructures. Capabilities of the latest systems are described, which include drilling 30-microm diameter holes in 50 to 100 microm thick metal foils and subsurface engraving of transparent materials.

  16. A standalone perfusion platform for drug testing and target validation in micro-vessel networks.

    Zhang, Boyang; Peticone, Carlotta; Murthy, Shashi K; Radisic, Milica


    Studying the effects of pharmacological agents on human endothelium includes the routine use of cell monolayers cultivated in multi-well plates. This configuration fails to recapitulate the complex architecture of vascular networks in vivo and does not capture the relationship between shear stress (i.e. flow) experienced by the cells and dose of the applied pharmacological agents. Microfluidic platforms have been applied extensively to create vascular systems in vitro; however, they rely on bulky external hardware to operate, which hinders the wide application of microfluidic chips by non-microfluidic experts. Here, we have developed a standalone perfusion platform where multiple devices were perfused at a time with a single miniaturized peristaltic pump. Using the platform, multiple micro-vessel networks, that contained three levels of branching structures, were created by culturing endothelial cells within circular micro-channel networks mimicking the geometrical configuration of natural blood vessels. To demonstrate the feasibility of our platform for drug testing and validation assays, a drug induced nitric oxide assay was performed on the engineered micro-vessel network using a panel of vaso-active drugs (acetylcholine, phenylephrine, atorvastatin, and sildenafil), showing both flow and drug dose dependent responses. The interactive effects between flow and drug dose for sildenafil could not be captured by a simple straight rectangular channel coated with endothelial cells, but it was captured in a more physiological branching circular network. A monocyte adhesion assay was also demonstrated with and without stimulation by an inflammatory cytokine, tumor necrosis factor-α.

  17. 基于太阳能的微灌系统恒压供水自动控制装置研制%Constant pressure water supply automatic device designed for micro-irrigation system based on solar energy

    李加念; 洪添胜; 倪慧娜


      The stability of micro-irrigation system inlet water pressure affects the uniformity of the micro-irrigation and the mixed fertilizer accuracy of automatic fertilizer mixing device. In order to provide a constant inlet water pressure for small and medium-sized irrigation pipe network which adopts gravity drip irrigation, a constant pressure water supply automatic control device was developed, through employing a diaphragm pump DP-60 powered by solar energy to carry water to the reservoir built in high place, and maintaining the reservoir’ water level at a fixed height in the drip irrigation process. The water level was detected online by using a level sensor YZ-YO-LAG1, and the controller control DP-60 carrying water to the reservoir according to the water level detected. Due to the certain distance between reservoir water level detection terminal and DP-60 control terminal, two wireless communication modules CC1100 were installed in each terminal respectively to realize wireless data transmission and control between two terminals. To reduce power consumption of wireless communication, a regular communication strategy combining with sleeping mechanism was adopted, and a kind of time synchronization technology was employed to keep time synchronization between the communication parties, and the WOR (wake on radio) mode of CC1100 module was enabled while communicating, the communication success rate was 100%verified by practical test. Photovoltaic capacity of the system had been designed for obtaining an optimal capacity combination of solar cell array and lead-acid battery, and the solar panel power was determined to be 60 W and the battery capacity to be 60 A·h, the capacity combination could meet the electricity demand of 500L irrigation norm for each drip irrigation cycle, and ensure that the system operates normally in seven consecutive days without sunshine. In order to maximize the use of solar energy, the relationship between solar panel power and the

  18. Micro-Electro-Mechanical Systems

    Sarro, P.M.


    Micro-electro-mechanical systems (MEMS) or Microsystems technology (MST) is a fascinating and exciting field which significantly contributes to build a bridge between science and society. Physical properties and material characteristics are translated into structures and devices that can have a larg

  19. Micro-Electro-Mechanical Systems

    Sarro, P.M.


    Micro-electro-mechanical systems (MEMS) or Microsystems technology (MST) is a fascinating and exciting field which significantly contributes to build a bridge between science and society. Physical properties and material characteristics are translated into structures and devices that can have a

  20. Micro Manufacturing

    Hansen, Hans Nørgaard


    Manufacturing deals with systems that include products, processes, materials and production systems. These systems have functional requirements, constraints, design parameters and process variables. They must be decomposed in a systematic manner to achieve the best possible system performance....... If a micro manufacturing system isn’t designed rationally and correctly, it will be high-cost, unreliable, and not robust. For micro products and systems it is a continuously increasing challenge to create the operational basis for an industrial production. As the products through product development...... processes are made applicable to a large number of customers, the pressure in regard to developing production technologies that make it possible to produce the products at a reasonable price and in large numbers is growing. The micro/nano manufacturing programme at the Department of Manufacturing...

  1. Development of 3d micro-nano hybrid patterns using anodized aluminum and micro-indentation

    Shin, Hong Gue; Kwon, Jong Tae [Division of Mechanical Engineering and Mechatronics, Kangwon National University, 1 Kangwondaehakgil, Chunchon, Gangwon-do, 200-701 (Korea, Republic of); Seo, Young Ho [Division of Mechanical Engineering and Mechatronics, Kangwon National University, 1 Kangwondaehakgil, Chunchon, Gangwon-do, 200-701 (Korea, Republic of)], E-mail:; Kim, Byeong Hee [Division of Mechanical Engineering and Mechatronics, Kangwon National University, 1 Kangwondaehakgil, Chunchon, Gangwon-do, 200-701 (Korea, Republic of)


    We developed a simple and cost-effective method of fabricating 3D micro-nano hybrid patterns in which micro-indentation is applied on the anodized aluminum substrate. Nano-patterns were formed first on the aluminum substrate, and then micro-patterns were fabricated by deforming the nano-patterned aluminum substrate. Hemispherical nano-patterns with a 150 nm-diameter on an aluminum substrate were fabricated by anodizing and alumina removing process. Then, micro-pyramid patterns with a side-length of 50 {mu}m were formed on the nano-patterns using micro-indentation. To verify 3D micro-nano hybrid patterns, we replicated 3D micro-nano hybrid patterns by a hot-embossing process. 3D micro-nano hybrid patterns may be used in nano-photonic devices and nano-biochips applications.

  2. Development and Evaluation of Reverse Transcription-Loop-Mediated Isothermal Amplification (RT-LAMP) Assay Coupled with a Portable Device for Rapid Diagnosis of Ebola Virus Disease in Guinea.

    Kurosaki, Yohei; Magassouba, N'Faly; Oloniniyi, Olamide K; Cherif, Mahamoud S; Sakabe, Saori; Takada, Ayato; Hirayama, Kenji; Yasuda, Jiro


    Given the current absence of specific drugs or vaccines for Ebola virus disease (EVD), rapid, sensitive, and reliable diagnostic methods are required to stem the transmission chain of the disease. We have developed a rapid detection assay for Zaire ebolavirus based on reverse transcription-loop-mediated isothermal amplification (RT-LAMP) and coupled with a novel portable isothermal amplification and detection platform. The RT-LAMP assay is based on primer sets that target the untranscribed trailer region or nucleoprotein coding region of the viral RNA. The test could specifically detect viral RNAs of Central and West African Ebola virus strains within 15 minutes with no cross-reactivity to other hemorrhagic fever viruses and arboviruses, which cause febrile disease. The assay was evaluated using a total of 100 clinical specimens (serum, n = 44; oral swab, n = 56) collected from suspected EVD cases in Guinea. The specificity of this diagnostic test was 100% for both primer sets, while the sensitivity was 100% and 97.9% for the trailer and nucleoprotein primer sets, respectively, compared with a reference standard RT-PCR test. These observations suggest that our diagnostic assay is useful for identifying EVD cases, especially in the field or in settings with insufficient infrastructure.

  3. Sustainable Micro-Manufacturing of Micro-Components via Micro Electrical Discharge Machining

    Valeria Marrocco


    Full Text Available Micro-manufacturing emerged in the last years as a new engineering area with the potential of increasing peoples’ quality of life through the production of innovative micro-devices to be used, for example, in the biomedical, micro-electronics or telecommunication sectors. The possibility to decrease the energy consumption makes the micro-manufacturing extremely appealing in terms of environmental protection. However, despite this common belief that the micro-scale implies a higher sustainability compared to traditional manufacturing processes, recent research shows that some factors can make micro-manufacturing processes not as sustainable as expected. In particular, the use of rare raw materials and the need of higher purity of processes, to preserve product quality and manufacturing equipment, can be a source for additional environmental burden and process costs. Consequently, research is needed to optimize micro-manufacturing processes in order to guarantee the minimum consumption of raw materials, consumables and energy. In this paper, the experimental results obtained by the micro-electrical discharge machining (micro-EDM of micro-channels made on Ni–Cr–Mo steel is reported. The aim of such investigation is to shed a light on the relation and dependence between the material removal process, identified in the evaluation of material removal rate (MRR and tool wear ratio (TWR, and some of the most important technological parameters (i.e., open voltage, discharge current, pulse width and frequency, in order to experimentally quantify the material waste produced and optimize the technological process in order to decrease it.

  4. 21 CFR 864.7455 - Fetal hemoglobin assay.


    ... hemoglobin present. The assay may be used to detect fetal red cells in the maternal circulation or to detect... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fetal hemoglobin assay. 864.7455 Section 864.7455...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7455 Fetal...

  5. 数字微镜元件式自适应前照灯光学设计%Optical design of adaptive front lighting system based on digital micro mirror device

    武汉; 朱向冰; 朱骞; 陈春; 王程


    路面照明状况直接影响到汽车夜间行驶安全,自适应前照灯能根据汽车周围环境自动地调整照明模式,提高驾驶安全性.针对现有自适应前照灯照明模式不够灵活、光能利用率低等问题,提出了一种基于数字微镜元件的自适应前照灯光学方案,该方案以数字微镜元件为核心,并创新性地提出了利用第二导光管收集未利用的光能,采用光学软件Tracepro进行整个系统的仿真.实验结果表明:该方案能够实现自适应前照灯的多种照明模式,且通过使用第二导光管提高了光能利用率.由于可实现的照明模式多且照明灵活,能量利用率高,所以该系统具有广泛的市场前景.%The road safety of vehicles in night depends on the street illumination directly.Adaptive Front lighting System (AFS) can automatically provide different illumination modes by adjusting the shape,distance and light distribution of illumination according to the surrounding environment to improve the driving security.Considering the problems that less light efficiency of present AFS,one solution of AFS using Digital Micro mirror Device (DMD) was presented.It consists of lamp,reflector,light pipe,DMD and lens.DMD is the core of this system.And the second light pipe was used to collect the unused light energy.The experimental results show that the light efficiency is improved largely by the using of the second light pipe.And it can achieve different beams easily by accuracy controlling the luminance of every pixel on the screen.Because of its flexibility and higher light efficiency,this scheme is expected to show on market.

  6. Micro-machined calorimetric biosensors

    Doktycz, Mitchel J.; Britton, Jr., Charles L.; Smith, Stephen F.; Oden, Patrick I.; Bryan, William L.; Moore, James A.; Thundat, Thomas G.; Warmack, Robert J.


    A method and apparatus are provided for detecting and monitoring micro-volumetric enthalpic changes caused by molecular reactions. Micro-machining techniques are used to create very small thermally isolated masses incorporating temperature-sensitive circuitry. The thermally isolated masses are provided with a molecular layer or coating, and the temperature-sensitive circuitry provides an indication when the molecules of the coating are involved in an enthalpic reaction. The thermally isolated masses may be provided singly or in arrays and, in the latter case, the molecular coatings may differ to provide qualitative and/or quantitative assays of a substance.

  7. Motion Control of Micro-/Nanomotors.

    Teo, Wei Zhe; Pumera, Martin


    As we progress towards employing self-propelled micro-/nanomotors in envisioned applications such as cargo delivery, environmental remediation, and therapeutic treatments, precise control of the micro-/nanomotors direction and their speed is essential. In this Review, major emerging approaches utilized for the motion control of micro-/nanomotors have been discussed, together with the lastest publications describing these approaches. Future studies could incorporate investigations on micro-/nanomotors motion control in a real-world environment in which matrix complexity might disrupt successful manipulation of these small-scale devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. High precision laser forming for micro actuation

    Folkersma, Ger K.G.P.; Römer, G.R.B.E.; Brouwer, D.M.; Huis in 't Veld, A.J.; Nakata, Yoshiki; Xu, Xianfan; Roth, Stephan; Neuenschwander, Beat


    For assembly of micro-devices, such as photonic devices, the precision alignment of components is often critical for their performance. Laser forming, also known as laser-adjusting, can be used to create an integrated microactuator to align the components with sub-micron precision after bonding. In

  9. HistoFlex--a microfluidic device providing uniform flow conditions enabling highly sensitive, reproducible and quantitative in situ hybridizations.

    Søe, Martin Jensen; Okkels, Fridolin; Sabourin, David; Alberti, Massimo; Holmstrøm, Kim; Dufva, Martin


    A microfluidic device (the HistoFlex) designed to perform and monitor molecular biological assays under dynamic flow conditions on microscope slide-substrates, with special emphasis on analyzing histological tissue sections, is presented. Microscope slides were reversibly sealed onto a cast polydimethylsiloxane (PDMS) insert, patterned with distribution channels and reaction chambers. Topology optimization was used to design reaction chambers with uniform flow conditions. The HistoFlex provided uniform hybridization conditions, across the reaction chamber, as determined by hybridization to microscope slides of spotted DNA microarrays when applying probe concentrations generally used in in situ hybridization (ISH) assays. The HistoFlex's novel ability in online monitoring of an in situ hybridization assay was demonstrated using direct fluorescent detection of hybridization to 18S rRNA. Tissue sections were not visually damaged during assaying, which enabled adapting a complete ISH assay for detection of microRNAs (miRNA). The effects of flow based incubations on hybridization, antibody incubation and Tyramide Signal Amplification (TSA) steps were investigated upon adapting the ISH assay for performing in the HistoFlex. The hybridization step was significantly enhanced using flow based incubations due to improved hybridization efficiency. The HistoFlex device enabled a fast miRNA ISH assay (3 hours) which provided higher hybridization signal intensity compared to using conventional techniques (5 h 40 min). We further demonstrate that the improved hybridization efficiency using the HistoFlex permits more complex assays e.g. those comprising sequential hybridization and detection of two miRNAs to be performed with significantly increased sensitivity. The HistoFlex provides a new histological analysis platform that will allow multiple and sequential assays to be performed under their individual optimum assay conditions. Images can subsequently be recorded either in

  10. 21 CFR 866.2350 - Microbiological assay culture medium.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Microbiological assay culture medium. 866.2350... Microbiological assay culture medium. (a) Identification. A microbiological assay culture medium is a device that... organism in the innoculated medium. Test results aid in the diagnosis of disease resulting from either...

  11. 21 CFR 864.7470 - Glycosylated hemoglobin assay.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Glycosylated hemoglobin assay. 864.7470 Section... Glycosylated hemoglobin assay. (a) Identification. A glycosylated hemoglobin assay is a device used to measure the glycosylated hemoglobins (A1a, A1b, and A1c) in a patient's blood by a column...

  12. 21 CFR 864.7415 - Abnormal hemoglobin assay.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Abnormal hemoglobin assay. 864.7415 Section 864... hemoglobin assay. (a) Identification. An abnormal hemoglobin assay is a device consisting of the reagents... hemoglobin types. (b) Classification. Class II (performance standards)....

  13. Liquid chromatography-tandem mass spectrometric assay for aliskiren, a novel renin inhibitor in micro-volumes of human plasma: a pharmacokinetic application in healthy South Indian male subjects.

    Adireddy, Vinayender; Pilli, Nageswara Rao; Derangula, Venkata Ramu; Satla, Shobha Rani; Ganguri, Chinna Veera Badraiah; Ponneri, Venkateswarlu


    This paper describes a simple, rapid and sensitive liquid chromatography/tandem mass spectrometry assay for the determination of aliskiren in human plasma using nevirapine as an internal standard. Analyte and the internal standard were extracted from 100 μL of human plasma via liquid-liquid extraction using tert-butyl methyl ether. The chromatographic separation was achieved on a C18 column using a mixture of acetonitrile and 0.1% formic acid (90:10, v/v) as the mobile phase at a flow rate of 0.9 mL/min. The calibration curve obtained was linear (r(2) ≥ 0.99) over the concentration range of 0.10-1013 ng/mL. Method validation was performed as per US Food and Drug Administration guidelines and the results met the acceptance criteria. A run time of 2.2 min for each sample made it possible to analyze a greater number of samples in a short time, thus increasing the productivity. The proposed method was found to be applicable to clinical studies.

  14. Insertion devices

    Bahrdt, J


    The interaction of an insertion device with the electron beam in a storage ring is discussed. The radiation property including brightness, ux and polarization of an ideal and real planar and helical / elliptical device is described. The magnet design of planar, helical, quasiperiodic devices and of devices with a reduced on axis power density are resumed.

  15. 21 CFR 862.2170 - Micro chemistry analyzer for clinical use.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Micro chemistry analyzer for clinical use. 862... SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory Instruments § 862.2170 Micro chemistry analyzer for clinical use. (a) Identification. A micro...

  16. Integrated printed circuit board device for cell lysis and nucleic acid extraction.

    Marshall, Lewis A; Wu, Liang Li; Babikian, Sarkis; Bachman, Mark; Santiago, Juan G


    Preparation of raw, untreated biological samples remains a major challenge in microfluidics. We present a novel microfluidic device based on the integration of printed circuit boards and an isotachophoresis assay for sample preparation of nucleic acids from biological samples. The device has integrated resistive heaters and temperature sensors as well as a 70 μm × 300 μm × 3.7 cm microfluidic channel connecting two 15 μL reservoirs. We demonstrated this device by extracting pathogenic nucleic acids from 1 μL dispensed volume of whole blood spiked with Plasmodium falciparum. We dispensed whole blood directly onto an on-chip reservoir, and the system's integrated heaters simultaneously lysed and mixed the sample. We used isotachophoresis to extract the nucleic acids into a secondary buffer via isotachophoresis. We analyzed the convective mixing action with micro particle image velocimetry (micro-PIV) and verified the purity and amount of extracted nucleic acids using off-chip quantitative polymerase chain reaction (PCR). We achieved a clinically relevant limit of detection of 500 parasites per microliter. The system has no moving parts, and the process is potentially compatible with a wide range of on-chip hybridization or amplification assays.

  17. Fabrication and testing of novel blood separation devices based on microchannel bend structures

    Blattert, C.; Jurischka, R.; Schoth, A.; Kerth, P.; Menz, W.


    Most clinical chemistry tests are performed on cell-free serum or plasma. Therefore micro assay devices for blood tests require integrated on-chip microfluidics for separation of plasma or serum from blood. Polymers are ideally suited for these applications due to their material properties and their applicability for high volume production. These requirements are achieved by a new on-chip blood separation technique based on microchannel bend structures and a rapid processing technology for micro assay devices using injection molding or hot embossing. Different prototype polymer chips with channel dimensions down to 20 μm and aspect ratios of 4 have been fabricated by injection molding and hot embossing. The inserts for the molding tools were fabricated by an UV-LIGA technology. The separation efficiency of these chips has been tested with human blood samples. The results show different separation efficiencies up to 100 % for blood cells and plasma depending on microchannel geometry as well as cell concentration. As compared to present microfluidic devices for the separation of blood cells like filters, membranes or filtration by diffusion the microchannel bend is an integrated on-chip blood separation method. It combines the advantages of rapid separation times and a simple geometry that leads to cost-effective high volume production using injection molding.

  18. Micro Marketing

    Yu Yan


    In November the Chinese movie industry experienced a startling surprise.Love Is Not Blind,a low-budget movie with no prominent director or major star,hit 344.8million yuan ($54.5 million) in box office revenue,despite the film's budget was only 9 million yuan ($1.4 million).The film,which tells the 33-day experience of a girl named Huang Xiaoxian after she breaks up with her boyfriend,owes its unexpected blockbusting success to its innovative marketing strategy:micro-blog marketing.The number of followers of the official micro-blog for Love Is Not Blind hit nearly 100,000,attracted by rccommendations of related micro-blog messages,impressive box office lines,and positive word of mouth.By December 7,search queries for Love Is Not Blind had exceeded 8 million.Those for Wang Xiaojian,the lcading male,were close to 1.5 million.

  19. Applications of MEMS devices in nanosatellite

    You Zheng; Li Bin; Yu Shijie; Zhang Gaofei


    micro-electro-mechanical system (MEMS) device has the advantages of both electronic system and mechanical system. With the development of MEMS devices for satellite, it is possible to establish much lighter and smaller nanosatellites with higher performance and longer lifecyele. The power consumption of MEMS devices is usually much lower than that of traditional devices, which will greatly reduce the consumption of power. For its small size and simple architecture, MEMS devices can be easily integrated together and achieve redundancy. Launched on April 18, 2004, NS - 1 is a nanosatellite for science exploration and MEMS devices test. A mass of science data and images were acquired during its running. NS - 1 weights less than 25 kg. It consists of several MEMS devices, including one miniature inertial measurement unit(MIMU) , three micro complementary metal oxide semiconductor (CMOS)cameras, one sun sensor, three momentum wheels, and one micro magnetic sensor. By applying micro components based on MEMS technology, NS - 1 has made success in the experiments of integrative design, manufacture, and MEMS devices integration. In this paper, some MEMS devices for nanosatellite and picosatellite are introduced, which have been tested on NS -1 nanosatellite or on the ground.

  20. Toward the promise of microRNAs - Enhancing reproducibility and rigor in microRNA research.

    Witwer, Kenneth W; Halushka, Marc K


    The fields of applied and translational microRNA research have exploded in recent years as microRNAs have been implicated across a spectrum of diseases. MicroRNA biomarkers, microRNA therapeutics, microRNA regulation of cellular physiology and even xenomiRs have stimulated great interest, which have brought many researchers into the field. Despite many successes in determining general mechanisms of microRNA generation and function, the application of microRNAs in translational areas has not had as much success. It has been a challenge to localize microRNAs to a given cell type within tissues and assay them reliably. At supraphysiologic levels, microRNAs may regulate hosts of genes that are not the physiologic biochemical targets. Thus the applied and translational microRNA literature is filled with pitfalls and claims that are neither scientifically rigorous nor reproducible. This review is focused on increasing awareness of the challenges of working with microRNAs in translational research and recommends better practices in this area of discovery.

  1. Fabrication and characterisation of carbon-based devices


    Thin film material properties and measurement characterisation techniques are crucial for the development of micro-electromechanical systems (MEMS) devices. Furthermore, as the technology scales down from microtechnology towards nanotechnology, nanoscale materials such as carbon nanotubes (CNTs) are required in electronic devices to overcome the limitations encountered by conventional materials at the nanoscale. The integration of CNTs into micro-electronics and material app...

  2. Photovoltaic device

    Reese, Jason A; Keenihan, James R; Gaston, Ryan S; Kauffmann, Keith L; Langmaid, Joseph A; Lopez, Leonardo; Maak, Kevin D; Mills, Michael E; Ramesh, Narayan; Teli, Samar R


    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

  3. Photovoltaic device

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.


    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

  4. Concentration device


    A concentration device (2) for filter filtration concentration of particles (4) from a volume of a fluid (6). The concentration device (2) comprises a filter (8) configured to filter particles (4) of a predefined size in the volume of the fluid (6). The concentration device (2) comprises...

  5. Photovoltaic device

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.


    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device (10) with a multilayered photovoltaic cell assembly (100) and a body portion (200) joined at an interface region (410) and including an intermediate layer (500), at least one interconnecting structural member (1500), relieving feature (2500), unique component geometry, or any combination thereof.

  6. Low-cost thermoforming of micro fluidic analysis chips

    Truckenmüller, R.; Rummler, Z.; Schaller, Th; Schomburg, W. K.


    We present a new method for the low-cost manufacture of micro fluidic devices from polymers for single use. Within a one-step or two-step process inside a hot embossing press, micro channels are thermoformed into a thin plastic film and welded on to a thicker plastic film or sheet. Sterile, hermetically sealed micro fluidic structures were fabricated from polystyrene for easy opening immediately before use. It even appears to be possible to produce micro fluidic analysis chips from polymers on a coil from which single devices are cut off for use.

  7. Controllable Direct-Writing of Serpentine Micro/Nano Structures via Low Voltage Electrospinning

    Feiyu Fang; Xin Chen; Zefeng Du; Ziming Zhu; Xindu Chen; Han Wang; Peixuan Wu


    Micro/nanofibers prepared by direct-writing using an electrospinning (ES) technique have drawn more attention recently owing to their intriguing physical properties and great potential as building blocks for micro/nanoscale devices. In this work, a wavy direct-writing (WDW) process was developed to directly write serpentine micro/nano structures suitable for the fabrication of micro devices. This fabrication ability will realize the application of electrospun-nanofiber-based wiring of structu...

  8. Dose-response curve of a microfluidic magnetic bead-based surface coverage sandwich assay.

    Cornaglia, Matteo; Trouillon, Raphaël; Tekin, H Cumhur; Lehnert, Thomas; Gijs, Martin A M


    Magnetic micro- and nanoparticles ('magnetic beads') have been used to advantage in many microfluidic devices for sensitive antigen (Ag) detection. Today, assays that use as read-out of the signal the number count of immobilized beads on a surface for quantification of a sample's analyte concentration have been among the most sensitive and have allowed protein detection lower than the fgmL(-1) concentration range. Recently, we have proposed in this category a magnetic bead surface coverage assay (Tekin et al., 2013 [1]), in which 'large' (2.8μm) antibody (Ab)-functionalized magnetic beads captured their Ag from a serum and these Ag-carrying beads were subsequently exposed to a surface pattern of fixed 'small' (1.0μm) Ab-coated magnetic beads. When the system was exposed to a magnetic induction field, the magnet dipole attractive interactions between the two bead types were used as a handle to approach both bead surfaces and assist with Ag-Ab immunocomplex formation, while unspecific binding (in absence of an Ag) of a large bead was reduced by exploiting viscous drag flow. The dose-response curve of this type of assay had two remarkable features: (i) its ability to detect an output signal (i.e. bead number count) for very low Ag concentrations, and (ii) an output signal of the assay that was non-linear with respect to Ag concentration. We explain here the observed dose-response curves and show that the type of interactions and the concept of our assay are in favour of detecting the lowest analyte concentrations (where typically either zero or one Ag is carried per large bead), while higher concentrations are less efficiently detected. We propose a random walk process for the Ag-carrying bead over the magnetic landscape of small beads and this model description explains the enhanced overall capture probability of this assay and its particular non-linear dose response curves.

  9. Porous Microfluidic Devices - Fabrication adn Applications

    de Jong, J.; Geerken, M.J.; Lammertink, Rob G.H.; Wessling, Matthias


    The major part of microfluidic devices nowadays consists of a dense material that defines the fluidic structure. A generic fabrication method enabling the production of completely porous micro devices with user-defined channel networks is developed. The channel walls can be used as a (selective) bar

  10. Controllable Direct-Writing of Serpentine Micro/Nano Structures via Low Voltage Electrospinning

    Feiyu Fang


    Full Text Available Micro/nanofibers prepared by direct-writing using an electrospinning (ES technique have drawn more attention recently owing to their intriguing physical properties and great potential as building blocks for micro/nanoscale devices. In this work, a wavy direct-writing (WDW process was developed to directly write serpentine micro/nano structures suitable for the fabrication of micro devices. This fabrication ability will realize the application of electrospun-nanofiber-based wiring of structural and functional components in microelectronics, MEMS, sensor, and micro optoelectronics devices, and, especially, paves the way for the application of electrospinning in printing serpentine interconnector of large-area organic stretchable electronics.

  11. 试论微课在CAT教学中的应用:接口、原则与设计%Application of Micro-lecture in CAT Teaching:Interface, Principle and Device



    Micro-lecture is a new teaching method developed by scholars both abroad and at home. It takes into consideration the new features of education and teaching in the new social context by taking full advantage of developments in media technology, e-learning and online resources. Both the definition and the development of Micro-lecture highlight the significance of technology and resources in foreign language teaching. Based on cognitive psychology, Micro-lecture manifests itself in two aspects: fragmented learning and ubiquitous learning. These two features, combined with learning methods based on resources, become an effective interface between Micro-lecture and CAT.%微课是国内外学者针对教育教学的新时代特点,特别是媒体技术、网络学习和在线资源等不断发展的时代语境而提出的一种新的教学方法。微课的范畴界定与发展历史都突出了技术与资源在教学中特别是外语教学中的优势。基于认知心理学的依据,微课的设置突出了碎片化和泛在化学习的特点,因此与基于资源的学习方式成为微课与CAT课程的有效接口。

  12. Magnetic resonance propulsion, control and tracking at 24 Hz of an untethered device in the carotid artery of a living animal: an important step in the development of medical micro- and nanorobots.

    Martel, Sylvain


    Our recent demonstration of a ferromagnetic bead being navigated automatically inside the carotid artery of a living animal at an average speed of 10 cm/s using a clinical MRI system may be considered as a significant step in the field of medical micro- and nanorobotics. This is particularly true when we consider that an appropriate tracking method was embedded in the closed-loop control process allowing the blood vessels to be considered as navigational routes, providing maximum access for conducting operations inside the human body. But more importantly, this demonstration not only validates preliminary theoretical models but provides us with initial insights about the strategies and approaches that are likely to be used to navigate under computer control, micro- and nanodevices including nanorobots from the largest to the smallest diameter blood vessels that could be used to reach targets inside the human body. Here, based on these initial experimental data obtained in vivo, such strategies and methods are briefly described with some initial design concepts of medical interventional micro- and nanorobots.

  13. Surgical tools and medical devices

    Jackson, Mark


    This new edition presents information and knowledge on the field of biomedical devices and surgical tools. The authors look at the interactions between nanotechnology, nanomaterials, design, modeling, and tools for surgical and dental applications, as well as how nanostructured surfaces can be created for the purposes of improving cell adhesion between medical devices and the human body. Each original chapter is revised in this second edition and describes developments in coatings for heart valves, stents, hip and knee joints, cardiovascular devices, orthodontic applications, and regenerative materials such as bone substitutes. There are also 8 new chapters that address: Microvascular anastomoses Inhaler devices used for pulmonary delivery of medical aerosols Surface modification of interference screws Biomechanics of the mandible (a detailed case study) Safety and medical devices The synthesis of nanostructured material Delivery of anticancer molecules using carbon nanotubes Nano and micro coatings for medic...

  14. The study of double flank micro gear roll testing

    Liu, Yen-Chih; An, Nai-Chun; Yang, Shu-Han; Yan, Sheng-Zhan; Chen, Shih-Lu


    The recent fast development of multifunctional portable electronic devices results in the obvious requirement of micro mechanical components. Due to the popular application of the micro actuators and the micro gearboxes, micro gears become the frequently used micro mechanical component in a small device such as small intelligent robots or dental surgical devices. Metal Industries Research & Development Centre (MIRDC) has successfully developed a small speed reducer that comprises several micro planetary gear trains. The module of this micro planetary gear train is 0.12mm. Since all gears are small, no commercial instrument is available for inspection. How to evaluate the manufacturing quality of micro gears becomes an important issue. This study focuses on the double flank gear rolling test and a specialized apparatus is built referring to the testing requirements in the international standards. The center distance variation during the rolling test is recorded and two indices, the total radial composite deviation and the maximum tooth-to-tooth radial composite deviation, are calculated to evaluate the accuracy grade of the micro gears. Experimental results show that the accuracy of the micro gear made by the cold forging process conforms to grade 7 defined in the ISO 1328-2 while grade 2 is achieved if the JGMA 116-02 is specified.

  15. Microbead agglutination based assays

    Kodzius, Rimantas


    We report a simple and rapid room temperature assay for point-of-care (POC) testing that is based on specific agglutination. Agglutination tests are based on aggregation of microbeads in the presence of a specific analyte thus enabling the macroscopic observation. Such tests are most often used to explore antibody-antigen reactions. Agglutination has been used for protein assays using a biotin/streptavidin system as well as a hybridization based assay. The agglutination systems are prone to selftermination of the linking analyte, prone to active site saturation and loss of agglomeration at high analyte concentrations. We investigated the molecular target/ligand interaction, explaining the common agglutination problems related to analyte self-termination, linkage of the analyte to the same bead instead of different microbeads. We classified the agglutination process into three kinds of assays: a two- component assay, a three-component assay and a stepped three- component assay. Although we compared these three kinds of assays for recognizing DNA and protein molecules, the assay can be used for virtually any molecule, including ions and metabolites. In total, the optimized assay permits detecting analytes with high sensitivity in a short time, 5 min, at room temperature. Such a system is appropriate for POC testing.

  16. Microfluidic Device

    Tai, Yu-Chong (Inventor); Zheng, Siyang (Inventor); Lin, Jeffrey Chun-Hui (Inventor); Kasdan, Harvey L. (Inventor)


    Described herein are particular embodiments relating to a microfluidic device that may be utilized for cell sensing, counting, and/or sorting. Particular aspects relate to a microfabricated device that is capable of differentiating single cell types from dense cell populations. One particular embodiment relates a device and methods of using the same for sensing, counting, and/or sorting leukocytes from whole, undiluted blood samples.

  17. 3-D interactive physically based micro world

    Waters, Keith; Wang, SerKuang


    This paper describes an approach to synthetic three-dimensional object manipulation using three different haptic I/O devices in a virtual workspace on a graphics superworkstation. The devices involve the operator in unique mode8 of interaction that require positioning a six degree-of-freedom sensor, applying torques to a static ball, or creating interpreted hand ge8tures. With these devices, the user can select, rotate and deposit synthetic virtual objects in the micro world. The micro world is an "artificial reality" in which elementary physical forces of gravity, volume preservation, collision, and external user input may be applied. The techniques developed overcome some of the difficulties experienced with two-dimensional input devices in a three-dimensional space. Furthermore, the ability of the user to continuous modify physical constraints while observing the results in real-time facilitates data interpretation tasks.

  18. Micro club

    Micro club


    Opération NEMO   Pour finir en beauté les activités spéciales que le CMC a réalisé pendant cette année 2014, pour commémorer le 60ème anniversaire du CERN, et le 30ème du Micro Club, l’ Opération NEMO aura cette année un caractère très particulier. Nous allons proposer 6 fabricants de premier ordre qui offriront chacun deux ou trois produits à des prix exceptionnels. L’opération débute le lundi 17 novembre 2014. Elle se poursuivra  jusqu’au samedi 6 décembre inclus. Les délais de livraison seront de deux à trois semaines, selon les fabricants. Donc les commandes faites la dernière semaine, du 1 au 6 décembre, risquent d’arriver qu'au début du mois de janvier 2015. Liste de fabricants part...

  19. Micro club

    Micro Club


    Jeudi 18 septembre 2014 à 18h30 au Bât. 567 R-029 Le CERN MICRO CLUB organise un Atelier sur la sécurité informatique. La Cyber-sécurité : Ce qui se passe vraiment, comment ne pas en être victime ! Orateur : Sebastian Lopienski Adjoint au Computer Security Officer du Département IT. Sujet : Cet exposé vous présentera les modes de sécurité actuels et les problèmes touchants les applications logicielles des ordinateurs, les réseaux ainsi que leurs utilisateurs. Cela inclus des informations sur les nouveaux types de vulnérabilité, les vecteurs d'attaque récents et une vue d'ensemble sur le monde de la cyber-sécurité en 2014. Biographie : Sebastian Lopienski travaille au CERN depuis 2001. Il est actuellement adjoint au Computer Security Officer et s'occupe de la protection de...

  20. Absolute nuclear material assay

    Prasad, Manoj K [Pleasanton, CA; Snyderman, Neal J [Berkeley, CA; Rowland, Mark S [Alamo, CA


    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  1. 21 CFR 866.3310 - Hepatitis A virus (HAV) serological assays.


    ... Hepatitis A virus (HAV) serological assays. (a) Identification. HAV serological assays are devices that... tissue donors. (b) Classification. Class II (special controls). The special control is “Guidance...

  2. Validation of the MicroSnap Coliform and E. coli test system for enumeration and detection of coliforms and E. coli in a variety of foods. Performance Tested Method 071302.

    Meighan, Paul


    The MicroSnap Coliform and E. coli system was devised to give rapid enumeration and detection of coliforms and/or Escherichia coli strains in a sample of food within an 8 h working shift. The method measures beta-galactosidase and beta-glucuronidase enzymes using novel bioluminogenic substrates which develop an output light signal proportional to the concentration of enzyme discovered. The assay uses two different phases to determine the enzyme concentration. The first phase is an enrichment of the sample in a nutrient-rich broth device at 37 +/- 0.5 degrees C. After 6 or 8 h, an aliquot is taken from the enrichment device and injected into the Coliform Detection Device, which is assayed in a luminometer after 10 min of incubation at 37 +/- 0.5 degrees C. Samples testing positive in the Coliform Detection Device can be subsequently assayed specifically for E. coli using the E. coli Detection Device. The relative light unit output from the detection device is proportional to the bacterial concentration when the incubation was initiated, which is proportional to the contamination level in the matrix being assessed. The MicroSnap Coliform and E. coli system was evaluated for both quantitative and qualitative analysis of coliforms and E. coli in a variety of foods. Three different luminometers were used in the analysis, each of which has different functionalities and different sensitivities. The MicroSnap method showed good correlation with the appropriate corresponding reference method for enumeration of coliforms and E. coli. A statistically significant difference was seen in detection of E. coli in milk, as reported by the independent laboratory. The reference method reported higher mean Log10 CFU counts than the MicroSnap method; however, no significant differences were seen between the MicroSnap system and reference methods for any of the other matrixes. Inclusivity testing was conducted on 25 different non-E. coli coliforms and 25 different E. coli strains, and

  3. Modulation of microRNA activity by semi-microRNAs (smiRNAs

    Isabelle ePlante


    Full Text Available The ribonuclease Dicer plays a central role in the microRNA pathway by catalyzing the formation of 19 to 24-nucleotide (nt long microRNAs. Subsequently incorporated into Ago2 effector complexes, microRNAs are known to regulate messenger RNA (mRNA translation. Whether shorter RNA species derived from microRNAs exist and play a role in mRNA regulation remains unknown. Here, we report the serendipitous discovery of a 12-nt long RNA species corresponding to the 5’ region of the microRNA let-7, and tentatively termed semi-microRNA, or smiRNA. Using a smiRNA derived from the precursor of miR-223 as a model, we show that 12-nt long smiRNA species are devoid of any direct mRNA regulatory activity, as assessed in a reporter gene activity assay in transfected cultured human cells. However, smiR-223 was found to modulate the ability of the microRNA from which it derives to mediate translational repression or cleavage of reporter mRNAs. Our findings suggest that smiRNAs may be generated along the microRNA pathway and participate to the control of gene expression by regulating the activity of the related full-length mature microRNA in vivo.

  4. Micro-and nano-structured conducting polymeric materials

    LU Gewu; CHEN Feng'en; WU Xufeng; QU Liangti; ZHANG Jiaxin; SHI Gaoquan


    Conducting polymeric materials with micro-/nano-structures have potential applications in fabrication of various optical, electronic, sensing and electrochemical devices. This is mainly because these materials not only possess the characteristics of conducting polymers, but also have special functions based on their micro- or nano-structures. In this review, we summarize the recent work on "soft" and "hard" template-guided syntheses of micro-/nano-structured conducting polymers and open up the prospects of the main trends in this field.

  5. Injection molding tools with micro/nano-meter pattern


    The present invention relates to methods for embedded a micrometer and/or nanometer pattern into an injection molding tool. In a first main aspect, a micro/nanometer structured imprinting device is applied in, or on, an active surface so as to transfer the micro/nanometer patterned structure to t...

  6. Electrokinetic Particle Transport in Micro-Nanofluidics Direct Numerical Simulation Analysis

    Qian, Shizhi


    Numerous applications of micro-/nanofluidics are related to particle transport in micro-/nanoscale channels, and electrokinetics has proved to be one of the most promising tools to manipulate particles in micro/nanofluidics. Therefore, a comprehensive understanding of electrokinetic particle transport in micro-/nanoscale channels is crucial to the development of micro/nano-fluidic devices. Electrokinetic Particle Transport in Micro-/Nanofluidics: Direct Numerical Simulation Analysis provides a fundamental understanding of electrokinetic particle transport in micro-/nanofluidics involving elect

  7. The repertoire and features of human platelet microRNAs.

    Hélène Plé

    Full Text Available Playing a central role in the maintenance of hemostasis as well as in thrombotic disorders, platelets contain a relatively diverse messenger RNA (mRNA transcriptome as well as functional mRNA-regulatory microRNAs, suggesting that platelet mRNAs may be regulated by microRNAs. Here, we elucidated the complete repertoire and features of human platelet microRNAs by high-throughput sequencing. More than 492 different mature microRNAs were detected in human platelets, whereas the list of known human microRNAs was expanded further by the discovery of 40 novel microRNA sequences. As in nucleated cells, platelet microRNAs bear signs of post-transcriptional modifications, mainly terminal adenylation and uridylation. In vitro enzymatic assays demonstrated the ability of human platelets to uridylate microRNAs, which correlated with the presence of the uridyltransferase enzyme TUT4. We also detected numerous microRNA isoforms (isomiRs resulting from imprecise Drosha and/or Dicer processing, in some cases more frequently than the reference microRNA sequence, including 5' shifted isomiRs with redirected mRNA targeting abilities. This study unveils the existence of a relatively diverse and complex microRNA repertoire in human platelets, and represents a mandatory step towards elucidating the intraplatelet and extraplatelet role, function and importance of platelet microRNAs.

  8. Micro sphere with nanoporosity by electrospinning

    He Jihuan [College of Science, Donghua University, 1882 Yan' an Xilu Road, Shanghai 200051 (China) and Modern Textile Institute, Donghua University, Shanghai (China)]. E-mail:; Liu Yong [College of Textile, Donghua University, Shanghai (China); Xu Lan [College of Science, Donghua University, 1882 Yan' an Xilu Road, Shanghai 200051 (China) and Modern Textile Institute, Donghua University, Shanghai (China); Yu Jianyong [Modern Textile Institute, Donghua University, Shanghai (China); College of Textile, Donghua University, Shanghai (China)


    Nanoporous structures are potentially of great technological interest for the development of electronic, catalytic and hydrogen-storage systems, invisibility device (e.g. stealth plane) and others. Here we describe a general strategy for the synthesis of micro sphere with nanoporosity by electrospinning, the porous sizes having uniform but tunable diameters can be controlled by voltage applied in the electrospinning process.

  9. Stretchable Micro-Electrode Array

    Maghribi, M; Hamilton, J; Polla, D; Rose, K; Wilson, T; Krulevitch, P


    This paper focuses on the design consideration, fabrication processes and preliminary testing of the stretchable micro-electrode array. We are developing an implantable, stretchable micro-electrode array using polymer-based microfabrication techniques. The device will serve as the interface between an electronic imaging system and the human eye, directly stimulating retinal neurons via thin film conducting traces and electroplated electrodes. The metal features are embedded within a thin ({approx}50 micron) substrate fabricated using poly (dimethylsiloxane) (PDMS), a biocompatible elastomeric material that has very low water permeability. The conformable nature of PDMS is critical for ensuring uniform contact with the curved surface of the retina. To fabricate the device, we developed unique processes for metalizing PDMS to produce robust traces capable of maintaining conductivity when stretched (5%, SD 1.5), and for selectively passivating the conductive elements. An in situ measurement of residual strain in the PDMS during curing reveals a tensile strain of 10%, explaining the stretchable nature of the thin metalized devices.

  10. Injection moulding for macro and micro products

    Islam, Mohammad Aminul

    The purpose of the literature survey is to investigate the injection moulding technology in the macro and micro areas from the basic to the state-of-the-art recent technology. Injection moulding is a versatile production process for the manufacturing of plastic parts and the process is extensively...... used for macro products but with the ages it is going deep into the micro areas having machine and process improvements. Extensive research work on injection moulding is going on all over the world. New ideas are flowing into the machines, materials and processes. The technology has made significant...... advancement in the area of micro injection moulding, multi-component and two component injection mounding. In near future it is likely to be the way of manufacturing moulded interconnects devices (MID) for a low cost integration of electrical and mechanical functionalities on a single device. This paper...

  11. Analysis of bistable inductive micro-switch based on surface micro size effect

    Tian, Wenchao; Chen, Zhiqiang


    The inductive micro-switch can not only induce an external acceleration, but also be controlled by the external acceleration to realize a trigger action. It is an integrative device of a sensor and an actuator. However, little work has been done to develop a comprehensive model to accurately analyze the micro size effect during micro-switch contact process. So its malfunctions related to "fail-to-closure" and "transient-closure" result in low reliability and weak anti-jamming capability. A bistable inductive micro-switch is presented based on nano electro-mechanical system (NEMS) technology and micro size effect. And the sine-model is used to describe the rough contact surface of the micro-switch. Micro size forces such as the Casimir force and van der Waals (vdW) force are analyzed in detail using the principles of vacuum energy and the Wigner-Seitz micro-continuum media. The vdW force includes the repulsive force. The simulation results of the Casimir force varied with the gap are obtained, which is compared with the relative experimental result. The dynamic equation of the bistable inductive micro-switch is established. Dynamic simulation results are shown to be in agreement with experimental results. The threshold acceleration is 6.8 g, and the response time is 17.5 μs.

  12. The micro-vibration analysis for the large aperture grating tiling device%大口径光栅拼接装置的微振动响应分析

    周忆; 廖云飞; 刘有海; 罗跃飞; 王逍; 周海


    A new grating tiling device with 2×2 gratings is developed to obtain a large aperture grating.For the stability of the device impacted by the HVAC vibration,a dynamic finite element analysis model is established.The random vibration response of the model under the measured power spectral density as stimulus has been carried out by the ANSYS software,and the data has been compared to the experimental data.The results show that the device can meet the stability requirements in the work environment.%针对2×2大口径光栅拼接装置在暖通空调振动影响下的稳定性问题,建立了有限元动力分析模型。以实测的震动功率谱密度为激励,运用ANSYS软件对其随机振动响应进行分析计算,并与实测结果进行了比较。结果表明,该装置在工作环境中满足稳定性要求。

  13. Ferroelectric devices

    Uchino, Kenji


    Updating its bestselling predecessor, Ferroelectric Devices, Second Edition assesses the last decade of developments-and setbacks-in the commercialization of ferroelectricity. Field pioneer and esteemed author Uchino provides insight into why this relatively nascent and interdisciplinary process has failed so far without a systematic accumulation of fundamental knowledge regarding materials and device development.Filling the informational void, this collection of information reviews state-of-the-art research and development trends reflecting nano and optical technologies, environmental regulat

  14. Eye vision system using programmable micro-optics and micro-electronics

    Riza, Nabeel A.; Amin, M. Junaid; Riza, Mehdi N.


    Proposed is a novel eye vision system that combines the use of advanced micro-optic and microelectronic technologies that includes programmable micro-optic devices, pico-projectors, Radio Frequency (RF) and optical wireless communication and control links, energy harvesting and storage devices and remote wireless energy transfer capabilities. This portable light weight system can measure eye refractive powers, optimize light conditions for the eye under test, conduct color-blindness tests, and implement eye strain relief and eye muscle exercises via time sequenced imaging. Described is the basic design of the proposed system and its first stage system experimental results for vision spherical lens refractive error correction.

  15. A micromachined piezoelectric microgripper for manipulation of micro/nanomaterials

    Shi, Huaduo; Shi, Weiliang; Zhang, Ran; Zhai, Junyi; Chu, Jinkui; Dong, Shuxiang


    Micro/nanomaterials and devices have attracted great interest in recent years because of their extensive application prospects in almost all kinds of fields. However, the manipulations of the material at the micro/nanoscale, such as the separation or transfer of a micro/nano-object in the process of assembling micro/nanodevices, are quite difficult. In this paper, we present a micromachined micro-gripper made of photoresist material (SU-8) and driven by piezoelectric Pb(Mg,Nb)O3-PbTiO3 single crystal pieces. In order to keep two grasping jaws of the micro-gripper operating in the same plane at the micro/nanometer scale, a fine circular flexure hinge was fabricated for elastically connecting them together. After introducing the interface effect, the relationship between the opening stroke of two jaws and the applied voltage was developed and then confirmed by finite element simulation. The micro-gripper was finally installed on a six degree of freedom stage for performing a pick-up, release, and transfer manipulation of a 2 μm ZnO micro-fiber. The presented piezoelectric micro-gripper shows a great potential for the precise manipulation of a single piece of micro/nanomaterial for micro/nanodevices' assembling.

  16. A micromachined piezoelectric microgripper for manipulation of micro/nanomaterials.

    Shi, Huaduo; Shi, Weiliang; Zhang, Ran; Zhai, Junyi; Chu, Jinkui; Dong, Shuxiang


    Micro/nanomaterials and devices have attracted great interest in recent years because of their extensive application prospects in almost all kinds of fields. However, the manipulations of the material at the micro/nanoscale, such as the separation or transfer of a micro/nano-object in the process of assembling micro/nanodevices, are quite difficult. In this paper, we present a micromachined micro-gripper made of photoresist material (SU-8) and driven by piezoelectric Pb(Mg,Nb)O3-PbTiO3 single crystal pieces. In order to keep two grasping jaws of the micro-gripper operating in the same plane at the micro/nanometer scale, a fine circular flexure hinge was fabricated for elastically connecting them together. After introducing the interface effect, the relationship between the opening stroke of two jaws and the applied voltage was developed and then confirmed by finite element simulation. The micro-gripper was finally installed on a six degree of freedom stage for performing a pick-up, release, and transfer manipulation of a 2 μm ZnO micro-fiber. The presented piezoelectric micro-gripper shows a great potential for the precise manipulation of a single piece of micro/nanomaterial for micro/nanodevices' assembling.

  17. Laser beam micro-milling of nickel alloy: dimensional variations and RSM optimization of laser parameters

    Ahmed, Naveed; Alahmari, Abdulrahman M.; Darwish, Saied; Naveed, Madiha


    Micro-channels are considered as the integral part of several engineering devices such as micro-channel heat exchangers, micro-coolers, micro-pulsating heat pipes and micro-channels used in gas turbine blades for aerospace applications. In such applications, a fluid flow is required to pass through certain micro-passages such as micro-grooves and micro-channels. The fluid flow characteristics (flow rate, turbulence, pressure drop and fluid dynamics) are mainly established based on the size and accuracy of micro-passages. Variations (oversizing and undersizing) in micro-passage's geometry directly affect the fluid flow characteristics. In this study, the micro-channels of several sizes are fabricated in well-known aerospace nickel alloy (Inconel 718) through laser beam micro-milling. The variations in geometrical characteristics of different-sized micro-channels are studied under the influences of different parameters of Nd:YAG laser. In order to have a minimum variation in the machined geometries of each size of micro-channel, the multi-objective optimization of laser parameters has been carried out utilizing the response surface methodology approach. The objective was set to achieve the targeted top widths and depths of micro-channels with minimum degree of taperness associated with the micro-channel's sidewalls. The optimized sets of laser parameters proposed for each size of micro-channel can be used to fabricate the micro-channels in Inconel 718 with minimum amount of geometrical variations.

  18. MicroRNA expression profiles associated with pancreatic adenocarcinoma and ampullary adenocarcinoma

    Schultz, Nicolai A; Werner, Jens; Willenbrock, Hanni;


    MicroRNAs have potential as diagnostic cancer biomarkers. The aim of this study was (1) to define microRNA expression patterns in formalin-fixed parafin-embedded tissue from pancreatic ductal adenocarcinoma, ampullary adenocarcinoma, normal pancreas and chronic pancreatitis without using micro......, normal pancreas and duodenal adenocarcinoma. In all, 43 microRNAs had higher and 41 microRNAs reduced expression in pancreatic cancer compared with normal pancreas. In all, 32 microRNAs were differently expressed in pancreatic adenocarcinoma compared with chronic pancreatitis (17 higher; 15 reduced......-dissection and (2) to discover new diagnostic microRNAs and combinations of microRNAs in cancer tissue. The expression of 664 microRNAs in tissue from 170 pancreatic adenocarcinomas and 107 ampullary adenocarcinomas were analyzed using a commercial microRNA assay. Results were compared with chronic pancreatitis...

  19. Fabrication and Optical Recombination in III-Nitride Microstructures and Devices


    Fabrication and optical investigations of III-nitride microstructures Our group has pioneered the fabrication of micro - and nano -size photonic... pumped individual III-nitride micro -size LEDs and micro -LED arrays and observed enhanced quantum efficiencies. The micro -size LEDs were fabricated...quality III-nitride QWs, heterostructures, microstructures, and micro -devices and to study their optical and optoeletronic properties. By optimizing

  20. Cell viability assays: introduction.

    Stoddart, Martin J


    The measurement of cell viability plays a fundamental role in all forms of cell culture. Sometimes it is the main purpose of the experiment, such as in toxicity assays. Alternatively, cell viability can be used to -correlate cell behaviour to cell number, providing a more accurate picture of, for example, anabolic -activity. There are wide arrays of cell viability methods which range from the most routine trypan blue dye exclusion assay to highly complex analysis of individual cells, such as using RAMAN microscopy. The cost, speed, and complexity of equipment required will all play a role in determining the assay used. This chapter aims to provide an overview of many of the assays available today.

  1. Tube-Forming Assays.

    Brown, Ryan M; Meah, Christopher J; Heath, Victoria L; Styles, Iain B; Bicknell, Roy


    Angiogenesis involves the generation of new blood vessels from the existing vasculature and is dependent on many growth factors and signaling events. In vivo angiogenesis is dynamic and complex, meaning assays are commonly utilized to explore specific targets for research into this area. Tube-forming assays offer an excellent overview of the molecular processes in angiogenesis. The Matrigel tube forming assay is a simple-to-implement but powerful tool for identifying biomolecules involved in angiogenesis. A detailed experimental protocol on the implementation of the assay is described in conjunction with an in-depth review of methods that can be applied to the analysis of the tube formation. In addition, an ImageJ plug-in is presented which allows automatic quantification of tube images reducing analysis times while removing user bias and subjectivity.

  2. Transgenic Animal Mutation Assays

    Tao Chen; Ph.D.D.A.B.T.


    @@ The novel transgenic mouse and rat mutation assays have provided a tool for analyzing in vivo mutation in any tissue, thus permitting the direct comparison of cancer incidence with mutant frequency.

  3. Assays for thrombopoietin

    McDonald, T.P.


    In summary, thrombopoietin levels have been determined indirectly by measuring thrombocytopoiesis in assay animals (platelet counting, measurement of isotope incorporation into newly formed platelets, changes in platelet sizes, or alterations in number and size of megakaryocytes) and by use of an immunoassay. Although much work remains, it seems clear at the present time that isotopic uptake into platelets of specially prepared assay mice (rebound-thrombocytosis) is superior to the other techniques now available for the measurement of thrombopoietin. However, the ideal assay for TSF which is specific, rapid, and inexpensive is yet to be developed. An immunoassay is in the development stage, but will require additional work before it can be utilized for the routine assay of TSF.

  4. Fabrication of micro metallic valve and pump

    Yang, Ming; Kabasawa, Yasunari; Ito, Kuniyoshi


    Fabrication of micro devices by using micro metal forming was proposed by the authors. We developed a desktop servo-press machine with precise tooling system. Precise press forming processes including micro forging and micro joining has been carried out in a progressive die. In this study, micro metallic valve and pump were fabricated by using the precise press forming. The components are made of sheet metals, and assembled in to a unit in the progressive die. A micro check-valve with a diameter of 3mm and a length of 3.2mm was fabricated, and the property of flow resistance was evaluated. The results show that the check valve has high property of leakage proof. Since the valve is a unit parts with dimensions of several millimeters, it has advantage to be adapted to various pump design. Here, two kinds of micro pumps with the check-valves were fabricated. One is diaphragm pump actuated by vibration of the diaphragm, and another is tube-shaped pump actuated by resonation. The flow quantities of the pumps were evaluated and the results show that both of the pumps have high pumping performance.

  5. Development of micro power generators - A review

    Chou, S.K.; Yang, W.M.; Chua, K.J.; Li, J. [Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore); Zhang, K.L. [Department of Manufacturing Engineering and Engineering Management, City University of Hong Kong, 83 Tat Chee Avenue (China)


    The demand for energy sources that are compact, lightweight and powerful has significantly increased in recent years. Traditional chemical batteries which are highly developed are unable to meet the demand for high energy intensity. This gap is expected to widen in the future as electronic devices need more power to support enhanced functionalities. Hydrocarbon fuels have energy densities much greater than the best batteries. Therefore, taking advantage of the high energy density of chemical fuels to generate power becomes an attractive technological alternative to batteries. To address the growing demand for smaller scale and higher energy density power sources, various combustion-based micro power generators are being developed around the world. This review paper provides an update on recent progresses and developments in micro-scale combustion and micro power generators. The paper, broadly divided into four main sections, begins with a review of various methods to enhance and stabilize the combustion at micro-scale, subsequently improving the efficiency. This is followed by a description of various micro-thermophotovoltaic power generators. The third section focuses on MEMS based solid propellant micro-propulsion system. Lastly, a brief review is made to other micro power generators. (author)

  6. Integrated self-aligned tips for dispersion tuning in a photonic crystal micro-cavity

    Chakkalakkal Abdulla, S.M.; Kauppinen, L.J.; de Ridder, R.M.; Krijnen, Gijsbertus J.M.


    A micro-bimorph cantilever is monolithically integrated with a photonic crystal micro-cavity based device, using surface micro-machining techniques. The integrated cantilever is equipped with self-aligned dielectric tips with respect to the holes of the photonic crystal and on electrostatic

  7. Experimental study and simulation of a micro-discharge with limited cathode area

    Dufour, Thierry; Dussart, Remi; Pitchford, L C; Sadeghi, N; Lefaucheux, P; Kulsreshath, M; Ranson, P


    We report in this paper simulation results and experimental measurements to characterize a micro-discharge generated in a single micro cavity device operating in helium. By spatially limiting the cathode surface area using a dielectric layer, we demonstrate the ability of the micro-discharge to work in a steady-state abnormal glow regime. The physical properties of this regime are discussed.

  8. New Rapid Spore Assay

    Kminek, Gerhard; Conley, Catharine


    The presentation will detail approved Planetary Protection specifications for the Rapid Spore Assay for spacecraft components and subsystems. Outlined will be the research and studies on which the specifications were based. The research, funded by ESA and NASA/JPL, was conducted over a period of two years and was followed by limited cleanroom studies to assess the feasibility of this assay during spacecraft assembly.

  9. 漂浮式微型波力发电装置原理与结构%Principle & Structure of Floating Micro-type Device for Wave-activated Power Generation

    苏毅; 张涛; 张镇; 林梅


      为了满足偏远岛屿小功率用电保障需求,根据波浪能特点,提出一种新型漂浮式微型波力发电装置。利用重锤惯性定心原理,建立浮动“机架”,解决漂浮体内部相对固定问题;采用机-电直接转换系统,提高波浪能的利用效率;研究系统的原理与结构,分析系统的功能特点和主要运动参数。研究结果表明,漂浮式微型波力发电装置具有结构原理新颖、传动效率高、传动质量好与轻巧便携等优点。该研究为漂浮式微型波力发电装置的研发与应用奠定了基础。%To meet the needs for small power electricity utilization on islands,and based on the characteristics of ocean wave energy, a new floating micro⁃type device for wave⁃activated power generation is proposed. In order to solve the problem of station being fixed in buoy device,a floating frame is used by the inertial stabilization principle of ballast. The utilization efficiency of ocean wave energy is raised by direct machinery⁃electricity conversion system. And then,the structural principles and functional characteristics of the power generation system,especially main movement parameters of the system,are described for further research and application. Results show advantages of the floating micro⁃type device for wave⁃activated power generation including novel structural principle,high drive efficiency, good drive effect,easy carrying,and so on. The study could provide sound basis for the research&development and application of the proposed floating micro⁃type device.

  10. An integrated microfluidic device in marine microalgae culture for toxicity screening application.

    Zheng, Guoxia; Wang, Yunhua; Wang, Zumin; Zhong, Weiliang; Wang, Hu; Li, Yajie


    Algal assay using marine microalgae has emerged as an important method to evaluate the toxicity of chemicals, which is currently undertaken using conventional culture and additional detection of physiological cellular endpoints. While effective, this approach can be labor-intensive and thus could benefit from a more streamlined, integrated approach. Microfluidics offers a way to accomplish this goal. Here, we demonstrate a microfluidic device which consists of a concentration gradient generator (CGG), diffusible culturing module and power-free valve system. It allows the processes of chemical liquid dilution and diffusion, micro-scale microalgal culture (in batch or chemostatic conditions), cell stimulation and on-lined screening to be integrated into a single device. Using the device, marine microalgae were successfully cultured and stressed on-chip. The simple assay provides multi-biological response measurements of cell division rate, autofluorescence and esterase activity. This work showed promising in developing a microfluidic platform for toxicity screening based on marine microalgal culture. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. 微纳薄膜器件的电阻率精确测量方法%Method for Accurate Measurement of Micro-Nano Thin Film Device Resistivity

    吴蕾; 居冰峰; 杨春晖; 林军


    微纳级别的铝薄膜因宽度和厚度尺寸缩小其试件尺寸接近电极的最小间距、电极间的位置误差等因素的影响,导致电阻率四电极法在测量过程中产生较大的误差.通过对微纳级的导电薄膜的四电极测量法进行数学建模分析,建立了新的四电极测量法数学计算模型,提供精确的电阻率修正系数,并利用基于原子力显微镜的四电极电阻率测量技术精确测量了厚度为400 nm、宽度为30 μm的铝薄膜的电阻率,且取不同的作用力重复实验.实验结果证明,基于修正后数学模型的微四电极技术对微纳级别薄膜的电阻率测量方面的准确性和稳定性.%Because of the width and thickness of the micro-nano thin film is very close to the minimum distance of the electrodes and the position error between electrodes, which led to errors during the measurement process using the four-point-probe. By analyzing the traditional four-point-probe method, a new four-point-probe method model for measurement of micron-nano aluminum thin film' s resistivity was created. The four-point-AFM-probe technique was applied for the purpose of quantitatively measuring resistivity of the aluminum film with 400 nm thickness and 30 祄 width. The repeatability of resistivity measurements indicates that this new four-point-probe model technique could be used for fast in situ cha racterization of electrical properties of micro-nano thin film.

  12. Planar nanophotonic devices and integration technologies

    De La Rue, Richard M.; Sorel, Marc; Samarelli, Antonio; Velha, Philippe; Strain, Michael; Johnson, Nigel P.; Sharp, Graham; Rahman, Faiz; Khokhar, Ali Z.; Macintyre, Douglas S.; McMeekin, Scott G.; Lahiri, Basudev


    Planar devices that can be categorised as having a nanophotonic dimension constitute an increasingly important area of photonics research. Device structures that come under the headings of photonic crystals, photonic wires and metamaterials are all of interest - and devices based on combinations of these conceptual approaches may also play an important role. Planar micro-/nano-photonic devices seem likely to be exploited across a wide spectrum of applications in optoelectronics and photonics. This spectrum includes the domains of display devices, biomedical sensing and sensing more generally, advanced fibre-optical communications systems - and even communications down to the local area network (LAN) level. This article will review both device concepts and the applications possibilities of the various different devices.

  13. 微柱凝胶卡式法Coombs试验在自身免疫性溶血性贫血诊断中的应用%Application of micro-column gel cards assay for direct Coombs test in diagnosis of autoimmune hemolyric anemia

    周雪丽; 阎石; 李鹏; 赵玉平


    目的 采用微柱凝胶卡式检测方法进行直接Coombs试验,探讨其在自身免疫性溶血性贫血( AIHA)诊断中的临床意义.方法 对临床怀疑为AIHA的128例患者标本同时用试管法和微柱凝胶卡式法进行直接Coombs试验,对两种检测方法进行比较.检测患者同期血红蛋白水平、网织红细胞比例、胆红素及游离血红蛋白水平,比较不同型别患者间的差异.结果 应用微柱凝胶卡式法进行直接Coombs试验阳性检出率为88.4%,试管法阳性检出率为37.7%,患者红细胞包被不同免疫球蛋白时溶血程度不同.结论 微柱凝胶卡式法较试管法敏感,操作简单,易标准化,结果判读客观,可长期保存.对AIHA的诊断具有临床意义.%Objective To evaluate the clinic value of micro-column gel cards direct Coombs test (gel test) in dignosis of autoimmune hemolytic anemia (AIHA).Methods Specimens of 128 suspected AIHA patients were performed direct Coombs test by conventional tube or gel cards.The results of the two tests were compared.The hemoglobin concentrations,proportions of reticulocyte,serum levels of bilirubin and free hemoglobin were detected simultaneously and compared in subgroups.Results The positive detection rate of direct Coombs test performed by gel test or tube were 88.4% and 37.7%,respectively.Conclusion Compared with the tube tests,gel test assay is more sensitive,easy to perform and standardized in diagnosis of AIHA,and the gel card can be stored for a long time.The gel test is valuble for the diagnosis of AIHA.

  14. Recent advances in micro- and nano-machining technologies

    Gao, Shang; Huang, Han


    Device miniaturization is an emerging advanced technology in the 21st century. The miniaturization of devices in different fields requires production of micro- and nano-scale components. The features of these components range from the sub-micron to a few hundred microns with high tolerance to many engineering materials. These fields mainly include optics, electronics, medicine, bio-technology, communications, and avionics. This paper reviewed the recent advances in micro- and nano-machining technologies, including micro-cutting, micro-electrical-discharge machining, laser micro-machining, and focused ion beam machining. The four machining technologies were also compared in terms of machining efficiency, workpiece materials being machined, minimum feature size, maximum aspect ratio, and surface finish.

  15. Liquid-liquid extraction of uranium(VI) with Aliquat® 336 from HCl media in microfluidic devices: Combination of micro-unit operations and online ICP-MS determination.

    Hellé, Gwendolyne; Mariet, Clarisse; Cote, Gérard


    The analysis of radionuclides is carried out according to operating protocols which include a series of chemical operations such as separation/purification steps and therefore is usually time-consuming, complex and difficult to put in place in a hostile environment (gloves box). In the present work, the liquid-liquid extraction of uranium in HCl media by Aliquat® 336 was performed in microsystem to demonstrate the potential of miniaturization in radiochemistry compared to classical protocols (decrease in volumes, analysis time, radiations received and feasibility of automation). Through the investigation of the influence of different parameters (flow rates, length of the microchannel, specific interfacial area), it was shown that the same performances of liquid-liquid extraction can be obtained in microsystem and in batch. Then, the coupling of different micro-unit operations for continuous process was performed to highlight the advantages of the miniaturized analytical techniques. The online ICP-MS determination of uranium(VI) was successfully coupled with the stripping of the latter from pre-loaded organic phases in microsystem, which constitutes a proof of concept and a first step towards a global analytical process with continuous flow.

  16. Precision manufacturing of polymer micro-nano fluidic systems

    Garnæs, Jørgen; Calaon, Matteo; Tosello, Guido


    Lab-on-a-Chip (LoC) technologies require the possibility of fabricating devices which include micro down to sub-micrometre features with high production rate and low cost. In the present study precision injection moulding is performed using a COC Topas 5013 L10 polymer to produce LoC devices...

  17. Modular Thruster and Feeding System for Micro-Satellite

    Louwerse, M.C.; Jansen, Henricus V.; Elwenspoek, Michael Curt


    The miniaturization of space applicable devices by means of micro system technology (MST) is pursued by many research groups. MST devices are often designed as stand alone and require individual packaging which makes them still quite large. Focusing on the integration of several MST components has

  18. Ventricular assist device

    VAD; RVAD; LVAD; BVAD; Right ventricular assist device; Left ventricular assist device; Biventricular assist device; Heart pump; Left ventricular assist system; LVAS; Implantable ventricular assist device

  19. Levitated micro-accelerometer.

    Warne, Larry Kevin; Schmidt, Carrie Frances; Peterson, Kenneth Allen; Kravitz, Stanley H.; Renn, Rosemarie A.; Peter, Frank J.; Kinney, Ragon D.; Gilkey, Jeffrey C.


    The objective is a significant advancement in the state-of-the-art of accelerometer design for tactical grade (or better) applications. The design goals are <1 milli-G bias stability across environments and $200 cost. This quantum leap in performance improvement and cost reduction can only be achieved by a radical new approach, not incremental improvements to existing concepts. This novel levitated closed-loop accelerometer is implemented as a hybrid micromachine. The hybrid approach frees the designer from the limitations of any given monolithic process and dramatically expands the available design space. The design can be tailored to the dynamic range, resolution, bandwidth, and environmental requirements of the application while still preserving all of the benefits of monolithic MEMS fabrication - extreme precision, small size, low cost, and low power. An accelerometer was designed and prototype hardware was built, driving the successful development and refinement of several 'never been done before' fabrication processes. Many of these process developments are commercially valuable and are key enablers for the realization of a wide variety of useful micro-devices. While controlled levitation of a proof mass has yet to be realized, the overall design concept remains sound. This was clearly demonstrated by the stable and reliable closed-loop control of a proof mass at the test structure level. Furthermore, the hybrid MEMS implementation is the most promising approach for achieving the ambitious cost and performance targets. It is strongly recommended that Sandia remain committed to the original goal.

  20. Approaches to hybrid synthetic devices

    Verma, Vivek

    All living creatures are made up of cells that have the ability to replicate themselves in a repetitive process called cell division. As these cells mature and divide into two there is an extensive movement of cellular components. In order to perform this essential task that sustains life, cells have evolved machines composed of proteins. Biological motors, such as kinesin, transport intracellular cargo and position organelles in eukaryotic cells via unidirectional movement on cytoskeletal tracts called microtubules. Biomolecular motor proteins have the potential to be used as 'nano-engines' for switchable devices, directed self assembly, controlled bioseparations and powering nano- and microelectromechanical systems. However, engineering such systems requires fabrication processes that are compatible with biological materials such as kinesin motor proteins and microtubules. The first objective of the research was to establish biocompatibility between protein systems and nanofabrication. The second objective was to use current micro- and nanofabrication techniques for patterning proteins at specific locations and to study role of casein in supporting the operation of surface bound kinesin. The third objective was to link kinesin and microtubule system to cellulose nanowhiskers. The effects of micro- and nanofabrication processing chemicals and resists on the functionality of casein, kinesin, and microtubule proteins are systematically examined to address the important missing link of the biocompatibility of micro- and nanofabrication processes needed to realize hybrid system fabrication. It was found that both casein, which is used to prevent motor denaturation on surfaces, and kinesin motors are surprisingly tolerant of most of the processing chemicals examined. Microtubules, however, are much more sensitive. Exposure to the processing chemicals leads to depolymerization, which is partially attributed to the pH of the solutions examined. When the chemicals were

  1. Micro-bubbles seeding for flow characterization

    Aumelas, V.; Lecoffre, Y.; Maj, G.; Franc, J.-P.


    Micro-bubbles injection has long been used in hydrodynamic facilities for the control of dissolved and free air. In some cavitation tunnels [9], very large quantities of microbubbles (billions per second) are injected for rapid degassing and, in smaller quantities (millions per second), for cavitation nuclei seeding. Micro-bubbles can also be used as tracers for optical measurements including visualization, LDV or PIV. For these applications, bubbles must be sufficiently small to faithfully follow the flow. Depending on the quality and spatial characteristics of the micro-bubbles seeding, several optical methods can be applied: simple visualization gives access to semi-quantitative information on the behaviour of flows; LASER velocimetry provides information on the mean velocity and other temporal local characteristics of the flow. This paper presents some new micro-bubbles seeding devices recently developed by YLEC Consultants. These devices have been designed to fulfill specific requirements related to integration into cavitation tunnels and permit optical velocimetry measurement techniques such as Particle Image Velocimetry (PIV). The LEGI cavitation tunnel is the first tunnel which has been equipped with these microbubbles seeding systems dedicated to optical velocimetry. This paper presents the final integration schemes selected for micro-bubbles seeding into LEGI tunnel and discuss about practical concerns related to the use of the injection system for optical velocimetry.

  2. Self-assembly micro optical filter

    Zhang, Ping (Cerina); Le, Kevin; Malalur-Nagaraja-Rao, Smitha; Hsu, Lun-Chen; Chiao, J.-C.


    Optical communication and sensor industry face critical challenges in manufacturing for system integration. Due to the assembly complexity and integration platform variety, micro optical components require costly alignment and assembly procedures, in which many required manual efforts. Consequently, self-assembly device architectures have become a great interest and could provide major advantages over the conventional optical devices. In this paper, we discussed a self-assembly integration platform for micro optical components. To demonstrate the adaptability and flexibility of the proposed optical device architectures, we chose a commercially available MEMS fabrication foundry service - MUMPs (Multi-User MEMS Process). In this work, polysilicon layers of MUMPS are used as the 3-D structural material for construction of micro component framework and actuators. However, because the polysilicon has high absorption in the visible and near infrared wavelength ranges, it is not suitable for optical interaction. To demonstrate the required optical performance, hybrid integration of materials was proposed and implemented. Organic compound materials were applied on the silicon-based framework to form the required optical interfaces. Organic compounds provide good optical transparency, flexibility to form filters or lens and inexpensive manufacturing procedures. In this paper, we have demonstrated a micro optical filter integrated with self-assembly structures. We will discuss the self-assembly mechanism, optical filter designs, fabrication issues and results.

  3. Biofilms on Indwelling Urologic Devices: Microbes and Antimicrobial ...


    The patients' history including age, sex, hospital stay, duration of device application and .... Table 1: Organism isolated from culture positive catheters and stents. Name of micro- .... periodic voiding, and sloughing of colonized cells. However.

  4. Separating device

    De Jong, T.P.R.


    A sorting device (1) suitable for sorting wire from a waste stream, comprising a body (2) that moves when in use, and provided with spikes or similar projections. The body is embodied as a rotatable roll (2), which oscillates axially during its rotation. The roll is coupled to an oscillation engine

  5. Detection device

    Smith, J.E.


    The present invention is directed to a detection device comprising: (1) an entrance chamber; (2) a central chamber; and (3) an exit chamber. The central chamber includes an ionizing gas, anode, and means for connecting the anode with an external power supply and pulse counter.

  6. Assistive Devices

    ... a number of assistive devices. These are tools, products or types of equipment that help you perform tasks and activities. They may help you move around, see, communicate, eat, or get dressed. Some are high-tech tools, such as computers. Others are much simpler, ...

  7. Printing Device

    Berg, van den M.J.; Markies, P.R.; Zuilhof, H.


    An ink jetprinting device includes a pressure chamber formed by a plurality of wall segments, a first aperture extending through a wall segment and communicating with an ink jet orifice and a second aperture extending through a wall segment and communicating with an ink supply duct. The pressure

  8. Electrochemical device

    Grimes, Patrick G.; Einstein, Harry; Bellows, Richard J.


    A tunnel protected electrochemical device features channels fluidically communicating between manifold, tunnels and cells. The channels are designed to provide the most efficient use of auxiliary power. The channels have a greater hydraulic pressure drop and electrical resistance than the manifold. This will provide a design with the optimum auxiliary energy requirements.

  9. Printing Device

    Berg, van den M.J.; Markies, P.R.; Zuilhof, H.


    An ink jetprinting device includes a pressure chamber formed by a plurality of wall segments, a first aperture extending through a wall segment and communicating with an ink jet orifice and a second aperture extending through a wall segment and communicating with an ink supply duct. The pressure cha

  10. Balancing device

    Van Dorsser, W.D.; Herder, J.L.; Wisse B.M.; Barents, R.


    The invention relates to a balancing device for a mass, comprising an arm that is adjustable about a pivoting point and with which the mass is coupled, and an adjustable spring system that is coupled with the arm, which spring system comprises at least one spring, wherein the spring system comprises

  11. CMOS MEMS Fabrication Technologies and Devices

    Hongwei Qu


    Full Text Available This paper reviews CMOS (complementary metal-oxide-semiconductor MEMS (micro-electro-mechanical systems fabrication technologies and enabled micro devices of various sensors and actuators. The technologies are classified based on the sequence of the fabrication of CMOS circuitry and MEMS elements, while SOI (silicon-on-insulator CMOS MEMS are introduced separately. Introduction of associated devices follows the description of the respective CMOS MEMS technologies. Due to the vast array of CMOS MEMS devices, this review focuses only on the most typical MEMS sensors and actuators including pressure sensors, inertial sensors, frequency reference devices and actuators utilizing different physics effects and the fabrication processes introduced. Moreover, the incorporation of MEMS and CMOS is limited to monolithic integration, meaning wafer-bonding-based stacking and other integration approaches, despite their advantages, are excluded from the discussion. Both competitive industrial products and state-of-the-art research results on CMOS MEMS are covered.

  12. Optically Reconfigurable Photonic Devices

    Wang, Qian; Gholipour, Behrad; Wang, Chih-Ming; Yuan, Guanghui; Teng, Jinghua; Zheludev, Nikolay I


    Optoelectronic components with adjustable parameters, from variable-focal-length lenses to spectral filters that can change functionality upon stimulation, have enormous technological importance. Tuning of such components is conventionally achieved by either micro- or nano-mechanical actuation of their consitutive parts, stretching or application of thermal stimuli. Here we report a new dielectric metasurface platform for reconfigurable optical components that are created with light in a non-volatile and reversible fashion. Such components are written, erased and re-written as two-dimensional binary or grey-scale patterns into a nanoscale film of phase change material by inducing a refractive-index-changing phase-transition with tailored trains of femtosecond pulses. We combine germanium-antimony-tellurium-based films optimized for high-optical-contrast ovonic switching with a sub-wavelength-resolution optical writing process to demonstrate technologically relevant devices: visible-range reconfigurable bi-chr...

  13. Development and in-use evaluation of a novel Luminex MicroPlex microsphere-based (TRIOL) assay for simultaneous identification of Mycobacterium tuberculosis and detection of first-line and second-line anti-tuberculous drug resistance in China.

    Yin, Feifei; Chan, Jasper Fuk-Woo; Zhu, Qixuan; Fu, Ruijia; Chen, Jonathan Hon-Kwan; Choi, Garnet Kwan-Yue; Tee, Kah-Meng; Li, Lihua; Qian, Shiuyun; Yam, Wing-Cheong; Lu, Gang; Yuen, Kwok-Yung


    Rapid and accurate diagnostic assays with simultaneous microbial identification and drug resistance detection are essential for optimising treatment and control of tuberculosis. We developed a novel multiplex (TRIOL, Tuberculosis-Rifampicin-Isoniazid-Ofloxacin-Luminex) assay using the Luminex xMAP system that simultaneously identifies Mycobacterium tuberculosis and detects resistance to first-line and second-line anti-tuberculous drugs, and compared its performance with that by PCR sequencing, using phenotypic drug susceptibility testing as the gold standard. Identification of M. tuberculosis by the TRIOL assay was highly sensitive (100%) and specific (100%). The overall drug-specific specificities were excellent (100%). The overall sensitivity of the TRIOL assay was lower than that of the PCR-sequencing assays (72.4% vs 82.8%) because of a lower sensitivity of detecting rifampicin resistance (71.4% vs 92.9%). The sensitivity of detecting isoniazid and ofloxacin resistance was as good as the PCR-sequencing assays. Importantly, the TRIOL assay did not miss any mutations that were included in the assay. All of the resistant isolates that were missed had uncommon mutations or unknown resistance mechanisms that were not included in the assay. The TRIOL assay has higher throughput, lower cost and is less labour intensive than the PCR-sequencing assays. The TRIOL assay is advantageous in having the capability to detect resistance to multiple drugs and an open-architecture system that allows addition of more specific primers to detect uncommon mutations. Inclusion of additional primers for the identification of non-tuberculous mycobacteria, spoligotyping and improvement of rifampicin resistance detection would enhance the use of the TRIOL assay in future clinical and epidemiological studies. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to

  14. Rover waste assay system

    Akers, D.W.; Stoots, C.M.; Kraft, N.C.; Marts, D.J. [Idaho National Engineering Lab., Idaho Falls, ID (United States)


    The Rover Waste Assay System (RWAS) is a nondestructive assay system designed for the rapid assay of highly-enriched {sup 235}U contaminated piping, tank sections, and debris from the Rover nuclear rocket fuel processing facility at the Idaho Chemical Processing Plant. A scanning system translates a NaI(Tl) detector/collimator system over the structural components where both relative and calibrated measurements for {sup 137}Cs are made. Uranium-235 concentrations are in operation and is sufficiently automated that most functions are performed by the computer system. These functions include system calibration, problem identification, collimator control, data analysis, and reporting. Calibration of the system was done through a combination of measurements on calibration standards and benchmarked modeling. A description of the system is presented along with the methods and uncertainties associated with the calibration and analysis of the system for components from the Rover facility. 4 refs., 2 figs., 4 tabs.

  15. Compact MR fluid clutch device for human-friendly actuator

    Kikuchi, T; Ikeda, K; Otsuki, K; Kakehashi, T; Furusho, J [Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)], E-mail:


    In this paper, we describe a design method and experimental results of a newly developed MR Fluid clutch which has a multi-layered disks and micro-size (50 micro meters) gaps of MR Fluid. The micro-size gap works for the reduction of magnetic resistance, amount of power supply and size of the total system. Static torques of the device was predictable with conventional magnetostatic analyses. Additionally, dynamic test shows that its response time is about 20 milliseconds.

  16. Nanomaterials-Based Sensing Strategies for Electrochemical Detection of MicroRNAs

    Ning Xia


    Full Text Available MicroRNAs (miRNAs play important functions in post-transcriptional regulation of gene expression. They have been regarded as reliable molecular biomarkers for many diseases including cancer. However, the content of miRNAs in cells can be low down to a few molecules per cell. Thus, highly sensitive analytical methods for miRNAs detection are desired. Recently, electrochemical biosensors have held great promise as devices suitable for point-of-care diagnostics and multiplexed platforms for fast, simple and low-cost nucleic acid analysis. Signal amplification by nanomaterials is one of the most popular strategies for developing ultrasensitive assay methods. This review surveys the latest achievements in the use of nanomaterials to detect miRNAs with a focus on electrochemical techniques.

  17. CTL ELISPOT assay.

    Ranieri, Elena; Popescu, Iulia; Gigante, Margherita


    Enzyme-linked immune absorbent spot (Elispot) is a quantitative method for measuring relevant parameters of T cell activation. The sensitivity of Elispot allows the detection of low-frequency antigen-specific T cells that secrete cytokines and effector molecules, such as granzyme B and perforin. Cytotoxic T cell (CTL) studies have taken advantage with this high-throughput technology by providing insights into quantity and immune kinetics. Accuracy, sensitivity, reproducibility, and robustness of Elispot resulted in a wide range of applications in research as well as in diagnostic field. Actually, CTL monitoring by Elispot is a gold standard for the evaluation of antigen-specific T cell immunity in clinical trials and vaccine candidates where the ability to detect rare antigen-specific T cells is of relevance for immune diagnostic. The most utilized Elispot assay is the interferon-gamma (IFN-γ) test, a marker for CD8(+) CTL activation, but Elispot can also be used to distinguish different subsets of activated T cells by using other cytokines such as T-helper (Th) 1-type cells (characterized by the production of IFN-γ, IL-2, IL-6, IL-12, IL-21, and TNF-α), Th2 (producing cytokines like IL-4, IL-5, IL-10, and IL-13), and Th17 (IL-17) cells. The reliability of Elispot-generated data, by the evaluation of T cell frequency recognizing individual antigen/peptide, is the core of this method currently applied widely to investigate specific immune responses in cancer, infections, allergies, and autoimmune diseases. The Elispot assay is competing with other methods measuring single-cell cytokine production, e.g., intracellular cytokine by FACS or Miltenyi cytokine secretion assay. Other types of lymphocyte frequency and function assays include limiting dilution assay (LDA), cytotoxic T cell assay (CTL), and tetramer staining. Compared with respect to sensitivity the Elispot assay is outranking other methods to define frequency of antigen-specific lymphocytes. The method

  18. Assays for calcitonin receptors

    Teitelbaum, A.P.; Nissenson, R.A.; Arnaud, C.D.


    The assays for calcitonin receptors described focus on their use in the study of the well-established target organs for calcitonin, bone and kidney. The radioligand used in virtually all calcitonin binding studies is /sup 125/I-labelled salmon calcitonin. The lack of methionine residues in this peptide permits the use of chloramine-T for the iodination reaction. Binding assays are described for intact bone, skeletal plasma membranes, renal plasma membranes, and primary kidney cell cultures of rats. Studies on calcitonin metabolism in laboratory animals and regulation of calcitonin receptors are reviewed.

  19. Micro string resonators as temperature sensors

    Larsen, T.; Schmid, S.; Boisen, A.


    The resonance frequency of strings is highly sensitive to temperature. In this work we have investigated the applicability of micro string resonators as temperature sensors. The resonance frequency of strings is a function of the tensile stress which is coupled to temperature by the thermal...... was done with silicon rich silicon nitride (SiNx), nickel (Ni) and aluminum (Al) micro strings. Aluminum strings show a relative sensitivity of up to 15±1 %/°C, which is more than 100 times higher than values reported by other groups for similar devices. Sub-millisecond time constants can be achieved due...

  20. Micro-Ramps for Hypersonic Flow Control

    Konstantinos Kontis


    Full Text Available Shock/boundary layer interaction (SBLI is an undesirable phenomenon, occurring in high-speed propulsion systems. The conventional method to manipulate and control SBLI is using a bleed system that involves the removal of a certain amount of mass of the inlet flow to control boundary layer separation. However, the system requires a larger nacelle to compensate the mass loss, larger nacelles contribute to additional weight and drag and reduce the overall performance. This study investigates a novel type of flow control device called micro-ramps, a part of the micro vortex generators (VGs family that intends to replace the bleed technique. Micro-ramps produce pairs of counter-rotating streamwise vortices, which help to suppress SBLI and reduce the chances of flow separation. Experiments were done at Mach 5 with two micro-ramp models of different sizes. Schlieren photography, surface flow visualization and infrared thermography were used in this investigation. The results revealed the detailed flow characteristics of the micro-ramp, such as the primary and secondary vortices. This helps us to understand the overall flow physics of micro-ramps in hypersonic flow and their application for SBLI control.

  1. New oligosaccharyltransferase assay method.

    Kohda, Daisuke; Yamada, Masaki; Igura, Mayumi; Kamishikiryo, Jun; Maenaka, Katsumi


    We developed a new in vitro assay for oligosaccharyltransferase (OST), which catalyzes the transfer of preassembled oligosaccharides on lipid carriers onto asparagine residues in polypeptide chains. The asparagine residues reside in the sequon, Asn-X-Thr/Ser, where X can be any amino acid residue except Pro. We demonstrate the potency of our assay using the OST from yeast. In our method, polyacrylamide gel electrophoresis is used to separate the glycopeptide products from the peptide substrates. The substrate peptide is fluorescently labeled and the formation of glycopeptides is analyzed by fluorescence gel imaging. Two in vitro OST assay methods are now widely used, but both the methods depend on previous knowledge of the oligosaccharide moiety: One method uses lectin binding as the separation mechanism and the other method uses biosynthetically or chemoenzymatically synthesized lipid-linked oligosaccharides as donors. N-linked protein glycosylation is found in all three domains of life, but little is known about the N-glycosylation in Archaea. Thus, our new assay, which does not require a priori knowledge of the oligosaccharides, will be useful in such cases. Indeed, we have detected the OST activity in the membrane fraction from a hyperthermophilic archaeon, Pyrococcus furiosus.

  2. Hyaluronic Acid Assays

    Itenov, Theis S; Kirkby, Nikolai S; Bestle, Morten H


    BACKGROUD: Hyaluronic acid (HA) is proposed as a marker of functional liver capacity. The aim of the present study was to compare a new turbidimetric assay for measuring HA with the current standard method. METHODS: HA was measured by a particle-enhanced turbidimetric immunoassay (PETIA) and enzyme...

  3. Instrument for assaying radiation

    Coleman, Jody Rustyn; Farfan, Eduardo B.


    An instrument for assaying radiation includes a flat panel detector having a first side opposed to a second side. A collimated aperture covers at least a portion of the first side of the flat panel detector. At least one of a display screen or a radiation shield may cover at least a portion of the second side of the flat panel detector.

  4. "Distinvar" device

    CERN PhotoLab


    The alignment of one of the accelerator magnets being checked by the AR Division survey group. A "distinvar" device, invented by the group, using calibrated invar wires stretched between the fixed survey pillar (on the left) and a fixed point on the magnet. In two days it is thus possible to measure the alignment of the 100 magnets with an accuracy better than 1/10.

  5. Magnetohydrodynamic device

    Gorlin, S.M.; Ljubimov, G.A.; Bitjurin, V.A.; Kovbasjuk, V.I.; Maximenko, V.I.; Medin, S.A.; Barshak, A.E.


    A magnetohydrodynamic device having a duct for a conducting gas to flow at an angle with the direction of the magnetic field induction vector is described. The duct is situated in the magnetic system and is provided with a plurality of electrodes adapted to interact electrically with the gas, whereas the cross-sectional shape of the duct working space is bounded by a closed contour formed by a curve inscribed into a rectangle. 1 claim.

  6. The MicroObservatory Net

    Brecher, K.; Sadler, P.


    A group of scientists, engineers and educators based at the Harvard-Smithsonian Center for Astrophysics (CfA) has developed a prototype of a small, inexpensive and fully integrated automated astronomical telescope and image processing system. The project team is now building five second generation instruments. The MicroObservatory has been designed to be used for classroom instruction by teachers as well as for original scientific research projects by students. Probably in no other area of frontier science is it possible for a broad spectrum of students (not just the gifted) to have access to state-of-the-art technologies that would allow for original research. The MicroObservatory combines the imaging power of a cooled CCD, with a self contained and weatherized reflecting optical telescope and mount. A microcomputer points the telescope and processes the captured images. The MicroObservatory has also been designed to be used as a valuable new capture and display device for real time astronomical imaging in planetariums and science museums. When the new instruments are completed in the next few months, they will be tried with high school students and teachers, as well as with museum groups. We are now planning to make the MicroObservatories available to students, teachers and other individual users over the Internet. We plan to allow the telescope to be controlled in real time or in batch mode, from a Macintosh or PC compatible computer. In the real-time mode, we hope to give individual access to all of the telescope control functions without the need for an "on-site" operator. Users would sign up for a specific period of time. In the batch mode, users would submit jobs for the telescope. After the MicroObservatory completed a specific job, the images would be e-mailed back to the user. At present, we are interested in gaining answers to the following questions: (1) What are the best approaches to scheduling real-time observations? (2) What criteria should be used

  7. Optoelectronic Devices Advanced Simulation and Analysis

    Piprek, Joachim


    Optoelectronic devices transform electrical signals into optical signals and vice versa by utilizing the sophisticated interaction of electrons and light within micro- and nano-scale semiconductor structures. Advanced software tools for design and analysis of such devices have been developed in recent years. However, the large variety of materials, devices, physical mechanisms, and modeling approaches often makes it difficult to select appropriate theoretical models or software packages. This book presents a review of devices and advanced simulation approaches written by leading researchers and software developers. It is intended for scientists and device engineers in optoelectronics, who are interested in using advanced software tools. Each chapter includes the theoretical background as well as practical simulation results that help to better understand internal device physics. The software packages used in the book are available to the public, on a commercial or noncommercial basis, so that the interested r...

  8. Personalized biomedical devices & systems for healthcare applications

    Chen, I.-Ming; Phee, Soo Jay; Luo, Zhiqiang; Lim, Chee Kian


    With the advancement in micro- and nanotechnology, electromechanical components and systems are getting smaller and smaller and gradually can be applied to the human as portable, mobile and even wearable devices. Healthcare industry have started to benefit from this technology trend by providing more and more miniature biomedical devices for personalized medical treatments in order to obtain better and more accurate outcome. This article introduces some recent development in non-intrusive and intrusive biomedical devices resulted from the advancement of niche miniature sensors and actuators, namely, wearable biomedical sensors, wearable haptic devices, and ingestible medical capsules. The development of these devices requires carful integration of knowledge and people from many different disciplines like medicine, electronics, mechanics, and design. Furthermore, designing affordable devices and systems to benefit all mankind is a great challenge ahead. The multi-disciplinary nature of the R&D effort in this area provides a new perspective for the future mechanical engineers.

  9. The role of body-on-a-chip devices in drug and toxicity studies.

    Esch, M B; King, T L; Shuler, M L


    High-quality, in vitro screening tools are essential in identifying promising compounds during drug development. Tests with currently used cell-based assays provide an indication of a compound's potential therapeutic benefits to the target tissue, but not to the whole body. Data obtained with animal models often cannot be extrapolated to humans. Multicompartment microfluidic-based devices, particularly those that are physical representations of physiologically based pharmacokinetic (PBPK) models, may contribute to improving the drug development process. These scaled-down devices, termed micro cell culture analogs (μCCAs) or body-on-a-chip devices, can simulate multitissue interactions under near-physiological fluid flow conditions and with realistic tissue-to-tissue size ratios. Because the device can be used with both animal and human cells, it can facilitate cross-species extrapolation. Used in conjunction with PBPK models, the devices permit an estimation of effective concentrations that can be used for studies with animal models or predict the human response. The devices also provide a means for relatively high-throughput screening of drug combinations and, when utilized with a patient's tissue sample, an opportunity for individualized medicine. Here we review efforts made toward the development of microfabricated cell culture systems and give examples that demonstrate their potential use in drug development, such as identifying synergistic drug interactions as well as simulating multiorgan metabolic interactions. In addition to their use in drug development, the devices also can be used to estimate the toxicity of chemicals as occupational hazards and environmental contaminants.

  10. Ecotoxicological Assessment of Aquatic Genotoxicity Using the Comet Assay



    Full Text Available Comet assay is a novel biological analysis, which is a sensitive, flexible, simple, rapid, and inexpensive method to assess aquatic genotoxicant. Since Singh and co-workers developed the method in 1988, its use has increased exponentially in various fields. This review discourses on the application of this assay in aquatic ecosystems. Various types of cells from various aquatic organisms have been tested by various genotoxicant both direct- and indirect-acting using the comet assay. The applications of this assay suggest that it is a useful assay to assess aquatic genotoxicants. However, there are some factors, which should be taken into account when using this assay as aquatic ecotoxicological assessment device such as inter-animal and cell variability.

  11. An integrated microfludic device for culturing and screening of Giardia lamblia.

    Zheng, Guo-Xia; Zhang, Xue-Mei; Yang, Yu-Suo; Zeng, Shu-Rui; Wei, Jun-Feng; Wang, Yun-Hua; Li, Ya-Jie


    In vitro culturing of trophozoites was important for research of Giardia lamblia (G. lamblia), especially in discovery of anti-Giardia agents. The current culture methods mainly suffer from lab-intension or the obstacle in standardizing the gas condition. Thus, it could benefit from a more streamlined and integrated approach. Microfluidics offers a way to accomplish this goal. Here we presented an integrated microfluidic device for culturing and screening of G. lamblia. The device consisted of a polydimethylsiloxane (PDMS) microchip with an aerobic culture system. In the microchip, the functionality of integrated concentration gradient generator (CGG) with micro-scale cell culture enables dose-response experiment to be performed in a simple and reagent-saving way. The diffusion-based culture chambers allowed growing G. lamblia at the in vivo like environment. It notable that the highly air permeable material of parallel chambers maintain uniform anaerobic environment in different chambers easily. Using this device, G. lamblia were successfully cultured and stressed on-chip. In all cases, a dose-related inhibitory response was detected. The application of this device for these purposes represents the first step in developing a completely integrated microfluidic platform for high-throughput screening and might be expanded to other assays based on in vitro culture of G. lamblia with further tests.

  12. Carbon for sensing devices

    Tagliaferro, Alberto


    This book reveals why carbon is playing such an increasingly prominent role as a sensing material. The various steps that transform a raw material in a sensing device are thoroughly presented and critically discussed.  The authors deal with all aspects of carbon-based sensors, starting from the various hybridization and allotropes of carbon, with specific focus on micro and nanosized carbons (e.g., carbon nanotubes, graphene) and their growth processes. The discussion then moves to the role of functionalization and the different routes to achieve it. Finally, a number of sensing applications in various fields are presented, highlighting the connection with the basic properties of the various carbon allotropes.  Readers will benefit from this book’s bottom-up approach, which starts from the local bonding in carbon solids and ends with sensing applications, linking the local hybridization of carbon atoms and its modification by functionalization to specific device performance. This book is a must-have in th...

  13. Nanotechnology for electronic materials and devices

    Korkin, Anatoli; Labanowski, Jan K


    Quickly becoming the hottest topic of the new millennium (2.4 billion dollars funding in US alone) Current status and future trends of micro and nanoelectronics research Written by leading experts in the corresponding research areas Excellent tutorial for graduate students and reference for "gurus" Provides a broad overlook and fundamentals of nanoscience and nanotechnology from chemistry to electronic devices.

  14. Development of a simple device for processing whole-blood samples into measured aliquots of plasma.

    Burtis, C A; Johnson, W F; Walker, W A


    A capillary processor and aliquoter has been designed and fabricated that is capable of accepting aliquots of whole blood and automatically processing them into discrete aliquots of plasma. The device consists of two disks, each of which contains 16 individual capillaries and a processing rotor. One disk accepts larger capillaries that hold approximately 100 microL of whole blood each. The second disk accepts 2.54-cm-long precision capillaries of various internal diameters, which provide exact sample volumes from 1 to 10 microL. The processing rotor contains 16 individual compartments and chambers to accept both disks. Applying centrifugal force transfers the aliquots of whole blood into their respective compartments, where they are separated into cellular and plasma fractions. As the rotor speed is slowly decreased, an aliquot of plasma is withdrawn by capillary action into each measuring capillary. The disk containing the 16 measured aliquots of plasma is then removed and placed into a modified rotor for conventional centrifugal analysis. This device can entrain and deliver microliter volumes of liquids with precision and accuracy (1-2%) near that of mechanical pipettes. Assays of the separated plasma aliquots also have acceptable precision (e.g., CVs approximately 3% for measurements of serum enzymes).

  15. Micro-manufacturing technologies and their applications a theoretical and practical guide

    Shipley, David


    This book provides in-depth theoretical and practical information on recent advances in micro-manufacturing technologies and processes, covering such topics as micro-injection moulding, micro-cutting, micro-EDM, micro-assembly, micro-additive manufacturing, moulded interconnected devices, and microscale metrology. It is designed to provide complementary material for the related e-learning platform on micro-manufacturing developed within the framework of the Leonardo da Vinci project 2013-3748/542424: MIMAN-T: Micro-Manufacturing Training System for SMEs. The book is mainly addressed to technicians and prospective professionals in the sector and will serve as an easily usable tool to facilitate the translation of micro-manufacturing technologies into tangible industrial benefits. Numerous examples are included to assist readers in learning and implementing the described technologies. In addition, an individual chapter is devoted to technological foresight, addressing market analysis and business models for mic...

  16. Micro Flow Cytometer Chip Integrated with Micro-Pumps/Micro-Valves for Multi-Wavelength Cell Counting and Sorting

    Chang, Chen-Min; Hsiung, Suz-Kai; Lee, Gwo-Bin


    Flow cytometry is a popular technique for counting and sorting of individual cells. This study presents a new chip-based flow cytometer capable of cell injection, counting and switching in an automatic format. The new microfluidic system is also capable of multi-wavelength detection of fluorescence-labeled cells by integrating multiple buried optical fibers within the chip. Instead of using large-scale syringe pumps, this study integrates micro-pumps and micro-valves to automate the entire cell injection and sorting process. By using pneumatic serpentine-shape (S-shape) micro-pumps to drive sample and sheath flows, the developed chip can generate hydrodynamic focusing to allow cells to pass detection regions in sequence. Two pairs of optical fibers are buried and aligned with the microchannels, which can transmit laser light sources with different wavelengths and can collect induced fluorescence signals. The cells labeled with different fluorescent dyes can be excited by the corresponding light source at different wavelengths. The fluorescence signals are then collected by avalanche photodiode (APD) sensors. Finally, a flow switching device composed of three pneumatic micro-valves is used for cell sorting function. Experimental data show that the developed flow cytometer can distinguish specific cells with different dye-labeling from mixed cell samples in one single process. The target cell samples can be also switched into appropriate outlet channels utilizing the proposed microvalve device. The developed microfluidic system is promising for miniature cell-based biomedical applications.

  17. Pinched flow fractionation devices for detection of single nucleotide polymorphisms

    Larsen, Asger Vig; Poulsen, Lena; Birgens, Henrik


    We demonstrate a new and flexible micro fluidic based method for genotyping single nucleotide polymorphisms ( SNPs). The method relies on size separation of selectively hybridized polystyrene microspheres in a micro fluidic pinched flow fractionation (PFF) device. The micro fluidic PFF devices...... with 13 mu m deep channels were fabricated by thermal nanoimprint lithography ( NIL) in a thin film of cyclic-olefin copolymer (mr-I T85) on a silicon wafer substrate, and the channels were sealed by thermal polymer bonding. Streptavidin coated polystyrene microspheres with a mean diameter of 3.09 mu m...

  18. The corneal pocket assay.

    Ziche, Marina; Morbidelli, Lucia


    The cornea in most species is physiologically avascular, and thus this assay allows the measurement of newly formed vessels. The continuous monitoring of neovascular growth in the same animal allows the evaluation of drugs acting as suppressors or stimulators of angiogenesis. Under anesthesia a micropocket is produced in the cornea thickness and the angiogenesis stimulus (tumor tissue, cell suspension, growth factor) is placed into the pocket in order to induce vascular outgrowth from the limbal capillaries. Neovascular development and progression can be modified by the presence of locally released or applied inhibitory factors or by systemic treatments. In this chapter the experimental details of the avascular cornea assay, the technical challenges, and advantages and disadvantages in different species are discussed. Protocols for local drug treatment and tissue sampling for histology and pharmacokinetic profile are reported.

  19. Kinetic Tetrazolium Microtiter Assay

    Pierson, Duane L.; Stowe, Raymond; Koenig, David


    Kinetic tetrazolium microtiter assay (KTMA) involves use of tetrazolium salts and Triton X-100 (or equivalent), nontoxic, in vitro color developer solubilizing colored metabolite formazan without injuring or killing metabolizing cells. Provides for continuous measurement of metabolism and makes possible to determine rate of action of antimicrobial agent in real time as well as determines effective inhibitory concentrations. Used to monitor growth after addition of stimulatory compounds. Provides for kinetic determination of efficacy of biocide, greatly increasing reliability and precision of results. Also used to determine relative effectiveness of antimicrobial agent as function of time. Capability of generating results on day of test extremely important in treatment of water and waste, disinfection of hospital rooms, and in pharmaceutical, agricultural, and food-processing industries. Assay also used in many aspects of cell biology.

  20. Electrooptical devices

    Hurwitz, C. E.


    This report covers work carried out with support of the Department of the Air Force during the period 1 October 1979 through 31 March 1980. A part of this support was provided by the Rome Air Development Center. CW operation at temperatures up to 55 C has been achieved for GaInAsP/InP double-heterostructure (DH) lasers emitting at 1.5 micrometers, which were grown without a GaInAsP buffer layer. These devices are of interest for use as sources in fiber-optics communications systems, since the lowest transmission loss reported for fused-silica optical fibers occurs at 1.55 micrometers. Surface passivation techniques developed for InP and GaInAsP avalanche photodiodes have resulted in reductions of dark current as large as four orders of magnitude, to values as low as .0000016 A/sq cm at 0.9 V(b) where V(b) is the breakdown voltage. Devices consisting entirely of InP have been passivated with plasma-deposited Si3N4, and those with a GaInAsP layer but with the p-n junction in InP have been passivated with polyimide. Neither of these techniques successfully reduces dark currents in devices with the p-n junction in the GaInAsP, but a film of photoresist sprayed with SF6 as the propellant has given excellent results. The electrical characteristics in InP ion implanted with Sn, Ge, Si, and C have been investigated. All of these column IV elements yielded n-type conductivity and Sn, Ge, and Si showed high electrical activation; however, implanted C was found to have a net electrical activation of only about 5 percent.

  1. [Surgical treatment of micro-ophthalmic syndromes].

    Pellerin, P; Mouriaux, F; Dhellemmes-Defoort, S; Guilbert, F


    The complex embryology of the oculo-orbito-palpebral region is responsible for a number of heterogeneous clinicopathological situations, associating variable proportions of the three components of the malformation: micro-anophthalmia, microblepharism, micro-orbitism. Application of the double principle of skin expansion for the eyelids and distraction of the callus for the orbit, as early as possible (first year of life), is possible by means of a device which consists of a combination of an intraorbital expansion balloon, an antireflux valve to avoid effective pressure losses in the balloon, and an injection site for progressive filling of the expansion balloon. The response to these treatments is excellent for cases of simple microphthalmia and micro-orbitism; in complex craniofacial malformations, it generally only partially resolves the problem, but provides a precious complement to the quality of the final repair.

  2. B cell helper assays.

    Abrignani, Sergio; Tonti, Elena; Casorati, Giulia; Dellabona, Paolo


    Activation, proliferation and differentiation of naïve B lymphocytes into memory B cells and plasma cells requires engagement of the B cell receptor (BCR) coupled to T-cell help (1, 2). T cells deliver help in cognate fashion when they are activated upon recognition of specific MHC-peptide complexes presented by B cells. T cells can also deliver help in a non-cognate or bystander fashion, when they do not find specific MHC-peptide complexes on B cells and are activated by alternative mechanisms. T-cell dependent activation of B cells can be studied in vitro by experimental models called "B cell helper assays" that are based on the co-culture of B cells with activated T cells. These assays allow to decipher the molecular bases for productive T-dependent B cell responses. We show here examples of B cell helper assays in vitro, which can be reproduced with any subset of T lymphocytes that displays the appropriate helper signals.

  3. In-membrane micro fuel cell

    Omosebi, Ayokunle; Besser, Ronald


    An in-membrane micro fuel cell comprises an electrically-insulating membrane that is permissive to the flow of cations, such as protons, and a pair of electrodes deposited on channels formed in the membrane. The channels are arranged as conduits for fluids, and define a membrane ridge between the channels. The electrodes are porous and include catalysts for promoting the liberation of a proton and an electron from a chemical species and/or or the recombination of a proton and an electron with a chemical specie. The fuel cell may be provided a biosensor, an electrochemical sensor, a microfluidic device, or other microscale devices fabricated in the fuel cell membrane.

  4. Micro-propulsion and micro-combustion; Micropropulsion microcombustion

    Ribaud, Y.; Dessornes, O.


    The AAAF (french space and aeronautic association) organized at Paris a presentation on the micro-propulsion. The first part was devoted to the thermal micro-machines for micro drones, the second part to the micro-combustion applied to micro-turbines. (A.L.B.)

  5. Metal oxide nanostructures as gas sensing devices

    Eranna, G


    Metal Oxide Nanostructures as Gas Sensing Devices explores the development of an integrated micro gas sensor that is based on advanced metal oxide nanostructures and is compatible with modern semiconductor fabrication technology. This sensor can then be used to create a compact, low-power, handheld device for analyzing air ambience. The book first covers current gas sensing tools and discusses the necessity for miniaturized sensors. It then focuses on the materials, devices, and techniques used for gas sensing applications, such as resistance and capacitance variations. The author addresses th

  6. Scalable devices

    Krüger, Jens J.


    In computer science in general and in particular the field of high performance computing and supercomputing the term scalable plays an important role. It indicates that a piece of hardware, a concept, an algorithm, or an entire system scales with the size of the problem, i.e., it can not only be used in a very specific setting but it\\'s applicable for a wide range of problems. From small scenarios to possibly very large settings. In this spirit, there exist a number of fixed areas of research on scalability. There are works on scalable algorithms, scalable architectures but what are scalable devices? In the context of this chapter, we are interested in a whole range of display devices, ranging from small scale hardware such as tablet computers, pads, smart-phones etc. up to large tiled display walls. What interests us mostly is not so much the hardware setup but mostly the visualization algorithms behind these display systems that scale from your average smart phone up to the largest gigapixel display walls.

  7. Micro- and nanocrystals of organic semiconductors.

    Li, Rongjin; Hu, Wenping; Liu, Yunqi; Zhu, Daoben


    Organic semiconductors have attracted wide attention in recent decades, resulting in the rapid development of organic electronics. For example, the solution processibility of organic semiconductors allows researchers to use unconventional deposition methods (such as inkjet printing and stamping) to fabricate large area devices at low cost. The mechanical properties of organic semiconductors also allow for flexible electronics. However, the most distinguishing feature of organic semiconductors is their chemical versatility, which permits the incorporation of functionalities through molecular design. However, key scientific challenges remain before organic electronics technology can advance further, including both the materials' low charge carrier mobility and researchers' limited knowledge of structure-property relationships in organic semiconductors. We expect that high-quality organic single crystals could overcome these challenges: their purity and long-range ordered molecular packing ensure high device performance and facilitate the study of structure-property relationships. Micro- and nanoscale organic crystals could offer practical advantages compared with their larger counterparts. First, growing small crystals conserves materials and saves time. Second, devices based on the smaller crystals could maintain the functional advantages of larger organic single crystals but would avoid the growth of large crystals, leading to the more efficient characterization of organic semiconductors. Third, the effective use of small crystals could allow researchers to integrate these materials into micro- and nanoelectronic devices using a "bottom-up" approach. Finally, unique properties of crystals at micro- and nanometer scale lead to new applications, such as flexible electronics. In this Account, we focus on organic micro- and nanocrystals, including their design, the controllable growth of crystals, and structure-property studies. We have also fabricated devices and

  8. Practical microwave electron devices

    Meurant, Gerard


    Practical Microwave Electron Devices provides an understanding of microwave electron devices and their applications. All areas of microwave electron devices are covered. These include microwave solid-state devices, including popular microwave transistors and both passive and active diodes; quantum electron devices; thermionic devices (including relativistic thermionic devices); and ferrimagnetic electron devices. The design of each of these devices is discussed as well as their applications, including oscillation, amplification, switching, modulation, demodulation, and parametric interactions.

  9. Microfluidics and Lab-on-a-Chip Devices

    Castillo, Jaime


    The rapid advances in microfabrication and nanofabrication in combination with the synthesis and discovery of new materials have propelled the drive to develop new technological devices such as smartphones, personal and tablet computers. These devices have changed the way humankind interacts...... communicate what is happening around us. Following the advances of all these communication devices as well as those in microfabrication and nanofabrication and the emergence of new materials, technologies such as lab-on-a-chip (LOC) and micro total analysis systems (microTAS) were also boosted, albeit...... at a slower pace. LOC and microTAS applications have principally been utilized in the biomedical, food and environmental fields. But lately they have also found their place in the synthesis of new chemical compounds and the fabrication of nanostructures. It has become obvious that the LOC and micro...



    The invention relates to an assembly for sterilizing surfaces and lumens of a medical device with a light source. The light source can emit light that reduces the number of or removes micro organisms from the lumen and/or surfaces of the medical device. The invention relates to an assembly compri...



    The invention relates to an assembly for sterilizing surfaces and lumens of a medical device with a light source. The light source can emit light that reduces the number of or removes micro organisms from the lumen and/or surfaces of the medical device. The invention relates to an assembly...

  12. 3D-printed microfluidic devices.

    Amin, Reza; Knowlton, Stephanie; Hart, Alexander; Yenilmez, Bekir; Ghaderinezhad, Fariba; Katebifar, Sara; Messina, Michael; Khademhosseini, Ali; Tasoglu, Savas


    Microfluidics is a flourishing field, enabling a wide range of biochemical and clinical applications such as cancer screening, micro-physiological system engineering, high-throughput drug testing, and point-of-care diagnostics. However, fabrication of microfluidic devices is often complicated, time consuming, and requires expensive equipment and sophisticated cleanroom facilities. Three-dimensional (3D) printing presents a promising alternative to traditional techniques such as lithography and PDMS-glass bonding, not only by enabling rapid design iterations in the development stage, but also by reducing the costs associated with institutional infrastructure, equipment installation, maintenance, and physical space. With the recent advancements in 3D printing technologies, highly complex microfluidic devices can be fabricated via single-step, rapid, and cost-effective protocols, making microfluidics more accessible to users. In this review, we discuss a broad range of approaches for the application of 3D printing technology to fabrication of micro-scale lab-on-a-chip devices.

  13. Scaling from discs to pleated devices.

    Giglia, Sal; Yavorsky, David


    Membrane discs offer a convenient format for evaluating membrane performance in normal flow filtration. However, while pleated devices of different sizes tend to scale in close proportion to their contained areas, they do not necessarily scale in direct proportion from flat discs. The objectives of this study are to quantify differences in performance among sterilizing-grade membrane devices as a function of device type and size, to develop an understanding of the factors that affect device scalability, and to develop a mathematical model to predict a cartridge-to-disc scalability factor based on membrane properties and porous support properties and dimensions. Measured and predicted normalized water permeability scalability factors for seven types of pleated cartridges, including 0.1-micro and 0.2-micro rated PES, and 0.2-micro rated polyvinylidene fluoride (PVDF) sterilizing-grade filters in nominal 1-inch to 5-inch lengths, were determined. The results of this study indicate that pleated cartridge performance can be closely predicted based on 47-mm disc performance provided that a number of measured device parameters are properly accounted for, most importantly parasitic pressure losses in the filter device and plumbing connections, intrinsic membrane variability, true effective device filtration area, and the hydraulic properties of all porous support materials. Throughput scalability factors (discs to devices) tend to converge towards unity, especially for highly plugging streams. As the membrane fouls, the resistance through the membrane dominates other resistances, so the flux scales more linearly with membrane area and the overall scaling factor becomes close to one. The results of throughput tests on seven different cartridge types and five different challenge streams (with widely varying fouling characteristics) show that most of the throughput scaling factors were within +/-10% of 1.0. As part of this study, the effects of pressure and temperature were

  14. Electrophoresis device

    Rhodes, P. H.; Snyder, R. S. (Inventor)


    A device for separating cellular particles of a sample substance into fractionated streams of different cellular species includes a casing having a distribution chamber, a separation chamber, and a collection chamber. The electrode chambers are separated from the separation chamber interior by means of passages such that flow variations and membrane variations around the slotted portion of the electrode chamber do not enduce flow perturbations into the laminar buffer curtain flowing in the separation chamber. The cellular particles of the sample are separated under the influence of the electrical field and the separation chamber into streams of different cellular species. The streams of separated cells enter a partition array in the collection chamber where they are fractionated and collected.

  15. Stratification devices

    Andersen, Elsa; Furbo, Simon


    heating system. High temperatures in the top of the storage tank established by the energy from the solar collector reduce the use of auxiliary energy. Low temperatures in the bottom of the storage tank improve the operation conditions for the solar collector. Using thermal stratified heat storages...... results in longer operation periods and improved utilization of the solar collector. Thermal stratification can be achieved, for example by using inlet stratification devices at all inlets to the storage tank. This paper presents how thermal stratification is established and utilized by means of inlet......Thermal stratification in the storage tank is extremely important in order to achieve high thermal performance of a solar heating system. High temperatures in the top of the storage tank and low temperatures in the bottom of the storage tank lead to the best operation conditions for any solar...

  16. Improving rotation behaviour of robotic structures for micro-assembly.

    Hériban, David; Thiebault, Arnaud; Gauthier, Michaël; Fortier, Guillaume


    International audience; Serial micro-assembly requires high precision robots able to produce translations and rotations to position and orient objects during assembly. In micro-scale, the translation ranges required are typically up to the millimeter and can be obtained with smart devices (piezomotor, etc...). In the other hand, the rotation ranges stay identical to the macroscale (eg. 90°) and require standard guidings like ball bearings which induce disturbances on the linear position. Thus...

  17. Topology Detection in Microgrids with Micro-Synchrophasors

    Arghandeh, Reza; Gahr, Martin; von Meier, Alexandra; Cavraro, Guido; Ruh, Monika; Andersson, Göran


    Network topology in distribution networks is often unknown, because most switches are not equipped with measurement devices and communication links. However, knowledge about the actual topology is critical for safe and reliable grid operation. This paper proposes a voting-based topology detection method based on micro-synchrophasor measurements. The minimal difference between measured and calculated voltage angle or voltage magnitude, respectively, indicates the actual topology. Micro-synchro...

  18. Micro Photo Detector Fabricated of Ferroelectric–Metal Heterostructure



    The anomalous photovoltaic effect (APE) in ferroelectric thin films has been utilized for the development of an optical micro-detector active in the visible range (from 350 to 800 nm). La-doped Pb(Zr,Ti)O3 (PLZT) ferroelectric films epitaxially grown on Pt(001)/Mg(001) substrate were fabricated into micro-detector arrays and characterized as to their optical response. The Au/PLZT/Pt/MgO device was self-polarized in the as-deposited form with the polarization vector perpendicular to film surface. The heterostructure photovoltage response ranged from 100 to 200 mV, and the photocurrent was ~30 nA/cm2 for devices of ~250 μm diameter under illumination of 100 mW/cm2 at wavelengths from 400 to 580 nm. Such micro-detectors can be used for optical sensors in MEMS devices as well as for electrical stimulators of biological cells. PMID:21472042

  19. Growth cone collapse assay.

    Cook, Geoffrey M W; Jareonsettasin, Prem; Keynes, Roger J


    The growth cone collapse assay has proved invaluable in detecting and purifying axonal repellents. Glycoproteins/proteins present in detergent extracts of biological tissues are incorporated into liposomes, added to growth cones in culture and changes in morphology are then assessed. Alternatively purified or recombinant molecules in aqueous solution may be added directly to the cultures. In both cases after a defined period of time (up to 1 h), the cultures are fixed and then assessed by inverted phase contrast microscopy for the percentage of growth cones showing a collapsed profile with loss of flattened morphology, filopodia, and lamellipodia.

  20. Radon assay for SNO+

    Rumleskie, Janet [Laurentian University, Greater Sudbury, Ontario (Canada)


    The SNO+ experiment will study neutrinos while located 6,800 feet below the surface of the earth at SNOLAB. Though shielded from surface backgrounds, emanation of radon radioisotopes from the surrounding rock leads to back-grounds. The characteristic decay of radon and its daughters allows for an alpha detection technique to count the amount of Rn-222 atoms collected. Traps can collect Rn-222 from various positions and materials, including an assay skid that will collect Rn-222 from the organic liquid scintillator used to detect interactions within SNO+.


    Minoru KAMATA


    Full Text Available The authors propose the use of micro-electric vehicles called “silver vehicles” (SV as mobility devices for older drivers who have difficulty driving automobiles. Previous reports have described research on characteristics of the elderly, proposed the SV concept and evaluated it in townmobility field tests. This report addresses feasibility of the SV concept and issues of town planning through a follow-up study of characteristics of the elderly three years later, long-term in-use testing of SV-comparable production vehicles, and investigations of elderly driver characteristics and trailing behavior in mixed traffic situations.

  2. Advances in Assays and Analytical Approaches for Botulinum Toxin Detection

    Grate, Jay W.; Ozanich, Richard M.; Warner, Marvin G.; Bruckner-Lea, Cindy J.; Marks, James D.


    Methods to detect botulinum toxin, the most poisonous substance known, are reviewed. Current assays are being developed with two main objectives in mind: 1) to obtain sufficiently low detection limits to replace the mouse bioassay with an in vitro assay, and 2) to develop rapid assays for screening purposes that are as sensitive as possible while requiring an hour or less to process the sample an obtain the result. This review emphasizes the diverse analytical approaches and devices that have been developed over the last decade, while also briefly reviewing representative older immunoassays to provide background and context.

  3. Intelligent micro blood typing system using a fuzzy algorithm

    Kang, Taeyun; Lee, Seung-Jae; Kim, Yonggoo; Lee, Gyoo-Whung; Cho, Dong-Woo


    ABO typing is the first analysis performed on blood when it is tested for transfusion purposes. The automated machines used in hospitals for this purpose are typically very large and the process is complicated. In this paper, we present a new micro blood typing system that is an improved version of our previous system (Kang et al 2004 Trans. ASME, J. Manuf. Sci. Eng. 126 766, Lee et al 2005 Sensors Mater. 17 113). This system, fabricated using microstereolithography, has a passive valve for controlling the flow of blood and antibodies. The intelligent micro blood typing system has two parts: a single-line micro blood typing device and a fuzzy expert system for grading the strength of agglutination. The passive valve in the single-line micro blood typing device makes the blood stop at the entrance of a micro mixer and lets it flow again after the blood encounters antibodies. Blood and antibodies are mixed in the micro mixer and agglutination occurs in the chamber. The fuzzy expert system then determines the degree of agglutination from images of the agglutinated blood. Blood typing experiments using this device were successful, and the fuzzy expert system produces a grading decision comparable to that produced by an expert conducting a manual analysis.

  4. The Development of a Hybrid Underwater Micro Biped Robot

    S. Guo


    Full Text Available There has been a great demand, in the medical field and in industrial applications, for a novel micro biped robot with multiple degrees of freedom that can swim smoothly in water or in aqueous medium. The fish-like micro-robot studied is a type of miniature device that is installed with sensing and actuating elements. This article describes the new structure and motion mechanism of a hybrid type of underwater micro-robot using an ion-conducting polymer film (ICPF actuator, and discusses the swimming and floating characteristics of the micro-robot in water, measured by changing the voltage frequency and the amplitude of the input voltage. Results indicate that the swimming speed of the proposed underwater micro-robot can be controlled by changing the frequency of the input voltage, and the direction (upward or downward can be manipulated by changing the frequency of the electric current applied and the amplitude of the voltage.

  5. Micro-relay technology for energy-efficient integrated circuits

    Kam, Hei


    This book describes the design of relay-based circuit systems from device fabrication to circuit micro-architectures. This book is ideal for both device engineers as well as circuit system designers and highlights the importance of co-design across design hierarchies when optimizing system performance (in this case, energy-efficiency). This book is ideal for researchers and engineers focused on semiconductors, integrated circuits, and energy efficient electronics. This book also: ·         Covers microsystem fabrication, MEMS device design, circuit design, circuit micro-architecture, and CAD ·         Describes work previously done in the field and also lays the groundwork and criteria for future energy-efficient device and system design ·         Maximizes reader insights into the design and modeling of micro-relay, micro-relay reliability, integrated circuit design with micro-relays, and more

  6. RAS - Screens & Assays - Drug Discovery

    The RAS Drug Discovery group aims to develop assays that will reveal aspects of RAS biology upon which cancer cells depend. Successful assay formats are made available for high-throughput screening programs to yield potentially effective drug compounds.

  7. VLSI micro- and nanophotonics science, technology, and applications

    Lee, El-Hang; Razeghi, Manijeh; Jagadish, Chennupati


    Addressing the growing demand for larger capacity in information technology, VLSI Micro- and Nanophotonics: Science, Technology, and Applications explores issues of science and technology of micro/nano-scale photonics and integration for broad-scale and chip-scale Very Large Scale Integration photonics. This book is a game-changer in the sense that it is quite possibly the first to focus on ""VLSI Photonics"". Very little effort has been made to develop integration technologies for micro/nanoscale photonic devices and applications, so this reference is an important and necessary early-stage pe

  8. Integrated micro ring resonator displacement sensor for scanning probe microscopies

    Kiyat, Isa; Kocabas, Coskun; Aydinli, Atilla


    We describe a novel displacement sensor for scanning probe microscopies using an integrated optical micro ring resonator. This device operates by means of monitoring the changes in the transmission spectrum of a high finesse micro ring resonator. Finite element method simulations were carried out to obtain the optimum sensor design and finite difference time domain simulation was used to obtain the transfer characteristics of micro ring resonators. Operation principles and sensitivity calculations are discussed in detail. To achieve high sensitivity, we have studied different types of ring resonator. The highest sensitivity is obtained in a race-track resonator. This new design should provide sensitivities as high as ~10-4 Å-1.

  9. Analysis of a Micro-Optomechatronic Force Sensor

    Fakhrabadi, M. M. S.; Ghanbari, A.; Rostami, A.; Janabi Sharifi, F.


    The purpose of this article is to study the dynamic behavior and modal analysis of a micro-optomechatronic device with primary applications to force sensing and optical attenuation/coupling. The system consists of two initially aligned micro-cantilevers with a narrow gap between them. The light beam enters to the first waveguide and, after propagation along it, couples to second waveguide through the mentioned narrow gap. The externally static or dynamic applied force on the first micro-cantilever deflects it and results in reduced optical coupling between the two waveguides. Changes in this factor are measured to give the properties of the applied force.

  10. Biomass based micro-turbine plant and distribution network stability

    Jurado, F.; Cano, A. [Jaen Univ., Linares (Spain). Dept. of Electrical Engineering; Carpio, J. [Universidad Nacional de Educacion a Distancia, Madrid (Spain). Dept. of Electrical and Computer Engineering


    Micro-turbine systems that enable the use of biomass are important for future technologies for electricity production. These distributed resources are dynamic devices, and when connected to the distribution system, they will affect its dynamic behavior. The micro-turbine is capable of providing effective load following service in the distribution system. However, the results also show that the micro-turbine system is not an uninterruptible power supply and does not protect the load from voltage instability while in a grid connect mode. (Author)

  11. Review on Micro- and Nanolithography Techniques and Their Applications

    Werayut Srituravanich


    Full Text Available This article reviews major micro- and nanolithography techniques and their applications from commercial micro devices to emerging applications in nanoscale science and engineering. Micro- and nanolithography has been the key technology in manufacturing of integrated circuits and microchips in the semiconductor industry. Such a technology is also sparking a magnificent transformation of nanotechnology. The lithography techniques including photolithography, electron beam lithography, focused ion beam lithography, soft lithography, nanoimprint lithography and scanning probe lithography are discussed. Furthermore, their applications are reviewed and summarized into four major areas: electronics and microsystems, medical and biotech, optics and photonics, and environment and energy harvesting.

  12. Integrated device architectures for electrochromic devices

    Frey, Jonathan Mack; Berland, Brian Spencer


    This disclosure describes systems and methods for creating monolithically integrated electrochromic devices which may be a flexible electrochromic device. Monolithic integration of thin film electrochromic devices may involve the electrical interconnection of multiple individual electrochromic devices through the creation of specific structures such as conductive pathway or insulating isolation trenches.

  13. Recent Developments in Micro-Structured Fiber Optic Sensors

    Yanping Xu


    Full Text Available Recent developments in fiber-optic sensing have involved booming research in the design and manufacturing of novel micro-structured optical fiber devices. From the conventional tapered fiber architectures to the novel micro-machined devices by advanced laser systems, thousands of micro-structured fiber-optic sensors have been proposed and fabricated for applications in measuring temperature, strain, refractive index (RI, electric current, displacement, bending, acceleration, force, rotation, acoustic, and magnetic field. The renowned and unparalleled merits of sensors-based micro-machined optical fibers including small footprint, light weight, immunity to electromagnetic interferences, durability to harsh environment, capability of remote control, and flexibility of directly embedding into the structured system have placed them in highly demand for practical use in diverse industries. With the rapid advancement in micro-technology, micro-structured fiber sensors have benefitted from the trends of possessing high performance, versatilities and spatial miniaturization. Here, we comprehensively review the recent progress in the micro-structured fiber-optic sensors with a variety of architectures regarding their fabrications, waveguide properties and sensing applications.


    WANG Rui-jin; LIN Jian-zhong


    The diffusion-based micro flow of a T-sensor with three inlets in which various species are injected was simulated numerically. The results show that the Reynolds number is an important factor of affecting the efficiency of diffusion The smaller the channel width is, the more strongly the species diffuse. The velocity gradient across the channel width plays a key role in the diffusion of species. The conclusions are helpful to the design of micro-fluidic devices and the analysis of data collected from such devices.

  15. Modelling of micro-Hall sensors for magnetization imaging

    Manzin, A.; Nabaei, V.


    This paper presents a numerical model for the study of micro-Hall magnetometry applications, aiming at evaluating the sensitivity of semiconductor miniaturized devices to the stray field of permalloy nanostructures with ring and disk geometry. The procedure couples a micromagnetic code, for the calculation of the stray field generated by the nanomagnet, to a 2D classical transport model for the determination of the electric potential distribution inside the Hall plate. The model is applied to study the sensitivity of a micro-Hall device in the detection of magnetization switching processes characterized by vortex state, focusing on the influence of magnetic nanostructure position.

  16. A new generation of low-voltage single-photon micro-sensors with timing capability

    Finocchiaro, P. [INFN-Laboratori Nazionali del Sud, Via Santa Sofia 64, 95125 Catania (Italy)]. E-mail:; Campisi, A. [INFN-Laboratori Nazionali del Sud, Via Santa Sofia 64, 95125 Catania (Italy); Cosentino, L. [INFN-Laboratori Nazionali del Sud, Via Santa Sofia 64, 95125 Catania (Italy); Pappalardo, A. [INFN-Laboratori Nazionali del Sud, Via Santa Sofia 64, 95125 Catania (Italy); Musumeci, F. [INFN-Laboratori Nazionali del Sud, Via Santa Sofia 64, 95125 Catania (Italy); DMFCI-Universita di Catania, Viale A. Doria 6, 95125 Catania (Italy); Privitera, S. [INFN-Laboratori Nazionali del Sud, Via Santa Sofia 64, 95125 Catania (Italy); DMFCI-Universita di Catania, Viale A. Doria 6, 95125 Catania (Italy); Scordino, A. [INFN-Laboratori Nazionali del Sud, Via Santa Sofia 64, 95125 Catania (Italy); DMFCI-Universita di Catania, Viale A. Doria 6, 95125 Catania (Italy); Tudisco, S. [INFN-Laboratori Nazionali del Sud, Via Santa Sofia 64, 95125 Catania (Italy); DMFCI-Universita di Catania, Viale A. Doria 6, 95125 Catania (Italy); Fallica, G. [ST-Microelectronics, Stradale Primosole 50, I95100 Catania (Italy); Sanfilippo, D. [ST-Microelectronics, Stradale Primosole 50, I95100 Catania (Italy); Mazzillo, M. [ST-Microelectronics, Stradale Primosole 50, I95100 Catania (Italy); Piazza, A. [ST-Microelectronics, Stradale Primosole 50, I95100 Catania (Italy); Van Erps, J. [Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels (Belgium); Vervaeke, M. [Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels (Belgium); Volckaerts, B. [Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels (Belgium); Vynck, P. [Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels (Belgium); Hermanne, A. [Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels (Belgium); Thienpont, H. [Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels (Belgium); Lombardo, S. [CNR-IMM, Catania (Italy); Sciacca, E. [CNR-IMM, Catania (Italy)


    We briefly describe a project which aims at proving that single-photon sensing can be made accessible in form of low-cost off-the-shelf micro-devices with micro-optical/micro-mechanical coupling systems. In order to achieve this challenging goal, we are making use of two different micro-technologies, not yet fully established but promising and innovative in and of themselves. We then plan to combine them into a more challenging micro-technology, capable of bringing the single-photon handling to the shelf.

  17. Search for Bs0 --> micro+ micro- and B0 --> micro+ micro- decays with 2 fb-1 of pp collisions.

    Aaltonen, T; Adelman, J; Akimoto, T; Albrow, M G; Alvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Bednar, P; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'orso, M; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Genser, K; Gerberich, H; Gerdes, D; Giagu, S; Giakoumopolou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Koay, S A; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lu, R-S; Lucchesi, D; Lueck, J; Luci, C; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; Macqueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moed, S; Moggi, N; Moon, C S; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyria, A; Shalhout, S Z; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thompson, G A; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner-Kuhr, J; Wagner, W; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zheng, Y; Zucchelli, S


    We have performed a search for B(s)(0) --> micro(+) micro(-) and B(0) --> micro(+) micro(-) decays in pp collisions at square root s = 1.96 TeV using 2 fb(-1) of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron Collider. The observed number of B(s)(0) and B0 candidates is consistent with background expectations. The resulting upper limits on the branching fractions are B(B(s)0) --> micro(+) micro(-)) micro(+) micro(-))<1.8 x 10(-8) at 95% C.L.

  18. Extraction, amplification and detection of DNA in microfluidic chip-based assays

    Wu, Jinbo


    This review covers three aspects of PCR-based microfluidic chip assays: sample preparation, target amplification, and product detection. We also discuss the challenges related to the miniaturization and integration of each assay and make a comparison between conventional and microfluidic schemes. In order to accomplish these essential assays without human intervention between individual steps, the micro-components for fluid manipulation become critical. We therefore summarize and discuss components such as microvalves (for fluid regulation), pumps (for fluid driving) and mixers (for blending fluids). By combining the above assays and microcomponents, DNA testing of multi-step bio-reactions in microfluidic chips may be achieved with minimal external control. The combination of assay schemes with the use of micro-components also leads to rapid methods for DNA testing via multi-step bioreactions. Contains 259 references.

  19. Laser device

    Scott, Jill R.; Tremblay, Paul L.


    A laser device includes a target position, an optical component separated a distance J from the target position, and a laser energy source separated a distance H from the optical component, distance H being greater than distance J. A laser source manipulation mechanism exhibits a mechanical resolution of positioning the laser source. The mechanical resolution is less than a spatial resolution of laser energy at the target position as directed through the optical component. A vertical and a lateral index that intersect at an origin can be defined for the optical component. The manipulation mechanism can auto align laser aim through the origin during laser source motion. The laser source manipulation mechanism can include a mechanical index. The mechanical index can include a pivot point for laser source lateral motion and a reference point for laser source vertical motion. The target position can be located within an adverse environment including at least one of a high magnetic field, a vacuum system, a high pressure system, and a hazardous zone. The laser source and an electro-mechanical part of the manipulation mechanism can be located outside the adverse environment. The manipulation mechanism can include a Peaucellier linkage.

  20. Bacterial assays for recombinagens.

    Hoffmann, G R


    Two principal strategies have been used for studying recombinagenic effects of chemicals and radiation in bacteria: (1) measurement of homologous recombination involving defined alleles in a partially diploid strain, and (2) measurement of the formation and loss of genetic duplications in the bacterial chromosome. In the former category, most methods involve one allele in the bacterial chromosome and another in a plasmid, but it is also possible to detect recombination between two chromosomal alleles or between two extrachromosomal alleles. This review summarizes methods that use each of these approaches for detecting recombination and tabulates data on agents that have been found to be recombinagenic in bacteria. The assays are discussed with respect to their effectiveness in testing for recombinagens and their potential for elucidating mechanisms underlying recombinagenic effects.