Development of a Surface Micromachined On-Chip Flat Disk Micropump

Directory of Open Access Journals (Sweden)

M. I. KILANI

2009-08-01

Full Text Available The paper presents research progress in the development of a surface micromachined flat disk micropump which employs the viscous and centrifugal effects acting on a layer of fluid sandwiched between a rotating flat disk and a stationary plate. The pump is fabricated monolithically on-chip using Sandia’s Ultraplanar Multilevel MEMS Technology (SUMMiT™ where an electrostatic comb-drive Torsional Ratcheting Actuator (TRA drives the flat disk through a geared transmission. The paper reviews available analytical models for flow geometries similar to that of the described pump, and presents a set of experiments which depict its performance and possible failure modes. Those experiments highlight future research directions in the development of electrostatically-actuated, CMOS-compatible, surface micromachined pumps.

High definition surface micromachining of LiNbO 3 by ion implantation

Science.gov (United States)

Chiarini, M.; Bentini, G. G.; Bianconi, M.; De Nicola, P.

2010-10-01

High Energy Ion Implantation (HEII) of both medium and light mass ions has been successfully applied for the surface micromachining of single crystal LiNbO 3 (LN) substrates. It has been demonstrated that the ion implantation process generates high differential etch rates in the LN implanted areas, when suitable implantation parameters, such as ion species, fluence and energy, are chosen. In particular, when traditional LN etching solutions are applied to suitably ion implanted regions, etch rates values up to three orders of magnitude higher than the typical etching rates of the virgin material, are registered. Further, the enhancement in the etching rate has been observed on x, y and z-cut single crystalline material, and, due to the physical nature of the implantation process, it is expected that it can be equivalently applied also to substrates with different crystallographic orientations. This technique, associated with standard photolithographic technologies, allows to generate in a fast and accurate way very high aspect ratio relief micrometric structures on LN single crystal surface. In this work a description of the developed technology is reported together with some examples of produced micromachined structures: in particular very precisely defined self sustaining suspended structures, such as beams and membranes, generated on LN substrates, are presented. The developed technology opens the way to actual three dimensional micromachining of LN single crystals substrates and, due to the peculiar properties characterising this material, (pyroelectric, electro-optic, acousto-optic, etc.), it allows the design and the production of complex integrated elements, characterised by micrometric features and suitable for the generation of advanced Micro Electro Optical Systems (MEOS).

Enhancing structural integrity of adhesive bonds through pulsed laser surface micro-machining

KAUST Repository

Diaz, Edwin Hernandez

2015-06-01

Enhancing the effective peel resistance of plastically deforming adhesive joints through laser-based surface micro-machining Edwin Hernandez Diaz Inspired by adhesion examples commonly found in nature, we reached out to examine the effect of different kinds of heterogeneous surface properties that may replicate this behavior and the mechanisms at work. In order to do this, we used pulsed laser ablation on copper substrates (CuZn40) aiming to increase adhesion for bonding. A Yb-fiber laser was used for surface preparation of the substrates, which were probed with a Scanning Electron Microscope (SEM) and X-ray Photoelectron Spectroscopy (XPS). Heterogeneous surface properties were devised through the use of simplified laser micromachined patterns which may induce sequential events of crack arrest propagation, thereby having a leveraging effect on dissipation. The me- chanical performance of copper/epoxy joints with homogeneous and heterogeneous laser micromachined interfaces was then analyzed using the T-peel test. Fractured surfaces were analyzed using SEM to resolve the mechanism of failure and adhesive penetration within induced surface asperities from the treatment. Results confirm positive modifications of the surface morphology and chemistry from laser ablation that enable mechanical interlocking and cohesive failure within the adhesive layer. Remarkable improvements of apparent peel energy, bond toughness, and effective peel force were appreciated with respect to sanded substrates as control samples.

Optical micro-metrology of structured surfaces micro-machined by jet-ECM

DEFF Research Database (Denmark)

Quagliotti, Danilo; Tosello, Guido; Islam, Aminul

2015-01-01

A procedure for statistical analysis and uncertainty evaluation is presented with regards to measurements of step height and surface texture. Measurements have been performed with a focus-variation microscope over jet electrochemical micro-machined surfaces. Traceability has been achieved using a...

Surface-micromachined rotatable member having a low-contact-area hub

Science.gov (United States)

Rodgers, M. Steven; Sniegowski, Jeffry J.; Krygowski, Thomas W.

2003-11-18

A surface-micromachined rotatable member formed on a substrate and a method for manufacturing thereof are disclosed. The surface-micromachined rotatable member, which can be a gear or a rotary stage, has a central hub, and an annulus connected to the central hub by an overarching bridge. The hub includes a stationary axle support attached to the substrate and surrounding an axle. The axle is retained within the axle support with an air-gap spacing therebetween of generally 0.3 .mu.m or less. The rotatable member can be formed by alternately depositing and patterning layers of a semiconductor (e.g. polysilicon or a silicon-germanium alloy) and a sacrificial material and then removing the sacrificial material, at least in part. The present invention has applications for forming micromechanical or microelectromechanical devices requiring lower actuation forces, and providing improved reliability.

Surface--micromachined rotatable member having a low-contact-area hub

Science.gov (United States)

Rodgers, M. Steven; Sniegowski, Jeffry J.

2002-01-01

A surface-micromachined rotatable member formed on a substrate and a method for manufacturing thereof are disclosed. The surface-micromachined rotatable member, which can be a gear or a rotary stage, has a central hub, and an annulus connected to the central hub by an overarching bridge. The hub includes a stationary axle support attached to the substrate and surrounding an axle. The axle is retained within the axle support with an air-gap spacing therebetween of generally 0.3 .mu.m or less. The rotatable member can be formed by alternately depositing and patterning layers of a semiconductor (e.g. polysilicon or a silicon-germanium alloy) and a sacrificial material and then removing the sacrificial material, at least in part. The present invention has applications for forming micromechanical or microelectromechanical devices requiring lower actuation forces, and providing improved reliability.

First reliability test of a surface micromachined microengine using SHiMMeR

Energy Technology Data Exchange (ETDEWEB)

Tanner, D.M.; Smith, N.F.; Bowman, D.J. [and others

1997-08-01

The first-ever reliability stress test on surface micromachined microengines developed at Sandia National Laboratories (SNL) has been completed. We stressed 41 microengines at 36,000 RPM and inspected the functionality at 60 RPM. We have observed an infant mortality region, a region of low failure rate (useful life), and no signs of wearout in the data. The reliability data are presented and interpreted using standard reliability methods. Failure analysis results on the stressed microengines are presented. In our effort to study the reliability of MEMS, we need to observe the failures of large numbers of parts to determine the failure modes. To facilitate testing of large numbers of micromachines. The Sandia High Volume Measurement of Micromachine Reliability (SHiMMeR) system has computer controlled positioning and the capability to inspect moving parts. The development of this parallel testing system is discussed in detail.

A wafer mapping technique for residual stress in surface micromachined films

International Nuclear Information System (INIS)

Schiavone, G; Murray, J; Smith, S; Walton, A J; Desmulliez, M P Y; Mount, A R

2016-01-01

The design of MEMS devices employing movable structures is crucially dependant on the mechanical behaviour of the deposited materials. It is therefore important to be able to fully characterize the micromachined films and predict with confidence the mechanical properties of patterned structures. This paper presents a characterization technique that enables the residual stress in MEMS films to be mapped at the wafer level by using microstructures released by surface micromachining. These dedicated MEMS test structures and the associated measurement techniques are used to extract localized information on the strain and Young’s modulus of the film under investigation. The residual stress is then determined by numerically coupling this data with a finite element analysis of the structure. This paper illustrates the measurement routine and demonstrates it with a case study using electrochemically deposited alloys of nickel and iron, particularly prone to develop high levels of residual stress. The results show that the technique enables wafer mapping of film non-uniformities and identifies wafer-to-wafer differences. A comparison between the results obtained from the mapping technique and conventional wafer bow measurements highlights the benefits of using a procedure tailored to films that are non-uniform, patterned and surface-micromachined, as opposed to simple standard stress extraction methods. The presented technique reveals detailed information that is generally unexplored when using conventional stress extraction methods such as wafer bow measurements. (paper)

Fabrication of piezoresistive microcantilever using surface micromachining technique for biosensors

Energy Technology Data Exchange (ETDEWEB)

Na, Kwang-Ho [Department of Electrical Engineering and Nano-Bio Research Center, Myongji University, Yongin, Gyeonggido 449-728 (Korea, Republic of); Kim, Yong-Sang [Department of Electrical Engineering and Nano-Bio Research Center, Myongji University, Yongin, Gyeonggido 449-728 (Korea, Republic of); Kang, C.J. [Department of Physics and Nano-Bio Research Center, Myongji University, San38-2 Namdong, Yongin, Gyeonggido 449-728 (Korea, Republic of)]. E-mail: cjkang@mju.ac.kr

2005-11-15

A microcantilever-based biosensor with piezoresistor has been fabricated using surface micromachining technique, which is cost effective and simplifies a fabrication procedure. In order to evaluate the characteristics of the cantilever, the cystamine terminated with thiol was covalently immobilized on the gold-coated side of the cantilever and glutaraldehyde that would be bonded with amine group in the cystamine was injected subsequently. This process was characterized by measuring the deflection of the cantilever in real time monitoring. Using a piezoresistive read-out and a well-known optical beam deflection method as well, the measurement of deflection was carried out. The sensitivity of piezoresistive method is good enough compared with that of optical beam deflection method.

Minimizing stress in large-area surface micromachined perforated membranes with slits

International Nuclear Information System (INIS)

Ghaderi, M; Ayerden, N P; De Graaf, G; Wolffenbuttel, R F

2015-01-01

This paper presents the effectiveness of both design and fabrication techniques for avoiding the rupturing or excessive bending of perforated membranes after release in surface micromachining. Special lateral designs of arrays of slits in the membrane were investigated for a maximum yield at a given level of residual stress. Process parameters were investigated and optimized for minimum residual stress in multilayer thin-film membranes. A 2 µm thick sacrificial TEOS layer and a structural membrane that is composed of silicon nitride and polysilicon layers in the stack is the basis of this study. The effect of sharp corners on the local stress in membranes was investigated, and structures are proposed that reduce these effects, maximizing the yield at a given level of residual stress. The effects of perforation and slits were studied both theoretically and using finite element analysis. While the overall effect of perforation is negligible in typical MEMS structures, an optimum design for the slits reduces the von Mises stress considerably as compared to sharp corners. The fabrication process was also investigated and optimized for the minimum residual stress of both the layers within the stack and the complete layer stack. The main emphasis of this work is on placing a stress-compensating layer on the wafer backside and simultaneously removing it during the surface micromachining, as this has been found to be the most effective method to reduce the overall stress in a stack of layers after sacrificial etching. Implementation of a stress compensating layer reduced the total residual stress from 200 MPa compressive into almost 60 MPa, tensile. Even though a particular structure was studied here, the employed methods are expected to be applicable to similar MEMS design problems. (paper)

Micromachined silicon seismic accelerometer development

Energy Technology Data Exchange (ETDEWEB)

Barron, C.C.; Fleming, J.G.; Montague, S. [and others

1996-08-01

Batch-fabricated silicon seismic transducers could revolutionize the discipline of seismic monitoring by providing inexpensive, easily deployable sensor arrays. Our ultimate goal is to fabricate seismic sensors with sensitivity and noise performance comparable to short-period seismometers in common use. We expect several phases of development will be required to accomplish that level of performance. Traditional silicon micromachining techniques are not ideally suited to the simultaneous fabrication of a large proof mass and soft suspension, such as one needs to achieve the extreme sensitivities required for seismic measurements. We have therefore developed a novel {open_quotes}mold{close_quotes} micromachining technology that promises to make larger proof masses (in the 1-10 mg range) possible. We have successfully integrated this micromolding capability with our surface-micromachining process, which enables the formation of soft suspension springs. Our calculations indicate that devices made in this new integrated technology will resolve down to at least sub-{mu}G signals, and may even approach the 10{sup -10} G/{radical}Hz acceleration levels found in the low-earth-noise model.

Surface micromachined counter-meshing gears discrimination device

International Nuclear Information System (INIS)

Polosky, M.A.; Garcia, E.J.; Allen, J.J.

1998-01-01

This paper discusses the design, fabrication and testing of a surface micromachined Counter-Meshing Gears (CMG) discrimination device which functions as a mechanically coded lock, A 24 bit code is input to unlock the device. Once unlocked, the device provides a path for an energy or information signal to pass through the device. The device is designed to immediately lock up if any portion of the 24 bit code is incorrect. The motivation for the development of this device is based on occurrences referred to as High Consequence Events, A High Consequence Event is an event where an inadvertent operation of a system could result in the catastrophic loss of life, property, or damage to the environment

Modeling and identification of induction micromachines in microelectromechanical systems applications

Energy Technology Data Exchange (ETDEWEB)

Lyshevski, S.E. [Purdue University at Indianapolis (United States). Dept. of Electrical and Computer Engineering

2002-11-01

Microelectromechanical systems (MEMS), which integrate motion microstructures, radiating energy microdevices, controlling and signal processing integrated circuits (ICs), are widely used. Rotational and translational electromagnetic based micromachines are used in MEMS as actuators and sensors. Brushless high performance micromachines are the preferable choice in different MEMS applications, and therefore, synchronous and induction micromachines are the best candidates. Affordability, good performance characteristics (efficiency, controllability, robustness, reliability, power and torque densities etc.) and expanded operating envelopes result in a strong interest in the application of induction micromachines. In addition, induction micromachines can be easily fabricated using surface micromachining and high aspect ratio fabrication technologies. Thus, it is anticipated that induction micromachines, controlled using different control algorithms implemented using ICs, will be widely used in MEMS. Controllers can be implemented using specifically designed ICs to attain superior performance, maximize efficiency and controllability, minimize losses and electromagnetic interference, reduce noise and vibration, etc. In order to design controllers, the induction micromachine must be modeled, and its mathematical model parameters must be identified. Using microelectromechanics, nonlinear mathematical models are derived. This paper illustrates the application of nonlinear identification methods as applied to identify the unknown parameters of three phase induction micromachines. Two identification methods are studied. In particular, nonlinear error mapping technique and least squares identification are researched. Analytical and numerical results, as well as practical capabilities and effectiveness, are illustrated, identifying the unknown parameters of a three phase brushless induction micromotor. Experimental results fully support the identification methods. (author)

Comparison of residual stress measurement in thin films using surface micromachining method

International Nuclear Information System (INIS)

He, Q.; Luo, Z.X.; Chen, X.Y.

2008-01-01

Conductive, dielectric, semiconducting, piezoelectric and ferroelectric thin films are extensively used for MEMS/NEMS applications. One of the important parameters of thin films is residual stress. The residual stress can seriously affect the properties, performance and long-term stability of the films. Excessive compressive or tensile stress results in buckling, cracking, splintering and sticking problems. Stress measurement techniques are therefore essential for both process development and process monitoring. Many suggestions for stress measurement in thin films have been made over the past several decades. This paper is concentrated on the in situ stress measurement using surface micromachining techniques to determine the residual stress. The authors review and compare several types of stress measurement methods including buckling technique, rotating technique, micro strain gauge and long-short beam strain sensor

Micromachined sensor and actuator research at Sandia`s Microelectronics Development Laboratory

Energy Technology Data Exchange (ETDEWEB)

Smith, J.H.

1996-11-01

An overview of the surface micromachining program at the Microelectronics Development Laboratory of Sandia National Laboratories is presented. Development efforts are underway for a variety of surface micromachined sensors and actuators for both defense and commercial applications. A technology that embeds micromechanical devices below the surface of the wafer prior to microelectronics fabrication has been developed for integrating microelectronics with surface-micromachined micromechanical devices. The application of chemical-mechanical polishing to increase the manufacturability of micromechanical devices is also presented.

The Development of Micromachined Gyroscope Structure and Circuitry Technology

Directory of Open Access Journals (Sweden)

Dunzhu Xia

2014-01-01

Full Text Available This review surveys micromachined gyroscope structure and circuitry technology. The principle of micromachined gyroscopes is first introduced. Then, different kinds of MEMS gyroscope structures, materials and fabrication technologies are illustrated. Micromachined gyroscopes are mainly categorized into micromachined vibrating gyroscopes (MVGs, piezoelectric vibrating gyroscopes (PVGs, surface acoustic wave (SAW gyroscopes, bulk acoustic wave (BAW gyroscopes, micromachined electrostatically suspended gyroscopes (MESGs, magnetically suspended gyroscopes (MSGs, micro fiber optic gyroscopes (MFOGs, micro fluid gyroscopes (MFGs, micro atom gyroscopes (MAGs, and special micromachined gyroscopes. Next, the control electronics of micromachined gyroscopes are analyzed. The control circuits are categorized into typical circuitry and special circuitry technologies. The typical circuitry technologies include typical analog circuitry and digital circuitry, while the special circuitry consists of sigma delta, mode matching, temperature/quadrature compensation and novel special technologies. Finally, the characteristics of various typical gyroscopes and their development tendency are discussed and investigated in detail.

Advanced technology trend survey of micromachines in Europe; Oshu ni okeru micromachine sentan gijutsu doko chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-02-01

In this research survey, the development trend of micromachine technology in Europe was surveyed, development level of micromachine technology of European companies was grasped, and practical application fields of their target were investigated. Technology development level of private companies in Japan`s national projects and practical application fields of Japan`s target were arranged. Trends of micromachine technology development are compared between Japanese companies and European companies. Among micromachine technology development projects in Europe, ``8520 MUST`` is a part of the ESPRIT Project. About 40,000 companies among about 170,000 companies in whole Europe are relating to the MUST Project. The main fields include the manufacturing technology, process control of machines, technology of safety, sensor technology in environmental fields, and automotive technology. The marketing fields of application include the automobile, military technology, home automation, industrial process, medical technology, environmental technology, and games. The results can be compared with the direction of research and development in Japan. 22 figs., 8 tabs.

Dual-beam focused ion beam/electron microscopy processing and metrology of redeposition during ion-surface 3D interactions, from micromachining to self-organized picostructures.

Science.gov (United States)

Moberlychan, Warren J

2009-06-03

Focused ion beam (FIB) tools have become a mainstay for processing and metrology of small structures. In order to expand the understanding of an ion impinging a surface (Sigmund sputtering theory) to our processing of small structures, the significance of 3D boundary conditions must be realized. We consider ion erosion for patterning/lithography, and optimize yields using the angle of incidence and chemical enhancement, but we find that the critical 3D parameters are aspect ratio and redeposition. We consider focused ion beam sputtering for micromachining small holes through membranes, but we find that the critical 3D considerations are implantation and redeposition. We consider ion beam self-assembly of nanostructures, but we find that control of the redeposition by ion and/or electron beams enables the growth of nanostructures and picostructures.

Surface micromachined counter-meshing gears discrimination device

Science.gov (United States)

Polosky, Marc A.; Garcia, Ernest J.; Allen, James J.

2000-12-12

A surface micromachined Counter-Meshing Gears (CMG) discrimination device which functions as a mechanically coded lock. Each of two CMG has a first portion of its perimeter devoted to continuous driving teeth that mesh with respective pinion gears. Each EMG also has a second portion of its perimeter devoted to regularly spaced discrimination gear teeth that extend outwardly on at least one of three levels of the CMG. The discrimination gear teeth are designed so as to pass each other without interference only if the correct sequence of partial rotations of the CMG occurs in response to a coded series of rotations from the pinion gears. A 24 bit code is normally input to unlock the device. Once unlocked, the device provides a path for an energy or information signal to pass through the device. The device is designed to immediately lock up if any portion of the 24 bit code is incorrect.

A batch process micromachined thermoelectric energy harvester: fabrication and characterization

International Nuclear Information System (INIS)

Su, J; Goedbloed, M; Van Andel, Y; De Nooijer, M C; Elfrink, R; Wang, Z; Vullers, R J M; Leonov, V

2010-01-01

Micromachined thermopiles are considered as a cost-effective solution for energy harvesters working at a small temperature difference and weak heat flows typical for, e.g., the human body. They can be used for powering autonomous wireless sensor nodes in a body area network. In this paper, a micromachined thermoelectric energy harvester with 6 µm high polycrystalline silicon germanium (poly-SiGe) thermocouples fabricated on a 6 inch wafer is presented. An open circuit voltage of 1.49 V and an output power of 0.4 µW can be generated with 3.5 K temperature difference in a model of a wearable micromachined energy harvester of the discussed design, which has a die size of 1.0 mm × 2.5 mm inside a watch-size generator

Omega-X micromachining system

International Nuclear Information System (INIS)

Miller, D.M.

1978-01-01

A micromachining tool system with X- and omega-axes is used to machine spherical, aspherical, and irregular surfaces with a maximum contour error of 100 nonometers (nm) and surface waviness of no more than 0.8 nm RMS. The omega axis, named for the angular measurement of the rotation of an eccentric mechanism supporting one end of a tool bar, enables the pulse increments of the tool toward the workpiece to be as little as 0 to 4.4 nm. A dedicated computer coordinates motion in the two axes to produce the workpiece contour. Inertia is reduced by reducing the mass pulsed toward the workpiece to about one-fifth of its former value. The tool system includes calibration instruments to calibrate the micromachining tool system. Backlash is reduced and flexing decreased by using a rotary table and servomotor to pulse the tool in the omega-axis instead of a ball screw mechanism. A thermally-stabilized spindle roates the workpiece and is driven by a motor not mounted on the micromachining tool base through a torque-smoothing pulley and vibrationless rotary coupling. Abbe offset errors are almost eliminated by tool setting and calibration at spindle center height. Tool contour and workpiece contour are gaged on the machine; this enables the source of machining errors to be determined more readily, because the workpiece is gaged before its shape can be changed by removal from the machine

UV laser micromachining of ceramic materials: formation of columnar topographies

International Nuclear Information System (INIS)

Oliveira, V.; Vilar, R.; Conde, O.

2001-01-01

Laser machining is increasingly appearing as an alternative for micromachining of ceramics. Using ceramic materials using excimer lasers can result in smooth surfaces or in the formation of cone-like or columnar topography. Potential applications of cone-shaped or columnar surface topography include, for example, light trapping in anti-reflection coatings and improvement of adhesion bonding between ceramic materials. In this communication results of a comparative study of surface topography change during micromachining of several ceramic materials with different ablation behaviors are reported. (orig.)

A novel hybrid surface micromachined segmented mirror for large aperture laser applications

Science.gov (United States)

Li, Jie; Chen, Haiqing; Yu, Hongbin

2006-07-01

A novel hybrid surface micromachined segmented mirror array is described. This device is capable of scaling to large apertures for correcting time-varying aberrations in laser applications. Each mirror is composed of bottom electrode, support part, and mirror plate, in which a T-shaped beam structure is used to support the mirror plate. It can provide mirror with vertical movement and rotation around two horizontal axes. The test results show that the maximum deflection along the vertical direction of the mirror plate is 2 microns, while the rotation angles around x and y axes are +-2.3 deg. and +-1.45 deg., respectively.

Design and Performance of a Focus-Detection System for Use in Laser Micromachining

Directory of Open Access Journals (Sweden)

Binh Xuan Cao

2016-01-01

Full Text Available We describe a new approach for locating the focal position in laser micromachining. This approach is based on a feedback system that uses a charge-coupled device (CCD camera, a beam splitter, and a mirror to focus a laser beam on the surface of a work piece. We tested the proposed method for locating the focal position by using Zemax simulations, as well as physically carrying out drilling processes. Compared with conventional methods, this approach is advantageous because: the implementation is simple, the specimen can easily be positioned at the focal position, and the dynamically adjustable scan amplitude and the CCD camera can be used to monitor the laser beam’s profile. The proposed technique will be particularly useful for locating the focal position on any surface in laser micromachining.

FY 1998 report on the R and D of micromachine technology. R and D of micromachine technology; 1998 nendo micromachine gijutsu no kenkyu kaihatsu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

In the comprehensive investigational study of micromachine technology, the paper aims at clarifying the improvement of functional devices and the future development of micromachine technology for establishment of the technology needed to realize a micromachine system composing of small-functional elements for conducting diagnosis/cure/repair, movement and independent work in small portions in living organism, disaster site, etc. and a medical-use micromachine system to analyze/react on a trace of liquid. In this fiscal year, the following were carried out: 1) study of micromachine systems, 2) study of a medical-use micromachine system to analyze/react on a trace liquid, and 3) comprehensive investigational study. In 1), studies were made toward the minuteness and improvement of micro laser catheter and micro tactile sensor catheter as functional devices which become the main components of micro catheter for cerebrovascular diagnosis/therapy use and toward the minuteness and improvement of disaster relief use micromachine system. In 2), study was made of element technology of a micro-machine system having functions of sampling/analysis/reaction of a trace of liquid. (NEDO)

Silicon-micromachined microchannel plates

International Nuclear Information System (INIS)

Beetz, Charles P.; Boerstler, Robert; Steinbeck, John; Lemieux, Bryan; Winn, David R.

2000-01-01

Microchannel plates (MCP) fabricated from standard silicon wafer substrates using a novel silicon micromachining process, together with standard silicon photolithographic process steps, are described. The resulting SiMCP microchannels have dimensions of ∼0.5 to ∼25 μm, with aspect ratios up to 300, and have the dimensional precision and absence of interstitial defects characteristic of photolithographic processing, compatible with positional matching to silicon electronics readouts. The open channel areal fraction and detection efficiency may exceed 90% on plates up to 300 mm in diameter. The resulting silicon substrates can be converted entirely to amorphous quartz (qMCP). The strip resistance and secondary emission are developed by controlled depositions of thin films, at temperatures up to 1200 deg. C, also compatible with high-temperature brazing, and can be essentially hydrogen, water and radionuclide-free. Novel secondary emitters and cesiated photocathodes can be high-temperature deposited or nucleated in the channels or the first strike surface. Results on resistivity, secondary emission and gain are presented

Experimental and Modeling Study of Liquid-Assisted—Laser Beam Micromachining of Smart Ceramic Materials

Directory of Open Access Journals (Sweden)

Mayur Parmar

2018-05-01

Full Text Available Smart ceramic materials are next generation materials with the inherent intelligence to adapt to change in the external environment. These materials are destined to play an essential role in several critical engineering applications. Machining these materials using traditional machining processes is a challenge. The laser beam micromachining (LBMM process has the potential to machine such smart materials. However, laser machining when performed in air induces high thermal stress on the surface, often leading to crack formation, recast and re-deposition of ablated material, and large heat-affected zones (HAZ. Performing laser beam machining in the presence of a liquid medium could potentially resolve these issues. This research investigates the possibility of using a Liquid Assisted—Laser Beam Micromachining (LA-LBMM process for micromachining smart ceramic materials. Experimental studies are performed to compare the machining quality of laser beam machining process in air and in a liquid medium. The study reveals that the presence of liquid medium helps in controlling the heat-affected zone and the taper angle of the cavity drilled, thereby enhancing the machining quality. Analytical modeling is developed for the prediction of HAZ and cavity diameter both in air and underwater conditions, and the model is capable of predicting the experimental results to within 10% error.

Laser Micromachining and Information Discovery Using a Dual Beam Interferometry

Energy Technology Data Exchange (ETDEWEB)

Theppakuttaikomaraswamy, Senthil P. [Iowa State Univ., Ames, IA (United States)

2001-01-01

Lasers have proven to be among the most promising tools for micromachining because they can process features down to the size of the laser wavelength (smaller than 1 micrometer) and they provide a non-contact technology for machining. The demand for incorporating in-situ diagnostics technology into the micromachining environment is driven by the increasing need for producing micro-parts of high quality and accuracy. Laser interferometry can be used as an on-line monitoring tool and it is the aim of this work to enhance the understanding and application of Michelson interferometry principle for the in-situ diagnostics of the machining depth on the sub-micron and micron scales. micromachining is done on two different materials and a comprehensive investigation is done to control the width and depth of the machined feature. To control the width of the feature, laser micromachining is done on copper and a detailed analysis is performed. The objective of this experiment is to make a precision mask for sputtering with an array of holes on it using an Nd:YAG laser of 532 nm wavelength. The diameter of the hole is 50 μm and the spacing between holes (the distance between the centers) is 100 μm. Michelson interferometer is integrated with a laser machining system to control the depth of machining. An excimer laser of 308 nm wavelength is used for micromachining. A He-Ne laser of 632.8 nm wavelength is used as the light source for the interferometer. Interference patterns are created due to the change in the path length between the two interferometer arms. The machined depth information is obtained from the interference patterns on an oscilloscope detected by a photodiode. To compare the predicted depth by the interferometer with the true machining depth, a surface profilometer is used to measure the actual machining depth on the silicon. It is observed that the depths of machining obtained by the surface profile measurement are in accordance with the interferometer

Micromachining Lithium Niobate for Rapid Prototyping of Resonant Biosensors

International Nuclear Information System (INIS)

Al-Shibaany, Zeyad Yousif Abdoon; Hedley, John; Huo, Dehong; Hu, Zhongxu

2014-01-01

Lithium niobate material is widely used in MEMS application due to its piezoelectric properties. This paper presents the micromachining process of lithium niobate to rapid prototype a resonant biosensor design. A high precision CNC machine was used to machine a sample of lithium niobate material at 5 different spindle speeds to find out the best conditions to machine this brittle material. A qualitative visual check of the surface was performed by using scanning electron microscopy, surface roughness was quantitatively investigated using an optical surface profiler and Raman spectroscopy to check the strain of the surface. Results show that the surface quality of the lithium niobate was significantly affected by the spindle speed with optimum conditions at 70k rpm giving a strained surface with 500 nm rms roughness

Resist materials for proton micromachining

International Nuclear Information System (INIS)

Kan, J.A. van; Sanchez, J.L.; Xu, B.; Osipowicz, T.; Watt, F.

1999-01-01

The production of high aspect ratio microstructures is a potential growth area. The combination of deep X-ray lithography with electroforming and micromolding (i.e. LIGA) is one of the main techniques used to produce 3D microstructures. The new technique of proton micromachining employs focused MeV protons in a direct write process which is complementary to LIGA, e.g. micromachining with 2 MeV protons results in microstructures with a height of 63 μm and lateral sub-micrometer resolution in PMMA resist. The aim of this paper is to investigate the capabilities of proton micromachining as a lithographic technique. This involves the study of different types of resists. The dose distribution of high molecular weight PMMA is compared with three other types of resist: First the positive photo resist AZ P4620 will be discussed and then PMGI SF 23, which can be used as a deep UV, e-beam or X-ray resist. Finally SU-8, a new deep UV negative type of chemically amplified resist will be discussed. All these polymers are applied using the spin coating technique at thicknesses of between 1 and 36 μm

Micromachined Ultrasonic Transducers for 3-D Imaging

DEFF Research Database (Denmark)

Christiansen, Thomas Lehrmann

of state-of-the-art 3-D ultrasound systems. The focus is on row-column addressed transducer arrays. This previously sparsely investigated addressing scheme offers a highly reduced number of transducer elements, resulting in reduced transducer manufacturing costs and data processing. To produce...... such transducer arrays, capacitive micromachined ultrasonic transducer (CMUT) technology is chosen for this project. Properties such as high bandwidth and high design flexibility makes this an attractive transducer technology, which is under continuous development in the research community. A theoretical...... treatment of CMUTs is presented, including investigations of the anisotropic plate behaviour and modal radiation patterns of such devices. Several new CMUT fabrication approaches are developed and investigated in terms of oxide quality and surface protrusions, culminating in a simple four-mask process...

Micromachined Integrated Transducers for Ultrasound Imaging

DEFF Research Database (Denmark)

la Cour, Mette Funding

The purpose of this project is to develop capacitive micromachined ultrasonic transducers (CMUTs) for medical imaging. Medical ultrasound transducers used today are fabricated using piezoelectric materials and bulk processing. To fabricate transducers capable of delivering a higher imaging...

Vascular tissue engineering by computer-aided laser micromachining.

Science.gov (United States)

Doraiswamy, Anand; Narayan, Roger J

2010-04-28

Many conventional technologies for fabricating tissue engineering scaffolds are not suitable for fabricating scaffolds with patient-specific attributes. For example, many conventional technologies for fabricating tissue engineering scaffolds do not provide control over overall scaffold geometry or over cell position within the scaffold. In this study, the use of computer-aided laser micromachining to create scaffolds for vascular tissue networks was investigated. Computer-aided laser micromachining was used to construct patterned surfaces in agarose or in silicon, which were used for differential adherence and growth of cells into vascular tissue networks. Concentric three-ring structures were fabricated on agarose hydrogel substrates, in which the inner ring contained human aortic endothelial cells, the middle ring contained HA587 human elastin and the outer ring contained human aortic vascular smooth muscle cells. Basement membrane matrix containing vascular endothelial growth factor and heparin was to promote proliferation of human aortic endothelial cells within the vascular tissue networks. Computer-aided laser micromachining provides a unique approach to fabricate small-diameter blood vessels for bypass surgery as well as other artificial tissues with complex geometries.

Real-time control of ultrafast laser micromachining by laser-induced breakdown spectroscopy

International Nuclear Information System (INIS)

Tong Tao; Li Jinggao; Longtin, Jon P.

2004-01-01

Ultrafast laser micromachining provides many advantages for precision micromachining. One challenging problem, however, particularly for multilayer and heterogeneous materials, is how to prevent a given material from being ablated, as ultrafast laser micromachining is generally material insensitive. We present a real-time feedback control system for an ultrafast laser micromachining system based on laser-induced breakdown spectroscopy (LIBS). The characteristics of ultrafast LIBS are reviewed and discussed so as to demonstrate the feasibility of the technique. Comparison methods to identify the material emission patterns are developed, and several of the resulting algorithms were implemented into a real-time computer control system. LIBS-controlled micromachining is demonstrated for the fabrication of microheater structures on thermal sprayed materials. Compared with a strictly passive machining process without any such feedback control, the LIBS-based system provides several advantages including less damage to the substrate layer, reduced machining time, and more-uniform machining features

Fabrication of a novel quartz micromachined gyroscope

Science.gov (United States)

Xie, Liqiang; Xing, Jianchun; Wang, Haoxu; Wu, Xuezhong

2015-04-01

A novel quartz micromachined gyroscope is proposed in this paper. The novel gyroscope is realized by quartz anisotropic wet etching and 3-dimensional electrodes deposition. In the quartz wet etching process, the quality of Cr/Au mask films affecting the process are studied by experiment. An excellent mask film with 100 Å Cr and 2000 Å Au is achieved by optimization of experimental parameters. Crystal facets after etching seriously affect the following sidewall electrodes deposition process and the structure's mechanical behaviours. Removal of crystal facets is successfully implemented by increasing etching time based on etching rate ratios between facets and crystal planes. In the electrodes deposition process, an aperture mask evaporation method is employed to prepare electrodes on 3-dimensional surfaces of the gyroscope structure. The alignments among the aperture masks are realized by the ABM™ Mask Aligner System. Based on the processes described above, a z-axis quartz gyroscope is fabricated successfully.

High speed micromachining with high power UV laser

Science.gov (United States)

Patel, Rajesh S.; Bovatsek, James M.

2013-03-01

Increasing demand for creating fine features with high accuracy in manufacturing of electronic mobile devices has fueled growth for lasers in manufacturing. High power, high repetition rate ultraviolet (UV) lasers provide an opportunity to implement a cost effective high quality, high throughput micromachining process in a 24/7 manufacturing environment. The energy available per pulse and the pulse repetition frequency (PRF) of diode pumped solid state (DPSS) nanosecond UV lasers have increased steadily over the years. Efficient use of the available energy from a laser is important to generate accurate fine features at a high speed with high quality. To achieve maximum material removal and minimal thermal damage for any laser micromachining application, use of the optimal process parameters including energy density or fluence (J/cm2), pulse width, and repetition rate is important. In this study we present a new high power, high PRF QuasarR 355-40 laser from Spectra-Physics with TimeShiftTM technology for unique software adjustable pulse width, pulse splitting, and pulse shaping capabilities. The benefits of these features for micromachining include improved throughput and quality. Specific example and results of silicon scribing are described to demonstrate the processing benefits of the Quasar's available power, PRF, and TimeShift technology.

Advanced measurement and analysis of surface textures produced by micro-machining processes

International Nuclear Information System (INIS)

Bordatchev, Evgueni V; Hafiz, Abdullah M K

2014-01-01

Surface texture of a part or a product has significant effects on its functionality, physical-mechanical properties and visual appearance. In particular for miniature products, the implication of surface quality becomes critical owing to the presence of geometrical features with micro/nano-scale dimensions. Qualitative and quantitative assessments of surface texture are carried out predominantly by profile parameters, which are often insufficient to address the contribution of constituent spatial components with varied amplitudes and wavelengths. In this context, this article presents a novel approach for advanced measurement and analysis of profile average roughness (R a ) and its spatial distribution at different wavelength intervals. The applicability of the proposed approach was verified for three different surface topographies prepared by grinding, laser micro-polishing and micro-milling processes. From the measurement and analysis results, R a (λ) spatial distribution was found to be an effective measure of revealing the contributions of various spatial components within specific wavelength intervals towards formation of the entire surface profile. In addition, the approach was extended to the measurement and analysis of areal average roughness S a (λ) spatial distribution within different wavelength intervals. Besides, the proposed method was demonstrated to be a useful technique in developing a functional correlation between a manufacturing process and its corresponding surface profile. (paper)

Micromachined Thin-Film Sensors for SOI-CMOS Co-Integration

Science.gov (United States)

Laconte, Jean; Flandre, D.; Raskin, Jean-Pierre

Co-integration of sensors with their associated electronics on a single silicon chip may provide many significant benefits regarding performance, reliability, miniaturization and process simplicity without significantly increasing the total cost. Micromachined Thin-Film Sensors for SOI-CMOS Co-integration covers the challenges and interests and demonstrates the successful co-integration of gas flow sensors on dielectric membrane, with their associated electronics, in CMOS-SOI technology. We firstly investigate the extraction of residual stress in thin layers and in their stacking and the release, in post-processing, of a 1 μm-thick robust and flat dielectric multilayered membrane using Tetramethyl Ammonium Hydroxide (TMAH) silicon micromachining solution.

Modelling of micromachining of human tooth enamel by erbium laser radiation

Energy Technology Data Exchange (ETDEWEB)

Belikov, A V; Skrypnik, A V; Shatilova, K V [St. Petersburg National Research University of Information Technologies, Mechanics and Optics, St. Petersburg (Russian Federation)

2014-08-31

We consider a 3D cellular model of human tooth enamel and a photomechanical cellular model of enamel ablation by erbium laser radiation, taking into account the structural peculiarities of enamel, energy distribution in the laser beam cross section and attenuation of laser energy in biological tissue. The surface area of the texture in enamel is calculated after its micromachining by erbium laser radiation. The influence of the surface area on the bond strength of enamel with dental filling materials is discussed. A good correlation between the computer simulation of the total work of adhesion and experimentally measured bond strength between the dental filling material and the tooth enamel after its micromachining by means of YAG : Er laser radiation is attained. (laser biophotonics)

Modelling of micromachining of human tooth enamel by erbium laser radiation

International Nuclear Information System (INIS)

Belikov, A V; Skrypnik, A V; Shatilova, K V

2014-01-01

We consider a 3D cellular model of human tooth enamel and a photomechanical cellular model of enamel ablation by erbium laser radiation, taking into account the structural peculiarities of enamel, energy distribution in the laser beam cross section and attenuation of laser energy in biological tissue. The surface area of the texture in enamel is calculated after its micromachining by erbium laser radiation. The influence of the surface area on the bond strength of enamel with dental filling materials is discussed. A good correlation between the computer simulation of the total work of adhesion and experimentally measured bond strength between the dental filling material and the tooth enamel after its micromachining by means of YAG : Er laser radiation is attained. (laser biophotonics)

Direct writing of microtunnels using proton beam micromachining

International Nuclear Information System (INIS)

Marot, Laurent; Munnik, Frans; Mikhailov, Serguei

2006-01-01

The production of high aspect ratio microstructures is a potential growth area. The combination of deep X-ray lithography with electroforming and micromolding (i.e. LIGA) is one of the main techniques used to produce 3D microstructures. The new technique of proton micromachining employs focused MeV protons in a direct write process which is complementary to LIGA. During ion exposure of positive photoresist like PMMA, scission of molecular chains occurs. These degraded polymer chains are removed by the developer. The aim of this paper is to investigate the capabilities of proton micromachining as a lithographic technique. We show the realization of sub-surface channels, or microtunnels, which have been fabricated in only one exposure and without cutting or resurfacing the material. Using our Van-de-Graaff accelerator, the resist (PMMA) has been exposed with high-energy protons (2.5 MeV). The range of charged particles in matter is well-defined and depends on the energy. Therefore, it is possible to obtain a dose which is sufficient to develop the bottom part of the ion paths but not the top part. Thus, by selecting the energy and the exposure time, a big variety of microtunnels can be realized

Trends in laser micromachining

Science.gov (United States)

Gaebler, Frank; van Nunen, Joris; Held, Andrew

2016-03-01

Laser Micromachining is well established in industry. Depending on the application lasers with pulse length from μseconds to femtoseconds and wavelengths from 1064nm and its harmonics up to 5μm or 10.6μm are used. Ultrafast laser machining using pulses with pico or femtosecond duration pulses is gaining traction, as it offers very precise processing of materials with low thermal impact. Large-scale industrial ultrafast laser applications show that the market can be divided into various sub segments. One set of applications demand low power around 10W, compact footprint and are extremely sensitive to the laser price whilst still demanding 10ps or shorter laser pulses. A second set of applications are very power hungry and only become economically feasible for large scale deployments at power levels in the 100+W class. There is also a growing demand for applications requiring fs-laser pulses. In our presentation we would like to describe these sub segments by using selected applications from the automotive and electronics industry e.g. drilling of gas/diesel injection nozzles, dicing of LED substrates. We close the presentation with an outlook to micromachining applications e.g. glass cutting and foil processing with unique new CO lasers emitting 5μm laser wavelength.

Polyimide as a versatile enabling material for microsystems fabrication: surface micromachining and electrodeposited nanowires integration

Science.gov (United States)

Walewyns, Thomas; Reckinger, Nicolas; Ryelandt, Sophie; Pardoen, Thomas; Raskin, Jean-Pierre; Francis, Laurent A.

2013-09-01

The interest of using polyimide as a sacrificial and anchoring layer is demonstrated for post-processing surface micromachining and for the incorporation of metallic nanowires into microsystems. In addition to properties like a high planarization factor, a good resistance to most non-oxidizing acids and bases, and CMOS compatibility, polyimide can also be used as a mold for nanostructures after ion track-etching. Moreover, specific polyimide grades, such as PI-2611 from HD Microsystems™, involve a thermal expansion coefficient similar to silicon and low internal stress. The process developed in this study permits higher gaps compared to the state-of-the-art, limits stiction problems with the substrate and is adapted to various top-layer materials. Most metals, semiconductors or ceramics will not be affected by the oxygen plasma required for polyimide etching. Released structures with vertical gaps from one to several tens of μm have been obtained, possibly using multiple layers of polyimide. Furthermore, patterned freestanding nanowires have been synthesized with diameters from 20 to 60 nm and up to 3 μm in length. These results have been applied to the fabrication of two specific devices: a generic nanomechanical testing lab-on-chip platform and a miniaturized ionization sensor.

Micro-machined resonator oscillator

Science.gov (United States)

Koehler, Dale R.; Sniegowski, Jeffry J.; Bivens, Hugh M.; Wessendorf, Kurt O.

1994-01-01

A micro-miniature resonator-oscillator is disclosed. Due to the miniaturization of the resonator-oscillator, oscillation frequencies of one MHz and higher are utilized. A thickness-mode quartz resonator housed in a micro-machined silicon package and operated as a "telemetered sensor beacon" that is, a digital, self-powered, remote, parameter measuring-transmitter in the FM-band. The resonator design uses trapped energy principles and temperature dependence methodology through crystal orientation control, with operation in the 20-100 MHz range. High volume batch-processing manufacturing is utilized, with package and resonator assembly at the wafer level. Unique design features include squeeze-film damping for robust vibration and shock performance, capacitive coupling through micro-machined diaphragms allowing resonator excitation at the package exterior, circuit integration and extremely small (0.1 in. square) dimensioning. A family of micro-miniature sensor beacons is also disclosed with widespread applications as bio-medical sensors, vehicle status monitors and high-volume animal identification and health sensors. The sensor family allows measurement of temperatures, chemicals, acceleration and pressure. A microphone and clock realization is also available.

Demonstration of robust micromachined jet technology and its application to realistic flow control problems

International Nuclear Information System (INIS)

Chang, Sung Pil

2006-01-01

This paper describes the demonstration of successful fabrication and initial characterization of micromachined pressure sensors and micromachined jets (microjets) fabricated for use in macro flow control and other applications. In this work, the microfabrication technology was investigated to create a micromachined fluidic control system with a goal of application in practical fluids problems, such as UAV (Unmanned Aerial Vehicle)-scale aerodynamic control. Approaches of this work include : (1) the development of suitable micromachined synthetic jets (microjets) as actuators, which obviate the need to physically extend micromachined structures into an external flow ; and (2) a non-silicon alternative micromachining fabrication technology based on metallic substrates and lamination (in addition to traditional MEMS technologies) which will allow the realization of larger scale, more robust structures and larger array active areas for fluidic systems. As an initial study, an array of MEMS pressure sensors and an array of MEMS modulators for orifice-based control of microjets have been fabricated, and characterized. Both pressure sensors and modulators have been built using stainless steel as a substrate and a combination of lamination and traditional micromachining processes as fabrication technologies

Demonstration of robust micromachined jet technology and its application to realistic flow control problems

Energy Technology Data Exchange (ETDEWEB)

Chang, Sung Pil [Inha University, Incheon (Korea, Republic of)

2006-04-15

This paper describes the demonstration of successful fabrication and initial characterization of micromachined pressure sensors and micromachined jets (microjets) fabricated for use in macro flow control and other applications. In this work, the microfabrication technology was investigated to create a micromachined fluidic control system with a goal of application in practical fluids problems, such as UAV (Unmanned Aerial Vehicle)-scale aerodynamic control. Approaches of this work include : (1) the development of suitable micromachined synthetic jets (microjets) as actuators, which obviate the need to physically extend micromachined structures into an external flow ; and (2) a non-silicon alternative micromachining fabrication technology based on metallic substrates and lamination (in addition to traditional MEMS technologies) which will allow the realization of larger scale, more robust structures and larger array active areas for fluidic systems. As an initial study, an array of MEMS pressure sensors and an array of MEMS modulators for orifice-based control of microjets have been fabricated, and characterized. Both pressure sensors and modulators have been built using stainless steel as a substrate and a combination of lamination and traditional micromachining processes as fabrication technologies.

Damping control of micromachined lowpass mechanical vibration isolation filters using electrostatic actuation with electronic signal processing

Science.gov (United States)

Dean, Robert; Flowers, George; Sanders, Nicole; MacAllister, Ken; Horvath, Roland; Hodel, A. S.; Johnson, Wayne; Kranz, Michael; Whitley, Michael

2005-05-01

Some harsh environments, such as those encountered by aerospace vehicles and various types of industrial machinery, contain high frequency/amplitude mechanical vibrations. Unfortunately, some very useful components are sensitive to these high frequency mechanical vibrations. Examples include MEMS gyroscopes and resonators, oscillators and some micro optics. Exposure of these components to high frequency mechanical vibrations present in the operating environment can result in problems ranging from an increased noise floor to component failure. Passive micromachined silicon lowpass filter structures (spring-mass-damper) have been demonstrated in recent years. However, the performance of these filter structures is typically limited by low damping (especially if operated in near-vacuum environments) and a lack of tunability after fabrication. Active filter topologies, such as piezoelectric, electrostrictive-polymer-film and SMA have also been investigated in recent years. Electrostatic actuators, however, are utilized in many micromachined silicon devices to generate mechanical motion. They offer a number of advantages, including low power, fast response time, compatibility with silicon micromachining, capacitive position measurement and relative simplicity of fabrication. This paper presents an approach for realizing active micromachined mechanical lowpass vibration isolation filters by integrating an electrostatic actuator with the micromachined passive filter structure to realize an active mechanical lowpass filter. Although the electrostatic actuator can be used to adjust the filter resonant frequency, the primary application is for increasing the damping to an acceptable level. The physical size of these active filters is suitable for use in or as packaging for sensitive electronic and MEMS devices, such as MEMS vibratory gyroscope chips.

Surface photo reaction processes using synchrotron radiation; Hoshako reiki ni yoru hyomenko hanno process

Energy Technology Data Exchange (ETDEWEB)

Imaizumi, Y. [Tohoku University, Sendai (Japan). Institute for Materials Research; Yoshigoe, A. [Toyohashi University of Technology, Aichi (Japan); Urisu, T. [Toyohashi University of Technology, Aichi (Japan). Institute for Molecular Science

1997-08-20

This paper introduces the surface photo reaction processes using synchrotron radiation, and its application. A synchrotron radiation process using soft X-rays contained in electron synchrotron radiated light as an excited light source has a possibility of high-resolution processing because of its short wave length. The radiated light can excite efficiently the electronic state of a substance, and can induce a variety of photochemical reactions. In addition, it can excite inner shell electrons efficiently. In the aspect of its application, it has been found that, if radiated light is irradiated on surfaces of solids under fluorine-based reaction gas or Cl2, the surfaces can be etched. This technology is utilized practically. With regard to radiated light excited CVD process, it may be said that anything that can be deposited by the ordinary plasma CVD process can be deposited. Its application to epitaxial crystal growth may be said a nano processing application in thickness direction, such as forming an ultra-lattice structure, the application being subjected to expectation. In micromachine fabricating technologies, a possibility is searched on application of a photo reaction process of the radiated light. 5 refs., 6 figs.

Micromachined tunable metamaterials: a review

International Nuclear Information System (INIS)

Liu, A Q; Zhu, W M; Tsai, D P; Zheludev, N I

2012-01-01

This paper reviews micromachined tunable metamaterials, whereby the tuning capabilities are based on the mechanical reconfiguration of the lattice and/or the metamaterial element geometry. The primary focus of this review is the feasibility of the realization of micromachined tunable metamaterials via structure reconfiguration and the current state of the art in the fabrication technologies of structurally reconfigurable metamaterial elements. The micromachined reconfigurable microstructures not only offer a new tuning method for metamaterials without being limited by the nonlinearity of constituent materials, but also enable a new paradigm of reconfigurable metamaterial-based devices with mechanical actuations. With recent development in nanomachining technology, it is possible to develop structurally reconfigurable metamaterials with faster tuning speed, higher density of integration and more flexible choice of the working frequencies. (review article)

Micromachined capacitive ultrasonic immersion transducer array

Science.gov (United States)

Jin, Xuecheng

Capacitive micromachined ultrasonic transducers (cMUTs) have emerged as an attractive alternative to conventional piezoelectric ultrasonic transducers. They offer performance advantages of wide bandwidth and sensitivity that have heretofore been attainable. In addition, micromachining technology, which has benefited from the fast-growing microelectronics industry, enables cMUT array fabrication and electronics integration. This thesis describes the design and fabrication of micromachined capacitive ultrasonic immersion transducer arrays. The basic transducer electrical equivalent circuit is derived from Mason's theory. The effects of Lamb waves and Stoneley waves on cross coupling and acoustic losses are discussed. Electrical parasitics such as series resistance and shunt capacitance are also included in the model of the transducer. Transducer fabrication technology is systematically studied. Device dimension control in both vertical and horizontal directions, process alternatives and variations in membrane formation, via etch and cavity sealing, and metalization as well as their impact on transducer performance are summarized. Both 64 and 128 element 1-D array transducers are fabricated. Transducers are characterized in terms of electrical input impedance, bandwidth, sensitivity, dynamic range, impulse response and angular response, and their performance is compared with theoretical simulation. Various schemes for cross coupling reduction is analyzed, implemented, and verified with both experiments and theory. Preliminary results of immersion imaging are presented using 64 elements 1-D array transducers for active source imaging.

Silicon micromachined vibrating gyroscopes

Science.gov (United States)

Voss, Ralf

1997-09-01

This work gives an overview of silicon micromachined vibrating gyroscopes. Market perspectives and fields of application are pointed out. The advantage of using silicon micromachining is discussed and estimations of the desired performance, especially for automobiles are given. The general principle of vibrating gyroscopes is explained. Vibrating silicon gyroscopes can be divided into seven classes. for each class the characteristic principle is presented and examples are given. Finally a specific sensor, based on a tuning fork for automotive applications with a sensitivity of 250(mu) V/degrees is described in detail.

The micromachined logo of Atomki

International Nuclear Information System (INIS)

Rajta, I.; Szilasi, S.Z.

2006-01-01

Complete text of publication follows. Proton Beam Micromachining, also known as P-beam Writing, is a direct write 3- dimensional lithographic technique. Conventional resist types are PMMA (polymethylmethacrylate), and SU-8 (of MicroChem Corp.); they are positive and negative resists, respectively. In this work we used SU-8, the most common negative resist material. SU-8 was spun on a flat surface, typically Silicon or glass. A direct write proton beam was scanned over an arbitary structure (the Atomki logo can be replaced by any other structure), which produces chain scissioning in the polymer. Post exposure bake (PEB) is usually needed in case of conventional optical lithography, but using protons this bake is done in situ as the ions heat up the sample in vacuum. Subsequently chemical etching takes place, the solvent is available at MicroChem Corp. The schematic diagram of the above described micromachining process is shown on Fig. 1. The irradiation requires a scanning proton microbeam system equipped with suitable beam scanning and blanking facilities. This is available in the Institute, our setup has been upgraded from doublet to triplet focusing system (Oxford Microbeams Ltd.). For scanning we use a DIO card (PCI-6731 of National Instruments), and the IonScan software [1]. Sample preparation was carried out at our 'semi clean' room. This is also where chemical development of the samples and the optical microscopy have been done too. A Zeiss Axio Imager microscope is available (equipped with 5 objective lenses, 4 different contrast methods, transmitted or reflected light illumination). Fig. 2. shows a typical example of the Atomki logo. This is a bright field image, a number of different nice and colourful images can be produced with the other contrast techniques (for more images see the Institute website: http://www.atomki.hu/ ). (author)

Optical wireless communications for micromachines

Science.gov (United States)

O'Brien, Dominic C.; Yuan, Wei Wen; Liu, Jing Jing; Faulkner, Grahame E.; Elston, Steve J.; Collins, Steve; Parry-Jones, Lesley A.

2006-08-01

A key challenge for wireless sensor networks is minimizing the energy required for network nodes to communicate with each other, and this becomes acute for self-powered devices such as 'smart dust'. Optical communications is a potentially attractive solution for such devices. The University of Oxford is currently involved in a project to build optical wireless links to smart dust. Retro-reflectors combined with liquid crystal modulators can be integrated with the micro-machine to create a low power transceiver. When illuminated from a base station a modulated beam is returned, transmitting data. Data from the base station can be transmitted using modulation of the illuminating beam and a receiver at the micro-machine. In this paper we outline the energy consumption and link budget considerations in the design of such micro-machines, and report preliminary experimental results.

Excimer laser micromachining for 3D microstructure

NARCIS (Netherlands)

Choi, Kyung Hyun; Meijer, J.; Masuzawa, Takahisa; Kim, Dae-Hyun

2004-01-01

A new 3D micromachining method, called Hole Area Modulation (HAM), has been introduced to enhance the current micromachining technology. In this method, information on the machining depth is converted to the sizes of holes on the mask. The machining is carried out with a simple 2D movement of the

Quasimetallic silicon micromachined photonic crystals

International Nuclear Information System (INIS)

Temelkuran, B.; Bayindir, Mehmet; Ozbay, E.; Kavanaugh, J. P.; Sigalas, M. M.; Tuttle, G.

2001-01-01

We report on fabrication of a layer-by-layer photonic crystal using highly doped silicon wafers processed by semiconductor micromachining techniques. The crystals, built using (100) silicon wafers, resulted in an upper stop band edge at 100 GHz. The transmission and defect characteristics of these structures were found to be analogous to metallic photonic crystals. We also investigated the effect of doping concentration on the defect characteristics. The experimental results agree well with predictions of the transfer matrix method simulations

Sub-band-gap laser micromachining of lithium niobate

DEFF Research Database (Denmark)

Christensen, F. K.; Müllenborn, Matthias

1995-01-01

method is reported which enables us to do laser processing of lithium niobate using sub-band-gap photons. Using high scan speeds, moderate power densities, and sub-band-gap photon energies results in volume removal rates in excess of 106µm3/s. This enables fast micromachining of small piezoelectric...

Micromachined Precision Inertial Instruments

National Research Council Canada - National Science Library

Najafi, Khalil

2003-01-01

This program focuses on developing inertial-grade micromachined accelerometers and gyroscopes and their associated electronics and packaging for use in a variety of military and commercial applications...

Fabrication of a Micromachined Capacitive Switch Using the CMOS-MEMS Technology

Directory of Open Access Journals (Sweden)

Cheng-Yang Lin

2015-11-01

Full Text Available The study investigates the design and fabrication of a micromachined radio frequency (RF capacitive switch using the complementary metal oxide semiconductor-microelectromechanical system (CMOS-MEMS technology. The structure of the micromachined switch is composed of a membrane, eight springs, four inductors, and coplanar waveguide (CPW lines. In order to reduce the actuation voltage of the switch, the springs are designed as low stiffness. The finite element method (FEM software CoventorWare is used to simulate the actuation voltage and displacement of the switch. The micromachined switch needs a post-CMOS process to release the springs and membrane. A wet etching is employed to etch the sacrificial silicon dioxide layer, and to release the membrane and springs of the switch. Experiments show that the pull-in voltage of the switch is 12 V. The switch has an insertion loss of 0.8 dB at 36 GHz and an isolation of 19 dB at 36 GHz.

Manufacture of Radio Frequency Micromachined Switches with Annealing

OpenAIRE

Lin, Cheng-Yang; Dai, Ching-Liang

2014-01-01

The fabrication and characterization of a radio frequency (RF) micromachined switch with annealing were presented. The structure of the RF switch consists of a membrane, coplanar waveguide (CPW) lines, and eight springs. The RF switch is manufactured using the complementary metal oxide semiconductor (CMOS) process. The switch requires a post-process to release the membrane and springs. The post-process uses a wet etching to remove the sacrificial silicon dioxide layer, and to obtain the suspe...

Laser micromachining of biofactory-on-a-chip devices

Science.gov (United States)

Burt, Julian P.; Goater, Andrew D.; Hayden, Christopher J.; Tame, John A.

2002-06-01

Excimer laser micromachining provides a flexible means for the manufacture and rapid prototyping of miniaturized systems such as Biofactory-on-a-Chip devices. Biofactories are miniaturized diagnostic devices capable of characterizing, manipulating, separating and sorting suspension of particles such as biological cells. Such systems operate by exploiting the electrical properties of microparticles and controlling particle movement in AC non- uniform stationary and moving electric fields. Applications of Biofactory devices are diverse and include, among others, the healthcare, pharmaceutical, chemical processing, environmental monitoring and food diagnostic markets. To achieve such characterization and separation, Biofactory devices employ laboratory-on-a-chip type components such as complex multilayer microelectrode arrays, microfluidic channels, manifold systems and on-chip detection systems. Here we discuss the manufacturing requirements of Biofactory devices and describe the use of different excimer laser micromachined methods both in stand-alone processes and also in conjunction with conventional fabrication processes such as photolithography and thermal molding. Particular attention is given to the production of large area multilayer microelectrode arrays and the manufacture of complex cross-section microfluidic channel systems for use in simple distribution and device interfacing.

Hybrid micromachining using a nanosecond pulsed laser and micro EDM

International Nuclear Information System (INIS)

Kim, Sanha; Chung, Do Kwan; Shin, Hong Shik; Chu, Chong Nam; Kim, Bo Hyun

2010-01-01

Micro electrical discharge machining (micro EDM) is a well-known precise machining process that achieves micro structures of excellent quality for any conductive material. However, the slow machining speed and high tool wear are main drawbacks of this process. Though the use of deionized water instead of kerosene as a dielectric fluid can reduce the tool wear and increase the machine speed, the material removal rate (MRR) is still low. In contrast, laser ablation using a nanosecond pulsed laser is a fast and non-wear machining process but achieves micro figures of rather low quality. Therefore, the integration of these two processes can overcome the respective disadvantages. This paper reports a hybrid process of a nanosecond pulsed laser and micro EDM for micromachining. A novel hybrid micromachining system that combines the two discrete machining processes is introduced. Then, the feasibility and characteristics of the hybrid machining process are investigated compared to conventional EDM and laser ablation. It is verified experimentally that the machining time can be effectively reduced in both EDM drilling and milling by rapid laser pre-machining prior to micro EDM. Finally, some examples of complicated 3D micro structures fabricated by the hybrid process are shown

Studying the mechanism of micromachining by short pulsed laser

Science.gov (United States)

Gadag, Shiva

The semiconductor materials like Si and the transparent dielectric materials like glass and quartz are extensively used in optoelectronics, microelectronics, and microelectromechanical systems (MEMS) industries. The combination of these materials often go hand in hand for applications in MEMS such as in chips for pressure sensors, charge coupled devices (CCD), and photovoltaic (PV) cells for solar energy generation. The transparent negative terminal of the solar cell is made of glass on one surface of the PV cell. The positive terminal (cathode) on the other surface of the solar cell is made of silicon with a glass negative terminal (anode). The digital watches and cell phones, LEDs, micro-lens, optical components, and laser optics are other examples for the application of silicon and or glass. The Si and quartz are materials extensively used in CCD and LED for digital cameras and CD players respectively. Hence, three materials: (1) a semiconductor silicon and transparent dielectrics,- (2) glass, and (3) quartz are chosen for laser micromachining as they have wide spread applications in microelectronics industry. The Q-switched, nanosecond pulsed lasers are most extensively used for micro-machining. The nanosecond type of short pulsed laser is less expensive for the end users than the second type, pico or femto, ultra-short pulsed lasers. The majority of the research work done on these materials (Si, SiO 2, and glass) is based on the ultra-short pulsed lasers. This is because of the cut quality, pin point precision of the drilled holes, formation of the nanometer size microstructures and fine features, and minimally invasive heat affected zone. However, there are many applications such as large surface area dicing, cutting, surface cleaning of Si wafers by ablation, and drilling of relatively large-sized holes where some associated heat affected zone due to melting can be tolerated. In such applications the nanosecond pulsed laser ablation of materials is very

Silicon Micromachined Microlens Array for THz Antennas

Science.gov (United States)

Lee, Choonsup; Chattopadhyay, Goutam; Mehdi, IImran; Gill, John J.; Jung-Kubiak, Cecile D.; Llombart, Nuria

2013-01-01

5 5 silicon microlens array was developed using a silicon micromachining technique for a silicon-based THz antenna array. The feature of the silicon micromachining technique enables one to microfabricate an unlimited number of microlens arrays at one time with good uniformity on a silicon wafer. This technique will resolve one of the key issues in building a THz camera, which is to integrate antennas in a detector array. The conventional approach of building single-pixel receivers and stacking them to form a multi-pixel receiver is not suited at THz because a single-pixel receiver already has difficulty fitting into mass, volume, and power budgets, especially in space applications. In this proposed technique, one has controllability on both diameter and curvature of a silicon microlens. First of all, the diameter of microlens depends on how thick photoresist one could coat and pattern. So far, the diameter of a 6- mm photoresist microlens with 400 m in height has been successfully microfabricated. Based on current researchers experiences, a diameter larger than 1-cm photoresist microlens array would be feasible. In order to control the curvature of the microlens, the following process variables could be used: 1. Amount of photoresist: It determines the curvature of the photoresist microlens. Since the photoresist lens is transferred onto the silicon substrate, it will directly control the curvature of the silicon microlens. 2. Etching selectivity between photoresist and silicon: The photoresist microlens is formed by thermal reflow. In order to transfer the exact photoresist curvature onto silicon, there needs to be etching selectivity of 1:1 between silicon and photoresist. However, by varying the etching selectivity, one could control the curvature of the silicon microlens. The figure shows the microfabricated silicon microlens 5 x5 array. The diameter of the microlens located in the center is about 2.5 mm. The measured 3-D profile of the microlens surface has a

The Influence of Coating Structure on Micromachine Stiction

Energy Technology Data Exchange (ETDEWEB)

Kushmerick, J.G.; Hankins, M.G.; De Boer, M.P.; Clews, P.J.; Carpick, R.W.; Bunker, B.C.

2000-10-03

We have clearly shown that the film morphology dictates the anti-stiction properties of FDTS coatings. Release stiction is not observed when ideal monolayer films are present but can be extensive when thicker aggregate structures are present. This finding is significant because it indicates that agglomerate formation during processing is a major source of irreproducible behavior when FDTS coatings are used to release micromachined parts. The results could also help explain why coatings that are aged at high. humidity start to stick to each other. (AFM results show that humid environments promote the formation of aggregates from monolayer films.) The reason why aggregate structures promote stiction is currently unknown. However, it appears that aggregates interfere with the ability of FDTS to form dense, well-ordered coatings under microstructures, leading to surfaces that are sufficiently hydrophilic to allow for release stiction via an attractive Laplace force during drying.

Acceleration sensitivity of micromachined pressure sensors

Science.gov (United States)

August, Richard; Maudie, Theresa; Miller, Todd F.; Thompson, Erik

1999-08-01

Pressure sensors serve a variety of automotive applications, some which may experience high levels of acceleration such as tire pressure monitoring. To design pressure sensors for high acceleration environments it is important to understand their sensitivity to acceleration especially if thick encapsulation layers are used to isolate the device from the hostile environment in which they reside. This paper describes a modeling approach to determine their sensitivity to acceleration that is very general and is applicable to different device designs and configurations. It also describes the results of device testing of a capacitive surface micromachined pressure sensor at constant acceleration levels from 500 to 2000 g's.

Silicon-micromachined microchannel plates

CERN Document Server

Beetz, C P; Steinbeck, J; Lemieux, B; Winn, D R

2000-01-01

Microchannel plates (MCP) fabricated from standard silicon wafer substrates using a novel silicon micromachining process, together with standard silicon photolithographic process steps, are described. The resulting SiMCP microchannels have dimensions of approx 0.5 to approx 25 mu m, with aspect ratios up to 300, and have the dimensional precision and absence of interstitial defects characteristic of photolithographic processing, compatible with positional matching to silicon electronics readouts. The open channel areal fraction and detection efficiency may exceed 90% on plates up to 300 mm in diameter. The resulting silicon substrates can be converted entirely to amorphous quartz (qMCP). The strip resistance and secondary emission are developed by controlled depositions of thin films, at temperatures up to 1200 deg. C, also compatible with high-temperature brazing, and can be essentially hydrogen, water and radionuclide-free. Novel secondary emitters and cesiated photocathodes can be high-temperature deposite...

Structure optimization and simulation analysis of the quartz micromachined gyroscope

Directory of Open Access Journals (Sweden)

Xuezhong Wu

2014-02-01

Full Text Available Structure optimization and simulation analysis of the quartz micromachined gyroscope are reported in this paper. The relationships between the structure parameters and the frequencies of work mode were analysed by finite element analysis. The structure parameters of the quartz micromachined gyroscope were optimized to reduce the difference between the frequencies of the drive mode and the sense mode. The simulation results were proved by testing the prototype gyroscope, which was fabricated by micro-electromechanical systems (MEMS technology. Therefore, the frequencies of the drive mode and the sense mode can match each other by the structure optimization and simulation analysis of the quartz micromachined gyroscope, which is helpful in the design of the high sensitivity quartz micromachined gyroscope.

Numerical modelling of micro-machining of f.c.c. single crystal: Influence of strain gradients

KAUST Repository

Demiral, Murat

2014-11-01

A micro-machining process becomes increasingly important with the continuous miniaturization of components used in various fields from military to civilian applications. To characterise underlying micromechanics, a 3D finite-element model of orthogonal micro-machining of f.c.c. single crystal copper was developed. The model was implemented in a commercial software ABAQUS/Explicit employing a user-defined subroutine VUMAT. Strain-gradient crystal-plasticity and conventional crystal-plasticity theories were used to demonstrate the influence of pre-existing and evolved strain gradients on the cutting process for different combinations of crystal orientations and cutting directions. Crown Copyright © 2014.

Fabrication and Characterization of Capacitive Micromachined Ultrasonic Transducers with Low-Temperature Wafer Direct Bonding

Directory of Open Access Journals (Sweden)

Xiaoqing Wang

2016-12-01

Full Text Available This paper presents a fabrication method of capacitive micromachined ultrasonic transducers (CMUTs by wafer direct bonding, which utilizes both the wet chemical and O2plasma activation processes to decrease the bonding temperature to 400 °C. Two key surface properties, the contact angle and surface roughness, are studied in relation to the activation processes, respectively. By optimizing the surface activation parameters, a surface roughness of 0.274 nm and a contact angle of 0° are achieved. The infrared images and static deflection of devices are assessed to prove the good bonding effect. CMUTs having silicon membranes with a radius of 60 μm and a thickness of 2 μm are fabricated. Device properties have been characterized by electrical and acoustic measurements to verify their functionality and thus to validate this low-temperature process. A resonant frequency of 2.06 MHz is obtained by the frequency response measurements. The electrical insertion loss and acoustic signal have been evaluated. This study demonstrates that the CMUT devices can be fabricated by low-temperature wafer direct bonding, which makes it possible to integrate them directly on top of integrated circuit (IC substrates.

Predictive modeling, simulation, and optimization of laser processing techniques: UV nanosecond-pulsed laser micromachining of polymers and selective laser melting of powder metals

Science.gov (United States)

Criales Escobar, Luis Ernesto

One of the most frequently evolving areas of research is the utilization of lasers for micro-manufacturing and additive manufacturing purposes. The use of laser beam as a tool for manufacturing arises from the need for flexible and rapid manufacturing at a low-to-mid cost. Laser micro-machining provides an advantage over mechanical micro-machining due to the faster production times of large batch sizes and the high costs associated with specific tools. Laser based additive manufacturing enables processing of powder metals for direct and rapid fabrication of products. Therefore, laser processing can be viewed as a fast, flexible, and cost-effective approach compared to traditional manufacturing processes. Two types of laser processing techniques are studied: laser ablation of polymers for micro-channel fabrication and selective laser melting of metal powders. Initially, a feasibility study for laser-based micro-channel fabrication of poly(dimethylsiloxane) (PDMS) via experimentation is presented. In particular, the effectiveness of utilizing a nanosecond-pulsed laser as the energy source for laser ablation is studied. The results are analyzed statistically and a relationship between process parameters and micro-channel dimensions is established. Additionally, a process model is introduced for predicting channel depth. Model outputs are compared and analyzed to experimental results. The second part of this research focuses on a physics-based FEM approach for predicting the temperature profile and melt pool geometry in selective laser melting (SLM) of metal powders. Temperature profiles are calculated for a moving laser heat source to understand the temperature rise due to heating during SLM. Based on the predicted temperature distributions, melt pool geometry, i.e. the locations at which melting of the powder material occurs, is determined. Simulation results are compared against data obtained from experimental Inconel 625 test coupons fabricated at the National

Cryogenically assisted abrasive jet micromachining of polymers

International Nuclear Information System (INIS)

Getu, H; Papini, M; Spelt, J K

2008-01-01

The abrasive jet micromachining (AJM) of elastomers and polymers such as polydimethylsiloxane (PDMS), acrylonitrile butadiene styrene (ABS) and polytetrafluoroethylene (PTFE) for use in micro-fluidic devices was found to be very slow or impossible at room temperature. To enhance the material removal rate in such materials, a stream of liquid nitrogen (LN 2 ) was injected into the abrasive jet, cooling the target to cryogenic temperatures. Erosion rate measurements on the three polymeric materials (PDMS, ABS and PTFE) with and without the use of LN 2 were compared along with the profiles of micromachined channels and holes. It was found that the use of LN 2 cooling caused brittle erosion in PDMS, allowing it to be micromachined successfully. An erosion rate increase was also observed in PTFE and ABS at high and intermediate impact angles. The use of LN 2 also was found to reduce particle embedding

Micromachining with copper lasers

Science.gov (United States)

Knowles, Martyn R. H.; Bell, Andy; Foster-Turner, Gideon; Rutterford, Graham; Chudzicki, J.; Kearsley, Andrew J.

1997-04-01

In recent years the copper laser has undergone extensive development and has emerged as a leading and unique laser for micromachining. The copper laser is a high average power (10 - 250 W), high pulse repetition rate (2 - 32 kHz), visible laser (511 nm and 578 nm) that produces high peak power (typically 200 kW), short pulses (30 ns) and very good beam quality (diffraction limited). This unique set of laser parameters results in exceptional micro-machining in a wide variety of materials. Typical examples of the capabilities of the copper laser include the drilling of small holes (10 - 200 micrometer diameter) in materials as diverse as steel, ceramic, diamond and polyimide with micron precision and low taper (less than 1 degree) cutting and profiling of diamond. Application of the copper laser covers the electronic, aerospace, automotive, nuclear, medical and precision engineering industries.

Fiscal 1996 report on technological results. R and D on micromachine technology; 1996 nendo micromachine gijutsu no kenkyu kaihatsu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-03-01

Researches on basic element technology of micromachines are conducted that operate autonomously in a narrow small part in a complicated apparatus or in vivo. The areas of activity are (1) research on micromachine systems, (2) a subminiature liquid synthesizing system, and (3) comprehensive investigation and research. In (1), the researches were carried out on the miniaturization and functional combination of a micro laser catheter and a micro tactile sensor catheter, which are the primary components of a coeliac diagnostic and therapeutic system, a 'micro catheter for cerebral blood vessel/treatment', as a micromachine system in the medical field. In (2), R and D was conducted on a system element technology assuming it contributed to a subminiature liquid synthesizing system capable of preparing various liquids including pharmaceuticals accurately with a trace amount. In (3), examination was made on the application area of a micromachine system with priority given to a medical field and also on technological subjects to be tapped, as well as on the contents of (2), with a device installed for evaluating the operating characteristic of a distribution type fluid actuator as needed for the development. (NEDO)

High-frequency micro-machined power inductors

International Nuclear Information System (INIS)

Wang, N.; O'Donnell, T.; Roy, S.; Brunet, M.; McCloskey, P.; O'Mathuna, S.C.

2005-01-01

Power inductors have been fabricated on silicon substrates using low-temperature IC compatible processes. The electrical properties of these micro-inductors have been measured and discussed. A maximum quality factor of 6 at 4 MHz has been achieved with an inductance value of about 160 nH. The DC saturation currents of the non-gapped and gapped inductors are ∼500 and 700 mA, respectively. The relatively high Q factor and the load current characteristics allow these micro-machined inductors to be used in integrated power converters

Apparatus for precision micromachining with lasers

Science.gov (United States)

Chang, J.J.; Dragon, E.P.; Warner, B.E.

1998-04-28

A new material processing apparatus using a short-pulsed, high-repetition-rate visible laser for precision micromachining utilizes a near diffraction limited laser, a high-speed precision two-axis tilt-mirror for steering the laser beam, an optical system for either focusing or imaging the laser beam on the part, and a part holder that may consist of a cover plate and a back plate. The system is generally useful for precision drilling, cutting, milling and polishing of metals and ceramics, and has broad application in manufacturing precision components. Precision machining has been demonstrated through percussion drilling and trepanning using this system. With a 30 W copper vapor laser running at multi-kHz pulse repetition frequency, straight parallel holes with size varying from 500 microns to less than 25 microns and with aspect ratios up to 1:40 have been consistently drilled with good surface finish on a variety of metals. Micromilling and microdrilling on ceramics using a 250 W copper vapor laser have also been demonstrated with good results. Materialographic sections of machined parts show little (submicron scale) recast layer and heat affected zone. 1 fig.

Micromachined ultrasonic droplet generator based on a liquid horn structure

Science.gov (United States)

Meacham, J. M.; Ejimofor, C.; Kumar, S.; Degertekin, F. L.; Fedorov, A. G.

2004-05-01

A micromachined ultrasonic droplet generator is developed and demonstrated for drop-on-demand fluid atomization. The droplet generator comprises a bulk ceramic piezoelectric transducer for ultrasound generation, a reservoir for the ejection fluid, and a silicon micromachined liquid horn structure as the nozzle. The nozzles are formed using a simple batch microfabrication process that involves wet etching of (100) silicon in potassium hydroxide solution. Device operation is demonstrated by droplet ejection of water through 30 μm orifices at 1.49 and 2.30 MHz. The finite-element simulations of the acoustic fields in the cavity and electrical impedance of the device are in agreement with the measurements and indicate that the device utilizes cavity resonances in the 1-5 MHz range in conjunction with acoustic wave focusing by the pyramidally shaped nozzles to achieve low power operation.

CO2-laser micromachining and back-end processing for rapid production of PMMA-based microfluidic systems

DEFF Research Database (Denmark)

Klank, Henning; Kutter, Jörg Peter; Geschke, Oliver

2002-01-01

, a three-layer polymer microstructure with included optical fibers was fabricated within two days. The use of CO2-laser systems to produce microfluidic systems has not been published before. These systems provide a cost effective alternative to UV-laser systems and they are especially useful......In this article, we focus on the enormous potential of a CO2-laser system for rapidly producing polymer microfluidic structures. The dependence was assessed of the depth and width of laser-cut channels on the laser beam power and on the number of passes of the beam along the same channel...... for microstructured PMMA [poly( methyl methacrylate)] parts were investigated, such as solvent-assisted glueing, melting, laminating and surface activation using a plasma asher. A solvent-assisted thermal bonding method proved to be the most time-efficient one. Using laser micromachining together with bonding...

Micromachined thin-film sensors for SOI-CMOS co-integration

CERN Document Server

Laconte, Jean; Raskin, Jean-Pierre

2006-01-01

Co-integration of MEMS and MOS in SOI technology is promising and well demonstrated hereThe impact of Micromachining on SOI devices is deeply analyzed for the first timeInclude extensive TMAH etching, residual stress, microheaters, gas-flow sensors reviewResidual stresses in thin films need to be more and more monitored in MEMS designsTMAH micromachining is an attractive alternative to KOH.

Ultrafast disk technology enables next generation micromachining laser sources

Science.gov (United States)

Heckl, Oliver H.; Weiler, Sascha; Luzius, Severin; Zawischa, Ivo; Sutter, Dirk

2013-02-01

Ultrashort pulsed lasers based on thin disk technology have entered the 100 W regime and deliver several tens of MW peak power without chirped pulse amplification. Highest uptime and insensitivity to back reflections make them ideal tools for efficient and cost effective industrial micromachining. Frequency converted versions allow the processing of a large variety of materials. On one hand, thin disk oscillators deliver more than 30 MW peak power directly out of the resonator in laboratory setups. These peak power levels are made possible by recent progress in the scaling of the pulse energy in excess of 40 μJ. At the corresponding high peak intensity, thin disk technology profits from the limited amount of material and hence the manageable nonlinearity within the resonator. Using new broadband host materials like for example the sesquioxides will eventually reduce the pulse duration during high power operation and further increase the peak power. On the other hand industry grade amplifier systems deliver even higher peak power levels. At closed-loop controlled 100W, the TruMicro Series 5000 currently offers the highest average ultrafast power in an industry proven product, and enables efficient micromachining of almost any material, in particular of glasses, ceramics or sapphire. Conventional laser cutting of these materials often requires UV laser sources with pulse durations of several nanoseconds and an average power in the 10 W range. Material processing based on high peak power laser sources makes use of multi-photon absorption processes. This highly nonlinear absorption enables micromachining driven by the fundamental (1030 nm) or frequency doubled (515 nm) wavelength of Yb:YAG. Operation in the IR or green spectral range reduces the complexity and running costs of industrial systems initially based on UV light sources. Where UV wavelength is required, the TruMicro 5360 with a specified UV crystal life-time of more than 10 thousand hours of continues

A silicon micromachined resonant pressure sensor

International Nuclear Information System (INIS)

Tang Zhangyang; Fan Shangchun; Cai Chenguang

2009-01-01

This paper describes the design, fabrication and test of a silicon micromachined resonant pressure sensor. A square membrane and a doubly clamped resonant beam constitute a compound structure. The former senses the pressure directly, while the latter changes its resonant frequency according to deformation of the membrane. The final output relation between the resonant frequency and the applied pressure is deducted according to the structure mechanical properties. Sensors are fabricated by micromachining technology, and then sealed in vaccum. These sensors are tested by open-loop and close-loop system designed on purpose. The experiment results demonstrate that the sensor has a sensitivity of 49.8Hz/kPa and repeatability of 0.08%.

Unveiling the wet chemical etching characteristics of polydimethylsiloxane film for soft micromachining applications

International Nuclear Information System (INIS)

Kakati, A; Maji, D; Das, S

2017-01-01

Micromachining of a polydimethylsiloxane (PDMS) microstructure by wet chemical etching is explored for microelectromechanical systems (MEMS) and microfluidic applications. A 100 µ m thick PDMS film was patterned with different microstructure designs by wet chemical etching using a N-methyl-2-pyrrolidone (C 16 H 36 FN) and tetra-n-butylammonium fluoride (C 5 H 9 NO) mixture solution with 3:1 volume ratio after lithography for studying etching characteristics. The patterning parameters, such as etch rate, surface roughness, pH of etchant solution with time, were thoroughly investigated. A detailed study of surface morphology with etching time revealed nonlinear behaviour of the PDMS surface roughness and etch rate. A maximum rate of 1.45 µ m min −1 for 10 min etching with surface roughness of 360 nm was achieved. A new approach of wet chemical etching with pH controlled doped etchant was introduced for lower surface roughness of etched microstructures, and a constant etch rate during etching. Variation of the etching rate and surface roughness by pH controlled etching was performed by doping 5–15 gm l −1 of silicic acid (SiO 2xH2 O) into the traditional etchant solution. PDMS etching by silicic acid doped etchant solution showed a reduction in surface roughness from 400 nm to 220 nm for the same 15 µ m etching. This study is beneficial for micromachining of various MEMS and microfluidic structures such as micropillars, microchannels, and other PDMS microstructures. (paper)

Influence of micromachined targets on laser accelerated proton beam profiles

Science.gov (United States)

Dalui, Malay; Permogorov, Alexander; Pahl, Hannes; Persson, Anders; Wahlström, Claes-Göran

2018-03-01

High intensity laser-driven proton acceleration from micromachined targets is studied experimentally in the target-normal-sheath-acceleration regime. Conical pits are created on the front surface of flat aluminium foils of initial thickness 12.5 and 3 μm using series of low energy pulses (0.5-2.5 μJ). Proton acceleration from such micromachined targets is compared with flat foils of equivalent thickness at a laser intensity of 7 × 1019 W cm-2. The maximum proton energy obtained from targets machined from 12.5 μm thick foils is found to be slightly lower than that of flat foils of equivalent remaining thickness, and the angular divergence of the proton beam is observed to increase as the depth of the pit approaches the foil thickness. Targets machined from 3 μm thick foils, on the other hand, show evidence of increasing the maximum proton energy when the depths of the structures are small. Furthermore, shallow pits on 3 μm thick foils are found to be efficient in reducing the proton beam divergence by a factor of up to three compared to that obtained from flat foils, while maintaining the maximum proton energy.

Development of a Novel Transparent Flexible Capacitive Micromachined Ultrasonic Transducer

Directory of Open Access Journals (Sweden)

Da-Chen Pang

2017-06-01

Full Text Available This paper presents the world’s first transparent flexible capacitive micromachined ultrasonic transducer (CMUT that was fabricated through a roll-lamination technique. This polymer-based CMUT has advantages of transparency, flexibility, and non-contacting detection which provide unique functions in display panel applications. Comprising an indium tin oxide-polyethylene terephthalate (ITO-PET substrate, SU-8 sidewall and vibrating membranes, and silver nanowire transparent electrode, the transducer has visible-light transmittance exceeding 80% and can operate on curved surfaces with a 40 mm radius of curvature. Unlike the traditional silicon-based high temperature process, the CMUT can be fabricated on a flexible substrate at a temperature below 100 °C to reduce residual stress introduced at high temperature. The CMUT on the curved surfaces can detect a flat target and finger at distances up to 50 mm and 40 mm, respectively. The transparent flexible CMUT provides a better human-machine interface than existing touch panels because it can be integrated with a display panel for non-contacting control in a health conscious environment and the flexible feature is critical for curved display and wearable electronics.

Sub 100 nm proton beam micromachining: theoretical calculations on resolution limits

International Nuclear Information System (INIS)

Kan, J.A. van; Sum, T.C.; Osipowicz, T.; Watt, F.

2000-01-01

Proton beam micromachining is a novel direct-write process for the production of three-dimensional (3D) microstructures. A focused beam of MeV protons is scanned in a pre-determined pattern over a suitable resist material (e.g. PMMA or SU-8) and the latent image formed is subsequently developed chemically. In this paper calculations on theoretical resolution limits of proton beam micromachined three-dimensional microstructures are presented. Neglecting the finite beam size, a Monte Carlo ion transport code was used in combination with a theoretical model describing the delta-ray (δ-ray) energy deposition to determine the lateral energy deposition distribution in PMMA resist material. The energy deposition distribution of ion induced secondary electrons (δ-rays) has been parameterized using analytical models. It is assumed that the attainable resolution is limited by a convolution of the spread of the ion beam and energy deposition of the δ-rays

Laser micromachining of sputtered DLC films

International Nuclear Information System (INIS)

Fu, Y.Q.; Luo, J.K.; Flewitt, A.J.; Ong, S.E.; Zhang, S.; Milne, W.I.

2006-01-01

DLC films with different thicknesses (from 100 nm to 1.9 μm) were deposited using sputtering of graphite target in pure argon atmosphere without substrate heating. Film microstructures (sp 2 /sp 3 ratio) and mechanical properties (modulus, hardness, stress) were characterized as a function of film thickness. A thin layer of aluminum about 60 nm was deposited on the DLC film surface. Laser micromachining of Al/DLC layer was performed to form microcantilever structures, which were released using a reactive ion etching system with SF 6 plasma. Due to the intrinsic stress in DLC films and bimorph Al/DLC structure, the microcantilevers bent up with different curvatures. For DLC film of 100 nm thick, the cantilever even formed microtubes. The relationship between the bimorph beam bending and DLC film properties (such as stress, modulus, etc.) were discussed in details

Electron beam micromachining of plastics

Czech Academy of Sciences Publication Activity Database

Dupák, Libor

2014-01-01

Roč. 49, 5-6 (2014), s. 310-314 ISSN 0861-4717 R&D Projects: GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01; GA MŠk EE.2.3.20.0103 Institutional support: RVO:68081731 Keywords : micromachining of plastics * Electron beam Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

Surface-micromachined magnetic undulator with period length between 10μm and 1 mm for advanced light sources

Science.gov (United States)

Harrison, Jere; Joshi, Abhijeet; Lake, Jonathan; Candler, Rob; Musumeci, Pietro

2012-07-01

A technological gap exists between the μm-scale wiggling periods achieved using electromagnetic waves of high intensity laser pulses and the mm scale of permanent-magnet and superconducting undulators. In the sub-mm range, surface-micromachined soft-magnetic micro-electro-mechanical system inductors with integrated solenoidal coils have already experimentally demonstrated 100 to 500 mT field amplitude across air gaps as large as 15μm. Simulations indicate that magnetic fields as large as 1.5 T across 50μm inductor gaps are feasible. A simple rearranging of the yoke and pole geometry allows for fabrication of 10+ cm long undulator structures with period lengths between 12.5μm and 1 mm. Such undulators find application both in high average power spontaneous emission sources and, if used in combination with ultrahigh-brightness electron beams, could lead to the realization of low energy compact free-electron lasers. Challenges include electron energy broadening due to wakefields and Joule heating in the electromagnet.

Study of ablation on surfaces of nuclear-use metals irradiated with Femtosecond laser

International Nuclear Information System (INIS)

Nogueira, Alessandro F.; Samad, Ricardo E.; Vieira Junior, Nilson D.; Rossi, Wagner de

2017-01-01

The use of ultrashort pulsed lasers is an alternative for micro-machining in metal surfaces, with diverse applications in several industrial areas, such as aeronautics, aerospace, naval, nuclear, among others, where there is a growing concern with reliability in service. In this work, micro-machining were performed on titanium surfaces using femtosecond ultrashort pulses. Such a process resulted in minimal heat transfer to the material, thus avoiding and surface deformation of the titanium plate and the formation of resolidified material in the ablated region, which are drawbacks present in the use of the long pulsed keyed laser of the order of nanoseconds. Three types of micro-machining were performed, with variations in the distances between the machined lines. It was also verified that the wettability increases when there is an increase in the distance between machined lines. Finally, in order to change the surface with minimal removal of material, it has been found that the use of ultra-short pulse lasers provide great benefits for the integrity of the ablated material. This initial study is the starting point for the study of other metals, such as Maraging Steels and Zircaloy that will be the target of future work. (author)

Study of ablation on surfaces of nuclear-use metals irradiated with Femtosecond laser

Energy Technology Data Exchange (ETDEWEB)

Nogueira, Alessandro F.; Samad, Ricardo E.; Vieira Junior, Nilson D.; Rossi, Wagner de, E-mail: alessandro.nogueira@usp.br, E-mail: resamad@ipen.br [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), Sorocaba, SP (Brazil); Faculdade de Engenharia de Sorocaba (FACENS), Ipero, SP (Brazil); Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2017-11-01

The use of ultrashort pulsed lasers is an alternative for micro-machining in metal surfaces, with diverse applications in several industrial areas, such as aeronautics, aerospace, naval, nuclear, among others, where there is a growing concern with reliability in service. In this work, micro-machining were performed on titanium surfaces using femtosecond ultrashort pulses. Such a process resulted in minimal heat transfer to the material, thus avoiding and surface deformation of the titanium plate and the formation of resolidified material in the ablated region, which are drawbacks present in the use of the long pulsed keyed laser of the order of nanoseconds. Three types of micro-machining were performed, with variations in the distances between the machined lines. It was also verified that the wettability increases when there is an increase in the distance between machined lines. Finally, in order to change the surface with minimal removal of material, it has been found that the use of ultra-short pulse lasers provide great benefits for the integrity of the ablated material. This initial study is the starting point for the study of other metals, such as Maraging Steels and Zircaloy that will be the target of future work. (author)

Demonstration of Robust Micromachined Jet Technology and its Application to Realistic Flow Control Problems

National Research Council Canada - National Science Library

Allen, Mark

2000-01-01

.... Our approaches include: (1) the development of suitable micromachined synthetic jets (microjets) as actuators, which obviate the need to physically extend micromachined structures into an external flow...

Micro benchtop optics by bulk silicon micromachining

Science.gov (United States)

Lee, Abraham P.; Pocha, Michael D.; McConaghy, Charles F.; Deri, Robert J.

2000-01-01

Micromachining of bulk silicon utilizing the parallel etching characteristics of bulk silicon and integrating the parallel etch planes of silicon with silicon wafer bonding and impurity doping, enables the fabrication of on-chip optics with in situ aligned etched grooves for optical fibers, micro-lenses, photodiodes, and laser diodes. Other optical components that can be microfabricated and integrated include semi-transparent beam splitters, micro-optical scanners, pinholes, optical gratings, micro-optical filters, etc. Micromachining of bulk silicon utilizing the parallel etching characteristics thereof can be utilized to develop miniaturization of bio-instrumentation such as wavelength monitoring by fluorescence spectrometers, and other miniaturized optical systems such as Fabry-Perot interferometry for filtering of wavelengths, tunable cavity lasers, micro-holography modules, and wavelength splitters for optical communication systems.

Design and development of a surface micro-machined push–pull-type true-time-delay phase shifter on an alumina substrate for Ka-band T/R module application

International Nuclear Information System (INIS)

Dey, Sukomal; Koul, Shiban K

2012-01-01

A radio frequency micro-electro-mechanical system (RF-MEMS) phase shifter based on the distributed MEMS transmission line (DMTL) concept towards maximum achievable phase shift with low actuation voltage with good figure of merit (FOM) is presented in this paper. This surface micro-machined analog DMTL phase shifter demonstrates low power consumption for implementation in a Ka-band transmit/receive (T/R) module. The push–pull-type switch has been designed and optimized with an analytical method and validated with simulation, which is the fundamental building block of the design of a true-time-delay phase shifter. Change in phase has been designed and optimized in push and pull states with reference to the up-state performance of the phase shifter. The working principle of this push–pull-type DMTL phase shifter has been comprehensively worked out. A thorough detail of the design and performance analysis of the phase shifter has been carried out with various structural parameters using commercially available simulation tools with reference to a change in phase shift and has been verified using a system level simulation. The phase shifter is fabricated on the alumina substrate, using a suspended gold bridge membrane with a surface micromachining process. Asymmetric behaviour of push–pull bridge configuration has been noted and a corresponding effect on mechanical, electrical and RF performances has been extensively investigated. It is demonstrated 114° dB −1 FOM over 0–40 GHz band, which is the highest achievable FOM from a unit cell on an alumina substrate reported so far. A complete phase shifter contributes to a continuous differential phase shift of 0°–360° over 0–40 GHz band with a minimum actuation voltage of 8.1 V which is the highest achievable phase shift with the lowest actuation voltage as per till date on the alumina substrate with good repeatability and return loss better than 11.5 dB over 0–40 GHz band. (paper)

Discretely tunable micromachined injection-locked lasers

International Nuclear Information System (INIS)

Cai, H; Yu, M B; Lo, G Q; Kwong, D L; Zhang, X M; Liu, A Q; Liu, B

2010-01-01

This paper reports a micromachined injection-locked laser (ILL) to provide tunable discrete wavelengths. It utilizes a non-continuously tunable laser as the master to lock a Fabry–Pérot semiconductor laser chip. Both lasers are integrated into a deep-etched silicon chip with dimensions of 3 mm × 3 mm × 0.8 mm. Based on the experimental results, significant improvements in the optical power and spectral purity have been achieved in the fully locked state, and optical hysteresis and bistability have also been observed in response to the changes of the output wavelength and optical power of the master laser. As a whole system, the micromachined ILL is able to provide single mode, discrete wavelength tuning, high power and direct modulation with small size and single-chip solution, making it promising for advanced optical communications such as wavelength division multiplexing optical access networks.

A level set methodology for predicting the effect of mask wear on surface evolution of features in abrasive jet micro-machining

International Nuclear Information System (INIS)

Burzynski, T; Papini, M

2012-01-01

A previous implementation of narrow-band level set methodology developed by the authors was extended to allow for the modelling of mask erosive wear in abrasive jet micro-machining (AJM). The model permits the prediction of the surface evolution of both the mask and the target simultaneously, by representing them as a hybrid and continuous mask–target surface. The model also accounts for the change in abrasive mass flux incident to both the target surface and, for the first time, the eroding mask edge, that is brought about by the presence of the mask edge itself. The predictions of the channel surface and eroded mask profiles were compared with measurements on channels machined in both glass and poly-methyl-methacrylate (PMMA) targets at both normal and oblique incidence, using tempered steel and elastomeric masks. A much better agreement between the predicted and measured profiles was found when mask wear was taken into account. Mask wear generally resulted in wider and deeper glass target profiles and wider PMMA target profiles, respectively, when compared to cases where no mask wear was present. This work has important implications for the AJM of complex MEMS and microfluidic devices that require longer machining times. (paper)

A micromachined calorimetric gas sensor: an application of electrodeposited nanostructured palladium for the detection of combustible gases.

Science.gov (United States)

Bartlett, Philip N; Guerin, Samuel

2003-01-01

Palladium films with regular nanoarchitectures were electrochemically deposited from the hexagonal (H1) lyotropic liquid crystalline phase of the nonionic surfactant octaethyleneglycol monohexadecyl ether (C16EO8) onto micromachined silicon hotplate structures. The H1-e Pd films were shown to have high surface areas (approximately 28 m2 g(-1)) and to act as effective and stable catalysts for the detection of methane in air on heating to 500 degrees C. The response of the H1-e Pd-coated planar pellistors was found to be linearly proportional to the concentration of methane between 0 and 2.5% in air with a detection limit below 0.125%. Our results show that the electrochemical deposition of nanostructured metal films offers a promising approach to the fabrication of micromachined calorimetric gas sensors for combustible gases.

High-intensity fibre laser design for micro-machining applications

Science.gov (United States)

Ortiz-Neria, D. I.; Martinez-Piñón, F.; Hernandez-Escamilla, H.; Alvarez-Chavez, J. A.

2010-11-01

This work is focused on the design of a 250W high-intensity continuous-wave fibre optic laser with a 15μm spot size beam and a beam parameter product (BPP) of 1.8 for its use on Laser-assisted Cold Spray process (LCS) in the micro-machining areas. The metal-powder deposition process LCS, is a novel method based on Cold Spray technique (CS) assisted by laser technology. The LCS accelerates metal powders by the use of a high-pressure gas in order to achieve flash welding of particles over substrate. In LCS, the critical velocity of impact is lower with respect with CS while the powder particle is heated before the deposition by a laser beam. Furthermore, LCS does not heat the powder to achieve high temperatures as it happens in plasma processes. This property puts aside cooling problems which normally happen in sintered processes with high oxygen/nitrogen concentration levels. LCS will be used not only in deposition of thin layers. After careful design, proof of concept, experimental data, and prototype development, it should be feasible to perform micro-machining precise work with the use of the highintensity fibre laser presented in this work, and selective deposition of particles, in a similar way to the well-known Direct Metal Laser Sintering process (DMLS). The fibre laser consists on a large-mode area, Yb3+-doped, semi-diffraction limited, 25-m fibre laser cavity, operating in continuous wave regime. The fibre shows an arguably high slope-efficiency with no signs of roll-over. The measured M2 value is 1.8 and doping concentration of 15000ppm. It was made with a slight modification of the traditional MCVD technique. A full optical characterization will be presented.

Micromachined integrated quantum circuit containing a superconducting qubit

Science.gov (United States)

Brecht, Teresa; Chu, Yiwen; Axline, Christopher; Pfaff, Wolfgang; Blumoff, Jacob; Chou, Kevin; Krayzman, Lev; Frunzio, Luigi; Schoelkopf, Robert

We demonstrate a functional multilayer microwave integrated quantum circuit (MMIQC). This novel hardware architecture combines the high coherence and isolation of three-dimensional structures with the advantages of integrated circuits made with lithographic techniques. We present fabrication and measurement of a two-cavity/one-qubit prototype, including a transmon coupled to a three-dimensional microwave cavity micromachined in a silicon wafer. It comprises a simple MMIQC with competitive lifetimes and the ability to perform circuit QED operations in the strong dispersive regime. Furthermore, the design and fabrication techniques that we have developed are extensible to more complex quantum information processing devices.

Mechanical characterization of biocompatible thin film materials by scanning along micro-machined cantilevers for micro-/nano-system

International Nuclear Information System (INIS)

He, J.H.; Luo, J.K.; Le, H.R.; Moore, D.F.

2006-01-01

Mechanical characterization is vital for the design of micro-/nano-electro-mechanical system (MEMS/NEMS). This paper describes a new characterization method to extract the mechanical properties of the thin film materials, which is simple, inexpensive and applicable to a wide range of materials including biocompatible ones described in this paper. The beams of the material under tests, are patterned by laser micro-machining and released by alkaline etch. A surface profilometer is used to scan along micro-machined cantilevers and produce a bending profile, from which the Young's modulus can be extracted. Biocompatible SiN x , SiC and nanocrystal diamond cantilevers have been fabricated and their Young's modulus has been evaluated as 154 ± 12, 360 ± 50 and 504 ± 50 GPa, respectively, which is consistent with those measured by nano-indentation. Residual stress gradient has also been extracted by surface profilometer, which is comparable with the results inferred from ZYGO interferometer measurements. This method can be extended to atomic force microscopy stylus or nanometer-stylus profilometer for Bio-NEMS mechanical characterization

Frontside-micromachined planar piezoresistive vibration sensor: Evaluating performance in the low frequency test range

Directory of Open Access Journals (Sweden)

Lan Zhang

2014-01-01

Full Text Available Using a surface piezoresistor diffusion method and front-side only micromachining process, a planar piezoresistive vibration sensor was successfully developed with a simple structure, lower processing cost and fewer packaging difficulties. The vibration sensor had a large sector proof mass attached to a narrow flexure. Optimization of the boron diffusion piezoresistor placed on the edge of the narrow flexure greatly improved the sensitivity. Planar vibration sensors were fabricated and measured in order to analyze the effects of the sensor dimensions on performance, including the values of flexure width and the included angle of the sector. Sensitivities of fabricated planar sensors of 0.09–0.46 mV/V/g were measured up to a test frequency of 60 Hz. The sensor functioned at low voltages (<3 V and currents (<1 mA with a high sensitivity and low drift. At low background noise levels, the sensor had performance comparable to a commercial device.

Frontside-micromachined planar piezoresistive vibration sensor: Evaluating performance in the low frequency test range

Energy Technology Data Exchange (ETDEWEB)

Zhang, Lan; Lu, Jian, E-mail: jian-lu@aist.go.jp; Takagi, Hideki; Maeda, Ryutaro [Research Center for Ubiquitous MEMS and Micro Engineering (UMEMSME), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, 305-8564 (Japan)

2014-01-15

Using a surface piezoresistor diffusion method and front-side only micromachining process, a planar piezoresistive vibration sensor was successfully developed with a simple structure, lower processing cost and fewer packaging difficulties. The vibration sensor had a large sector proof mass attached to a narrow flexure. Optimization of the boron diffusion piezoresistor placed on the edge of the narrow flexure greatly improved the sensitivity. Planar vibration sensors were fabricated and measured in order to analyze the effects of the sensor dimensions on performance, including the values of flexure width and the included angle of the sector. Sensitivities of fabricated planar sensors of 0.09–0.46 mV/V/g were measured up to a test frequency of 60 Hz. The sensor functioned at low voltages (<3 V) and currents (<1 mA) with a high sensitivity and low drift. At low background noise levels, the sensor had performance comparable to a commercial device.

Micromachined high-performance RF passives in CMOS substrate

International Nuclear Information System (INIS)

Li, Xinxin; Ni, Zao; Gu, Lei; Wu, Zhengzheng; Yang, Chen

2016-01-01

This review systematically addresses the micromachining technologies used for the fabrication of high-performance radio-frequency (RF) passives that can be integrated into low-cost complementary metal-oxide semiconductor (CMOS)-grade (i.e. low-resistivity) silicon wafers. With the development of various kinds of post-CMOS-compatible microelectromechanical systems (MEMS) processes, 3D structural inductors/transformers, variable capacitors, tunable resonators and band-pass/low-pass filters can be compatibly integrated into active integrated circuits to form monolithic RF system-on-chips. By using MEMS processes, including substrate modifying/suspending and LIGA-like metal electroplating, both the highly lossy substrate effect and the resistive loss can be largely eliminated and depressed, thereby meeting the high-performance requirements of telecommunication applications. (topical review)

Model Design of Piezoelectric Micromachined Modal Gyroscope

Directory of Open Access Journals (Sweden)

Xiaojun Hu

2011-01-01

Full Text Available This paper reports a novel kind of solid-state microgyroscope, which is called piezoelectric micromachined modal gyroscope (PMMG. PMMG has large stiffness and robust resistance to shake and strike because there is no evident mass-spring component in its structure. This work focused on quantitative optimization of the gyroscope, which is still blank for such gyroscope. The modal analysis by the finite element method (FEM was firstly conducted. A set of quantitative indicators were developed to optimize the operation mode. By FEM, the harmonic analysis was conducted to find the way to efficiently actuate the operational mode needed. The optimal configuration of driving electrodes was obtained. At last, the Coriolis analysis was conducted to show the relation between angular velocity and differential output voltage by the Coriolis force under working condition. The results obtained in this paper provide theoretical basis for realizing this novel kind of micromachined gyroscope.

Manufacture of Radio Frequency Micromachined Switches with Annealing

Directory of Open Access Journals (Sweden)

Cheng-Yang Lin

2014-01-01

Full Text Available The fabrication and characterization of a radio frequency (RF micromachined switch with annealing were presented. The structure of the RF switch consists of a membrane, coplanar waveguide (CPW lines, and eight springs. The RF switch is manufactured using the complementary metal oxide semiconductor (CMOS process. The switch requires a post-process to release the membrane and springs. The post-process uses a wet etching to remove the sacrificial silicon dioxide layer, and to obtain the suspended structures of the switch. In order to improve the residual stress of the switch, an annealing process is applied to the switch, and the membrane obtains an excellent flatness. The finite element method (FEM software CoventorWare is utilized to simulate the stress and displacement of the RF switch. Experimental results show that the RF switch has an insertion loss of 0.9 dB at 35 GHz and an isolation of 21 dB at 39 GHz. The actuation voltage of the switch is 14 V.

Manufacture of radio frequency micromachined switches with annealing.

Science.gov (United States)

Lin, Cheng-Yang; Dai, Ching-Liang

2014-01-17

The fabrication and characterization of a radio frequency (RF) micromachined switch with annealing were presented. The structure of the RF switch consists of a membrane, coplanar waveguide (CPW) lines, and eight springs. The RF switch is manufactured using the complementary metal oxide semiconductor (CMOS) process. The switch requires a post-process to release the membrane and springs. The post-process uses a wet etching to remove the sacrificial silicon dioxide layer, and to obtain the suspended structures of the switch. In order to improve the residual stress of the switch, an annealing process is applied to the switch, and the membrane obtains an excellent flatness. The finite element method (FEM) software CoventorWare is utilized to simulate the stress and displacement of the RF switch. Experimental results show that the RF switch has an insertion loss of 0.9 dB at 35 GHz and an isolation of 21 dB at 39 GHz. The actuation voltage of the switch is 14 V.

A versatile multi-user polyimide surface micromachinning process for MEMS applications

KAUST Repository

Carreno, Armando Arpys Arevalo

2015-04-01

This paper reports a versatile multi-user micro-fabrication process for MEMS devices, the \\'Polyimide MEMS Multi-User Process\\' (PiMMPs). The reported process uses polyimide as the structural material and three separate metallization layers that can be interconnected depending on the desired application. This process enables for the first time the development of out-of-plane compliant mechanisms that can be designed using six different physical principles for actuation and sensing on a wafer from a single fabrication run. These principles are electrostatic motion, thermal bimorph actuation, capacitive sensing, magnetic sensing, thermocouple-based sensing and radio frequency transmission and reception. © 2015 IEEE.

Resonant gravimetric immunosensing based on capacitive micromachined ultrasound transducers

KAUST Repository

Viržonis, Darius

2014-04-08

High-frequency (40 MHz) and low-frequency (7 MHz) capacitive micromachined ultrasound transducers (CMUT) were fabricated and tested for use in gravimetric detection of biomolecules. The low-frequency CMUT sensors have a gold-coated surface, while the high-frequency sensors have a silicon nitride surface. Both surfaces were functionalized with bovine leukemia virus antigen gp51 acting as the antigen. On addition of an a specific antibody labeled with horseradish peroxidase (HRP), the antigen/antibody complex is formed on the surface and quantified by HRP-catalyzed oxidation of tetramethylbenzidine. It has been found that a considerably smaller quantity of immuno complex is formed on the high frequency sensor surface. In parallel, the loading of the surface of the CMUT was determined via resonance frequency and electromechanical resistance readings. Following the formation of the immuno complexes, the resonance frequencies of the low-frequency and high-frequency sensors decrease by up to 420 and 440 kHz, respectively. Finite element analysis reveals that the loading of the (gold-coated) low frequency sensors is several times larger than that on high frequency sensors. The formation of the protein film with pronounced elasticity and stress on the gold surface case is discussed. We also discuss the adoption of this method for the detection of DNA using a hybridization assay following polymerase chain reaction.

Surface processing by high power excimer laser

Energy Technology Data Exchange (ETDEWEB)

Stehle, M [SOPRA, 92 - Bois-Colombes (France)

1995-03-01

Surface processing with lasers is a promising field of research and applications because lasers bring substantial advantages : laser beams work at distance, laser treatments are clean in respect of environment consideration and they offer innovative capabilities for surface treatment which cannot be reached by other way. Excimer lasers are pulsed, gaseous lasers which emit in UV spectral range - the most common are XeCl (308 nm), KrF (248 nm), ArF (193 nm). From 1980 up to 1994, many of them have been used for research, medical and industrial applications such as spectroscopy, PRK (photo-refractive keratotomy) and micro-machining. In the last six years, from 1987 up to 1993, efforts have been done in order to jump from 100 W average power up to 1 kW for XeCl laser at {lambda} = 308 nm. It was the aim of AMMTRA project in Japan as EU205 and EU213 Eureka projects in Europe. In this framework, SOPRA developed VEL (Very large Excimer Laser). In 1992, 1 kW (10 J x 100 Hz) millstone has been reached for the first time, this technology is based on X-Ray preionization and large laser medium (5 liters). Surface treatments based on this laser source are the main purpose of VEL Lasers. Some of them are given for instance : (a) Turbine blades made with metallic substrate and ceramic coatings on the top, are glazed in order to increase corrosion resistance of ceramic and metal sandwich. (b) Selective ablation of organic coatings deposited on fragile composite material is investigated in Aerospace industry. (c) Chock hardening of bulk metallic materials or alloys are investigated for automotive industry in order to increase wear resistance. (d) Ablation of thin surface oxides of polluted steels are under investigation in nuclear industry for decontamination. (J.P.N.).

Surface processing by high power excimer laser

International Nuclear Information System (INIS)

Stehle, M.

1995-01-01

Surface processing with lasers is a promising field of research and applications because lasers bring substantial advantages : laser beams work at distance, laser treatments are clean in respect of environment consideration and they offer innovative capabilities for surface treatment which cannot be reached by other way. Excimer lasers are pulsed, gaseous lasers which emit in UV spectral range - the most common are XeCl (308 nm), KrF (248 nm), ArF (193 nm). From 1980 up to 1994, many of them have been used for research, medical and industrial applications such as spectroscopy, PRK (photo-refractive keratotomy) and micro-machining. In the last six years, from 1987 up to 1993, efforts have been done in order to jump from 100 W average power up to 1 kW for XeCl laser at λ = 308 nm. It was the aim of AMMTRA project in Japan as EU205 and EU213 Eureka projects in Europe. In this framework, SOPRA developed VEL (Very large Excimer Laser). In 1992, 1 kW (10 J x 100 Hz) millstone has been reached for the first time, this technology is based on X-Ray preionization and large laser medium (5 liters). Surface treatments based on this laser source are the main purpose of VEL Lasers. Some of them are given for instance : a) Turbine blades made with metallic substrate and ceramic coatings on the top, are glazed in order to increase corrosion resistance of ceramic and metal sandwich. b) Selective ablation of organic coatings deposited on fragile composite material is investigated in Aerospace industry. c) Chock hardening of bulk metallic materials or alloys are investigated for automotive industry in order to increase wear resistance. d) Ablation of thin surface oxides of polluted steels are under investigation in nuclear industry for decontamination. (J.P.N.)

Micromachined Piezoelectric Actuators for Cryogenic Adaptive Optics, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — TRS Technologies proposes micromachined single crystal piezoelectric actuator arrays to enable ultra-large stroke, high precision shape control for large aperture,...

High lane density slab-gel electrophoresis using micromachined instrumentation.

Science.gov (United States)

Papautsky, I; Mohanty, S; Weiss, R; Frazier, A B

2001-10-01

In this paper, micromachined pipette arrays (MPAs) and microcombs were studied as a means of enabling high lane density gel electrophoresis. The MPA provide a miniaturized format to interface sub-microliter volumes of samples between macroscale sample preparation formats and microscale biochemical analysis systems. The microcombs provide a means of creating sample loading wells in the gel material on the same center-to-center spacing as the MPAs. Together, the two micromachined instruments provide an alternative to current combs and pipetting technologies used for creating sample loading wells and sample delivery in gel electrophoresis systems. Using three designs for the microcomb-MPA pair, center-to-center spacings of 1.0 mm, 500 microm, and 250 microm are studied. The results demonstrate an approximate 10-fold increase in lane density and a 10-fold reduction in sample size from 5 microL to 500 pL. As a result, the number of theoretical plates has increased 2.5-fold, while system resolution has increased 1.5-fold over the conventional agarose gel systems. An examination of changes in resolution across the width of individual separation lanes in both systems revealed dependence in the case of the conventional gels and no dependence for the gels loaded with the micromachined instrumentation.

Micromachined microphone array on a chip for turbulent boundary layer measurements

Science.gov (United States)

Krause, Joshua Steven

A surface micromachined microphone array on a single chip has been successfully designed, fabricated, characterized, and tested for aeroacoustic purposes. The microphone was designed to have venting through the diaphragm, 64 elements (8x8) on the chip, and used a capacitive transduction scheme. The microphone was fabricated using the MEMSCAP PolyMUMPs process (a foundry polysilicon surface micromachining process) along with facilities at Tufts Micro and Nano Fabrication Facility (TMNF) where a Parylene-C passivation layer deposition and release of the microstructures were performed. The devices are packaged with low profile interconnects, presenting a maximum of 100 mum of surface topology. The design of an individual microphone was completed through the use of a lumped element model (LEM) to determine the theoretical performance of the microphone. Off-chip electronics were created to allow the microphone array outputs to be redirected to one of two channels, allowing dynamic reconfiguration of the effective transducer shape in software and provide 80 dB off isolation. The characterization was completed through the use of laser Doppler vibrometry (LDV), acoustic plane wave tube and free-field calibration, and electrical noise floor testing in a Faraday cage. Measured microphone sensitivity is 0.15 mV/Pa for an individual microphone and 8.7 mV/Pa for the entire array, in close agreement with model predictions. The microphones and electronics operate over the 200--40 000 Hz band. The dynamic range extends from 60 dB SPL in a 1 Hz band to greater than 150 dB SPL. Element variability was +/-0.05 mV/Pa in sensitivity with an array yield of 95%. Wind tunnel testing at flow rates of up to 205.8 m/s indicates that the devices continue to operate in flow without damage, and can be successfully reconfigured on the fly. Care has been taken to systematically remove contaminating signals (acoustic, vibration, and noise floor) from the wind tunnel data to determine actual

Fabrication and characterization of a micromachined swirl-shaped ionic polymer metal composite actuator with electrodes exhibiting asymmetric resistance.

Science.gov (United States)

Feng, Guo-Hua; Liu, Kim-Min

2014-05-12

This paper presents a swirl-shaped microfeatured ionic polymer-metal composite (IPMC) actuator. A novel micromachining process was developed to fabricate an array of IPMC actuators on a glass substrate and to ensure that no shortcircuits occur between the electrodes of the actuator. We demonstrated a microfluidic scheme in which surface tension was used to construct swirl-shaped planar IPMC devices of microfeature size and investigated the flow velocity of Nafion solutions, which formed the backbone polymer of the actuator, within the microchannel. The unique fabrication process yielded top and bottom electrodes that exhibited asymmetric surface resistance. A tool for measuring surface resistance was developed and used to characterize the resistances of the electrodes for the fabricated IPMC device. The actuator, which featured asymmetric electrode resistance, caused a nonzero-bias current when the device was driven using a zero-bias square wave, and we propose a circuit model to describe this phenomenon. Moreover, we discovered and characterized a bending and rotating motion when the IPMC actuator was driven using a square wave. We observed a strain rate of 14.6% and a displacement of 700 μm in the direction perpendicular to the electrode surfaces during 4.5-V actuation.

New technique for fabrication of high frequency piezoelectric Micromachined Ultrasound Transducers

DEFF Research Database (Denmark)

Pedersen, T; Thomsen, Erik Vilain; Zawada, T

2008-01-01

A novel technique for fabrication of linear arrays of high frequency piezoelectric Micromachined Ultrasound Transducers (pMUT) on silicon substrates is presented. Piezoelectric elements are formed by deposition of PZT ((PbZrxTi1-x)O3) into etched features of the silicon substrate such that the de......A novel technique for fabrication of linear arrays of high frequency piezoelectric Micromachined Ultrasound Transducers (pMUT) on silicon substrates is presented. Piezoelectric elements are formed by deposition of PZT ((PbZrxTi1-x)O3) into etched features of the silicon substrate...

Integration of Capacitive Micromachined Ultrasound Transducers to Microfluidic Devices

KAUST Repository

Viržonis, Darius; Kodzius, Rimantas; Vanagas, Galius

2013-01-01

The design and manufacturing flexibility of capacitive micromachined ultrasound transducers (CMUT) makes them attractive option for integration with microfluidic devices both for sensing and fluid manipulation. CMUT concept is introduced here

Microfabrication in free-standing gallium nitride using UV laser micromachining

International Nuclear Information System (INIS)

Gu, E.; Howard, H.; Conneely, A.; O'Connor, G.M.; Illy, E.K.; Knowles, M.R.H.; Edwards, P.R.; Martin, R.W.; Watson, I.M.; Dawson, M.D.

2006-01-01

Gallium nitride (GaN) and related alloys are important semiconductor materials for fabricating novel photonic devices such as ultraviolet (UV) light-emitting diodes (LEDs) and vertical cavity surface-emitting lasers (VCSELs). Recent technical advances have made free-standing GaN substrates available and affordable. However, these materials are strongly resistant to wet chemical etching and also, low etch rates restrict the use of dry etching. Thus, to develop alternative high-resolution processing for these materials is increasingly important. In this paper, we report the fabrication of microstructures in free-standing GaN using pulsed UV lasers. An effective method was first developed to remove the re-deposited materials due to the laser machining. In order to achieve controllable machining and high resolution in GaN, machining parameters were carefully optimised. Under the optimised conditions, precision features such as holes (through holes, blind or tapered holes) on a tens of micrometer length scale have been machined. To fabricate micro-trenches in GaN with vertical sidewalls and a flat bottom, different process strategies of laser machining were tested and optimised. Using this technique, we have successfully fabricated high-quality micro-trenches in free-standing GaN with various widths and depths. The approach combining UV laser micromachining and other processes is also discussed. Our results demonstrate that the pulsed UV laser is a powerful tool for fabricating precision microstructures and devices in gallium nitride

Silicon Micromachines for Science and Technology

International Nuclear Information System (INIS)

Bishop, David J.

2002-01-01

The era of silicon micromechanics is upon us. In areas as diverse as telecommunications, automotive, aerospace, chemistry, entertainment and basic science, the ability to build microscopic machines from silicon is having a revolutionary impact. In my talk, I will discuss what micromachines are, how they are built and show examples of how they will have a revolutionary impact in many areas of science as well as technology.

Micro-machined calorimetric biosensors

Science.gov (United States)

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.

2002-01-01

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.

Integration of Capacitive Micromachined Ultrasound Transducers to Microfluidic Devices

KAUST Repository

Viržonis, Darius

2013-10-22

The design and manufacturing flexibility of capacitive micromachined ultrasound transducers (CMUT) makes them attractive option for integration with microfluidic devices both for sensing and fluid manipulation. CMUT concept is introduced here by presentin

Micromachined Polycrystalline Si Thermopiles in a T-shirt

Directory of Open Access Journals (Sweden)

Vladimir Leonov

2011-04-01

Full Text Available The technology for in-plane poly-Si thermopiles has been developed. The bulk-micromachined thermopiles are located between two Si bars and connected thermally with those bars through thin-film thermal shunts. The patterned strips of thermocouple material together with thermal shunts form bridges between Si bars. Two versions of a thermoelectric generator (TEG with micromachined thermopiles have been assembled and tested on a person’s wrist, and when integrated in a T-shirt. The TEG still produces less than 1 μW in the office, but at ambient temperatures below 11-13 °C it produces more than 1 μW at a voltage of more than 2 V on the matched load. The new way of integration of wearable TEG in clothing is shown. The TEG is located under the textile, and the fabric is used as a flexible radiator.

Predicting the Deflections of Micromachined Electrostatic Actuators Using Artificial Neural Network (ANN

Directory of Open Access Journals (Sweden)

Hing Wah LEE

2009-03-01

Full Text Available In this study, a general purpose Artificial Neural Network (ANN model based on the feed-forward back-propagation (FFBP algorithm has been used to predict the deflections of a micromachined structures actuated electrostatically under different loadings and geometrical parameters. A limited range of simulation results obtained via CoventorWare™ numerical software will be used initially to train the neural network via back-propagation algorithm. The micromachined structures considered in the analyses are diaphragm, fixed-fixed beams and cantilevers. ANN simulation results are compared with results obtained via CoventorWare™ simulations and existing analytical work for validation purpose. The proposed ANN model accurately predicts the deflections of the micromachined structures with great reduction of simulation efforts, establishing the method superiority. This method can be extended for applications in other sensors particularly for modeling sensors applying electrostatic actuation which are difficult in nature due to the inherent non-linearity of the electro-mechanical coupling response.

Capacitive micromachined ultrasonic transducers for medical imaging and therapy

International Nuclear Information System (INIS)

Khuri-Yakub, Butrus T; Oralkan, Ömer

2011-01-01

Capacitive micromachined ultrasonic transducers (CMUTs) have been subject to extensive research for the last two decades. Although they were initially developed for air-coupled applications, today their main application space is medical imaging and therapy. This paper first presents a brief description of CMUTs, their basic structure and operating principles. Our progression of developing several generations of fabrication processes is discussed with an emphasis on the advantages and disadvantages of each process. Monolithic and hybrid approaches for integrating CMUTs with supporting integrated circuits are surveyed. Several prototype transducer arrays with integrated front-end electronic circuits we developed and their use for 2D and 3D, anatomical and functional imaging, and ablative therapies are described. The presented results prove the CMUT as a micro-electro-mechanical systems technology for many medical diagnostic and therapeutic applications

Capacitive micromachined ultrasonic transducers for medical imaging and therapy.

Science.gov (United States)

Khuri-Yakub, Butrus T; Oralkan, Omer

2011-05-01

Capacitive micromachined ultrasonic transducers (CMUTs) have been subject to extensive research for the last two decades. Although they were initially developed for air-coupled applications, today their main application space is medical imaging and therapy. This paper first presents a brief description of CMUTs, their basic structure, and operating principles. Our progression of developing several generations of fabrication processes is discussed with an emphasis on the advantages and disadvantages of each process. Monolithic and hybrid approaches for integrating CMUTs with supporting integrated circuits are surveyed. Several prototype transducer arrays with integrated frontend electronic circuits we developed and their use for 2-D and 3-D, anatomical and functional imaging, and ablative therapies are described. The presented results prove the CMUT as a MEMS technology for many medical diagnostic and therapeutic applications.

Novel in situ mechanical testers to enable integrated metal surface micro-machines.

Energy Technology Data Exchange (ETDEWEB)

Follstaedt, David Martin; de Boer, Maarten Pieter; Kotula, Paul Gabriel; Hearne, Sean Joseph; Foiles, Stephen Martin; Buchheit, Thomas Edward; Dyck, Christopher William

2005-10-01

The ability to integrate metal and semiconductor micro-systems to perform highly complex functions, such as RF-MEMS, will depend on developing freestanding metal structures that offer improved conductivity, reflectivity, and mechanical properties. Three issues have prevented the proliferation of these systems: (1) warpage of active components due to through-thickness stress gradients, (2) limited component lifetimes due to fatigue, and (3) low yield strength. To address these issues, we focus on developing and implementing techniques to enable the direct study of the stress and microstructural evolution during electrodeposition and mechanical loading. The study of stress during electrodeposition of metal thin films is being accomplished by integrating a multi-beam optical stress sensor into an electrodeposition chamber. By coupling the in-situ stress information with ex-situ microstructural analysis, a scientific understanding of the sources of stress during electrodeposition will be obtained. These results are providing a foundation upon which to develop a stress-gradient-free thin film directly applicable to the production of freestanding metal structures. The issues of fatigue and yield strength are being addressed by developing novel surface micromachined tensile and bend testers, by interferometry, and by TEM analysis. The MEMS tensile tester has a ''Bosch'' etched hole to allow for direct viewing of the microstructure in a TEM before, during, and after loading. This approach allows for the quantitative measurements of stress-strain relations while imaging dislocation motion, and determination of fracture nucleation in samples with well-known fatigue/strain histories. This technique facilitates the determination of the limits for classical deformation mechanisms and helps to formulate a new understanding of the mechanical response as the grain sizes are refined to a nanometer scale. Together, these studies will result in a science

Characterization of bulk-micromachined direct-bonded silicon nanofilters

Science.gov (United States)

Tu, Jay K.; Huen, Tony; Szema, Robert; Ferrari, Mauro

1998-03-01

The ability to separate 30-100 nm particles - nanofiltration - is critical for many biomedical applications. Where this filtration needs to be absolute, such as for viral elimination in the blood fractionation process, the large variations in pore size found with conventional polymeric filters can lead to the unwanted presence of viruses in the filtrate. To overcome this problem, we have developed a filter with micromachined channels sandwiched between two bonded silicon wafers. These channels are formed through the selective deposition and then removal of a thermally-grown oxide, the thickness of which can be controlled to +/- 4 percent for 30 nm pores. In this paper, we will present both the gas and liquid characterization, and the filtration studies done on 44 and 100 nm beads.

Study of surfactant-added TMAH for applications in DRIE and wet etching-based micromachining

Science.gov (United States)

Tang, B.; Shikida, M.; Sato, K.; Pal, P.; Amakawa, H.; Hida, H.; Fukuzawa, K.

2010-06-01

In this paper, etching anisotropy is evaluated for a number of different crystallographic orientations of silicon in a 0.1 vol% Triton-X-100 added 25 wt% tetramethylammonium hydroxide (TMAH) solution using a silicon hemisphere. The research is primarily aimed at developing advanced applications of wet etching in microelectromechanical systems (MEMS). The etching process is carried out at different temperatures in the range of 61-81 °C. The etching results of silicon hemisphere and different shapes of three-dimensional structures in {1 0 0}- and {1 1 0}-Si surfaces are analyzed. Significantly important anisotropy, different from a traditional etchant (e.g. pure KOH and TMAH), is investigated to extend the applications of the wet etching process in silicon bulk micromachining. The similar etching behavior of exact and vicinal {1 1 0} and {1 1 1} planes in TMAH + Triton is utilized selectively to remove the scalloping from deep reactive-ion etching (DRIE) etched profiles. The direct application of the present research is demonstrated by fabricating a cylindrical lens with highly smooth etched surface finish. The smoothness of a micro-lens at different locations is measured qualitatively by a scanning electron microscope and quantitatively by an atomic force microscope. The present paper provides a simple and effective fabrication method of the silicon micro-lens for optical MEMS applications.

Modeling and Experimental Study on Characterization of Micromachined Thermal Gas Inertial Sensors

Directory of Open Access Journals (Sweden)

Yan Su

2010-09-01

Full Text Available Micromachined thermal gas inertial sensors based on heat convection are novel devices that compared with conventional micromachined inertial sensors offer the advantages of simple structures, easy fabrication, high shock resistance and good reliability by virtue of using a gaseous medium instead of a mechanical proof mass as key moving and sensing elements. This paper presents an analytical modeling for a micromachined thermal gas gyroscope integrated with signal conditioning. A simplified spring-damping model is utilized to characterize the behavior of the sensor. The model relies on the use of the fluid mechanics and heat transfer fundamentals and is validated using experimental data obtained from a test-device and simulation. Furthermore, the nonideal issues of the sensor are addressed from both the theoretical and experimental points of view. The nonlinear behavior demonstrated in experimental measurements is analyzed based on the model. It is concluded that the sources of nonlinearity are mainly attributable to the variable stiffness of the sensor system and the structural asymmetry due to nonideal fabrication.

Microfabrication on a curved surface using 3D microlens array projection

International Nuclear Information System (INIS)

Li, Lei; Yi, Allen Y

2009-01-01

Accurate three-dimensional microstructures on silicon or other substrates are becoming increasingly important for optical, electronic, biomedical and medical applications. Traditional microfabrication processes based on cleanroom lithography and dry or wet etching processes are essentially two-dimensional methods. In the past, complicated procedures were designed to create some three-dimensional microstructures; however, these processes were mainly used to create features on planar silicon wafer substrates using the bulk silicon machining technique. In a major departure from previous micromachining processes, a microfabrication process based on microlens projection is presented in this paper. The proposed microfabrication system will have the capabilities of a typical conventional micromachining process plus the unique true three-dimensional replication features based on microlenses that were created on a steep curved substrate. These microlenses were precisely fabricated with a specific pattern on the curved surface that can be used to create microstructures on a pre-defined nonplanar substrate where a layer of photoresist was spin coated. After proper exposure and development, the desired micro patterns are created on the photoresist layer. These micro features can eventually be replicated on the substrate via wet or dry etching processes. The results show that the fabricated three-dimensional microlens array has very high dimensional accuracy and the profile error is less than 6 µm over the entire surface

A flexible ultrasound transducer array with micro-machined bulk PZT.

Science.gov (United States)

Wang, Zhe; Xue, Qing-Tang; Chen, Yuan-Quan; Shu, Yi; Tian, He; Yang, Yi; Xie, Dan; Luo, Jian-Wen; Ren, Tian-Ling

2015-01-23

This paper proposes a novel flexible piezoelectric micro-machined ultrasound transducer, which is based on PZT and a polyimide substrate. The transducer is made on the polyimide substrate and packaged with medical polydimethylsiloxane. Instead of etching the PZT ceramic, this paper proposes a method of putting diced PZT blocks into holes on the polyimide which are pre-etched. The device works in d31 mode and the electromechanical coupling factor is 22.25%. Its flexibility, good conformal contacting with skin surfaces and proper resonant frequency make the device suitable for heart imaging. The flexible packaging ultrasound transducer also has a good waterproof performance after hundreds of ultrasonic electric tests in water. It is a promising ultrasound transducer and will be an effective supplementary ultrasound imaging method in the practical applications.

A Flexible Ultrasound Transducer Array with Micro-Machined Bulk PZT

Directory of Open Access Journals (Sweden)

Zhe Wang

2015-01-01

Full Text Available This paper proposes a novel flexible piezoelectric micro-machined ultrasound transducer, which is based on PZT and a polyimide substrate. The transducer is made on the polyimide substrate and packaged with medical polydimethylsiloxane. Instead of etching the PZT ceramic, this paper proposes a method of putting diced PZT blocks into holes on the polyimide which are pre-etched. The device works in d31 mode and the electromechanical coupling factor is 22.25%. Its flexibility, good conformal contacting with skin surfaces and proper resonant frequency make the device suitable for heart imaging. The flexible packaging ultrasound transducer also has a good waterproof performance after hundreds of ultrasonic electric tests in water. It is a promising ultrasound transducer and will be an effective supplementary ultrasound imaging method in the practical applications.

The Laser MicroJet (LMJ): a multi-solution technology for high quality micro-machining

Science.gov (United States)

Mai, Tuan Anh; Richerzhagen, Bernold; Snowdon, Paul C.; Wood, David; Maropoulos, Paul G.

2007-02-01

The field of laser micromachining is highly diverse. There are many different types of lasers available in the market. Due to their differences in irradiating wavelength, output power and pulse characteristic they can be selected for different applications depending on material and feature size [1]. The main issues by using these lasers are heat damages, contamination and low ablation rates. This report examines on the application of the Laser MicroJet(R) (LMJ), a unique combination of a laser beam with a hair-thin water jet as a universal tool for micro-machining of MEMS substrates, as well as ferrous and non-ferrous materials. The materials include gallium arsenide (GaAs) & silicon wafers, steel, tantalum and alumina ceramic. A Nd:YAG laser operating at 1064 nm (infra red) and frequency doubled 532 nm (green) were employed for the micro-machining of these materials.

Silicon micromachining using a high-density plasma source

International Nuclear Information System (INIS)

McAuley, S.A.; Ashraf, H.; Atabo, L.; Chambers, A.; Hall, S.; Hopkins, J.; Nicholls, G.

2001-01-01

Dry etching of Si is critical in satisfying the demands of the micromachining industry. The micro-electro-mechanical systems (MEMS) community requires etches capable of high aspect ratios, vertical profiles, good feature size control and etch uniformity along with high throughput to satisfy production requirements. Surface technology systems' (STS's) high-density inductively coupled plasma (ICP) etch tool enables a wide range of applications to be realized whilst optimizing the above parameters. Components manufactured from Si using an STS ICP include accelerometers and gyroscopes for military, automotive and domestic applications. STS's advanced silicon etch (ASE TM ) has also allowed the first generation of MEMS-based optical switches and attenuators to reach the marketplace. In addition, a specialized application for fabricating the next generation photolithography exposure masks has been optimized for 200 mm diameter wafers, to depths of ∼750 μm. Where the profile is not critical, etch rates of greater than 8 μm min -1 have been realized to replace previous methods such as wet etching. This is also the case for printer applications. Specialized applications that require etching down to pyrex or oxide often result in the loss of feature size control at the interface; this is an industry wide problem. STS have developed a technique to address this. The rapid progression of the industry has led to development of the STS ICP etch tool, as well as the process. (author)

Micromachined Parts Advance Medicine, Astrophysics, and More

Science.gov (United States)

2015-01-01

In the mid-1990s, Marshall Space Flight Center awarded two SBIR contracts to Potomac Photonics, now based in Baltimore, for the development of computerized workstations capable of mass-producing tiny, intricate, diffractive optical elements. While the company has since discontinued the workstations, those contracts set the stage for Potomac Photonics to be a leader in the micromachining industry, where NASA remains one of its clients.

Surface-micromachined magnetic undulator with period length between 10  μm and 1 mm for advanced light sources

Directory of Open Access Journals (Sweden)

Jere Harrison

2012-07-01

Full Text Available A technological gap exists between the μm-scale wiggling periods achieved using electromagnetic waves of high intensity laser pulses and the mm scale of permanent-magnet and superconducting undulators. In the sub-mm range, surface-micromachined soft-magnetic micro-electro-mechanical system inductors with integrated solenoidal coils have already experimentally demonstrated 100 to 500 mT field amplitude across air gaps as large as 15  μm. Simulations indicate that magnetic fields as large as 1.5 T across 50  μm inductor gaps are feasible. A simple rearranging of the yoke and pole geometry allows for fabrication of 10+ cm long undulator structures with period lengths between 12.5  μm and 1 mm. Such undulators find application both in high average power spontaneous emission sources and, if used in combination with ultrahigh-brightness electron beams, could lead to the realization of low energy compact free-electron lasers. Challenges include electron energy broadening due to wakefields and Joule heating in the electromagnet.

Development of a focused ion beam micromachining system

Energy Technology Data Exchange (ETDEWEB)

Pellerin, J.G.; Griffis, D.; Russell, P.E.

1988-12-01

Focused ion beams are currently being investigated for many submicron fabrication and analytical purposes. An FIB micromachining system consisting of a UHV vacuum system, a liquid metal ion gun, and a control and data acquisition computer has been constructed. This system is being used to develop nanofabrication and nanomachining techniques involving focused ion beams and scanning tunneling microscopes.

Effects of Laser Operating Parameters on Piezoelectric Substrates Micromachining with Picosecond Laser

Directory of Open Access Journals (Sweden)

Lamia EL Fissi

2014-12-01

Full Text Available Ten picoseconds (200 kHz ultrafast laser micro-structuring of piezoelectric substrates including AT-cut quartz, Lithium Niobate and Lithium Tantalate have been studied for the purpose of piezoelectric devices application ranging from surface acoustic wave devices, e.g., bandpass filters, to photonic devices such as optical waveguides and holograms. The study examines the impact of changing several laser parameters on the resulting microstructural shapes and morphology. The micromachining rate has been observed to be strongly dependent on the operating parameters, such as the pulse fluence, the scan speed and the scan number. The results specifically indicate that ablation at low fluence and low speed scan tends to form a U-shaped cross-section, while a V-shaped profile can be obtained by using a high fluence and a high scan speed. The evolution of surface morphology revealed that laser pulses overlap in a range around 93% for both Lithium Niobate (LiNbO3 and Lithium Tantalate (LiTaO3 and 98% for AT-cut quartz can help to achieve optimal residual surface roughness.

FY1995 development of micromachine technology based on insects; 1995 nendo konchu wo kihan to suru micromachine gijutsu no kakuritsu to jitsuyoka

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

If we develop micromachines by reducing simply the size of conventional mechanical systems, we cannot get sufficient performances of them because of scale-effect. Small natural creatures, insects, have very good structures and functions reasonable for their small size. In this research, basic characteristics of sensors, actuators, information processing functions, etc. of insects are studied and artificial systems similar to them are developed for industrial application. (1) Compound eyes: Insect compound eyes is the visual sensor which is composed of microlenses which are distributed three-dimensionally, receptors which vibrate with small amplitude around an optical axis and neural networks. In this research, the large scale model (several centimeters sized) of insect compound eyes has been developed. (2) Pheromone sensor: Pheromone gas sensor has been made of real male silkworm moth antenae. This sensor has been proved to work well as the female pheromone detector. This sensor was installed at the nose part of a wheeled mobile robot and this robot was observed to act like a real silkworm moth subjected to female pheromone stream. (3) Electrostatic microactuator: Generally speaking, high voltage(higher than 100V) electric power is necessary to actuate the electrostatic actuator. It was considered to be impossible to actuate them directly from CMOS. In this research, a new electrostatic actuator which can be actuated with less than 10V voltage can cause a fairly large displacement. (4) Hydraulic actuator: For micromachines, hydraulic pressure will be applicable for actuation. Structures may be simple and scale effect may give an advantageous characteristics for microsize. A butterfly-type flying robot was developed and it flied up along a vertical bar. (NEDO)

Micromachined two dimensional resistor arrays for determination of gas parameters

NARCIS (Netherlands)

van Baar, J.J.J.; Verwey, Willem B.; Dijkstra, Mindert; Dijkstra, Marcel; Wiegerink, Remco J.; Lammerink, Theodorus S.J.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt

A resistive sensor array is presented for two dimensional temperature distribution measurements in a micromachined flow channel. This allows simultaneous measurement of flow velocity and fluid parameters, like thermal conductivity, diffusion coefficient and viscosity. More general advantages of

Femtosecond laser micro-machined polyimide films for cell scaffold applications

DEFF Research Database (Denmark)

Antanavičiute, Ieva; Šimatonis, Linas; Ulčinas, Orestas

2018-01-01

of commercially available 12.7 and 25.4μm thickness polyimide (PI) film was applied. Mechanical properties of the fabricated scaffolds, i.e. arrays of differently spaced holes, were examined via custom-built uniaxial micro-tensile testing and finite element method simulations. We demonstrate that experimental...... micro-tensile testing results could be numerically simulated and explained by two-material model, assuming that 2-6μm width rings around the holes possessed up to five times higher Young's modulus and yield stress compared with the rest of the laser intacted PI film areas of 'dog-bone'-shaped specimens......Engineering of sophisticated synthetic 3D scaffolds that allow controlling behaviour and location of the cells requires advanced micro/nano-fabrication techniques. Ultrafast laser micro-machining employing a 1030-nm wavelength Yb:KGW femtosecond laser and a micro-fabrication workstation for micro-machining...

An in-pipe mobile micromachine using fluid power. A mechanism adaptable to pipe diameters

International Nuclear Information System (INIS)

Yoshida, Kazuhiro; Yokota, Shinichi; Takahashi, Ken

2000-01-01

To realize micro maintenance robots for small diameter pipes of nuclear reactors and so on, high power in-pipe mobile micromachines have been required. The authors have proposed the bellows microactuator using fluid power and have tried to apply the actuators to in-pipe mobile micromachines. In the previous papers, some inchworm mobile machine prototypes with 25 mm in diameter are fabricated and the traveling performances are experimentally investigated. In this paper, to miniaturize the in-pipe mobile machine and to make it adaptable to pipe diameters, firstly, a simple rubber-tube actuator constrained with a coil-spring is proposed and the static characteristics are investigated. Secondly, a supporting mechanism which utilizes a toggle mechanism and is adaptable to pipe diameters is proposed and the supporting forces are investigated. Finally, an in-pipe mobile micromachine for pipe with 4 - 5 mm in diameter is fabricated and the maximum traveling velocity of 7 mm/s in both ahead and astern movements is experimentally verified. (author)

Monolithic integration of micromachined sensors and CMOS circuits based on SOI technologies

International Nuclear Information System (INIS)

Yu Xiaomei; Tang Yaquan; Zhang Haitao

2008-01-01

This note presents a novel way to monolithically integrate micro-cantilever sensors and signal conditioning circuits by combining SOI CMOS and SOI micromachining technologies. In order to improve the sensor performance and reduce the system volume, an integrated sensor system composed of a piezoresistive cantilever array, a temperature-compensation current reference, a digitally controlled multiplexer and an instrument amplifier is designed and finally fabricated. A post-SOI CMOS process is developed to realize the integrated sensor system which is based on a standard CMOS process with one more mask to define the cantilever structure at the end of the process. Measurements on the finished SOI CMOS devices and circuits show that the integration process has good compatibility both for the cantilever sensors and for the CMOS circuits, and the SOI CMOS integration process can decrease about 25% sequences compared with the bulk silicon CMOS process. (note)

New Effective Material Couple--Oxide Ceramic and Carbon Nanotube-- Developed for Aerospace Microsystem and Micromachine Technologies

Science.gov (United States)

Miyoshi, Kazuhisa; VanderWal, Randall L.; Tomasek, Aaron J.; Sayir, Ali; Farmer, Serene C.

2004-01-01

lubrication task because of their potential for superior friction and wearf properties in air and in an ultrahigh vacuum, spacelike environment. At the NASA Glenn Research Center, two-phase oxide ceramic eutectics, Al2O3/ZrO2(Y2O3), were directionally solidified using the laser-float-zone process, and carbon nanotubes were synthesized within a high-temperature tube furnace at 800 C. Physical vapor deposition was used to coat all quartz substrates with 5-nm-thick iron as catalyst and bondcoat, which formed iron islands resembling droplets and serving as catalyst particles on the quartz. A series of scanning electron micrographs showing multiwalled carbon nanotubes directionally grown as aligned "nanograss" on quartz is presented. Unidirectional sliding friction eperiments were conducted at Glenn with the two-layered CNT coatings in contact with the two-phase Al2O3/ZrO2(Y2O3) eutectics in air and in ultrachigh vacuum. The main criteria for judging the performance of the materials couple for solid lubrication and antistick applications in a space environment were the coefficient of friction and the wear resistance (reciprocal of wear rate), which had to be less than 0.2 and greater than 10(exp 5) N(raised dot)/cubic millimetes, respectively, in ultrahigh vacuum. In air, the coefficient of friction for the CNT coatings in contact with Al2O3/ZrO2 (Y2O3) eutectics was 0.04, one-fourth of that for quartz. In an ultrahigh vacuum, the coefficient of friction for CNT coatings in contact with Al2O3/ZrO2 (Y2O3) was one-third of that for quartz. The two-phase Al2O3/ZrO2 (Y2O3) eutectic coupled with the two-layered CNT coating met the coefficient of friction and wear resistance criteria both in air and in an ultrahigh vacuum, spacelike environment. This material's couple can dramatically improve the stiction (or adhesion), friction, and wear resistance of the contacting surfaces, which are major issues for microdevices and micromachines.

Characterization and modeling of 2D-glass micro-machining by spark-assisted chemical engraving (SACE) with constant velocity

International Nuclear Information System (INIS)

Didar, Tohid Fatanat; Dolatabadi, Ali; Wüthrich, Rolf

2008-01-01

Spark-assisted chemical engraving (SACE) is an unconventional micro-machining technology based on electrochemical discharge used for micro-machining nonconductive materials. SACE 2D micro-machining with constant speed was used to machine micro-channels in glass. Parameters affecting the quality and geometry of the micro-channels machined by SACE technology with constant velocity were presented and the effect of each of the parameters was assessed. The effect of chemical etching on the geometry of micro-channels under different machining conditions has been studied, and a model is proposed for characterization of the micro-channels as a function of machining voltage and applied speed

Monitoring of yeast cell concentration using a micromachined impedance sensor

NARCIS (Netherlands)

Krommenhoek, E.E.; Gardeniers, Johannes G.E.; Bomer, Johan G.; van den Berg, Albert; Li, X.; Ottens, M.; van der Wielen, L.A.M.; van Dedem, G.W.K.; van Leeuwen, M.; van Gulik, W.M.; Heijnen, J.J.

2005-01-01

The paper describes the design, modelling and experimental characterization of a micromachined impedance sensor for on-line monitoring of the viable yeast cell concentration (biomass) in a miniaturized cell assay. Measurements in a Saccharomyces cerevisiae cell culture show that the permittivity of

Modeling and analysis of micro-WEDM process of titanium alloy (Ti–6Al–4V using response surface approach

Directory of Open Access Journals (Sweden)

P. Sivaprakasam

2014-12-01

Full Text Available Micro-machining technology is effectively used in modern manufacturing industries. This paper investigates the influence of three different input parameters such as voltage, capacitance and feed rate of micro-wire electrical discharge machining (micro-WEDM performances of material removal rate (MRR, Kerf width (KW and surface roughness (SR using response surface methodology with central composite design (CCD. The experiments are carried out on titanium alloy (Ti–6Al–4V. The machining characteristics are significantly influenced by the electrical and non-electrical parameters in micro-WEDM process. Analysis of variance (ANOVA was performed to find out the significant influence of each factor. The model developed can use a genetic algorithm (GA to determine the optimal machining conditions using multi-objective optimization technique. The optimal machining performance of material removal rate, Kerf width and surface roughness are 0.01802 mm3/min, 101.5 μm and 0.789 μm, respectively, using this optimal machining conditions viz. voltage 100 V, capacitance 10 nF and feed rate 15 μm/s.

Micromachined millimeter-wave photonic band-gap crystals

International Nuclear Information System (INIS)

Oezbay, E.; Michel, E.; Tuttle, G.; Biswas, R.; Sigalas, M.; Ho, K.

1994-01-01

We have developed a new technique for fabricating three-dimensional photonic band-gap crystals. Our method utilizes an orderly stacking of micromachined (110) silicon wafers to build the periodic structure. A structure with a full three-dimensional photonic band gap centered near 100 GHz was measured, with experimental results in good agreement with theoretical predictions. This basic approach described should be extendable to build structures with photonic band-gap frequencies ranging from 30 GHz to 3 THz

Fiscal 1997 report on technological results. R and D on micromachine technology; 1997 nendo micromachine gijutsu no kenkyu kaihatsu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-03-01

Researches on basic element technology of micromachines are conducted that operate autonomously in a narrow small part in a complicated apparatus or in vivo. The areas of activity are 1. research on micromachine systems and 2. comprehensive investigation and research. In 1, (1) a micro catheter and (2) a micro tactile sensor catheter were studied while, in 2, basic technology and technological problems, particularly those problems concerning sophistication in the medical field were examined and studied. Further, in (1), with the purpose of developing a micro laser catheter for diagnosis/treatment, researches were implemented on the technology of integrating micro laser and an optical fiber which were components of the catheter and on the fabrication of the fine diameter of a micro catheter as well as on the characteristical improvement of the base body on which minute elements were mounted. In (2), characteristical improvement and sophistication were carried out for a high sensitivity contact pressure sensor and a diagnostic tactile sensor, which are mounted on a catheter having a positive bulge control mechanism for insertion into body cavity, with a sensor probe manufactured experimentally. (NEDO)

Optofluidic Microlasers based on Femtosecond Micromachining Technology

Directory of Open Access Journals (Sweden)

Simoni F.

2017-08-01

Full Text Available We present the different optofluidic lasers which have been realized using the Femtosecond Micromachining technique to fabricate the monolithic optofluidic structures in glass chips. We show how the great flexibility of this 3D technique allows getting different kind of optical cavities. The most recent devices fabricated by this technique as ring shaped and Fabry-Perot resonators show excellent emission performances.We also point out how the addition of the inkjet printing technique provides further opportunities in realizing optofluidic chips.

Improving the Design of Capacitive Micromachined Ultrasonic Transducers Aided with Sensitivity Analysis

Directory of Open Access Journals (Sweden)

A Martowicz

2016-09-01

Full Text Available The paper presents the results of analysis performed to search for feasible design improvements for capacitive micromachined ultrasonic transducer. Carried out search has been aided with the sensitivity analysis and the application of Response Surface Method. The multiphysics approach has been taken into account in elaborated finite element model of one cell of described transducer in order to include significant physical phenomena present in modelled microdevice. The set of twelve input uncertain and design parameters consists of geometric, material and control properties. The amplitude of dynamic membrane deformation of the transducer has been chosen as studied parameter. The objective of performed study has been defined as the task of finding robust design configurations of the transducer, i.e. characterizing maximal value of deformation amplitude with its minimal variation.

Femtosecond laser micromachining of polylactic acid/graphene composites for designing interdigitated microelectrodes for sensor applications

Science.gov (United States)

Paula, Kelly T.; Gaál, Gabriel; Almeida, G. F. B.; Andrade, M. B.; Facure, Murilo H. M.; Correa, Daniel S.; Riul, Antonio; Rodrigues, Varlei; Mendonça, Cleber R.

2018-05-01

There is an increasing interest in the last years towards electronic applications of graphene-based materials and devices fabricated from patterning techniques, with the ultimate goal of high performance and temporal resolution. Laser micromachining using femtosecond pulses is an attractive methodology to integrate graphene-based materials into functional devices as it allows changes to the focal volume with a submicrometer spatial resolution due to the efficient nonlinear nature of the absorption, yielding rapid prototyping for innovative applications. We present here the patterning of PLA-graphene films spin-coated on a glass substrate using a fs-laser at moderate pulse energies to fabricate interdigitated electrodes having a minimum spatial resolution of 5 μm. Raman spectroscopy of the PLA-graphene films indicated the presence of multilayered graphene fibers. Subsequently, the PLA-graphene films were micromachined using a femtosecond laser oscillator delivering 50-fs pulses and 800 nm, where the pulse energy and scanning speed was varied in order to determine the optimum irradiation parameters (16 nJ and 100 μm/s) to the fabrication of microstructures. The micromachined patterns were characterized by optical microscopy and submitted to electrical measurements in liquid samples, clearly distinguishing all tastes tested. Our results confirm the femtosecond laser micromachining technique as an interesting approach to efficiently pattern PLA-graphene filaments with high precision and minimal mechanical defects, allowing the easy fabrication of interdigitated structures and an alternative method to those produced by conventional photolithography.

Femtosecond laser micromachining of compound parabolic concentrator fiber tipped glucose sensors

DEFF Research Database (Denmark)

Hassan, Hafeez Ul; Lacraz, Amédée; Kalli, Kyriacos

2017-01-01

We report on highly accurate femtosecond (fs) laser micromachining of a compound parabolic concentrator (CPC) fiber tip on a polymer optical fiber (POF). The accuracy is reflected in an unprecedented correspondence between the numerically predicted and experimentally found improvement in fluoresc...

Solid polymer electrolyte composite membrane comprising laser micromachined porous support

Science.gov (United States)

Liu, Han [Waltham, MA; LaConti, Anthony B [Lynnfield, MA; Mittelsteadt, Cortney K [Natick, MA; McCallum, Thomas J [Ashland, MA

2011-01-11

A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a rigid, non-electrically-conducting support, the support preferably being a sheet of polyimide having a thickness of about 7.5 to 15 microns. The support has a plurality of cylindrical pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores, which preferably have a diameter of about 5 microns, are made by laser micromachining and preferably are arranged in a defined pattern, for example, with fewer pores located in areas of high membrane stress and more pores located in areas of low membrane stress. The pores are filled with a first solid polymer electrolyte, such as a perfluorosulfonic acid (PFSA) polymer. A second solid polymer electrolyte, which may be the same as or different than the first solid polymer electrolyte, may be deposited over the top and/or bottom of the first solid polymer electrolyte.

Ultrasonic actuation for MEMS dormancy-related stiction reduction

Science.gov (United States)

Kaajakari, Ville; Kan, Shyi-Herng; Lin, Li-Jen; Lal, Amit; Rodgers, M. Steven

2000-08-01

The use of ultrasonic pulses incident on surface micromachines has been shown to reduce dormancy-related failure. We applied ultrasonic pulses from the backside of a silicon substrate carrying SUMMiT processed surface micromachined rotors, used earlier as ultrasonic motors. The amplitude of the pulses was less than what is required to actuate the rotor (sub-threshold actuation). By controlling the ultrasonic pulse exposure time it was found that pulsed samples had smaller actuation voltages as compared to non-pulsed samples after twelve-hour dormancy. This result indicates that the micromachine stiction to surfaces during dormant period can be effectively eliminated, resulting in long-term stability of surface micromachines in critical applications.

Millimeter length micromachining using a heavy ion nuclear microprobe with standard magnetic scanning

International Nuclear Information System (INIS)

Nesprías, F.; Debray, M.E.; Davidson, J.; Kreiner, A.J.

2013-01-01

In order to increase the scanning length of our microprobe, we have developed an irradiation procedure suitable for use in any nuclear microprobe, extending at least up to 400% the length of our heavy ion direct writing facility using standard magnetic exploration. Although this method is limited to patterns of a few millimeters in only one direction, it is useful for the manufacture of curved waveguides, optical devices such Mach–Zehnder modulators, directional couplers as well as channels for micro-fluidic applications. As an example, this technique was applied to the fabrication of 3 mm 3D-Mach–Zehnder modulators in lithium niobate with short Y input/output branches and long shaped parallel-capacitor control electrodes. To extend and improve the quality of the machined structures we developed new scanning control software in LabView™ platform. The new code supports an external dose normalization, electrostatic beam blanking and is capable of scanning figures at 16 bit resolution using a National Instruments™ PCI-6731 High-Speed I/O card. A deep and vertical micromachining process using swift 35 Cl ions 70 MeV bombarding energy and direct write patterning was performed on LiNbO 3 , a material which exhibits a strong natural anisotropy to conventional etching. The micromachined structures show the feasibility of this method for manufacturing micro-fluidic channels as well

Millimeter length micromachining using a heavy ion nuclear microprobe with standard magnetic scanning

Energy Technology Data Exchange (ETDEWEB)

Nesprías, F. [Gerencia de Investigación y Aplicaciones, Comisión Nacional de Energía Atómica, Av. Gral Paz 1499 (1650), San Martín, Buenos Aires (Argentina); Debray, M.E., E-mail: debray@tandar.cnea.gov.ar [Gerencia de Investigación y Aplicaciones, Comisión Nacional de Energía Atómica, Av. Gral Paz 1499 (1650), San Martín, Buenos Aires (Argentina); Escuela de Ciencia y Tecnología. Universidad Nacional de Gral. San Martín, M. De Irigoyen 3100 (1650), San Martín, Buenos Aires (Argentina); Davidson, J. [Gerencia de Investigación y Aplicaciones, Comisión Nacional de Energía Atómica, Av. Gral Paz 1499 (1650), San Martín, Buenos Aires (Argentina); CONICET, Avda. Rivadavia 1917 (C1033AAJ), Ciudad Autónoma de Buenos Aires (Argentina); Kreiner, A.J. [Gerencia de Investigación y Aplicaciones, Comisión Nacional de Energía Atómica, Av. Gral Paz 1499 (1650), San Martín, Buenos Aires (Argentina); Escuela de Ciencia y Tecnología. Universidad Nacional de Gral. San Martín, M. De Irigoyen 3100 (1650), San Martín, Buenos Aires (Argentina); CONICET, Avda. Rivadavia 1917 (C1033AAJ), Ciudad Autónoma de Buenos Aires (Argentina); and others

2013-04-01

In order to increase the scanning length of our microprobe, we have developed an irradiation procedure suitable for use in any nuclear microprobe, extending at least up to 400% the length of our heavy ion direct writing facility using standard magnetic exploration. Although this method is limited to patterns of a few millimeters in only one direction, it is useful for the manufacture of curved waveguides, optical devices such Mach–Zehnder modulators, directional couplers as well as channels for micro-fluidic applications. As an example, this technique was applied to the fabrication of 3 mm 3D-Mach–Zehnder modulators in lithium niobate with short Y input/output branches and long shaped parallel-capacitor control electrodes. To extend and improve the quality of the machined structures we developed new scanning control software in LabView™ platform. The new code supports an external dose normalization, electrostatic beam blanking and is capable of scanning figures at 16 bit resolution using a National Instruments™ PCI-6731 High-Speed I/O card. A deep and vertical micromachining process using swift {sup 35}Cl ions 70 MeV bombarding energy and direct write patterning was performed on LiNbO{sub 3}, a material which exhibits a strong natural anisotropy to conventional etching. The micromachined structures show the feasibility of this method for manufacturing micro-fluidic channels as well.

A Micromachined Infrared Senor for an Infrared Focal Plane Array

Directory of Open Access Journals (Sweden)

Seong M. Cho

2008-04-01

Full Text Available A micromachined infrared sensor for an infrared focal plane array has been designed and fabricated. Amorphous silicon was used as a sensing material, and silicon nitride was used as a membrane material. To get a good absorption in infrared range, the sensor structure was designed as a l/4 cavity structure. A Ni-Cr film was selected as an electrode material and mixed etching scheme was applied in the patterning process of the Ni-Cr electrode. All the processes were made in 0.5 μm iMEMS fabricated in the Electronics and Telecommunication Research Institute (ETRI. The processed MEMS sensor had a small membrane deflection less than 0.15 μm. This small deflection can be attributed to the rigorous balancing of the stresses of individual layers. The efficiency of infrared absorption was more than 75% in the wavelength range of 8 ~ 14 μm. The processed infrared sensor showed high responsivity of ~230 kV/W at 1.0V bias and 2 Hz operation condition. The time constant of the sensor was 8.6 msec, which means that the sensor is suitable to be operated in 30 Hz frame rate.

A novel micromachined shadow mask system with self-alignment and gap control capability

International Nuclear Information System (INIS)

Hong, Jung Moo; Zou Jun

2008-01-01

We present a novel micromachined shadow mask system, which is capable of accurate self-alignment and mask-substrate gap control. The shadow mask system consists of a silicon shadow mask and a silicon carrier wafer with pyramidal cavities fabricated with bulk micromachining. Self-alignment and gap control of the shadow mask and the fabrication substrate can readily be achieved by using matching pairs of pyramidal cavities and steel spheres placed between. The layer-to-layer alignment accuracy of the new shadow mask system has been experimentally characterized and verified using both optical and atomic force microscopic measurements. As an application of this new shadow mask system, an organic thin-film transistor (OTFT) using pentacene as the semiconductor layer has been successfully fabricated and tested

Optimized design of micromachined electric field mills to maximize electrostatic field sensitivity

Directory of Open Access Journals (Sweden)

Yu Zhou

2016-07-01

Full Text Available This paper describes the design optimization of a micromachined electric field mill, in relation to maximizing its output signal. The cases studied are for a perforated electrically grounded shutter vibrating laterally over sensing electrodes. It is shown that when modeling the output signal of the sensor, the differential charge on the sense electrodes when exposed to vs. visibly shielded from the incident electric field must be considered. Parametric studies of device dimensions show that the shutter thickness and its spacing from the underlying electrodes should be minimized as these parameters very strongly affect the MEFM signal. Exploration of the shutter perforation size and sense electrode width indicate that the best MEFM design is one where shutter perforation widths are a few times larger than the sense electrode widths. Keywords: MEFM, Finite element method, Electric field measurement, MEMS, Micromachining

Research on the effect of coverage rate on the surface quality in laser direct writing process

Science.gov (United States)

Pan, Xuetao; Tu, Dawei

2017-07-01

Direct writing technique is usually used in femtosecond laser two-photon micromachining. The size of the scanning step is an important factor affecting the surface quality and machining efficiency of micro devices. According to the mechanism of two-photon polymerization, combining the distribution function of light intensity and the free radical concentration theory, we establish the mathematical model of coverage of solidification unit, then analyze the effect of coverage on the machining quality and efficiency. Using the principle of exposure equivalence, we also obtained the analytic expressions of the relationship among the surface quality characteristic parameters of microdevices and the scanning step, and carried out the numerical simulation and experiment. The results show that the scanning step has little influence on the surface quality of the line when it is much smaller than the size of the solidification unit. However, with increasing scanning step, the smoothness of line surface is reduced rapidly, and the surface quality becomes much worse.

Micromachined single-level nonplanar polycrystalline SiGe thermal microemitters for infrared dynamic scene projection

Science.gov (United States)

Malyutenko, V. K.; Malyutenko, O. Yu.; Leonov, V.; Van Hoof, C.

2009-05-01

The technology for self-supported membraneless polycrystalline SiGe thermal microemitters, their design, and performance are presented. The 128-element arrays with a fill factor of 88% and a 2.5-μm-thick resonant cavity have been grown by low-pressure chemical vapor deposition and fabricated using surface micromachining technology. The 200-nm-thick 60×60 μm2 emitting pixels enforced with a U-shape profile pattern demonstrate a thermal time constant of 2-7 ms and an apparent temperature of 700 K in the 3-5 and 8-12 μm atmospheric transparency windows. The application of the devices to the infrared dynamic scene simulation and their benefit over conventional planar membrane-supported emitters are discussed.

Optimization of design parameters for bulk micromachined silicon membranes for piezoresistive pressure sensing application

International Nuclear Information System (INIS)

Belwanshi, Vinod; Topkar, Anita

2016-01-01

Finite element analysis study has been carried out to optimize the design parameters for bulk micro-machined silicon membranes for piezoresistive pressure sensing applications. The design is targeted for measurement of pressure up to 200 bar for nuclear reactor applications. The mechanical behavior of bulk micro-machined silicon membranes in terms of deflection and stress generation has been simulated. Based on the simulation results, optimization of the membrane design parameters in terms of length, width and thickness has been carried out. Subsequent to optimization of membrane geometrical parameters, the dimensions and location of the high stress concentration region for implantation of piezoresistors have been obtained for sensing of pressure using piezoresistive sensing technique.

Optimization of design parameters for bulk micromachined silicon membranes for piezoresistive pressure sensing application

Science.gov (United States)

Belwanshi, Vinod; Topkar, Anita

2016-05-01

Finite element analysis study has been carried out to optimize the design parameters for bulk micro-machined silicon membranes for piezoresistive pressure sensing applications. The design is targeted for measurement of pressure up to 200 bar for nuclear reactor applications. The mechanical behavior of bulk micro-machined silicon membranes in terms of deflection and stress generation has been simulated. Based on the simulation results, optimization of the membrane design parameters in terms of length, width and thickness has been carried out. Subsequent to optimization of membrane geometrical parameters, the dimensions and location of the high stress concentration region for implantation of piezoresistors have been obtained for sensing of pressure using piezoresistive sensing technique.

Bending-induced electromechanical coupling and large piezoelectric response in a micromachined diaphragm

KAUST Repository

Wang, Zhihong; Yao, Yingbang; Wang, Xianbin; Yue, Weisheng; Chen, Longqing; Zhang, Xixiang

2013-01-01

We investigated the dependence of electromechanical coupling and the piezoelectric response of a micromachined Pb(Zr 0.52 Ti 0.48)O 3 (PZT) diaphragm on its curvature by observing the impedance spectrum and central deflection responses to a small AC

Sensitivity of Micromachined Joule-Thomson Cooler to Clogging Due to Moisture

NARCIS (Netherlands)

Cao, Haishan; Vanapalli, Srinivas; Holland, Herman J.; Vermeer, Cristian Hendrik; ter Brake, Hermanus J.M.

2015-01-01

A major issue in long-term operation of micromachined Joule-Thomson coolers is the clogging of the microchannels and/or the restriction due to the deposition of water molecules present in the working fluid. In this study, we present the performance of a microcooler operated with nitrogen gas with

Micromachined Microwave Cavity Resonator Filters for 5G: a Feasibility Study

NARCIS (Netherlands)

Kemenade, van R.; Smolders, A.B.; Hon, de B.P.

2015-01-01

Micromachined microwave cavity filters offer a light-weight, high-Q and highly integrated alternative in the frequency range of 20 GHz–100 GHz as compared to conventional filter types. The filter technology shows potential for use in 5G portable devices and as such, the design of a duplexer

Arrayed architectures for multi-stage Si-micromachined high-flow Knudsen pumps

International Nuclear Information System (INIS)

Qin, Yutao; An, Seungdo; Gianchandani, Yogesh B

2015-01-01

This paper reports an evaluation and a comparison of two architectures for implementing Si-micromachined high-flow Knudsen pumps. Knudsen pumps, which operate on the principle of thermal transpiration, have been shown to have great promise for micro-scale gas phase fluidic systems such as micro gas chromatographs. Simultaneously achieving both a high flow rate and adequate blocking pressure has been a persistent challenge, which is addressed in this work by combining multiple pumps in series and addressing the resulting challenges in thermal management. The basic building block is a Si-micromachined pump with  ≈100 000 parallel channels in a 4 mm  ×  6 mm footprint. In the primary approach, multiple pump stages are stacked vertically with interleaved Si-micromachined spacers. A stacked 4-stage Knudsen pump has a form factor of 10 mm  ×  8 mm  ×  6 mm. In an alternate approach, multiple stages are arranged in a planar array. The experimental results demonstrate multiplication of the output pressure head with the number of stages, while the flow rate is maintained. For example, a stacked 4-stage Knudsen pump with 8 W power operated at atmospheric pressure provided a blocking pressure of 0.255 kPa, which was 3.6  ×  of that provided by a single-stage pump with 2 W power; while both provided a  ≈  30 sccm maximum flow rate. The performance can be customized for practical applications such as micro gas chromatography. (paper)

Biasing of Capacitive Micromachined Ultrasonic Transducers.

Science.gov (United States)

Caliano, Giosue; Matrone, Giulia; Savoia, Alessandro Stuart

2017-02-01

Capacitive micromachined ultrasonic transducers (CMUTs) represent an effective alternative to piezoelectric transducers for medical ultrasound imaging applications. They are microelectromechanical devices fabricated using silicon micromachining techniques, developed in the last two decades in many laboratories. The interest for this novel transducer technology relies on its full compatibility with standard integrated circuit technology that makes it possible to integrate on the same chip the transducers and the electronics, thus enabling the realization of extremely low-cost and high-performance devices, including both 1-D or 2-D arrays. Being capacitive transducers, CMUTs require a high bias voltage to be properly operated in pulse-echo imaging applications. The typical bias supply residual ripple of high-quality high-voltage (HV) generators is in the millivolt range, which is comparable with the amplitude of the received echo signals, and it is particularly difficult to minimize. The aim of this paper is to analyze the classical CMUT biasing circuits, highlighting the features of each one, and to propose two novel HV generator architectures optimized for CMUT biasing applications. The first circuit proposed is an ultralow-residual ripple (generator that uses an extremely stable sinusoidal power oscillator topology. The second circuit employs a commercially available integrated step-up converter characterized by a particularly efficient switching topology. The circuit is used to bias the CMUT by charging a buffer capacitor synchronously with the pulsing sequence, thus reducing the impact of the switching noise on the received echo signals. The small area of the circuit (about 1.5 cm 2 ) makes it possible to generate the bias voltage inside the probe, very close to the CMUT, making the proposed solution attractive for portable applications. Measurements and experiments are shown to demonstrate the effectiveness of the new approaches presented.

Nanofluidic bubble pump using surface tension directed gas injection

NARCIS (Netherlands)

Tas, Niels Roelof; Berenschot, Johan W.; Lammerink, Theodorus S.J.; Elwenspoek, Michael Curt; van den Berg, Albert

2002-01-01

A new concept for liquid manipulation has been developed and implemented in surface-micromachined fluid channels. It is based on the surface tension directed injection of a gas into the liquid flow through micrometer-sized holes in the microchannel wall. The injected gas is directed to an exhaust by

FY 1994 Report on the technical results. Research and development of micromachine technologies (Development of highly functional maintenance technologies for power plants); 1994 nendo micromachine gijutsu no kenkyu kaihatsu seika hokokusho. Hatsuden shisetsuyo kokino maintenance gijutsu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-09-01

This research and development project is aimed at development of the technologies for the micromachines provided with maintenance functions, e.g., for examination and maintenance of abnormal conditions in heat exchangers, piping systems or the like. The initial target is set at establishment of basic technologies for the micromachines, in consideration of the available technologies. The R and D activities are directed to (1) microcapsules for, e.g., micro power generators, (2) mother machines having controlling and instructing functions, (3) non-cabled examination modules, (4) cabled examination modules, and (5) total systems. The item (1) involves the micro power generators, and mechanisms of signal transmission, flaw finding and driving/suspension; the item (2) mechanisms of micro-optics and connection, group controlling, microbatteries, action type controlling, and artificial muscles; the item (3) expansion/contraction type transfer mechanisms, light energy supply, micro visual sensation, function connection, and concerted controlling; the item (4) tubular manipulators, and mechanisms of light-aided power generation and voltage elevation; and the item (5) maintenance and micromachine systems. (NEDO)

Silicon Micromachining in RF and Photonic Applications

Science.gov (United States)

Lin, Tsen-Hwang; Congdon, Phil; Magel, Gregory; Pang, Lily; Goldsmith, Chuck; Randall, John; Ho, Nguyen

1995-01-01

Texas Instruments (TI) has developed membrane and micromirror devices since the late 1970s. An eggcrate space membrane was used as the spatial light modulator in the early years. Discrete micromirrors supported by cantilever beams created a new era for micromirror devices. Torsional micromirror and flexure-beam micromirror devices were promising for mass production because of their stable supports. TI's digital torsional micromirror device is an amplitude modulator (known as the digital micromirror device (DMD) and is in production development, discussed elsewhere. We also use a torsional device for a 4 x 4 fiber-optic crossbar switch in a 2 cm x 2 cm package. The flexure-beam micromirror device is an analog phase modulator and is considered more efficient than amplitude modulators for use in optical processing systems. TI also developed millimeter-sized membranes for integrated optical switches for telecommunication and network applications. Using a member in radio frequency (RF) switch applications is a rapidly growing area because of the micromechanical device performance in microsecond-switching characteristics. Our preliminary membrane RF switch test structure results indicate promising speed and RF switching performance. TI collaborated with MIT for modeling of metal-based micromachining.

3D Printing, Ink Casting and Micromachined Lamination (3D PICLμM): A Makerspace Approach to the Fabrication of Biological Microdevices

OpenAIRE

Avra Kundu; Tariq Ausaf; Swaminathan Rajaraman

2018-01-01

We present a novel benchtop-based microfabrication technology: 3D printing, ink casting, micromachined lamination (3D PICLμM) for rapid prototyping of lab-on-a-chip (LOC) and biological devices. The technology uses cost-effective, makerspace-type microfabrication processes, all of which are ideally suited for low resource settings, and utilizing a combination of these processes, we have demonstrated the following devices: (i) 2D microelectrode array (MEA) targeted at in vitro neural and cardi...

Micro-machined high-frequency (80 MHz) PZT thick film linear arrays.

Science.gov (United States)

Zhou, Qifa; Wu, Dawei; Liu, Changgeng; Zhu, Benpeng; Djuth, Frank; Shung, K

2010-10-01

This paper presents the development of a micromachined high-frequency linear array using PZT piezoelectric thick films. The linear array has 32 elements with an element width of 24 μm and an element length of 4 mm. Array elements were fabricated by deep reactive ion etching of PZT thick films, which were prepared from spin-coating of PZT sol-gel composite. Detailed fabrication processes, especially PZT thick film etching conditions and a novel transferring-and-etching method, are presented and discussed. Array designs were evaluated by simulation. Experimental measurements show that the array had a center frequency of 80 MHz and a fractional bandwidth (-6 dB) of 60%. An insertion loss of -41 dB and adjacent element crosstalk of -21 dB were found at the center frequency.

Infra-red laser ablative micromachining of parylene-C on SiO2 substrates for rapid prototyping, high yield, human neuronal cell patterning

International Nuclear Information System (INIS)

Raos, B J; Unsworth, C P; Costa, J L; Rohde, C A; Simpson, M C; Doyle, C S; Dickinson, M E; Bunting, A S; Murray, A F; Delivopoulos, E; Graham, E S

2013-01-01

Cell patterning commonly employs photolithographic methods for the micro fabrication of structures on silicon chips. These require expensive photo-mask development and complex photolithographic processing. Laser based patterning of cells has been studied in vitro and laser ablation of polymers is an active area of research promising high aspect ratios. This paper disseminates how 800 nm femtosecond infrared (IR) laser radiation can be successfully used to perform laser ablative micromachining of parylene-C on SiO 2 substrates for the patterning of human hNT astrocytes (derived from the human teratocarcinoma cell line (hNT)) whilst 248 nm nanosecond ultra-violet laser radiation produces photo-oxidization of the parylene-C and destroys cell patterning. In this work, we report the laser ablation methods used and the ablation characteristics of parylene-C for IR pulse fluences. Results follow that support the validity of using IR laser ablative micromachining for patterning human hNT astrocytes cells. We disseminate the variation in yield of patterned hNT astrocytes on parylene-C with laser pulse spacing, pulse number, pulse fluence and parylene-C strip width. The findings demonstrate how laser ablative micromachining of parylene-C on SiO 2 substrates can offer an accessible alternative for rapid prototyping, high yield cell patterning with broad application to multi-electrode arrays, cellular micro-arrays and microfluidics. (paper)

The laser micro-machining system for diamond anvil cell experiments and general precision machining applications at the High Pressure Collaborative Access Team.

Science.gov (United States)

Hrubiak, Rostislav; Sinogeikin, Stanislav; Rod, Eric; Shen, Guoyin

2015-07-01

We have designed and constructed a new system for micro-machining parts and sample assemblies used for diamond anvil cells and general user operations at the High Pressure Collaborative Access Team, sector 16 of the Advanced Photon Source. The new micro-machining system uses a pulsed laser of 400 ps pulse duration, ablating various materials without thermal melting, thus leaving a clean edge. With optics designed for a tight focus, the system can machine holes any size larger than 3 μm in diameter. Unlike a standard electrical discharge machining drill, the new laser system allows micro-machining of non-conductive materials such as: amorphous boron and silicon carbide gaskets, diamond, oxides, and other materials including organic materials such as polyimide films (i.e., Kapton). An important feature of the new system is the use of gas-tight or gas-flow environmental chambers which allow the laser micro-machining to be done in a controlled (e.g., inert gas) atmosphere to prevent oxidation and other chemical reactions in air sensitive materials. The gas-tight workpiece enclosure is also useful for machining materials with known health risks (e.g., beryllium). Specialized control software with a graphical interface enables micro-machining of custom 2D and 3D shapes. The laser-machining system was designed in a Class 1 laser enclosure, i.e., it includes laser safety interlocks and computer controls and allows for routine operation. Though initially designed mainly for machining of the diamond anvil cell gaskets, the laser-machining system has since found many other micro-machining applications, several of which are presented here.

The laser micro-machining system for diamond anvil cell experiments and general precision machining applications at the High Pressure Collaborative Access Team

International Nuclear Information System (INIS)

Hrubiak, Rostislav; Sinogeikin, Stanislav; Rod, Eric; Shen, Guoyin

2015-01-01

We have designed and constructed a new system for micro-machining parts and sample assemblies used for diamond anvil cells and general user operations at the High Pressure Collaborative Access Team, sector 16 of the Advanced Photon Source. The new micro-machining system uses a pulsed laser of 400 ps pulse duration, ablating various materials without thermal melting, thus leaving a clean edge. With optics designed for a tight focus, the system can machine holes any size larger than 3 μm in diameter. Unlike a standard electrical discharge machining drill, the new laser system allows micro-machining of non-conductive materials such as: amorphous boron and silicon carbide gaskets, diamond, oxides, and other materials including organic materials such as polyimide films (i.e., Kapton). An important feature of the new system is the use of gas-tight or gas-flow environmental chambers which allow the laser micro-machining to be done in a controlled (e.g., inert gas) atmosphere to prevent oxidation and other chemical reactions in air sensitive materials. The gas-tight workpiece enclosure is also useful for machining materials with known health risks (e.g., beryllium). Specialized control software with a graphical interface enables micro-machining of custom 2D and 3D shapes. The laser-machining system was designed in a Class 1 laser enclosure, i.e., it includes laser safety interlocks and computer controls and allows for routine operation. Though initially designed mainly for machining of the diamond anvil cell gaskets, the laser-machining system has since found many other micro-machining applications, several of which are presented here

A Micromachined Capacitive Pressure Sensor Using a Cavity-Less Structure with Bulk-Metal/Elastomer Layers and Its Wireless Telemetry Application

Directory of Open Access Journals (Sweden)

Yogesh B. Gianchandani

2008-04-01

Full Text Available This paper reports a micromachined capacitive pressure sensor intended for applications that require mechanical robustness. The device is constructed with two micromachined metal plates and an intermediate polymer layer that is soft enough to deform in a target pressure range. The plates are formed of micromachined stainless steel fabricated by batch-compatible micro-electro-discharge machining. A polyurethane roomtemperature- vulcanizing liquid rubber of 38-μm thickness is used as the deformable material. This structure eliminates both the vacuum cavity and the associated lead transfer challenges common to micromachined capacitive pressure sensors. For frequency-based interrogation of the capacitance, passive inductor-capacitor tanks are fabricated by combining the capacitive sensor with an inductive coil. The coil has 40 turns of a 127-μmdiameter copper wire. Wireless sensing is demonstrated in liquid by monitoring the variation in the resonant frequency of the tank via an external coil that is magnetically coupled with the tank. The sensitivity at room temperature is measured to be 23-33 ppm/KPa over a dynamic range of 340 KPa, which is shown to match a theoretical estimation. Temperature dependence of the tank is experimentally evaluated.

Achievement report on commissioned research of R and D in fiscal 1999 on micro-machine technologies. R and D of micro-machine technologies; 1999 nendo kenkyu seika hokokusho. Maikuro mashin gijutsu no kenkyu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

With an objective to perform diagnoses and medical treatment in space limited portions in living organisms, research on micro-machine systems, research on a scanning type photographing unit in the medical micro-machine, and comprehensive surveys and researches have been conducted. This paper summarizes the achievements in fiscal 1999. In the research of a micro laser catheter, a prototype laser head having an outer diameter of 1 mm was fabricated, whereas composition was realized with a micro catheter having an outer diameter of 1.5 mm. With regard to the micro pressure sensor for catheterization, good active curving action was realized by a catheter in which a pressure sensor is mounted in the SMA curved catheter head. Research on the scanning type photographing unit has been carried out, for reducing further the diameter and size of an endoscope, on a photographing unit using laser beam whose cross section area of the tip optical section is about half of the conventional units. As a result, a high resolution scanning type photographing unit was realized based on the fiber optic system using a scanning mirror. In the comprehensive surveys and researches, items of information were collected in relation with the basic technologies for micro-machines. (NEDO)

Erosion resistant anti-ice surfaces generated by ultra short laser pulses

NARCIS (Netherlands)

Del Cerro, D.A.; Römer, G.R.B.E.; Huis in't Veld, A.J.

2010-01-01

Wetting properties of a wide range of materials can be modified by accurate laser micromachining with ultra short laser pulses. Controlling the surface topography in a micro and sub-micrometer scale allows the generation of water-repellent surfaces, which remain dry and prevent ice accumulation

Trend of advanced technology of micromachines in the USA; Beikoku ni okeru micro machine sentan gijutsu doko chosa hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

In this research, the data of advanced technology of micromachines in the USA have been searched, collected, and arranged from the US patent information, technical journal information, and newspaper and general journal information. According to demand, the main undertaking information was interviewed from well-informed persons. The data were compiled as advanced technology trend of micromachines in the USA. Sensors are remarkably predominant in the elemental technology. There are also important topics in the fields of actuators, motors, lenses, devices, and structures. On the other hand, materials, etchings, packages, motive powers, and softwares are also important elemental technology in spite of their less information. From the viewpoint of usage, detection systems are remarkably predominant. Then, robots, processing systems, optics, analysis systems, motive power systems, medical systems, and acoustic systems are also important. From the viewpoint of industrial sector, the environmental items are predominant. Automobiles, medical treatments, and information communications follow the above. When new relationships to the secondary usage and tertiary usage are not found, it would be rather hard to express such a technology development trend more clearly.

Fibroblast adhesion and activation onto micro-machined titanium surfaces.

Science.gov (United States)

Guillem-Marti, J; Delgado, L; Godoy-Gallardo, M; Pegueroles, M; Herrero, M; Gil, F J

2013-07-01

Surface modifications performed at the neck of dental implants, in the manner of micro-grooved surfaces, can reduce fibrous tissue encapsulation and prevent bacterial colonization, thereby improving fibrointegration and the formation of a biological seal. However, the applied procedures are technically complex and/or time consuming methods. The aim of this study was to analyse the fibroblast behaviour on modified titanium surfaces obtained, applying a simple and low-cost method. An array of titanium surfaces was obtained using a commercial computerized numerical control lathe, modifying the feed rate and the cutting depth. To elucidate the potential ability of the generated surfaces to activate connective tissue cells, a thorough gene (by real time - qPCR) and protein (by western blot or zymography) expression and cellular response characterization (cell morphology, cell adhesion and cell activation by secreting extracellular matrix (ECM) components and their enzyme regulators) was performed. Micro-grooved surfaces have statistically significant differences in the groove's width (approximately 10, 50 and 100 μm) depending on the applied advancing fixed speed. Field emission scanning electron microscopy images showed that fibroblasts oriented along the generated grooves, but they were only entirely accommodated on the wider grooves (≥50 μm). Micro-grooved surfaces exhibited an earlier cell attachment and activation, as seen by collagen Iα1 and fibronectin deposition and activation of ECM remodelling enzymes, compared with the other surfaces. However, fibroblasts could remain in an activated state on narrower surfaces (fibrotic response. © 2012 John Wiley & Sons A/S.

Benzocyclobutene-based electric micromachines supported on microball bearings: Design, fabrication, and characterization

Science.gov (United States)

Modafe, Alireza

This dissertation summarizes the research activities that led to the development of the first microball-bearing-supported linear electrostatic micromotor with benzocyclobutene (BCB) low-k polymer insulating layers. The primary application of this device is long-range, high-speed linear micropositioning. The future generations of this device include rotary electrostatic micromotors and microgenerators. The development of the first generation of microball-bearing-supported micromachines, including device theory, design, and modeling, material characterization, process development, device fabrication, and device test and characterization is presented. The first generation of these devices is based on a 6-phase, bottom-drive, linear, variable-capacitance micromotor (B-LVCM). The design of the electrical and mechanical components of the micromotor, lumped-circuit modeling of the device and electromechanical characteristics, including variable capacitance, force, power, and speed are presented. Electrical characterization of BCB polymers, characterization of BCB chemical mechanical planarization (CMP), development of embedded BCB in silicon (EBiS) process, and integration of device components using microfabrication techniques are also presented. The micromotor consists of a silicon stator, a silicon slider, and four stainless-steel microballs. The aligning force profile of the micromotor was extracted from simulated and measured capacitances of all phases. An average total aligning force of 0.27 mN with a maximum of 0.41 mN, assuming a 100 V peak-to-peak square-wave voltage, was measured. The operation of the micromotor was verified by applying square-wave voltages and characterizing the slider motion. An average slider speed of 7.32 mm/s when excited by a 40 Hz, 120 V square-wave voltage was reached without losing the synchronization. This research has a pivotal impact in the field of power microelectromechanical systems (MEMS). It establishes the foundation for the

Achievement report for fiscal 1996 on the research and development of micromachine technology. Development of microfactory technology; 1996 nendo micromachine gijutsu no kenkyu kaihatsu seika hokokusho. Microfactory gijutsu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

The goal is to save energy and minimize the working space by constructing a manufacturing system comprising various micromachines with their dimensions fit for parts and products they handle. Development continues relative to microprocessing (electrolysis, and optical processing) and microscopic liquid operation (micropump, and part holding device). Under research in relation to the assembly process are a micro-arm to handle tiny parts and precision techniques for interfitting within a very small microfactory, a piezoelectric actuator for microscopic position adjusting, and ultraprecise microprocessing techniques indispensable for their manufacture. Also under research are the incorporation of optically driven microdevices developed before the preceding fiscal year into a microfactory and the study of microservo actuators capable of sophisticated positioning and velocity control. Concerning the microscopic transport system to deal with microscopic parts and products, studies are under way so as to embody systems driven by actuators of the electromagnetic type and electrostatic type. In this paper, reference is made to inspection techniques and comprehensive investigations. (NEDO)

Planar Indium Tin Oxide Heater for Improved Thermal Distribution for Metal Oxide Micromachined Gas Sensors

Directory of Open Access Journals (Sweden)

M. Cihan Çakır

2016-09-01

Full Text Available Metal oxide gas sensors with integrated micro-hotplate structures are widely used in the industry and they are still being investigated and developed. Metal oxide gas sensors have the advantage of being sensitive to a wide range of organic and inorganic volatile compounds, although they lack selectivity. To introduce selectivity, the operating temperature of a single sensor is swept, and the measurements are fed to a discriminating algorithm. The efficiency of those data processing methods strongly depends on temperature uniformity across the active area of the sensor. To achieve this, hot plate structures with complex resistor geometries have been designed and additional heat-spreading structures have been introduced. In this work we designed and fabricated a metal oxide gas sensor integrated with a simple square planar indium tin oxide (ITO heating element, by using conventional micromachining and thin-film deposition techniques. Power consumption–dependent surface temperature measurements were performed. A 420 °C working temperature was achieved at 120 mW power consumption. Temperature distribution uniformity was measured and a 17 °C difference between the hottest and the coldest points of the sensor at an operating temperature of 290 °C was achieved. Transient heat-up and cool-down cycle durations are measured as 40 ms and 20 ms, respectively.

Planar Indium Tin Oxide Heater for Improved Thermal Distribution for Metal Oxide Micromachined Gas Sensors.

Science.gov (United States)

Çakır, M Cihan; Çalışkan, Deniz; Bütün, Bayram; Özbay, Ekmel

2016-09-29

Metal oxide gas sensors with integrated micro-hotplate structures are widely used in the industry and they are still being investigated and developed. Metal oxide gas sensors have the advantage of being sensitive to a wide range of organic and inorganic volatile compounds, although they lack selectivity. To introduce selectivity, the operating temperature of a single sensor is swept, and the measurements are fed to a discriminating algorithm. The efficiency of those data processing methods strongly depends on temperature uniformity across the active area of the sensor. To achieve this, hot plate structures with complex resistor geometries have been designed and additional heat-spreading structures have been introduced. In this work we designed and fabricated a metal oxide gas sensor integrated with a simple square planar indium tin oxide (ITO) heating element, by using conventional micromachining and thin-film deposition techniques. Power consumption-dependent surface temperature measurements were performed. A 420 °C working temperature was achieved at 120 mW power consumption. Temperature distribution uniformity was measured and a 17 °C difference between the hottest and the coldest points of the sensor at an operating temperature of 290 °C was achieved. Transient heat-up and cool-down cycle durations are measured as 40 ms and 20 ms, respectively.

Fabricación de micro-componentes mediante arranque de viruta. análisis del acabado superficial en aleaciones de aluminio y titanio

Directory of Open Access Journals (Sweden)

Francisco Mata Cabrera

2011-07-01

Se proponen modelos de predicción de la rugosidad, con buen grado de aproximación, para ayudar a la caracterización de los procesos de micro-mecanizado. Micro-machining is the most adequate technology for manufacturing of micro-components in the industry. This is a manufacturing precision process with applications in certain industrial field, for example the machining construction. The objective of this research is to analyze the surface quality in micro-machining processes and to evaluate her possible application in mechanical industry (surface roughness, geometry, aspect, etc. This work presents the experimental study of surface roughness (Ra and Rt using a specific micro-turning process. The measures of surface roughness reveal how it is possible to obtain superficial very good qualities up to diameters of 0.05 mm. For low diameters, it worsens the superficial quality and the faults of form increase, due to the low inflexibility of the piece. Prediction models of surface roughness are proposed to the characterization of micro-machining processes.  

Design challenges for stepper motor actuated microvalve based on fine and micro-machining

NARCIS (Netherlands)

Fazal, I.; Elwenspoek, Michael Curt

2007-01-01

We present a normally open stepper motor actuated microvalve based on micro and fine-machining technique. In this paper, first we have described how the larger controllable flow range can be achieved with simple micromachining techniques and secondly we have presented the results which show how the

A LabVIEWTM-based scanning and control system for proton beam micromachining

International Nuclear Information System (INIS)

Bettiol, Andrew A.; Kan, J.A. van; Sum, T.C.; Watt, F.

2001-01-01

LabVIEW TM is steadily gaining in popularity as the programming language of choice for scientific data acquisition and control. This is due to the vast array of measurement instruments and data acquisition cards supported by the LabVIEW TM environment, and the relative ease with which advanced software can be programmed. Furthermore, virtual instruments that are designed for a given system can be easily ported to other LabVIEW TM platforms and hardware. This paper describes the new LabVIEW TM based scanning and control system developed specifically for proton beam micromachining (PBM) applications. The new system is capable of scanning figures at 16-bit resolution with improved sub-microsecond scan rates. Support for electrostatic beam blanking and external dose normalization using a TTL signal have been implemented. The new software incorporates a semi-automated dose calibration system, and a number of novel dose normalization methods. Limitations of the current beam scanning hardware are discussed in light of new results obtained from micromachining experiments performed in SU-8 photoresist

Demonstration of superconducting micromachined cavities

Energy Technology Data Exchange (ETDEWEB)

Brecht, T., E-mail: teresa.brecht@yale.edu; Reagor, M.; Chu, Y.; Pfaff, W.; Wang, C.; Frunzio, L.; Devoret, M. H.; Schoelkopf, R. J. [Department of Applied Physics, Yale University, New Haven, Connecticut 06511 (United States)

2015-11-09

Superconducting enclosures will be key components of scalable quantum computing devices based on circuit quantum electrodynamics. Within a densely integrated device, they can protect qubits from noise and serve as quantum memory units. Whether constructed by machining bulk pieces of metal or microfabricating wafers, 3D enclosures are typically assembled from two or more parts. The resulting seams potentially dissipate crossing currents and limit performance. In this letter, we present measured quality factors of superconducting cavity resonators of several materials, dimensions, and seam locations. We observe that superconducting indium can be a low-loss RF conductor and form low-loss seams. Leveraging this, we create a superconducting micromachined resonator with indium that has a quality factor of two million, despite a greatly reduced mode volume. Inter-layer coupling to this type of resonator is achieved by an aperture located under a planar transmission line. The described techniques demonstrate a proof-of-principle for multilayer microwave integrated quantum circuits for scalable quantum computing.

Project: Micromachined High-Frequency Circuits For Sub-mm-wave Sensors

Science.gov (United States)

Papapolymerou, Ioannis John

2004-01-01

A novel micromachined resonator at 45 GHz based on a defect in a periodic electromagnetic bandgap structure (EBG) and a two-pole Tchebysbev filter with 1.4% 0.15 dB equiripple bandwidth and 2.3 dB loss employing this resonator are presented in this letter. The periodic bandgap structure is realized on a 400 micron thick high-resistivity silicon wafer using deep reactive ion etching techniques. The resonator and filter can be accessed via coplanar waveguide feeds.

High-power ultrashort fiber laser for solar cells micromachining

Science.gov (United States)

Lecourt, J.-B.; Duterte, C.; Liegeois, F.; Lekime, D.; Hernandez, Y.; Giannone, D.

2012-02-01

We report on a high-power ultra-short fiber laser for thin film solar cells micromachining. The laser is based on Chirped Pulse Amplification (CPA) scheme. The pulses are stretched to hundreds of picoseconds prior to amplification and can be compressed down to picosecond at high energy. The repetition rate is adjustable from 100 kHz to 1 MHz and the optical average output power is close to 13 W (before compression). The whole setup is fully fibred, except the compressor achieved with bulk gratings, resulting on a compact and reliable solution for cold ablation.

Numerical modelling of micro-machining of f.c.c. single crystal: Influence of strain gradients

KAUST Repository

Demiral, Murat; Roy, Anish; El Sayed, Tamer S.; Silberschmidt, Vadim V.

2014-01-01

of orthogonal micro-machining of f.c.c. single crystal copper was developed. The model was implemented in a commercial software ABAQUS/Explicit employing a user-defined subroutine VUMAT. Strain-gradient crystal-plasticity and conventional crystal

A surface-micromachining-based inertial micro-switch with compliant cantilever beam as movable electrode for enduring high shock and prolonging contact time

Energy Technology Data Exchange (ETDEWEB)

Xu, Qiu [National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Electronics Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240 (China); Yang, Zhuoqing, E-mail: yzhuoqing@sjtu.edu.cn [National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Electronics Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240 (China); Fu, Bo; Li, Jianhua; Wu, Hao [Huaihai Industrial Group Co., Ltd., Changzhi, Shanxi Province, 046012 (China); Zhang, Qihuan; Sun, Yunna; Ding, Guifu; Zhao, Xiaolin [National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Electronics Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240 (China)

2016-11-30

Highlights: • The designed cantilever beam attached to the proof mass can endure a larger shock acceleration (∼1000 g order of magnitude) compared to those traditional designs (∼100 g order of magnitude). • Effect of the pulse width on the threshold acceleration, the response time and the contact time is investigated. • A constraint sleeve structure is introduced to lower the off-axis sensitivity. - Abstract: A novel laterally-driven inertial micro-switch with two L-shaped elastic cantilever beams as the movable electrode, which is attached to the proof mass, is proposed in this paper. The advantage of this design is that the contact time of the inertial micro-switch can be prolonged. Meanwhile, the micro-switch can withstand a higher shock than the traditional designs whose cantilever beams are attached to the fixed electrode. The designed inertial micro-switch was simulated and optimized with ANSYS software and fabricated on a quartz substrate by surface micromachining technology. The simulated result demonstrates that the threshold acceleration (a{sub ths}) under stable switch-on state is about 288 g and the contact time is about 198 μs when the pulse width of acceleration loads is 1 ms. At the same time, it indicates that the threshold acceleration, the response time and the contact time of designed micro-switch all increase with the pulse width of acceleration loads. The simulation of impact process in non-sensitive direction shows that the introduced constraint sleeve structure in the novel inertial micro-switch can lower the off-axis sensitivity. The fabricated micro-switch prototype has been tested by a standard dropping hammer system under shock accelerations with various amplitudes and pulse widths. The experimental measurements show that the contact time is about 150 μs when the threshold acceleration is about 288 g. It also indicates that the response time and the contact time both increase with the pulse width, which is consistent with the

A Reuse Evaluation for Solar-Cell Silicon Wafers via Shift Revolution and Tool Rotation Using Magnetic Assistance in Ultrasonic Electrochemical Micromachining

Directory of Open Access Journals (Sweden)

P. S. Pa

2013-01-01

Full Text Available A new reuse fabrication using a tool module with rotation and revolution through a process of magnetic assistance in ultrasonic electrochemical micromachining (UEMM for removal of the surface layers from silicon wafers of solar cells is demonstrated. The target of the proposed reuse fabrication method is to replace the current approach, which uses strong acid and grinding and may damage the physical structure of silicon wafers and pollute to the environment. A precisely engineered clean production approach to removal of surface microstructure layers from silicon wafers is to develop a mass production system for recycling defective or discarded silicon wafers of solar cells that can reduce pollution and cost. The high revolution speed of the shift with the high rotation speed of the designed tool increases the discharge mobility and improves the removal effect associated with the high feed rate of the workpiece. High frequency and high power of ultrasonic with large electrolyte flow rate and high magnetic strengths with a small distance between the two magnets provide a large discharge effect and good removal; only a short period of time is required to remove the epoxy film and Si3N4 layer easily and cleanly.

Micromachined silicon cantilevers with integrated high-frequency magnetoimpedance sensors for simultaneous strain and magnetic field detection

Science.gov (United States)

Buettel, G.; Joppich, J.; Hartmann, U.

2017-12-01

Giant magnetoimpedance (GMI) measurements in the high-frequency regime utilizing a coplanar waveguide with an integrated Permalloy multilayer and micromachined on a silicon cantilever are reported. The fabrication process is described in detail. The aspect ratio of the magnetic multilayer in the magnetoresistive and magnetostrictive device was varied. Tensile strain and compressive strain were applied. Vector network analyzer measurements in the range from the skin effect to ferromagnetic resonance confirm the technological potential of GMI-based micro-electro-mechanical devices for strain and magnetic field sensing applications. The strain-impedance gauge factor was quantified by finite element strain calculations and reaches a maximum value of almost 200.

Modeling the Microstructure Curvature of Boron-Doped Silicon in Bulk Micromachined Accelerometer

Directory of Open Access Journals (Sweden)

Xiaoping He

2013-01-01

Full Text Available Microstructure curvature, or buckling, is observed in the micromachining of silicon sensors because of the doping of impurities for realizing certain electrical and mechanical processes. This behavior can be a key source of error in inertial sensors. Therefore, identifying the factors that influence the buckling value is important in designing MEMS devices. In this study, the curvature in the proof mass of an accelerometer is modeled as a multilayered solid model. Modeling is performed according to the characteristics of the solid diffusion mechanism in the bulk-dissolved wafer process (BDWP based on the self-stopped etch technique. Moreover, the proposed multilayered solid model is established as an equivalent composite structure formed by a group of thin layers that are glued together. Each layer has a different Young’s modulus value and each undergoes different volume shrinkage strain owing to boron doping in silicon. Observations of five groups of proof mass blocks of accelerometers suggest that the theoretical model is effective in determining the buckling value of a fabricated structure.

Etching characteristics of Si{110} in 20 wt% KOH with addition of hydroxylamine for the fabrication of bulk micromachined MEMS

Science.gov (United States)

Rao, A. V. Narasimha; Swarnalatha, V.; Pal, P.

2017-12-01

Anisotropic wet etching is a most widely employed for the fabrication of MEMS/NEMS structures using silicon bulk micromachining. The use of Si{110} in MEMS is inevitable when a microstructure with vertical sidewall is to be fabricated using wet anisotropic etching. In most commonly employed etchants (i.e. TMAH and KOH), potassium hydroxide (KOH) exhibits higher etch rate and provides improved anisotropy between Si{111} and Si{110} planes. In the manufacturing company, high etch rate is demanded to increase the productivity that eventually reduces the cost of end product. In order to modify the etching characteristics of KOH for the micromachining of Si{110}, we have investigated the effect of hydroxylamine (NH2OH) in 20 wt% KOH solution. The concentration of NH2OH is varied from 0 to 20% and the etching is carried out at 75 °C. The etching characteristics which are studied in this work includes the etch rates of Si{110} and silicon dioxide, etched surface morphology, and undercutting at convex corners. The etch rate of Si{110} in 20 wt% KOH + 15% NH2OH solution is measured to be four times more than that of pure 20 wt% KOH. Moreover, the addition of NH2OH increases the undercutting at convex corners and enhances the etch selectivity between Si and SiO2.

Generation of programmable temporal pulse shape and applications in micromachining

Science.gov (United States)

Peng, X.; Jordens, B.; Hooper, A.; Baird, B. W.; Ren, W.; Xu, L.; Sun, L.

2009-02-01

In this paper we presented a pulse shaping technique on regular solid-state lasers and the application in semiconductor micromachining. With a conventional Q-switched laser, all of the parameters can be adjusted over only limited ranges, especially the pulse width and pulse shape. However, some laser link processes using traditional laser pulses with pulse widths of a few nanoseconds to a few tens of nanoseconds tend to over-crater in thicker overlying passivation layers and thereby cause IC reliability problems. Use of a laser pulse with a special shape and a fast leading edge, such as tailored pulse, is one technique for controlling link processing. The pulse shaping technique is based on light-loop controlled optical modulation to shape conventional Q-switched solid-state lasers. One advantage of the pulse shaping technique is to provide a tailored pulse shape that can be programmed to have more than one amplitude value. Moreover, it has the capability of providing programmable tailored pulse shapes with discrete amplitude and time duration components. In addition, it provides fast rising and fall time of each pulse at fairly high repetition rate at 355nm with good beam quality. The regular-to-shaped efficiency is up to 50%. We conclude with a discussion of current results for laser processing of semiconductor memory link structures using programmable temporal pulse shapes. The processing experiments showed promising results with shaped pulse.

A Novel Piezo-Actuator-Sensor Micromachine for Mechanical Characterization of Micro-Specimens

Directory of Open Access Journals (Sweden)

Leila Ladani

2010-12-01

Full Text Available Difficulties associated with testing and characterization of materials at microscale demands for new technologies and devices that are capable of measuring forces and strains at microscale. To address this issue, a novel electroactive-based micro-electro-mechanical machine is designed. The micromachine is comprised of two electroactive (piezoelectric micro-elements mounted on a rigid frame. Electrical activation of one of the elements causes it to expand and induce a stress in the intervening micro-specimen. The response of the microspecimen to the stress is measured by the deformation and thereby voltage/resistance induced in the second electro-active element. The concept is theoretically proven using analytical modeling in conjunction with non-linear, three dimensional finite element analyses for the micromachine. Correlation of the output voltage to the specimen stiffness is shown. It is also demonstrated through finite element and analytical analysis that this technique is capable of detecting non-linear behavior of materials. A characteristic curve for an isotropic specimen exhibiting linear elastic behavior is developed. Application of the proposed device in measuring coefficient of thermal expansion is explored and analytical analysis is conducted.

Micromachining. CERN Courier, Jul-Aug 1995, v. 35(5)

International Nuclear Information System (INIS)

Wilson, Martin

1995-01-01

Full text: As well as making microcircuit components, X-ray lithography can also be used to make very small mechanical parts, either by using directly the exposed and developed photoresist, or as a mould to produce the component in another material such as ceramic or metal. In this revolutionary technology, metal components are made via the LIGA (Lithographic Galvanoformung und Abformung) technique in which the exposed and developed photoresist is coated with a conducting material and then electroplated, after which the resist is stripped away. In addition to fine size and precision resolution, X-rays offer the advantage of deep penetration and small scattering through the resist, so that patterns may be up to a millimetre deep, with very accurate straightness in directions parallel to the beam. Micromachining via LIGA was developed at KfK Karlsruhe; commercialization and further development is being vigorously pursued by the Institut fur Mikrotechnik in Mainz and by Microparts GmbH in Karlsruhe. Significant developments have been made at the Synchrotron Radiation Centre in Madison, Wisconsin, with new programmes start-ing at SRRC (Taiwan), CAMD (Baton Rouge, Louisiana), and LURE (Paris). There is now an active European Special Interest Group for LIGA. Commercially manufactured micromachines are starting to be used in sensors and connectors. The ability to integrate microdevices with microelectronics raises many interesting possibilities for the future, notably in medicine and for intelligent sensors. In all cases, however, widespread adoption will be governed by the ability to mass-produce cheaply, requiring high volume production. The high intensities of synchrotron radiation will assist in achieving these large throughputs

Synthesis and structure of large single crystalline silver hexagonal microplates suitable for micromachining

Energy Technology Data Exchange (ETDEWEB)

Lyutov, Dimitar L.; Genkov, Kaloyan V.; Zyapkov, Anton D.; Tsutsumanova, Gichka G.; Tzonev, Atanas N. [Department of Solid State Physics and Microelectronics, Faculty of Physics, University of Sofia, 5, J. Bouchier Blvd, Sofia (Bulgaria); Lyutov, Lyudmil G. [Department of General and Inorganic Chemistry, Faculty of Chemistry, University of Sofia, 1, J. Bouchier Blvd, Sofia (Bulgaria); Russev, Stoyan C., E-mail: scr@phys.uni-sofia.bg [Department of Solid State Physics and Microelectronics, Faculty of Physics, University of Sofia, 5, J. Bouchier Blvd, Sofia (Bulgaria)

2014-01-15

We report a simple one-step synthesis method of large single crystalline Ag (111) hexagonal microplates with sharp edges and a size of up to tens of microns. Single silver crystals were produced by reduction silver nitrate aqueous solution with 4-(methylamino)phenol sulfate. Scanning and transmission electron microscopy, energy-dispersive X-ray spectroscopy, selected area electron diffraction and optical microscopy techniques were combined to characterize the crystals. It is shown that the microplates can be easily dispersed and transferred as single objects onto different substrates and subsequently used as a high quality plasmonic starting material for micromachining of future nanocomponents, using modern top-down techniques like focused-ion beam milling and gas injection deposition. - Highlights: • Synthesis of large Ag hexagonal microplates with high crystallinity. • It is shown and discussed the role of twinning for the anisotropic 2D growth. • The Ag plates are stable in water and can be dispersed onto different substrates. • Their positioning and subsequent micromachining with FIB/GIS is demonstrated. • Suitable starting material for future plasmonic nanocomponents.

Short-pulse-width micromachining of hard materials using DPSS Nd:YAG lasers

Science.gov (United States)

Heglin, Michael; Govorkov, Sergei V.; Scaggs, Michael J.; Theoharidis, Haris; Schoelzel, T.

2002-06-01

The material processing of an industrial, short-pulse duration DPPS YAG laser producing peak powers greater than 0.2MW is discussed in this paper. This peak power provides sufficient materials processing capability to meet the micro machining needs in the automotive, semiconductor, micro- electronic, medical and telecommunication industries. All hard and soft materials including: plastics, metals, ceramics, diamond and other crystalline materials are suitable candidates for the processing capability of this laser. Micro level features can be machined in these materials to a depth in excess of 1mm with high quality results. In most applications feature sizes can be achieved that are not possible or economical with existing technologies. The optical beam delivery system requirements, and overall micro-machining set-up are also described. The drilling and cutting versatility down to feature sizes of less than 7 micrometers , as well as, complex shapes are shown. The wavelength, pulse length, and peakpower are described and relate to their effect on recast, micro-cracking and material removal rates. Material removal effects related to progressive penetration into the material will be reviewed. The requirements of this DPSS laser technology to meet the operational requirements for high duty cycle operation in industrial environments is covered along with processing flexibility and lower operating cost.

Manufacturing of a micro-tungsten carbide electrode using a supersonic-aided electrolysis process

International Nuclear Information System (INIS)

Weng, Feng-Tsai; Ho, Chi-Ting

2008-01-01

In this study, a novel micromachining technology for fabricating micro parts was described. The original diameter of a tungsten carbide rod was 3 mm, and it was first processed to a rod with a diameter of 50 µm by a precision-grinding process. It could then be machined to the desired diameter by a supersonic-aided electrolysis process. A high-aspect ratio of the micro-tungsten carbide rod was easily obtained by this process. The surface roughness of the sample that was processed by electrolysis with supersonic-aided agitation was compared with that of the sample obtained without agitation. The machined surface of the sample was smooth, and the reason may be that ionized particles in the anode could be removed by supersonic-aided agitation during the electrolysis process. A microelectrode with a tip of approximately 1 µm could be obtained by this process. (technical note)

Materials processing with superposed Bessel beams

Science.gov (United States)

Yu, Xiaoming; Trallero-Herrero, Carlos A.; Lei, Shuting

2016-01-01

We report experimental results of femtosecond laser processing on the surface of glass and metal thin film using superposed Bessel beams. These beams are generated by a combination of a spatial light modulator (SLM) and an axicon with >50% efficiency, and they possess the long depth-of-focus (propagation-invariant) property as found in ordinary Bessel beams. Through micromachining experiments using femtosecond laser pulses, we show that multiple craters can be fabricated on glass with single-shot exposure, and the 1+(⿿1) superposed beam can reduce collateral damage caused by the rings in zero-order Bessel beams in the scribing of metal thin film.

Modeling and Design of Capacitive Micromachined Ultrasonic Transducers Based-on Database Optimization

International Nuclear Information System (INIS)

Chang, M W; Gwo, T J; Deng, T M; Chang, H C

2006-01-01

A Capacitive Micromachined Ultrasonic Transducers simulation database, based on electromechanical coupling theory, has been fully developed for versatile capacitive microtransducer design and analysis. Both arithmetic and graphic configurations are used to find optimal parameters based on serial coupling simulations. The key modeling parameters identified can improve microtransducer's character and reliability effectively. This method could be used to reduce design time and fabrication cost, eliminating trial-and-error procedures. Various microtransducers, with optimized characteristics, can be developed economically using the developed database. A simulation to design an ultrasonic microtransducer is completed as an executed example. The dependent relationship between membrane geometry, vibration displacement and output response is demonstrated. The electromechanical coupling effects, mechanical impedance and frequency response are also taken into consideration for optimal microstructures. The microdevice parameters with the best output signal response are predicted, and microfabrication processing constraints and realities are also taken into consideration

Modeling of solid-state and excimer laser processes for 3D micromachining

Science.gov (United States)

Holmes, Andrew S.; Onischenko, Alexander I.; George, David S.; Pedder, James E.

2005-04-01

An efficient simulation method has recently been developed for multi-pulse ablation processes. This is based on pulse-by-pulse propagation of the machined surface according to one of several phenomenological models for the laser-material interaction. The technique allows quantitative predictions to be made about the surface shapes of complex machined parts, given only a minimal set of input data for parameter calibration. In the case of direct-write machining of polymers or glasses with ns-duration pulses, this data set can typically be limited to the surface profiles of a small number of standard test patterns. The use of phenomenological models for the laser-material interaction, calibrated by experimental feedback, allows fast simulation, and can achieve a high degree of accuracy for certain combinations of material, laser and geometry. In this paper, the capabilities and limitations of the approach are discussed, and recent results are presented for structures machined in SU8 photoresist.

Si Micro-turbine by Proton BeamWriting and Porous Silicon Micromachining

International Nuclear Information System (INIS)

Rajta, I.; Szilasi, S.Z.; Fekete, Z.

2008-01-01

Complete text of publication follows. A 3D Si micro-turbine characterized by high aspect ratio vertical walls was formed by the combination of proton beam writing (PBW) and subsequent selective porous Si (PS) etching. Crystal damages generated by the implanted protons result in increased resistivity, thereby limit or even prevent the current to flow through the implanted area during electrochemical etching. Characteristic feature of the proposed process is that the shape of the micro electromechanical (MEMS) components is defined by two implantation energies. A higher energy is applied for defining the housing of the device while the lower energy is used to write the moving components. The implantation energies were selected such as to result appropriate difference between the two projected ranges, thereby providing structures with different height after development. The thickness of the walls of the moving component and the isotropic etching profile of the electrochemical PS formation was also taken into consideration. The electrochemical etching is driven until the sacrificial PS layer completely under etches the moving components, but the etch-front does not reach the bottom of the housing. Therefore, the dissolution of PS results in a ready-to-operate device with a released moving component embedded in the cavity of the housing. The operation of the encapsulated device fabricated by the two-energy implantation is successfully demonstrated (Fig. 1). Rotation speed of the device is estimated in the range of thousands rpm, however, further analysis of the novel structure optimized for performance and MEMS compatible assembly will be done and precise characteristics will be determined by adequate optical read-out method. The feasibility of Proton Beam Writing combined with Porous Si Micromachining and conventional Si processing steps was successfully demonstrated by fabricating Si microturbine chip. The aligned, two-energy proton beam implantation can provide high

Nickel silicide thin films as masking and structural layers for silicon bulk micro-machining by potassium hydroxide wet etching

International Nuclear Information System (INIS)

Bhaskaran, M; Sriram, S; Sim, L W

2008-01-01

This paper studies the feasibility of using titanium and nickel silicide thin films as mask materials for silicon bulk micro-machining. Thin films of nickel silicide were found to be more resistant to wet etching in potassium hydroxide. The use of nickel silicide as a structural material, by fabricating micro-beams of varying dimensions, is demonstrated. The micro-structures were realized using these thin films with wet etching using potassium hydroxide solution on (1 0 0) and (1 1 0) silicon substrates. These results show that nickel silicide is a suitable alternative to silicon nitride for silicon bulk micro-machining

Simulation of the Mitra 15 micro-machine on IBM 360/91. Microprogramming of the fast Fourier transform

International Nuclear Information System (INIS)

Augustides, Jean

1973-01-01

As computing time did not allow working in real time, and as different methods had been proposed to reduce the computing time (the Cooley-Tuckey method, the use of specific FFT processors), this thesis proposes an intermediate solution, between the entirely programmed solution and the entirely cabled solution. After some generalities on micro-programming (definition, history, benefits and drawbacks, perspectives), the author reports the micro-programming of the Mitra 15 micro-machine: description of the machine, memory, command memory and associated circuits, interruptions and suspensions, descriptions of micro-statements, execution of a micro-statement. Programs and subroutines developed for the modelling of Mitra 15 micro-machine on IBM 360/91 are presented. Then, the author reports the micro-programming of the fast Fourier transform: theory, program description, and test

Experimental Study of the Ultrasonic Vibration-Assisted Abrasive Waterjet Micromachining the Quartz Glass

Directory of Open Access Journals (Sweden)

Rongguo Hou

2018-01-01

Full Text Available The ultrasonic vibration is used to enhance the capability of the abrasive water micromachining glass. And, the ultrasonic vibration is activated on the abrasive waterjet nozzle. The quality of the flow is improved, and the velocity of the abrasive is increased because of the addition of the ultrasonic energy. The relevant experimental results indicate that the erosion depth and the material volume removal of the glass are obviously increased when ultrasonic vibration is working. As for the influence of process parameters on the material removal of the glass such as vibration amplitude, system pressure, distance of the standoff, and abrasive size, the experimental results indicate that the system pressure and vibration contribute greatly to the glass material removal. Also, the erosion depth and the volume of material removal are increased with the increase in the vibration amplitude and system pressure. There are some uplifts found at the edge of erosion pit. Then, it can be inferred that the plastic method is an important material removal method during the machining process of ultrasonic vibration-assisted abrasive waterjet.

Hypersonic force measurements using internal balance based on optical micromachined Fabry-Perot interferometry

Science.gov (United States)

Qiu, Huacheng; Min, Fu; Zhong, Shaolong; Song, Xin; Yang, Yanguang

2018-03-01

Force measurements using wind tunnel balance are necessary for determining a variety of aerodynamic performance parameters, while the harsh environment in hypersonic flows requires that the measurement instrument should be reliable and robust, in against strong electromagnetic interference, high vacuum, or metal (oxide) dusts. In this paper, we demonstrated a three-component internal balance for hypersonic aerodynamic force measurements, using novel optical micromachined Fabry-Perot interferometric (FPI) strain gauges as sensing elements. The FPI gauges were fabricated using Micro-Opto-Electro-Mechanical Systems (MOEMS) surface and bulk fabrication techniques. High-reflectivity coatings are used to form a high-finesse Fabry-Perot cavity, which benefits a high resolution. Antireflective and passivation coatings are used to reduce unwanted interferences. The FPI strain gauge based balance has been calibrated and evaluated in a Mach 5 hypersonic flow. The results are compared with the traditional technique using the foil resistive strain gauge balance, indicating that the proposed balance based on the MOEMS FPI strain gauge is reliable and robust and is potentially suitable for the hypersonic wind tunnel harsh environment.

Capacitive micromachined ultrasonic transducer arrays as tunable acoustic metamaterials

Energy Technology Data Exchange (ETDEWEB)

Lani, Shane W., E-mail: shane.w.lani@gmail.com, E-mail: karim.sabra@me.gatech.edu, E-mail: levent.degertekin@me.gatech.edu; Sabra, Karim G. [George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801Ferst Drive, Georgia 30332-0405 (United States); Wasequr Rashid, M.; Hasler, Jennifer [School of Electrical and Computer Engineering, Georgia Institute of Technology, Van Leer Electrical Engineering Building, 777 Atlantic Drive NW, Atlanta, Georgia 30332-0250 (United States); Levent Degertekin, F. [George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801Ferst Drive, Georgia 30332-0405 (United States); School of Electrical and Computer Engineering, Georgia Institute of Technology, Van Leer Electrical Engineering Building, 777 Atlantic Drive NW, Atlanta, Georgia 30332-0250 (United States)

2014-02-03

Capacitive Micromachined Ultrasonic Transducers (CMUTs) operating in immersion support dispersive evanescent waves due to the subwavelength periodic structure of electrostatically actuated membranes in the array. Evanescent wave characteristics also depend on the membrane resonance which is modified by the externally applied bias voltage, offering a mechanism to tune the CMUT array as an acoustic metamaterial. The dispersion and tunability characteristics are examined using a computationally efficient, mutual radiation impedance based approach to model a finite-size array and realistic parameters of variation. The simulations are verified, and tunability is demonstrated by experiments on a linear CMUT array operating in 2-12 MHz range.

Optimized design of micromachined electric field mills to maximize electrostatic field sensitivity

OpenAIRE

Zhou, Yu; Shafai, Cyrus

2016-01-01

This paper describes the design optimization of a micromachined electric field mill, in relation to maximizing its output signal. The cases studied are for a perforated electrically grounded shutter vibrating laterally over sensing electrodes. It is shown that when modeling the output signal of the sensor, the differential charge on the sense electrodes when exposed to vs. visibly shielded from the incident electric field must be considered. Parametric studies of device dimensions show that t...

Polyimide and Metals MEMS Multi-User Processes

KAUST Repository

Arevalo, Arpys

2016-11-01

The development of a polyimide and metals multi-user surface micro-machining process for Micro-electro-mechanical Systems (MEMS) is presented. The process was designed to be as general as possible, and designed to be capable to fabricate different designs on a single silicon wafer. The process was not optimized with the purpose of fabricating any one specific device but can be tweaked to satisfy individual needs depending on the application. The fabrication process uses Polyimide as the structural material and three separated metallization layers that can be interconnected depending on the desired application. The technology allows the development of out-of-plane compliant mechanisms, which can be combined with six variations of different physical principles for actuation and sensing on a single processed silicon wafer. These variations are: electrostatic motion, thermal bimorph actuation, capacitive sensing, magnetic sensing, thermocouple-based sensing and radio frequency transmission and reception.

3D Printed Microtransporters: Compound Micromachines for Spatiotemporally Controlled Delivery of Therapeutic Agents.

Science.gov (United States)

Huang, Tian-Yun; Sakar, Mahmut Selman; Mao, Angelo; Petruska, Andrew J; Qiu, Famin; Chen, Xue-Bo; Kennedy, Stephen; Mooney, David; Nelson, Bradley J

2015-11-01

Functional compound micromachines are fabricated by a design methodology using 3D direct laser writing and selective physical vapor deposition of magnetic materials. Microtransporters with a wirelessly controlled Archimedes screw pumping mechanism are engineered. Spatiotemporally controlled collection, transport, and delivery of micro particles, as well as magnetic nanohelices inside microfluidic channels are demonstrated. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A sub-cm micromachined electron microscope

Science.gov (United States)

Feinerman, A. D.; Crewe, D. A.; Perng, D. C.; Shoaf, S. E.; Crewe, A. V.

1993-01-01

A new approach for fabricating macroscopic (approximately 10x10x10 mm(exp 3)) structures with micron accuracy has been developed. This approach combines the precision of semiconductor processing and fiber optic technologies. A (100) silicon wafer is anisotropically etched to create four orthogonal v-grooves and an aperture on each 10x12 mm die. Precision 308 micron optical fibers are sandwiched between the die to align the v-grooves. The fiber is then anodically bonded to the die above and below it. This procedure is repeated to create thick structures and a stack of 5 or 6 die will be used to create a miniature scanning electron microscope (MSEM). Two die in the structure will have a segmented electrode to deflect the beam and correct for astigmatism. The entire structure is UHV compatible. The performance of an SEM improves as its length is reduced and a sub-cm 2 keV MSEM with a field emission source should have approximately 1 nm resolution. A low voltage high resolution MSEM would be useful for the examination of biological specimens and semiconductors with a minimum of damage. The first MSEM will be tested with existing 6 micron thermionic sources. In the future a micromachined field emission source will be used. The stacking technology presented in this paper can produce an array of MSEMs 1 to 30 mm in length with a 1 mm or larger period. A key question being addressed by this research is the optimum size for a low voltage MSEM which will be determined by the required spatial resolution, field of view, and working distance.

Surface Modification and Surface - Subsurface Exchange Processes on Europa

Science.gov (United States)

Phillips, C. B.; Molaro, J.; Hand, K. P.

2017-12-01

The surface of Jupiter's moon Europa is modified by exogenic processes such as sputtering, gardening, radiolysis, sulfur ion implantation, and thermal processing, as well as endogenic processes including tidal shaking, mass wasting, and the effects of subsurface tectonic and perhaps cryovolcanic activity. New materials are created or deposited on the surface (radiolysis, micrometeorite impacts, sulfur ion implantation, cryovolcanic plume deposits), modified in place (thermal segregation, sintering), transported either vertically or horizontally (sputtering, gardening, mass wasting, tectonic and cryovolcanic activity), or lost from Europa completely (sputtering, plumes, larger impacts). Some of these processes vary spatially, as visible in Europa's leading-trailing hemisphere brightness asymmetry. Endogenic geologic processes also vary spatially, depending on terrain type. The surface can be classified into general landform categories that include tectonic features (ridges, bands, cracks); disrupted "chaos-type" terrain (chaos blocks, matrix, domes, pits, spots); and impact craters (simple, complex, multi-ring). The spatial distribution of these terrain types is relatively random, with some differences in apex-antiapex cratering rates and latitudinal variation in chaos vs. tectonic features. In this work, we extrapolate surface processes and rates from the top meter of the surface in conjunction with global estimates of transport and resurfacing rates. We combine near-surface modification with an estimate of surface-subsurface (and vice versa) transport rates for various geologic terrains based on an average of proposed formation mechanisms, and a spatial distribution of each landform type over Europa's surface area. Understanding the rates and mass balance for each of these processes, as well as their spatial and temporal variability, allows us to estimate surface - subsurface exchange rates over the average surface age ( 50myr) of Europa. Quantifying the timescale

3D capacitive tactile sensor using DRIE micromachining

Science.gov (United States)

Chuang, Chiehtang; Chen, Rongshun

2005-07-01

This paper presents a three dimensional micro capacitive tactile sensor that can detect normal and shear forces which is fabricated using deep reactive ion etching (DRIE) bulk silicon micromachining. The tactile sensor consists of a force transmission plate, a symmetric suspension system, and comb electrodes. The sensing character is based on the changes of capacitance between coplanar sense electrodes. High sensitivity is achieved by using the high aspect ratio interdigital electrodes with narrow comb gaps and large overlap areas. The symmetric suspension mechanism of this sensor can easily solve the coupling problem of measurement and increase the stability of the structure. In this paper, the sensor structure is designed, the capacitance variation of the proposed device is theoretically analyzed, and the finite element analysis of mechanical behavior of the structures is performed.

Description of two-process surface topography

International Nuclear Information System (INIS)

Grabon, W; Pawlus, P

2014-01-01

After two machining processes, a large number of surface topography measurements were made using Talyscan 150 stylus measuring equipment. The measured samples were divided into two groups. The first group contained two-process surfaces of random nature, while the second group used random-deterministic textures of random plateau parts and portions of deterministic valleys. For comparison, one-process surfaces were also analysed. Correlation and regression analysis was used to study the dependencies among surface texture parameters in 2D and 3D systems. As the result of this study, sets of parameters describing multi-process surface topography were obtained for two-process surfaces of random and of random-deterministic types. (papers)

An electro-magnetic micromachined actuator monolithically integrated with a vertical shutter for variable optical attenuation

International Nuclear Information System (INIS)

Hung, Shao Hsuan; Hsieh, Hsin-Ta; John Su, Guo-Dung

2008-01-01

The design, fabrication and test results of an electromagnetic-actuated micromachined variable optical attenuator (VOA) are reported in this paper. Optical attenuation is achieved by moving a shutter into the light path between a pair of single mode fiber collimators. The shutter, consisting of a 500 µm × 1200 µm vertical micromirror, is monolithically integrated with an actuation flap. The micromirror was made by tetra-methyl ammonium hydroxide (TMAH) anisotropic wet etching with a sharp edge and a smooth reflecting surface. By arranging fiber collimators in different configurations, the reported VOA can be used as either normally-on or normally-off modes due to its relatively large shutter surface. The insertion loss of the VOA is 0.2 dB and 0.4 dB for normally-on and normally-off modes, respectively. Both optical and mechanical simulation models of the device were discussed, and the theoretical calculations based on these models offered an efficient way to predict the performance of the shutter-type VOA. The controllable attenuation range is approximately 40 dB with a driving voltage less than 0.5 V, and the driving power is less than 2 mW. A response time of 5 ms is achieved by applying proper driving waveform

A piezoresistive cantilever for lateral force detection fabricated by a monolithic post-CMOS process

International Nuclear Information System (INIS)

Ji Xu; Li Zhihong; Li Juan; Wang Yangyuan; Xi Jianzhong

2008-01-01

This paper presents a post-CMOS process to monolithically integrate a piezoresistive cantilever for lateral force detection and signal processing circuitry. The fabrication process includes a standard CMOS process and one more lithography step to micromachine the cantilever structure in the post-CMOS process. The piezoresistors are doped in the CMOS process but defined in the post-CMOS micromachining process without any extra process required. A partially split cantilever configuration is developed for the lateral force detection. The piezoresistors are self-aligned to the split cantilever, and therefore the width of the beam is only limited by lithography. Consequently, this kind of cantilever potentially has a high resolution. The preliminary experimental results show expected performances of the fabricated piezoresistors and electronic circuits

Channeling-based collimators for generation of microbeams produced by silicon micromachining technology

International Nuclear Information System (INIS)

Guidi, V.; Antonini, A.; Milan, E.; Ronzoni, A.; Martinelli, G.; Biryukov, V.M.; Chesnokov, Yu.A.

2006-01-01

The growing interest on micro-beams in recent years and the combined development of channeling technology in high-energy physics have opened the way to new concepts for micro-beams devices. Silicon micromachining technology is here applied to manufacture micro-collimators in inexpensive and feasible ways. Both dry and wet etchings can be employed for the purpose, though the latter technique appears to be cheaper and easier. Two designs for micro-collimator devices have been considered and preliminary samples have been produced accordingly

Parallel-plate submicron gap formed by micromachined low-density pillars for near-field radiative heat transfer

International Nuclear Information System (INIS)

Ito, Kota; Miura, Atsushi; Iizuka, Hideo; Toshiyoshi, Hiroshi

2015-01-01

Near-field radiative heat transfer has been a subject of great interest due to the applicability to thermal management and energy conversion. In this letter, a submicron gap between a pair of diced fused quartz substrates is formed by using micromachined low-density pillars to obtain both the parallelism and small parasitic heat conduction. The gap uniformity is validated by the optical interferometry at four corners of the substrates. The heat flux across the gap is measured in a steady-state and is no greater than twice of theoretically predicted radiative heat flux, which indicates that the parasitic heat conduction is suppressed to the level of the radiative heat transfer or less. The heat conduction through the pillars is modeled, and it is found to be limited by the thermal contact resistance between the pillar top and the opposing substrate surface. The methodology to form and evaluate the gap promotes the near-field radiative heat transfer to various applications such as thermal rectification, thermal modulation, and thermophotovoltaics

Parallel-plate submicron gap formed by micromachined low-density pillars for near-field radiative heat transfer

Energy Technology Data Exchange (ETDEWEB)

Ito, Kota, E-mail: kotaito@mosk.tytlabs.co.jp [Toyota Central Research and Development Laboratories, Nagakute, Aichi 480-1192 (Japan); Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8904 (Japan); Miura, Atsushi; Iizuka, Hideo [Toyota Central Research and Development Laboratories, Nagakute, Aichi 480-1192 (Japan); Toshiyoshi, Hiroshi [Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8904 (Japan)

2015-02-23

Near-field radiative heat transfer has been a subject of great interest due to the applicability to thermal management and energy conversion. In this letter, a submicron gap between a pair of diced fused quartz substrates is formed by using micromachined low-density pillars to obtain both the parallelism and small parasitic heat conduction. The gap uniformity is validated by the optical interferometry at four corners of the substrates. The heat flux across the gap is measured in a steady-state and is no greater than twice of theoretically predicted radiative heat flux, which indicates that the parasitic heat conduction is suppressed to the level of the radiative heat transfer or less. The heat conduction through the pillars is modeled, and it is found to be limited by the thermal contact resistance between the pillar top and the opposing substrate surface. The methodology to form and evaluate the gap promotes the near-field radiative heat transfer to various applications such as thermal rectification, thermal modulation, and thermophotovoltaics.

A Three-Dimensional Enormous Surface Area Aluminum Microneedle Array with Nanoporous Structure

OpenAIRE

Chen, Po Chun; Hsieh, Sheng Jen; Chen, Chien Chon; Zou, Jun

2013-01-01

We proposed fabricating an aluminum microneedle array with a nanochannel structure on the surface by combining micromachining, electrolyte polishing, and anodization methods. The microneedle array provides a three-dimensional (3D) structure that possesses several hundred times more surface area than a traditional nanochannel template. Therefore, the microneedle array can potentially be used in many technology applications. This 3D microneedle array device can not only be used for painless inj...

High efficiency on-chip Dielectric Resonator Antennna using micromachining technology

KAUST Repository

Sallam, Mai O.

2015-10-26

In this paper, a novel cylindrical Dielectric Resonator Antenna (DRA) operating at 60 GHz is introduced. The antenna is fabricated using a high-resistivity silicon wafer. The DR is defined in the wafer using micromachining technology. The feeding network is located at the other side of the wafer. The proposed antenna is simulated using HFSS and the results are verified by measurements. The antenna radiation is mainly along the broadside direction. The measured gain, radiation efficiency, and bandwidth are 7 dBi, 74.65%, and 2.23 GHz respectively. The antenna is characterized by high polarization purity where the maximum cross-polarization is -15 dB. © 2015 IEEE.

High efficiency on-chip Dielectric Resonator Antennna using micromachining technology

KAUST Repository

Sallam, Mai O.; Serry, Mohamed; Shamim, Atif; De Raedt, Walter; Sedky, Sherif; Vandenbosch, Guy A. E.; Soliman, Ezzeldin A.

2015-01-01

In this paper, a novel cylindrical Dielectric Resonator Antenna (DRA) operating at 60 GHz is introduced. The antenna is fabricated using a high-resistivity silicon wafer. The DR is defined in the wafer using micromachining technology. The feeding network is located at the other side of the wafer. The proposed antenna is simulated using HFSS and the results are verified by measurements. The antenna radiation is mainly along the broadside direction. The measured gain, radiation efficiency, and bandwidth are 7 dBi, 74.65%, and 2.23 GHz respectively. The antenna is characterized by high polarization purity where the maximum cross-polarization is -15 dB. © 2015 IEEE.

RF Performance of a 600-720 GHz Sideband Separating Mixer with All-Copper Micromachined Waveguide Mixer Block

NARCIS (Netherlands)

Mena, F. P.; Kooi, J.; Baryshev, A. M.; Lodewijk, C. F. J.; Klapwijk, T. M.; Wild, W.; Desmaris, V.; Meledin, D.; Pavolotsky, A.; Belitsky, V.; Wild, Wolfgang

2008-01-01

Here we report on the RF performance of a 2SB mixer (600-720 GHz) fabricated in a new method that combines traditional micromachining with waveguide components fabricated by photolithography and electroplating. The latter allows reaching, in a reproducible way, the stringent accuracies necessary for

How to optimize ultrashort pulse laser interaction with glass surfaces in cutting regimes?

Energy Technology Data Exchange (ETDEWEB)

Bulgakova, Nadezhda M., E-mail: bulgakova@fzu.cz [HiLASE Centre, Institute of Physics ASCR, Za Radnicí 828, 25241 Dolní Břežany (Czech Republic); Institute of Thermophysics SB RAS, 1 Lavrentyev Ave., Novosibirsk 630090 (Russian Federation); Zhukov, Vladimir P. [Institute of Computational Technologies SB RAS, 6 Lavrentyev Ave., 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 20 Karl Marx Ave., 630073 Novosibirsk (Russian Federation); Collins, Adam R. [NCLA, NUI Galway, Galway (Ireland); Rostohar, Danijela; Derrien, Thibault J.-Y.; Mocek, Tomáš [HiLASE Centre, Institute of Physics ASCR, Za Radnicí 828, 25241 Dolní Břežany (Czech Republic)

2015-05-01

Highlights: • The factors influencing laser micromachining of transparent materials are analyzed. • Important role of ambient gas in laser processing is shown by numerical simulations. • The large potential of bi-wavelength laser processing is demonstrated. - Abstract: The interaction of short and ultrashort pulse laser radiation with glass materials is addressed. Particular attention is paid to regimes which are important in industrial applications such as laser cutting, drilling, functionalization of material surfaces, etc. Different factors influencing the ablation efficiency and quality are summarized and their importance is illustrated experimentally. The effects of ambient gas ionization in front of the irradiated target are also analyzed. A possibility to enhance laser coupling with transparent solids by bi-wavelength irradiation is discussed.

Development of micro capacitive accelerometer for subsurface microseismic measurement; Micromachining ni yoru chika danseiha kenshutsu no tame no silicon yoryogata kasokudo sensor no seisaku

Energy Technology Data Exchange (ETDEWEB)

Nishizawa, M; Niitsuma, H; Esashi, M [Tohoku University, Sendai (Japan). Faculty of Engineering

1997-05-27

A silicon capacitive accelerometer was fabricated to detect subsurface elastic waves by using micromachining technology. Characteristics required for it call for capability of detecting acceleration with amplitudes from 0.1 to 1 gal and flat amplitude characteristics in frequency bands of 10 Hz to several kHz. For the purpose of measuring transition phenomena, linear phase characteristics in the required bands must be guaranteed, cross sensitivity must be small, and resistance to water, pressure and heat is demanded. Sensitivity of the sensor is determined finally by noise level in a detection circuit. The sensor`s minimum detection capability was 40 mgal in the case of the distance between a weight and an electrode being 3 {mu}m. This specification value is a value realizable by the current micromachining technology. Dimensions for the weight and other members were decided with the natural frequency to make band width 2 kHz set to 4 kHz. Completion of the product has not been achieved yet, however, because of a problem that the weight gets stuck on the electrode plate in anode bonding in the assembly process. 7 refs., 5 figs., 1 tab.

Structural design considerations for micromachined solid-oxide fuel cells

Science.gov (United States)

Srikar, V. T.; Turner, Kevin T.; Andrew Ie, Tze Yung; Spearing, S. Mark

Micromachined solid-oxide fuel cells (μSOFCs) are among a class of devices being investigated for portable power generation. Optimization of the performance and reliability of such devices requires robust, scale-dependent, design methodologies. In this first analysis, we consider the structural design of planar, electrolyte-supported, μSOFCs from the viewpoints of electrochemical performance, mechanical stability and reliability, and thermal behavior. The effect of electrolyte thickness on fuel cell performance is evaluated using a simple analytical model. Design diagrams that account explicitly for thermal and intrinsic residual stresses are presented to identify geometries that are resistant to fracture and buckling. Analysis of energy loss due to in-plane heat conduction highlights the importance of efficient thermal isolation in microscale fuel cell design.

Fiscal 1997 report on technological results. R and D on micromachine technology (Development of micro-factory technology); 1997 nendo micromachine gijutsu no kenkyu kaihatsu seika hokokusho. Microfactory gijutsu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-03-01

Activities are conducted in search of a micromachine system in which devices and equipment relating to machining, assembly, transportation, inspection, etc., in use for a manufacturing process are integrated in a narrow space, for the purpose of conserving energy through the miniaturization of the process of manufacturing small industrial products. With the activities in the two fields of (1) R and D of systematization technology (experimental system for micro fabrication/assembly) and (2) comprehensive investigation and research, examination on detailed specification for the experimental system was carried out, as were the examination of element technologies, element device operating experiments, technological investigation, etc.. In (1), sophistication of the element technologies was contrived that were required for realizing each experimental system, while the detailed specification of each experimental system was decided. Further, a part of the element devices was experimentally manufactured, with the basic functions verified. In (2), research studies were compiled on radio interference for example in the case where various devices were integrated and highly densified through the formation of a micro-factory; also compiled was a joint research with Agency of Industrial Science and Technology, a research conducted for the purpose of building the conception of the micro-factory. (NEDO)

Fabrication process for CMUT arrays with polysilicon electrodes, nanometre precision cavity gaps and through-silicon vias

International Nuclear Information System (INIS)

Due-Hansen, J; Poppe, E; Summanwar, A; Jensen, G U; Breivik, L; Wang, D T; Schjølberg-Henriksen, K; Midtbø, K

2012-01-01

Capacitive micromachined ultrasound transducers (CMUTs) can be used to realize miniature ultrasound probes. Through-silicon vias (TSVs) allow for close integration of the CMUT and read-out electronics. A fabrication process enabling the realization of a CMUT array with TSVs is being developed. The integrated process requires the formation of highly doped polysilicon electrodes with low surface roughness. A process for polysilicon film deposition, doping, CMP, RIE and thermal annealing that resulted in a film with sheet resistance of 4.0 Ω/□ and a surface roughness of 1 nm rms has been developed. The surface roughness of the polysilicon film was found to increase with higher phosphorus concentrations. The surface roughness also increased when oxygen was present in the thermal annealing ambient. The RIE process for etching CMUT cavities in the doped polysilicon gave a mean etch depth of 59.2 ± 3.9 nm and a uniformity across the wafer ranging from 1.0 to 4.7%. The two presented processes are key processes that enable the fabrication of CMUT arrays suitable for applications in for instance intravascular cardiology and gastrointestinal imaging. (paper)

Proton beam micromachining on strippable aqueous base developable negative resist

International Nuclear Information System (INIS)

Rajta, I.; Uzonyi, I.; Baradacs, E.; Chatzichristidi, M.; Raptis, I.; Valamontes, E.S.

2004-01-01

Complete text of publication follows. Proton Beam Micromachining (PBM, also known as P-beam writing), a novel direct- write process for the production of 3D microstructures, can be used to make multilevel structures in a single layer of resist by varying the ion energy. The interaction between the bombarding ions and the target material is mainly ionization, and very few ions suffer high angle nuclear collisions, therefore structures made with PBM have smooth near vertical side walls. The most commony applied resists in PBM are the positive, conventional, polymethyl methacrylate (PMMA); and the negative, chemically amplified, SU-8 (Micro Chem Corp). SU-8 is an epoxy based resist suitable also for LIGA and UV-LIGA processes, it offers good sensitivity, good process latitude, very high aspect ratio and therefore it dominates in the high aspect ratio micromachining applications. SU-8 requires 30 nC/mm 2 fluence for PBM irradiations at 2 MeV protons. Its crosslinking chemistry is based on the eight epoxy rings in the polymer chain, which provide a very dense three dimensional network in the presence of suitably activated photo acid generators (PAGs) which is very difficult to be stripped away after development. Thus, stripping has to be assisted with plasma processes or with special liquid removers. Moreover, the SU-8 developer is organic, propylene glycol methyl ether acetate (PGMEA), and thus environmentally non-friendly. To overcome the SU-8 stripping limitations, design of a negative resist system where solubility change is not based solely on cross- linking but also on the differentiation of hydrophilicity between exposed and non-exposed areas is desirable. A new resist formulation, fulfilling the above specifications has been developed recently [1]. This formulation is based on a specific grade epoxy novolac (EP) polymer, a partially hydrogenated poly-4-hydroxy styrene (PHS) polymer, and an onium salt as photoacid generator (PAG), and has been successfully

Micromachined On-Chip Dielectric Resonator Antenna Operating at 60 GHz

KAUST Repository

Sallam, Mai

2015-06-01

This paper presents a novel cylindrical Dielectric Resonator Antenna (DRA) suitable for millimeter-wave on-chip systems. The antenna was fabricated from a single high resistivity silicon wafer via micromachining technology. The new antenna was characterized using HFSS and experimentally with good agreement been found between the simulations and experiment. The proposed DRA has good radiation characteristics, where its gain and radiation efficiency are 7 dBi and 79.35%, respectively. These properties are reasonably constant over the working frequency bandwidth of the antenna. The return loss bandwidth was 2.23 GHz, which corresponds to 3.78% around 60 GHz. The antenna was primarily a broadside radiator with -15 dB cross polarization level.

An experimental analysis of process parameters to manufacture micro-channels in AISI H13 tempered steel by laser micro-milling

Science.gov (United States)

Teixidor, D.; Ferrer, I.; Ciurana, J.

2012-04-01

This paper reports the characterization of laser machining (milling) process to manufacture micro-channels in order to understand the incidence of process parameters on the final features. Selection of process operational parameters is highly critical for successful laser micromachining. A set of designed experiments is carried out in a pulsed Nd:YAG laser system using AISI H13 hardened tool steel as work material. Several micro-channels have been manufactured as micro-mold cavities varying parameters such as scanning speed (SS), pulse intensity (PI) and pulse frequency (PF). Results are obtained by evaluating the dimensions and the surface finish of the micro-channel. The dimensions and shape of the micro-channels produced with laser-micro-milling process exhibit variations. In general the use of low scanning speeds increases the quality of the feature in both surface finishing and dimensional.

Sapphire capillaries for laser-driven wakefield acceleration in plasma. Fs-laser micromachining and characterization

International Nuclear Information System (INIS)

Schwinkendorf, Jan-Patrick

2012-05-01

Plasma wakefields are a promising approach for the acceleration of electrons with ultrahigh (10 to 100 GV/m) electric fields. Nowadays, high-intensity laser pulses are routinely utilized to excite these large-amplitude plasma waves. However, several detrimental effects such as laser diffraction, electron-wake dephasing and laser depletion may terminate the acceleration process. Two of these phenomena can be mitigated or avoided by the application of capillary waveguides, e.g. fabricated out of sapphire for longevity. Capillaries may compensate for laser diffraction like a fiber and allow for the creation of tapered gas-density profiles working against the dephasing between the accelerating wave and the particles. Additionally, they offer the possibility of controlled particle injection. This thesis is reporting on the set up of a laser for fs-micromachining of capillaries of almost arbitrary shapes and a test stand for density-profile characterization. These devices will permit the creation of tailored gas-density profiles for controlled electron injection and acceleration inside plasma.

Sapphire capillaries for laser-driven wakefield acceleration in plasma. Fs-laser micromachining and characterization

Energy Technology Data Exchange (ETDEWEB)

Schwinkendorf, Jan-Patrick

2012-08-15

Plasma wakefields are a promising approach for the acceleration of electrons with ultrahigh (10 to 100 GV/m) electric fields. Nowadays, high-intensity laser pulses are routinely utilized to excite these large-amplitude plasma waves. However, several detrimental effects such as laser diffraction, electron-wake dephasing and laser depletion may terminate the acceleration process. Two of these phenomena can be mitigated or avoided by the application of capillary waveguides, e.g. fabricated out of sapphire for longevity. Capillaries may compensate for laser diffraction like a fiber and allow for the creation of tapered gas-density profiles working against the dephasing between the accelerating wave and the particles. Additionally, they offer the possibility of controlled particle injection. This thesis is reporting on the set up of a laser for fs-micromachining of capillaries of almost arbitrary shapes and a test stand for density-profile characterization. These devices will permit the creation of tailored gas-density profiles for controlled electron injection and acceleration inside plasma.

A Micromachined Piezoresistive Pressure Sensor with a Shield Layer

Science.gov (United States)

Cao, Gang; Wang, Xiaoping; Xu, Yong; Liu, Sheng

2016-01-01

This paper presents a piezoresistive pressure sensor with a shield layer for improved stability. Compared with the conventional piezoresistive pressure sensors, the new one reported in this paper has an n-type shield layer that covers p-type piezoresistors. This shield layer aims to minimize the impact of electrical field and reduce the temperature sensitivity of piezoresistors. The proposed sensors have been successfully fabricated by bulk-micromachining techniques. A sensitivity of 0.022 mV/V/kPa and a maximum non-linearity of 0.085% FS are obtained in a pressure range of 1 MPa. After numerical simulation, the role of the shield layer has been experimentally investigated. It is demonstrated that the shield layer is able to reduce the drift caused by electrical field and ambient temperature variation. PMID:27529254

A top-crossover-to-bottom addressed segmented annular array using piezoelectric micromachined ultrasonic transducers

Science.gov (United States)

Jung, Joontaek; Lee, Wonjun; Kang, Woojin; Hong, Hyeryung; Yuen Song, Hi; Oh, Inn-yeal; Park, Chul Soon; Choi, Hongsoo

2015-11-01

We design and fabricate segmented annular arrays (SAAs) using piezoelectric micromachined ultrasonic transducers (pMUTs) to demonstrate the feasibility of acoustic focusing of ultrasound. The fabricated SAAs have 25 concentric top-electrode signal lines and eight bottom-electrodes for grounding to enable electronic steering of selectively grouped ultrasonic transducers from 2393 pMUT elements. Each element in the array is connected by top-crossover-to-bottom metal bridges, which reduce the parasitic capacitance. Circular-shaped pMUT elements, 120 μm in diameter, are fabricated using 1 μm-thick sol-gel lead zirconate titanate on a silicon wafer. To utilize the high-density pMUT array, a deep reactive ion etching process is used for anisotropic silicon etching to realize the transducer membranes. The resonant frequency and effective coupling coefficient of the elements, measured with an impedance analyzer, yields 1.517 MHz and 1.29%, respectively, in air. The SAAs using pMUTs are packaged on a printed circuit board and coated with parylene C for acoustic intensity measurements in water. The ultrasound generated by each segmented array is focused on a selected point in space. When a 5 Vpp, 1.5 MHz square wave is applied, the maximum spatial peak temporal average intensity ({{I}\\text{spta}} ) is found to be 79 mW cm-2 5 mm from the SAAs’ surface without beamforming. The beam widths (-3 dB) of ultrasonic radiation patterns in the elevation and azimuth directions are recorded as 3 and 3.4 mm, respectively. The results successfully show the feasibility of focusing ultrasound on a small area with SAAs using pMUTs.

Utilization of the UV laser with picosecond pulses for the formation of surface microstructures on elastomeric plastics

Science.gov (United States)

Antoszewski, B.; Tofil, S.; Scendo, M.; Tarelnik, W.

2017-08-01

Elastomeric plastics belong to a wide range of polymeric materials with special properties. They are used as construction material for seals and other components in many branches of industry and, in particular, in the biomedical industry, mechatronics, electronics and chemical equipment. The micromachining of surfaces of these materials can be used to build micro-flow, insulating, dispensing systems and chemical and biological reactors. The paper presents results of research on the effects of micro-machining of selected elastomeric plastics using a UV laser emitting picosecond pulses. The authors see the prospective application of the developed technology in the sealing technique in particular to shaping the sealing pieces co-operating with the surface of the element. The result of the study is meant to show parameters of the UV laser’s performance when producing typical components such as grooves, recesses for optimum ablation in terms of quality and productivity.

Achievement report for fiscal 1996 on the research and development of micromachine technology. Development of advanced-function maintenance technology for power generation facilities; 1996 nendo micromachine gijutsu no kenkyu kaihatsu seika hokokusho. Hatsuden shisetsuyo kokino maintenance gijutsu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

Technologies for integrating functions are studied for a self-propelled surroundings recognition system that travels in a small-diameter tube at power generation facilities. Parameters are analyzed, and piezoelectric locomotion devices are reduced in size. A disk shape microantenna is experimentally built and evaluated, which is for realizing energy supply and communication by means of microwaves. Studies are conducted to improve the performance of optical energy transmission devices and to realize their systematization. Basic specifications are established for the embodiment of CCD (charge coupled device) microcameras to be installed. A high-efficiency, high-reliability micromachine system is constructed, in which multiple machines coordinate with each other for the exterior inspection of groups of small-diameter tubes. Devices which are capable of driving, deceleration, and propulsion prove to be feasible. Basic specifications are established for microconnectors to connect, separate, and combine multiple machines as occasion calls. Also discussed is the development of a micromachine for tube interior check and repair which operates making use of the inspection hole enabling tube interior check and repair without the need of disassembling the equipment to be repaired.

Determination of young's modulus of PZT and CO80Ni20 thin films by means of micromachined cantilevers

NARCIS (Netherlands)

Nazeer, H.; Abelmann, Leon; Tas, Niels Roelof; van Honschoten, J.W.; Siekman, Martin Herman; Elwenspoek, Michael Curt

2009-01-01

This paper presents a technique to determine the Young’s modulus and residual stress of thin films using a simple micromachined silicon cantilever as the test structure. An analytical relation was developed based on the shift in resonance frequency caused by the addition of a thin film on the

Design and fabrication of PMMA-micromachined fluid lens based on electromagnetic actuation on PMMA–PDMS bonded membrane

International Nuclear Information System (INIS)

Lee, June Kyoo; Park, Kyung-Woo; Choi, Ju Chan; Kim, Hak-Rin; Kong, Seong Ho

2012-01-01

The fabrication of a poly(methyl methacrylate) (PMMA)-micromachined fluid lens with an optimally designed built-in electromagnetic actuator was demonstrated in this study. Through a finite element method, the number of winding turns and the distance between magnetic moments were estimated to design an effective and miniaturized electromagnetic actuator. The lens body composed of PMMA structures was simply and rapidly micromachined using computer numerical control micro-milling. The poly(dimethylsiloxane) (PDMS) membranes for electromagnetic actuation were bonded to the PMMA structures by using the proposed PMMA–PDMS bonding technique, which uses an SiO 2 intermediate layer. A physical repulsive force produced by the electromagnetic actuator applies a controllable fluidic pressure to a fluidic chamber that is sealed with the PDMS membrane, thus allowing dynamic focusing. The focus tunability of the fabricated lens was 67 diopters with a focus hysteresis of less than 1 mm and a response time of 2 ms. The solenoid of the built-in actuator showed negligible thermal crosstalk to the lens. (paper)

Fabrication of Microhotplates Based on Laser Micromachining of Zirconium Oxide

Science.gov (United States)

Oblov, Konstantin; Ivanova, Anastasia; Soloviev, Sergey; Samotaev, Nikolay; Lipilin, Alexandr; Vasiliev, Alexey; Sokolov, Andrey

We present a novel approach to the fabrication of MEMS devices, which can be used for gas sensors operating in harsh environment in wireless and autonomous information systems. MEMS platforms based on ZrO2/Y2O3 (YSZ) are applied in these devices. The methods of ceramic MEMS devices fabrication with laser micromachining are considered. It is shown that the application of YSZ membranes permits a decrease in MEMS power consumption at 4500C down to ∼75 mW at continuous heating and down to ∼ 1 mW at pulse heating mode. The application of the platforms is not restricted by gas sensors: they can be used for fast thermometers, bolometric matrices, flowmeteres and other MEMS devices working under harsh environmental conditions.

A bulk micromachined lead zinconate titanate cantilever energy harvester with inter-digital IrO(x) electrodes.

Science.gov (United States)

Park, Jongcheol; Park, Jae Yeong

2013-10-01

A piezoelectric vibration energy harvester with inter-digital IrO(x) electrode was developed by using silicon bulk micromachining technology. Most PZT cantilever based energy harvesters have utilized platinum electrode material. However, the PZT fatigue characteristics and adhesion/delamination problems caused by the platinum electrode might be serious problem in reliability of energy harvester. To address these problems, the iridium oxide was newly applied. The proposed energy harvester was comprised of bulk micromachined silicon cantilever with 800 x 1000 x 20 microm3, which having a silicon supporting membrane, sol-gel-spin coated Pb(Zr52, Ti48)O3 thin film, and sputtered inter-digitally shaped IrO(x) electrodes, and silicon inertial mass with 1000 x 1000 x 500 microm3 to adjust its resonant frequency. The fabricated energy harvester generated 1 microW of electrical power to 470 komega of load resistance and 1.4 V(peak-to-peak) from a vibration of 0.4 g at 1.475 kHz. The corresponding power density was 6.25 mW x cm(-3) x g(-2). As expected, its electrical failure was significantly improved.

193nm high power lasers for the wide bandgap material processing

Science.gov (United States)

Fujimoto, Junichi; Kobayashi, Masakazu; Kakizaki, Koji; Oizumi, Hiroaki; Mimura, Toshio; Matsunaga, Takashi; Mizoguchi, Hakaru

2017-02-01

Recently infrared laser has faced resolution limit of finer micromachining requirement on especially semiconductor packaging like Fan-Out Wafer Level Package (FO-WLP) and Through Glass Via hole (TGV) which are hard to process with less defect. In this study, we investigated ablation rate with deep ultra violet excimer laser to explore its possibilities of micromachining on organic and glass interposers. These results were observed with a laser microscopy and Scanning Electron Microscope (SEM). As the ablation rates of both materials were quite affordable value, excimer laser is expected to be put in practical use for mass production.

Design and Fabrication of Piezoresistive Based Encapsulated Poly-Si Cantilevers for Bio/chemical Sensing

Science.gov (United States)

Krishna, N. P. Vamsi; Murthy, T. R. Srinivasa; Reddy, K. Jayaprakash; Sangeeth, K.; Hegde, G. M.

Cantilever-based sensing is a growing research field not only within micro regime but also in nano technology. The technology offers a method for rapid, on-line and in-situ monitoring of specific bio/chemical substances by detecting the nanomechanical responses of a cantilever sensor. Cantilever with piezoresistive based detection scheme is more attractive because of its electronics compatibility. Majority of commercially available micromachined piezoresistive sensors are bulk micromachined devices and are fabricated using single crystal silicon wafers. As substrate properties are not important in surface micromachining, the expensive silicon wafers can be replaced by cheaper substrates, such as poly-silicon, glass or plastic. Here we have designed SU-8 based bio/chemical compatible micro electro mechanical device that includes an encapsulated polysilicon piezoresistor for bio/chemical sensing. In this paper we report the design, fabrication and analysis of the encapsulated poly-Si cantilevers. Design and theoretical analysis are carried out using Finite Element Analysis software. For fabrication of poly-silicon piezoresistive cantilevers we followed the surface micromachining process steps. Preliminary characterization of the cantilevers is presented.

Applications of picosecond lasers and pulse-bursts in precision manufacturing

Science.gov (United States)

Knappe, Ralf

2012-03-01

Just as CW and quasi-CW lasers have revolutionized the materials processing world, picosecond lasers are poised to change the world of micromachining, where lasers outperform mechanical tools due to their flexibility, reliability, reproducibility, ease of programming, and lack of mechanical force or contamination to the part. Picosecond lasers are established as powerful tools for micromachining. Industrial processes like micro drilling, surface structuring and thin film ablation benefit from a process, which provides highest precision and minimal thermal impact for all materials. Applications such as microelectronics, semiconductor, and photovoltaic industries use picosecond lasers for maximum quality, flexibility, and cost efficiency. The range of parts, manufactured with ps lasers spans from microscopic diamond tools over large printing cylinders with square feet of structured surface. Cutting glass for display and PV is a large application, as well. With a smart distribution of energy into groups of ps-pulses at ns-scale separation (known as burst mode) ablation rates can be increased by one order of magnitude or more for some materials, also providing a better surface quality under certain conditions. The paper reports on the latest results of the laser technology, scaling of ablation rates, and various applications in ps-laser micromachining.

Heavy ion beam micromachining on LiNbO3

International Nuclear Information System (INIS)

Nesprias, F.; Venturino, M.; Debray, M.E.; Davidson, J.; Davidson, M.; Kreiner, A.J.; Minsky, D.; Fischer, M.; Lamagna, A.

2009-01-01

In this work 3D micromachining of x-cut lithium niobate crystals was performed using the high energy heavy ion microbeam (HIM) at the Tandar Laboratory, Buenos Aires. The samples were machined using 35 Cl beams at 70 MeV bombarding energy combined with wet etching with hydrofluoric acid solutions at room temperature. As the ion beam penetrates the sample, it induces lattice damage increasing dramatically the local etching rate of the material. This technique was applied to the fabrication of 3D waveguides with long control electrodes. The resulting structures indicate that well defined contours with nearly vertical sidewalls can be made. The results also show that with fluences of only 5 x 10 12 ions/cm 2 , this technique is suitable for the fabrication of different shapes of LiNbO 3 control-waveguides that can be used in different optical devices and matched with the existing optical fibers.

Surface Energy and Setting Process of Contacting Surfaces

Directory of Open Access Journals (Sweden)

M. V. Musokhranov

2014-01-01

Full Text Available The paper deals with a challenge in terms of ensuring an accuracy of the relative position of the conjugated surfaces that is to determine a coefficient of friction. To solve it, there is a proposal to use the surface energy, as a tool that influences the contacting parts nature. Presently, energy of the surface layers at best is only stated, but not used in practice.Analysis of the conditions of interaction between two contacting surfaces, such as seizing and setting cannot be explained only from the position of the roughness parameters. It is found that these phenomena are explained by the appearing gripe (setting bridges, which result from the energy of interaction between two or more adjacent surfaces. The emerging phenomenon such as micro welding, i.e. occurring bonds, is caused by the overflow of energy, according to the theory of physics, from the surface with a high level of energy to the surface with the smaller one to balance the system as a whole.The paper shows that through the use of process, controlling the depth of the surface layer and creating a certain structure, the energy level of the material as a whole can be specified. And this will allow us to provide the necessary performance and mechanical properties. It means to create as many gripe bridges as possible to ensure continuous positioning i.e. a fixed connection of the contacting surfaces.It was determined that to increase a value of the friction coefficient, the physical and mechanical properties of the surface layer of the parts material must be taken into account, namely, in the part body accumulate the energy to be consumed for forming the surface.The paper gives recommendations for including the parts of the surface energy in the qualitative indicators of characteristics. This will make a technologist, when routing a process, to choose such operations and modes to provide the designer-specified parameters not only of the accuracy and surface finish, but also of the

Post-CMOS Micromachining of Surface and Bulk Structures

Science.gov (United States)

2002-05-06

Structures iii Acknowledgements I would like to thank my advisors, Professor Gary K. Fedder and Professor Dave W. Greve, for their continuing support...Donnelly, Plasma Chem. Plasma Process, vol. 1, pp. 37, 1981. [54] J. L. Mauer, J. S. Logan, L. B. Zielinski , and G. S. Schwartz, J. Vac. Sci. Technol

Earth Surface Processes, Landforms and Sediment Deposits

Science.gov (United States)

Bridge, John; Demicco, Robert

Earth surface processes, landforms and sediment deposits are intimately related - involving erosion of rocks, generation of sediment, and transport and deposition of sediment through various Earth surface environments. These processes, and the landforms and deposits that they generate, have a fundamental bearing on engineering, environmental and public safety issues; on recovery of economic resources; and on our understanding of Earth history. This unique textbook brings together the traditional disciplines of sedimentology and geomorphology to explain Earth surface processes, landforms and sediment deposits in a comprehensive and integrated way. It is the ideal resource for a two-semester course in sedimentology, stratigraphy, geomorphology, and Earth surface processes from the intermediate undergraduate to beginning graduate level. The book is also accompanied by a website hosting illustrations and material on field and laboratory methods for measuring, describing and analyzing Earth surface processes, landforms and sediments.

Surface studies of plasma processed Nb samples

International Nuclear Information System (INIS)

Tyagi, Puneet V.; Doleans, Marc; Hannah, Brian S.; Afanador, Ralph; Stewart, Stephen; Mammosser, John; Howell, Matthew P; Saunders, Jeffrey W; Degraff, Brian D; Kim, Sang-Ho

2015-01-01

Contaminants present at top surface of superconducting radio frequency (SRF) cavities can act as field emitters and restrict the cavity accelerating gradient. A room temperature in-situ plasma processing technology for SRF cavities aiming to clean hydrocarbons from inner surface of cavities has been recently developed at the Spallation Neutron Source (SNS). Surface studies of the plasma-processed Nb samples by Secondary ion mass spectrometry (SIMS) and Scanning Kelvin Probe (SKP) showed that the NeO_2 plasma processing is very effective to remove carbonaceous contaminants from top surface and improves the surface work function by 0.5 to 1.0 eV.

Progress in ultrafast laser processing and future prospects

Science.gov (United States)

Sugioka, Koji

2017-03-01

The unique characteristics of ultrafast lasers have rapidly revolutionized materials processing after their first demonstration in 1987. The ultrashort pulse width of the laser suppresses heat diffusion to the surroundings of the processed region, which minimizes the formation of a heat-affected zone and thereby enables ultrahigh precision micro- and nanofabrication of various materials. In addition, the extremely high peak intensity can induce nonlinear multiphoton absorption, which extends the diversity of materials that can be processed to transparent materials such as glass. Nonlinear multiphoton absorption enables three-dimensional (3D) micro- and nanofabrication by irradiation with tightly focused femtosecond laser pulses inside transparent materials. Thus, ultrafast lasers are currently widely used for both fundamental research and practical applications. This review presents progress in ultrafast laser processing, including micromachining, surface micro- and nanostructuring, nanoablation, and 3D and volume processing. Advanced technologies that promise to enhance the performance of ultrafast laser processing, such as hybrid additive and subtractive processing, and shaped beam processing are discussed. Commercial and industrial applications of ultrafast laser processing are also introduced. Finally, future prospects of the technology are given with a summary.

Superhydrophobic surfaces by electrochemical processes.

Science.gov (United States)

Darmanin, Thierry; Taffin de Givenchy, Elisabeth; Amigoni, Sonia; Guittard, Frederic

2013-03-13

This review is an exhaustive representation of the electrochemical processes reported in the literature to produce superhydrophobic surfaces. Due to the intensive demand in the elaboration of superhydrophobic materials using low-cost, reproducible and fast methods, the use of strategies based on electrochemical processes have exponentially grown these last five years. These strategies are separated in two parts: the oxidation processes, such as oxidation of metals in solution, the anodization of metals or the electrodeposition of conducting polymers, and the reduction processed such as the electrodeposition of metals or the galvanic deposition. One of the main advantages of the electrochemical processes is the relative easiness to produce various surface morphologies and a precise control of the structures at a micro- or a nanoscale. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

UV laser micromachining of piezoelectric ceramic using a pulsed Nd:YAG laser

International Nuclear Information System (INIS)

Zeng, D.W.; Xie, C.S.; Li, K.; Chan, H.L.W.; Choy, C.L.; Yung, K.C.

2004-01-01

UV laser (λ=355 nm) ablation of piezoelectric lead zirconate titanate (PZT) ceramics in air has been investigated under different laser parameters. It has been found that there is a critical pulse number (N=750). When the pulse number is smaller than the critical value, the ablation rate decreases with increasing pulse number. Beyond the critical value, the ablation rate becomes constant. The ablation rate and concentrations of O, Zr and Ti on the ablated surface increase with the laser fluence, while the Pb concentration decreases due to the selective evaporation of PbO. The loss of the Pb results in the formation of a metastable pyrochlore phase. ZrO 2 was detected by XPS in the ablated zone. Also, the concentrations of the pyrochlore phase and ZrO 2 increase with increasing laser fluence. These results clearly indicate that the chemical composition and phase structure in the ablated zone strongly depend on the laser fluence. The piezoelectric properties of the cut PZT ceramic samples completely disappear due to the loss of the Pb and the existence of the pyrochlore phase. After these samples were annealed at 1150 C for 1 h in a PbO-controlled atmosphere, their phase structure and piezoelectric properties were recovered again. Finally, 1-3 and concentric-ring 2-2 PZT/epoxy composites were fabricated by UV laser micromachining and their thickness modes were measured by impedance spectrum analysis and a d 33 meter. Both composites show high piezoelectric properties. (orig.)

A fully packaged micromachined single crystalline resonant force sensor

Energy Technology Data Exchange (ETDEWEB)

Cavalloni, C.; Gnielka, M.; Berg, J. von [Kistler Instrumente AG, Winterthur (Switzerland); Haueis, M.; Dual, J. [ETH Zuerich, Inst. of Mechanical Systems, Zuerich (Switzerland); Buser, R. [Interstate Univ. of Applied Science Buchs, Buchs (Switzerland)

2001-07-01

In this work a fully packaged resonant force sensor for static load measurements is presented. The working principle is based on the shift of the resonance frequency in response to the applied load. The heart of the sensor, the resonant structure, is fabricated by micromachining using single crystalline silicon. To avoid creep and hysteresis and to minimize temperature induced stress the resonant structure is encapsulated using an all-in-silicon solution. This means that the load coupling, the excitation of the microresonator and the detection of the oscillation signal are integrated in only one single crystalline silicon chip. The chip is packaged into a specially designed housing made of steel which has been designed with respect to application in harsh environments. The unloaded sensor has an initial frequency of about 22,5 kHz. The sensitivity amounts to 26 Hz/N with a linearity error significantly less than 0,5%FSO. (orig.)

Micromachined force sensors using thin film nickel–chromium piezoresistors

International Nuclear Information System (INIS)

Nadvi, Gaviraj S; Butler, Donald P; Çelik-Butler, Zeynep; Gönenli, İsmail Erkin

2012-01-01

Micromachined force/tactile sensors using nickel–chromium piezoresistors have been investigated experimentally and through finite-element analysis. The force sensors were designed with a suspended aluminum oxide (Al 2 O 3 ) membrane and optimally placed piezoresistors to measure the strain in the membrane when deflected with an applied force. Different devices, each with varying size and shape of both the membrane and the piezoresistors, were designed, fabricated and characterized. The piezoresistors were placed into a half-Wheatstone bridge configuration with two active and two passive nickel–chromium resistors to provide temperature drift compensation. The force sensors were characterized using a load cell and a nanopositioner to measure the sensor response with applied load. Piezoresistive gauge factors in the range of 1–5.2 have been calculated for the thin film nichrome (NiCr 80/20 wt%) from the measured results. The force sensors were calculated to have a noise equivalent force of 65–245 nN. (paper)

Performance Enhancement of the Patch Antennas Applying Micromachining Technology

Directory of Open Access Journals (Sweden)

Mohamed N. Azermanesh

2007-09-01

Full Text Available This paper reports on the application of micromachining technology for performance enhancement of two types of compact antennas which are becoming a common practice in microsystems. Shorted patch antennas (SPA and folded shorted patch antennas operating in the 5-6 GHz ISM band, with intended application in short-range wireless communications, are considered. The electrical length of antennas are modified by etching the substrate of the antennas, thus providing a new degree of freedom to control the antenna operating properties, which is the main novelty of our work. The gain and bandwidth of the antennas are increased by increasing the etching depth. However, etching the substrate affects the operating frequency as well. To keep the operating frequency at a pre-specified value, the dimension of the antennas must be increased by deepening the etching depth. Therefore, a trade off between the performance enhancement of the antennas and the dimensional enlargement is required.

Micro-machinable polymer-derived ceramic sensors for high-temperature applications

Science.gov (United States)

Liu, Jian; Xu, Chengying; An, Linan

2010-04-01

Micro-sensors are highly desired for on-line temperature/pressure monitoring in turbine engines to improve their efficiency and reduce pollution. The biggest challenge for developing this type of sensors is that the sensors have to sustain at extreme environments in turbine engine environments, such as high-temperatures (>800 °C), fluctuated pressure and oxidation/corrosion surroundings. In this paper, we describe a class of sensors made of polymer-derived ceramics (PDCs) for such applications. PDCs have the following advantages over conventional ceramics, making them particularly suitable for these applications: (i) micromachining capability, (ii) tunable electric properties, and (iii) hightemperature capability. Here, we will discuss the materials and their properties in terms of their applications for hightemperature micro-sensors, and microfabrication technologies. In addition, we will also discuss the design of a heat-flux sensor based on polymer-derived ceramics.

Sensors and Micromachined Devices for the Automotive and New Markets: The Delphi Delco Electronics MEMS Story.

Science.gov (United States)

Logsdon, James

2002-03-01

This presentation will provide a brief history of the development of MEMS products and technology, beginning with the manifold absolute pressure sensor in the late seventies through the current variety of Delphi Delco Electronics sensors available today. The technology development of micromachining from uncompensated P plus etch stops to deep reactive ion etching and the technology development of wafer level packaging from electrostatic bonding to glass frit sealing and silicon to silicon direct bonding will be reviewed.

A Novel Silicon Micromachined Integrated MCM Thermal Management System

Science.gov (United States)

Kazmierczak, M. J.; Henderson, H. T.; Gerner, F. M.

1997-01-01

"Micromachining" is a chemical means of etching three-dimensional structures, typically in single- crystalline silicon. These techniques are leading toward what is coming to be referred to as MEMS (Micro Electro Mechanical Systems), where in addition to the ordinary two-dimensional (planar) microelectronics, it is possible to build three-dimensional n-ticromotors, electrically- actuated raicrovalves, hydraulic systems and much more on the same microchip. These techniques become possible because of differential etching rates of various crystallographic planes and materials used for semiconductor n-ticrofabfication. The University of Cincinnati group in collaboration with Karl Baker at NASA Lewis were the first to form micro heat pipes in silicon by the above techniques. Current work now in progress using MEMS technology is now directed towards the development of the next generation in MCM (Multi Chip Module) packaging. Here we propose to develop a complete electronic thermal management system which will allow densifica6on in chip stacking by perhaps two orders of magnitude. Furthermore the proposed technique will allow ordinary conu-nercial integrated chips to be utilized. Basically, the new technique involves etching square holes into a silicon substrate and then inserting and bonding commercially available integrated chips into these holes. For example, over a 100 1/4 in. by 1 /4 in. integrated chips can be placed on a 4 in. by 4 in. silicon substrate to form a Multi-Chip Module (MCM). Placing these MCM's in-line within an integrated rack then allows for three-diniensional stacking. Increased miniaturization of microelectronic circuits will lead to very high local heat fluxes. A high performance thermal management system will be specifically designed to remove the generated energy. More specifically, a compact heat exchanger with milli / microchannels will be developed and tested to remove the heat through the back side of this MCM assembly for moderate and high

Micromachining of Al₂O₃-TiC ceramics by excimer laser

Directory of Open Access Journals (Sweden)

Oliveira, V.

1998-04-01

Full Text Available Micromachining of Al₂O₃-TiC ceramic using a KrF excimer laser was studied in the fluence range 2 to 8 J/cm² . The ablation rate decreases and the roughness increases with the first pulses but after about 200 pulses the process reaches a stationary stage where both roughness and ablation rate become constant. Observation of the processed areas by scanning electron microscopy showed that a globular topography is formed during the first stage and that the surface topography remains unchanged with further pulses. This globular topography is responsible for the variation of roughness and ablation rate observed during the first stage. EDS analysis showed that the globular features present an external region with higher titanium content and a core formed of unaffected material.

Se estudia el micromecanizado de cerámicas Al₂O₃-TiC mediante un láser de excímero de KrF con un rango de fluencia de 2 a 8 J/cm² . La velocidad de ablación disminuye y la rugosidad aumenta con los primeros pulsos. Sin embargo, después de 200 pulsos, el proceso alcanza el régimen estacionario, donde tanto la rugosidad como la velocidad de ablación permanecen constantes. La observación mediante SEM de determinadas áreas mostraban una topografía globular formada durante la primera etapa, mientras que con los siguientes pulsos permanece in cambios. Esta topografía globular es responsable de la variación de rugosidad y de la velocidad de ablación observada durante las primeras etapas del proceso. Los análisis de EDS sobre las zonas globulares mostraron la existencia de una región externa rica en titanio y un núcleo formado por el material sin afectar.

Experimental and theoretical analysis of defocused CO2 laser microchanneling on PMMA for enhanced surface finish

Science.gov (United States)

Prakash, Shashi; Kumar, Subrata

2017-02-01

The poor surface finish of CO2 laser-micromachined microchannel walls is a major limitation of its utilization despite several key advantages, like low fabrication cost and low time consumption. Defocused CO2 laser beam machining is an effective solution for fabricating smooth microchannel walls on polymer and glass substrates. In this research work, the CO2 laser microchanneling process on PMMA has been analyzed at different beam defocus positions. Defocused processing has been investigated both theoretically and experimentally, and the depth of focus and beam diameter have been determined experimentally. The effect of beam defocusing on the microchannel width, depth, surface roughness, heat affected zone and microchannel profile were examined. A previously developed analytical model for microchannel depth prediction has been improved by incorporating the threshold energy density factor. A semi-analytical model for predicting the microchannel width at different defocus positions has been developed. A semi-empirical model has also been developed for predicting microchannel widths at different defocusing conditions for lower depth values. The developed models were compared and verified by performing actual experiments. Multi-objective optimization was performed to select the best optimum set of input parameters for achieving the desired surface roughness.

A novel prototyping method for die-level monolithic integration of MEMS above-IC

International Nuclear Information System (INIS)

Cicek, Paul-Vahe; Zhang, Qing; Saha, Tanmoy; Mahdavi, Sareh; Allidina, Karim; Gamal, Mourad El; Nabki, Frederic

2013-01-01

This work presents a convenient and versatile prototyping method for integrating surface-micromachined microelectromechanical systems (MEMS) directly above IC electronics, at the die level. Such localized implementation helps reduce development costs associated with the acquisition of full-sized semiconductor wafers. To demonstrate the validity of this method, variants of an IC-compatible surface-micromachining MEMS process are used to build different MEMS devices above a commercial transimpedance amplifier chip. Subsequent functional assessments for both the electronics and the MEMS indicate that the integration is successful, validating the prototyping methodology presented in this work, as well as the suitability of the selected MEMS technology for above-IC integration. (paper)

Modeling, Fabrication and Testing of a Customizable Micromachined Hotplate for Sensor Applications.

Science.gov (United States)

Tommasi, Alessio; Cocuzza, Matteo; Perrone, Denis; Pirri, Candido Fabrizio; Mosca, Roberto; Villani, Marco; Delmonte, Nicola; Zappettini, Andrea; Calestani, Davide; Marasso, Simone Luigi

2016-12-30

In the sensors field the active sensing material frequently needs a controlled temperature in order to work properly. In microsystems technology, micro-machined hotplates represent a platform consisting of a thin suspended membrane where the sensing material can be deposited, usually integrating electrical stimuli and temperature readout. The micro-hotplate ensures a series of advantages such as miniaturized size, fast response, high sensitivity, low power consumption and selectivity for chemical sensing. This work compares the coplanar and the buried approach for the micro-hotplate heaters design with the aim to optimize the fabrication process and to propose a guideline for the choice of the suitable design with respect to the applications. In particular, robust Finite Element Method (FEM) models are set up in order to predict the electrical and thermal behavior of the micro-hotplates. The multiphysics approach used for the simulation allows to match as close as possible the actual device to the predictive model: geometries, materials, physics have been carefully linked to the fabricated devices to obtain the best possible accuracy. The materials involved in the fabrication process are accurately selected in order to improve the yield of the process and the performance of the devices. The fabricated micro-hotplates are able to warm the active region up to 400 °C (with a corresponding power consumption equal to 250 mW @ 400 °C) with a uniform temperature distribution in the buried micro-hotplate and a controlled temperature gradient in the coplanar one. A response time of about 70 ms was obtained on the virtual model, which perfectly agrees with the one measured on the fabricated device. Besides morphological, electrical and thermal characterizations, this work includes reliability tests in static and dynamic modes.

Modeling, Fabrication and Testing of a Customizable Micromachined Hotplate for Sensor Applications

Directory of Open Access Journals (Sweden)

Alessio Tommasi

2016-12-01

Full Text Available In the sensors field the active sensing material frequently needs a controlled temperature in order to work properly. In microsystems technology, micro-machined hotplates represent a platform consisting of a thin suspended membrane where the sensing material can be deposited, usually integrating electrical stimuli and temperature readout. The micro-hotplate ensures a series of advantages such as miniaturized size, fast response, high sensitivity, low power consumption and selectivity for chemical sensing. This work compares the coplanar and the buried approach for the micro-hotplate heaters design with the aim to optimize the fabrication process and to propose a guideline for the choice of the suitable design with respect to the applications. In particular, robust Finite Element Method (FEM models are set up in order to predict the electrical and thermal behavior of the micro-hotplates. The multiphysics approach used for the simulation allows to match as close as possible the actual device to the predictive model: geometries, materials, physics have been carefully linked to the fabricated devices to obtain the best possible accuracy. The materials involved in the fabrication process are accurately selected in order to improve the yield of the process and the performance of the devices. The fabricated micro-hotplates are able to warm the active region up to 400 °C (with a corresponding power consumption equal to 250 mW @ 400 °C with a uniform temperature distribution in the buried micro-hotplate and a controlled temperature gradient in the coplanar one. A response time of about 70 ms was obtained on the virtual model, which perfectly agrees with the one measured on the fabricated device. Besides morphological, electrical and thermal characterizations, this work includes reliability tests in static and dynamic modes.

Quantitative Modeling of Earth Surface Processes

Science.gov (United States)

Pelletier, Jon D.

This textbook describes some of the most effective and straightforward quantitative techniques for modeling Earth surface processes. By emphasizing a core set of equations and solution techniques, the book presents state-of-the-art models currently employed in Earth surface process research, as well as a set of simple but practical research tools. Detailed case studies demonstrate application of the methods to a wide variety of processes including hillslope, fluvial, aeolian, glacial, tectonic, and climatic systems. Exercises at the end of each chapter begin with simple calculations and then progress to more sophisticated problems that require computer programming. All the necessary computer codes are available online at www.cambridge.org/9780521855976. Assuming some knowledge of calculus and basic programming experience, this quantitative textbook is designed for advanced geomorphology courses and as a reference book for professional researchers in Earth and planetary science looking for a quantitative approach to Earth surface processes. More details...

Fiscal 1993 report on technological results. R and D on micromachine technology; 1993 nendo micro machine gijutsu no kenkyu kaihatsu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-12-01

Researches on basic element technology of micromachines are conducted with the view of establishing a mechanical system constituted of minute functional elements that perform autonomous operations in a narrow small part of complicated equipment in a power station for example or in a living body. The areas of activity are 1. research on micro actuators and 2. research on basic technology of micromachine; 1 is classified into researches of (1) shape-memory actuator, (2) bending and stretching type actuator, and (3) integrated micro actuator, while 2 is classified into researches of (1) total system for medical diagnosis, (2) micro tactile sensing technology and laser applied diagnosis/treatment technology, and (3) blood pressure/blood circulation sensing technology. In 1-(1), a chemo-mechanical actuator was studied using a shape memory alloy (SMA) and a high polymer gel, and in 1-(2), an SMA and bimetal were employed as a source of the driving force. Further, examination was also made on a fluid driving type actuator. (NEDO)

Two Capacitive Micro-Machined Ultrasonic Transducers for Wind Speed Measurement.

Science.gov (United States)

Bui, Gia Thinh; Jiang, Yu-Tsung; Pang, Da-Chen

2016-06-02

This paper presents a new wind speed measurement method using a single capacitive micro-machined ultrasonic transducer (CMUT). The CMUT was arranged perpendicular to the direction of the wind flow, and a reflector was set up a short distance away, facing the CMUT. To reduce the size, weight, cost, and power consumption of conventional ultrasonic anemometers this study proposes two CMUT designs for the measurement of wind speed using either the amplitude of the signal or the time of flight (TOF). Each CMUT with a double array element design can transmit and receive signals in five different operation modes. Experiments showed that the two CMUT designs utilizing the TOF were better than those utilizing the amplitude of the signal for wind speed measurements ranging from 1 m/s to 10 m/s, providing a measurement error of less than 0.2 m/s. These results indicate that the sensitivity of the TOF is independent of the five operation modes.

Corporate array of micromachined dipoles on silicon wafer for 60 GHz communication systems

KAUST Repository

Sallam, M. O.

2013-03-01

In this paper, an antenna array operating at 60 GHz and realized on 0.675 mm thick silicon substrate is presented. The array is constructed using four micromachined half-wavelength dipoles fed by a corporate feeding network. Isolation between the antenna array and its feeding network is achieved via a ground plane. This arrangement leads to maximizing the broadside radiation with relatively high front-to-back ratio. Simulations have been carried out using both HFSS and CST, which showed very good agreement. Results reveal that the proposed antenna array has good radiation characteristics, where the directivity, gain, and radiation efficiency are around 10.5 dBi, 9.5 dBi, and 79%, respectively. © 2013 IEEE.

Radon transport processes below the earth's surface

International Nuclear Information System (INIS)

Wilkening, M.

1980-01-01

Processes by which 222 Rn is transported from the soil to the earth's surface are reviewed. The mechanisms effective in transporting 222 Rn to the surface are related to the size and configuration of the spaces occupied by the soil gas which may vary from molecular interstices to large underground caverns. The near-surface transport processes are divided into two categories: (1) a microscopic process that includes molecular diffusion and viscous flow in fine capillaries and (2) macroscopic flow in fissures and channels. Underground air rich in 222 Rn can also reach the surface through cracks, fissures, and underground channels. This type of transport is shown for (1) a horizontal tunnel penetrating a fractured hillside, (2) a large underground cave, and (3) volcanic activity. Pressure differentials having various natural origins and thermal gradients are responsible for the transport in these examples. 222 Rn transport by ordinary molecular diffusion appears to be the dominant process

Surface-Assisted Dynamic Search Processes.

Science.gov (United States)

Shin, Jaeoh; Kolomeisky, Anatoly B

2018-03-01

Many chemical and biological systems exhibit intermittent search phenomena when participating particles alternate between dynamic regimes with different dimensionalities. Here we investigate theoretically a dynamic search process of finding a small target on a two-dimensional surface starting from a bulk solution, which is an example of such an intermittent search process. Both continuum and discrete-state stochastic descriptions are developed. It is found that depending on the scanning length λ, which describes the area visited by the reacting molecule during one search cycle, the system can exhibit three different search regimes: (i) For small λ values, the reactant finds the target mostly via three-dimensional bulk diffusion; (ii) for large λ values, the reactant molecule associates to the target mostly via surface diffusion; and (iii) for intermediate λ values, the reactant reaches the target via a combination of three-dimensional and two-dimensional search cycles. Our analysis also shows that the mean search times have different scalings as a function of the size of the surface segment depending on the nature of the dynamic search regime. Search dynamics are also sensitive to the position of the target for large scanning lengths. In addition, it is argued that the continuum description underestimates mean search times and does not always correctly describe the most optimal conditions for the surface-assisted dynamic processes. The importance of our findings for real natural systems is discussed.

Plasma surface interaction processes and possible synergisms

International Nuclear Information System (INIS)

Behrisch, R.; Roberto, J.B.

1984-08-01

The process determining the plasma surface interaction in today's high temperature plasma experiments are investigated following several lines. First, in plasma devices, the particle and energy fluxes to the different first wall areas the fluxes from the walls back into the plasma are measured and the boundary plasma parameters are determined. The surface composition and structure of the walls, limiters and divertor plates are analyzed following exposure to many discharges. Secondly, the different surface processes which are expected to contribute to the plasma surface interaction (particularly to hydrogen particle balance and impurity introduction) are studied in simulation experiments using well defined particle beams

Design and Analysis of Elliptical Nozzle in AJM Process using ...

African Journals Online (AJOL)

Abrasive jet machining (AJM) is a micromachining process, where material is removed from the work piece by the erosion effect of a high speed stream of abrasive particles carried in a gas medium, which are emerging from a nozzle. Abrasive machining includes grinding super finishing honing, lapping polishing etc.

Mechanisms and energetics of surface atomic processes

International Nuclear Information System (INIS)

Tsong, T.T.

1991-01-01

The energies involved in various surface atomic processes such as surface diffusion, the binding of small atomic clusters on the surface, the interaction between two adsorbed atoms, the dissociation of an atom from a small cluster or from a surface layer, the binding of kink size atoms or atoms at different adsorption sites to the surface etc., can be derived from an analysis of atomically resolved field ion microscope images and a kinetic energy measurement of low temperature field desorbed ions using the time-of-flight atom-probe field ion microscope. These energies can be used to compare with theories and to understand the transport of atoms on the surface in atomic reconstructions, epitaxial growth of surface layers and crystal growth, adsorption layer superstructure formation, and also why an atomic ordering or atomic reconstruction at the surface is energetically favored. Mechanisms of some of the surface atomic processes are also clarified from these quantitative, atomic resolution studies. In this paper work in this area is bris briefly reviewed

A 16-bit sigma-delta modulator applied in micro-machined inertial sensors

Science.gov (United States)

Honglin, Xu; Qiang, Fu; Hongna, Liu; Liang, Yin; Pengfei, Wang; Xiaowei, Liu

2014-04-01

A fourth-order low-distortion low-pass sigma-delta (ΣΔ) modulator is presented for micro-machined inertial sensors. The proposed single-loop single-bit feedback modulator is optimized with a feed-forward path to decrease the nonlinearities and power consumption. The IC is implemented in a standard 0.6 μm CMOS technology and operates at a sampling frequency of 3.846 MHz. The chip area is 2.12 mm2 with 23 pads. The experimental results indicate a signal-to-noise ratio (SNR) of 100 dB and dynamic range (DR) of 103 dB at an oversampling rate (OSR) of 128 with the input signal amplitude of -3.88 dBFS at 9.8 kHz; the power consumption is 15 mW at a 5 V supply.

A 16-bit sigma–delta modulator applied in micro-machined inertial sensors

International Nuclear Information System (INIS)

Xu Honglin; Fu Qiang; Liu Hongna; Yin Liang; Wang Pengfei; Liu Xiaowei

2014-01-01

A fourth-order low-distortion low-pass sigma–delta (ΣΔ) modulator is presented for micro-machined inertial sensors. The proposed single-loop single-bit feedback modulator is optimized with a feed-forward path to decrease the nonlinearities and power consumption. The IC is implemented in a standard 0.6 μm CMOS technology and operates at a sampling frequency of 3.846 MHz. The chip area is 2.12 mm 2 with 23 pads. The experimental results indicate a signal-to-noise ratio (SNR) of 100 dB and dynamic range (DR) of 103 dB at an oversampling rate (OSR) of 128 with the input signal amplitude of −3.88 dBFS at 9.8 kHz; the power consumption is 15 mW at a 5 V supply. (semiconductor integrated circuits)

Microencapsulation of silicon cavities using a pulsed excimer laser

KAUST Repository

Sedky, Sherif M.; Tawfik, Hani H.; Ashour, Mohamed; Graham, Andrew B.; Provine, John W.; Wang, Qingxiao; Zhang, Xixiang; Howe, Roger T.

2012-01-01

This work presents a novel low thermal-budget technique for sealing micromachined cavities in silicon. Cavities are sealed without deposition, similar to the silicon surface-migration sealing process. In contrast to the 1100°C furnace anneal

Process optimization in Nd:YAG laser microdrilling of alumina–aluminium interpenetrating phase composite

Directory of Open Access Journals (Sweden)

Ranjib Biswas

2015-07-01

Full Text Available In laser beam micromachining process, the quality of the drilled hole is of great importance. The quality of the microdrilled hole mainly depends on appropriate selection of process parameters. Predefined diameter of hole with minimum taper is of today's demand. The composite used for microdrilling operation is alumina–aluminium (Al2O3–Al interpenetrating phase composite (IPC, which is widely used in aircraft and space stations. Until date, no experimental study has been done to obtain microdrilled hole of desired diameter. In the present paper three hole qualities such as hole diameter at entry, at exit and hole taper have been optimized individually as well as simultaneously using a central composite design (CCD based on response surface methodology (RSM during pulsed Nd:YAG laser microdrilling operation on alumina–aluminium IPC sheet of 1.14 mm thickness. The analysis of variance (ANOVA test has also been done to identify the process parameters that contributed the most to get desired hole quality.

Micro Elector Mechanical Systems

International Nuclear Information System (INIS)

Yun, Jun Bo; Jo, Il Ju; Choi, Yoon Seok

1996-09-01

This book consists of seven chapters, which are the flow of the age from macro world to micro world, what is MEMS, semiconductor, micro machining and MEMS, where do MEMS goes to?, How to make MEMS, MEMS in the future and knowing about MEMS more than. This book is written to explain in ease and fun. It deals with MEMS in IT, BT, NT, ST, micro robot technology, basic process for making MEMS such as Bulk micromachining, surface micromachining LGA technology, DARPA and organization in domestic and overseas and academy and journal related MEMS.

Analysis of the current density characteristics in through-mask electrochemical micromachining (TMEMM for fabrication of micro-hole arrays on invar alloy film

Directory of Open Access Journals (Sweden)

Da-som JIN

2017-06-01

Full Text Available Invar alloy consisting of 64% iron and 36% nickel has been widely used for the production of shadow masks for organic light emitting diodes (OLEDs because of its low thermal expansion coefficient (1.86 × 10−6 cm/°C. To fabricate micro-hole arrays on 30 μm invar alloy film, through-mask electrochemical micromachining (TMEMM was developed and combined with a portion of the photolithography etching process. For precise hole shapes, patterned photoresist (PR film was applied as an insulating mask. To investigate the relationship between the current density and the material removal rate, the principle of the electrochemical machining was studied with a focus on the equation. The finite element method (FEM was used to verify the influence of each parameter on the current density on the invar alloy film surface. The parameters considered were the thickness of the PR mask, inter-electrode gap (IEG, and electrolyte concentration. Design of experiments (DOE was used to figure out the contribution of each parameter. A simulation was conducted with varying parameters to figure out their relationships with the current density. Optimization was conducted to select the suitable conditions. An experiment was carried out to verify the simulation results. It was possible to fabricate micro-hole arrays on invar alloy film using TMEMM, which is a promising method that can be applied to fabrications of OLEDs shadow masks.

Diffusion processes in bombardment-induced surface topography

International Nuclear Information System (INIS)

Robinson, R.S.

1984-01-01

A treatment is given of the problem of surface diffusion processes occurring during surface topography development, whenever a surface is simultaneously seeded with impurities and ion bombarded. The development of controllable topography and the importance of surface diffusion parameters, which can be obtained during these studies, are also analyzed. 101 refs.; 7 figs.; 2 tabs

Multifrequency Excitation Method for Rapid and Accurate Dynamic Test of Micromachined Gyroscope Chips

Directory of Open Access Journals (Sweden)

Yan Deng

2014-10-01

Full Text Available A novel multifrequency excitation (MFE method is proposed to realize rapid and accurate dynamic testing of micromachined gyroscope chips. Compared with the traditional sweep-frequency excitation (SFE method, the computational time for testing one chip under four modes at a 1-Hz frequency resolution and 600-Hz bandwidth was dramatically reduced from 10 min to 6 s. A multifrequency signal with an equal amplitude and initial linear-phase-difference distribution was generated to ensure test repeatability and accuracy. The current test system based on LabVIEW using the SFE method was modified to use the MFE method without any hardware changes. The experimental results verified that the MFE method can be an ideal solution for large-scale dynamic testing of gyroscope chips and gyroscopes.

Feasibility and its characteristics of CO2 laser micromachining-based PMMA anti-scattering grid estimated by MCNP code simulation.

Science.gov (United States)

Bae, Jun Woo; Kim, Hee Reyoung

2018-01-01

Anti-scattering grid has been used to improve the image quality. However, applying a commonly used linear or parallel grid would cause image distortion, and focusing grid also requires a precise fabrication technology, which is expensive. To investigate and analyze whether using CO2 laser micromachining-based PMMA anti-scattering grid can improve the performance of the grid at a lower cost. Thus, improvement of grid performance would result in improvement of image quality. The cross-sectional shape of CO2 laser machined PMMA is similar to alphabet 'V'. The performance was characterized by contrast improvement factor (CIF) and Bucky. Four types of grid were tested, which include thin parallel, thick parallel, 'V'-type and 'inverse V'-type of grid. For a Bucky factor of 2.1, the CIF of the grid with both the "V" and inverse "V" had a value of 1.53, while the thick and thick parallel types had values of 1.43 and 1.65, respectively. The 'V' shape grid manufacture by CO2 laser micromachining showed higher CIF than parallel one, which had same shielding material channel width. It was thought that the 'V' shape grid would be replacement to the conventional parallel grid if it is hard to fabricate the high-aspect-ratio grid.

Multi-surface topography targeted plateau honing for the processing of cylinder liner surfaces of automotive engines

Science.gov (United States)

Lawrence, K. Deepak; Ramamoorthy, B.

2016-03-01

Cylinder bores of automotive engines are 'engineered' surfaces that are processed using multi-stage honing process to generate multiple layers of micro geometry for meeting the different functional requirements of the piston assembly system. The final processed surfaces should comply with several surface topographic specifications that are relevant for the good tribological performance of the engine. Selection of the process parameters in three stages of honing to obtain multiple surface topographic characteristics simultaneously within the specification tolerance is an important module of the process planning and is often posed as a challenging task for the process engineers. This paper presents a strategy by combining the robust process design and gray-relational analysis to evolve the operating levels of honing process parameters in rough, finish and plateau honing stages targeting to meet multiple surface topographic specifications on the final running surface of the cylinder bores. Honing experiments were conducted in three stages namely rough, finish and plateau honing on cast iron cylinder liners by varying four honing process parameters such as rotational speed, oscillatory speed, pressure and honing time. Abbott-Firestone curve based functional parameters (Rk, Rpk, Rvk, Mr1 and Mr2) coupled with mean roughness depth (Rz, DIN/ISO) and honing angle were measured and identified as the surface quality performance targets to be achieved. The experimental results have shown that the proposed approach is effective to generate cylinder liner surface that would simultaneously meet the explicit surface topographic specifications currently practiced by the industry.

A Three-Dimensional Enormous Surface Area Aluminum Microneedle Array with Nanoporous Structure

Directory of Open Access Journals (Sweden)

Po Chun Chen

2013-01-01

Full Text Available We proposed fabricating an aluminum microneedle array with a nanochannel structure on the surface by combining micromachining, electrolyte polishing, and anodization methods. The microneedle array provides a three-dimensional (3D structure that possesses several hundred times more surface area than a traditional nanochannel template. Therefore, the microneedle array can potentially be used in many technology applications. This 3D microneedle array device can not only be used for painless injection or extraction, but also for storage, highly sensitive detection, drug delivery, and microelectrodes. From the calculation we made, the microneedle array not only increases surface area, but also enlarges the capacity of the device. Therefore, the microneedle array can further be used on many detecting, storing, or drug delivering applications.

GaAs micromachining in the 1 H2SO4:1 H2O2:8 H2O system. From anisotropy to simulation

Science.gov (United States)

Tellier, C. R.

2011-02-01

The bulk micromachining on (010), (110) and (111)A GaAs substrates in the 1 H2SO4:1 H2O2:8 H2O system is investigated. Focus is placed on anisotropy of 3D etching shapes with a special emphasis on convex and concave undercuts which are of prime importance in the wet micromachining of mechanical structures. Etched structures exhibit curved contours and more and less rounded sidewalls showing that the anisotropy is of type 2. This anisotropy can be conveniently described by a kinematic and tensorial model. Hence, a database composed of dissolution constants is further determined from experiments. A self-elaborated simulator which works with the proposed database is used to derive theoretical 3D shapes. Simulated shapes agree well with observed shapes of microstructures. The successful simulations open up two important applications for MEMS: CAD of mask patterns and meshing of simulated shapes for FEM simulation tools.

Texturing in titanium grade 2 surface irradiate with ultrashort pulse laser

International Nuclear Information System (INIS)

Nogueira, Alessandro Francelino

2015-01-01

The texturing laser micromachining is an important alternative to improve the bonding adhesion between composites and titanium, which are applied to structural components in the aerospace industry. The texturing running on titanium plates is due to the fact that the preferred joining technique for many composite materials is the adhesive bonding. In this work, titanium plates were texturized using laser ultrashort pulses temporal widths of femtoseconds. This process resulted in minimal heat transfer to the material, avoiding deformation of the titanium plate surface as well as the formation of resolidified material in the ablated region. These drawbacks have occurred with the use of nanoseconds pulses. Were performed three types of texturing using laser with femtosecond pulses, with variations in the distances between the machined lines. The analysis of the obtained surfaces found that the wettability increases when there is the increased distance between the texturing lines. Advancing in the analysis by optical profilometry of textured surfaces was observed that there is substantial increase in the volume available for penetration of structural adhesive when the distances between the textured lines are diminished. In tensile tests conducted it was observed that there is an increase in shear strength of the adhesive joint by reducing the distance between the textured lines. (author)

Vapour HF release of airgap-based UV-visible optical filters

NARCIS (Netherlands)

Ghaderi, M.; Ayerden, N.P.; De Graaf, G.; Wolffenbuttel, R.F.

2015-01-01

The design and CMOS-compatible fabrication of airgap-based optical filters in a surface micromachining process with sacrificial release using thevapour phase is presented. An airgap-dielectric layer combination offers a higher refractive index contrast, as compared to the conventional

Micromachined silicon acoustic delay line with improved structural stability and acoustic directivity for real-time photoacoustic tomography

Science.gov (United States)

Cho, Young; Kumar, Akhil; Xu, Song; Zou, Jun

2017-03-01

Recent studies have shown that micromachined silicon acoustic delay lines can provide a promising solution to achieve real-time photoacoustic tomography without the need for complex transducer arrays and data acquisition electronics. However, as its length increases to provide longer delay time, the delay line becomes more vulnerable to structural instability due to reduced mechanical stiffness. In addition, the small cross-section area of the delay line results in a large acoustic acceptance angle and therefore poor directivity. To address these two issues, this paper reports the design, fabrication, and testing of a new silicon acoustic delay line enhanced with 3D printed polymer micro linker structures. First, mechanical deformation of the silicon acoustic delay line (with and without linker structures) under gravity was simulated by using finite element method. Second, the acoustic crosstalk and acoustic attenuation caused by the polymer micro linker structures were evaluated with both numerical simulation and ultrasound transmission testing. The result shows that the use of the polymer micro linker structures significantly improves the structural stability of the silicon acoustic delay lines without creating additional acoustic attenuation and crosstalk. In addition, a new tapered design for the input terminal of the delay line was also investigate to improve its acoustic directivity by reducing the acoustic acceptance angle. These two improvements are expected to provide an effective solution to eliminate current limitations on the achievable acoustic delay time and out-of-plane imaging resolution of micromachined silicon acoustic delay line arrays.

Processing and finishing of granite surfaces

OpenAIRE

Klich, J. (Jiří); Hlaváček, P. (Petr); Ščučka, J. (Jiří); Sitek, L. (Libor); Foldyna, J. (Josef); Georgiovská, L. (Lucie); Souček, K. (Kamil); Staš, L. (Lubomír); Bortolussi, A.

2013-01-01

The article deals with granite surface processing and finishing by various methods including bush hammering, flaming, polishing, continuous and pulsating water jetting. Both optical and CT X-ray methods are used for analysis of surface and subsurface areas of tested samples. Advantages of pulsating water jetting compared to other techniques are discussed.

Project in fiscal 2000 of developing international standards for supporting new industries. Standardization of method for evaluating characteristics measurement for micromachine materials; 2000 nendo shinki sangyo shiengata kokusai hyojun kaihatsu jigyo seika hokokusho. Micro machine yo zairyo no tokusei keisoku hyoka hoho no hyojunka

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

Targeting the international standardization of the method for evaluating properties measurement for micro-machine materials, R and D has been performed on measurement and evaluation of mechanical properties of different thin film materials with a thickness of about 10 {mu}m or less and a width of 100 {mu}m or less. This paper summarizes the achievements in fiscal 2000. The current fiscal year has executed tensile tests of thin film materials for micro-machines, and surveys on technological trends related to the standardization thereof inside and outside the country. A working process was developed to manufacture test pieces of the thin film materials including mono-crystalline silicon for the purpose of executing the round robin test. Prototype test pieces were fabricated. The round robin test was performed by using these test pieces, wherein improvements were given on the test pieces, structure of the testing machine, the distortion measuring method, and the test piece mounting method. Furthermore, discussions were given on the film forming conditions and the heat treatment conditions with regard to mainly the thin titanium film made by using the sputtering process and thin nickel film made by using the plating process. The IEC/TC47/WG4 committee has announced to propose this evaluation technology as the future international standard. (NEDO)

A micromachined membrane-based active probe for biomolecular mechanics measurement

Science.gov (United States)

Torun, H.; Sutanto, J.; Sarangapani, K. K.; Joseph, P.; Degertekin, F. L.; Zhu, C.

2007-04-01

A novel micromachined, membrane-based probe has been developed and fabricated as assays to enable parallel measurements. Each probe in the array can be individually actuated, and the membrane displacement can be measured with high resolution using an integrated diffraction-based optical interferometer. To illustrate its application in single-molecule mechanics experiments, this membrane probe was used to measure unbinding forces between L-selectin reconstituted in a polymer-cushioned lipid bilayer on the probe membrane and an antibody adsorbed on an atomic force microscope cantilever. Piconewton range forces between single pairs of interacting molecules were measured from the cantilever bending while using the membrane probe as an actuator. The integrated diffraction-based optical interferometer of the probe was demonstrated to have floor for frequencies as low as 3 Hz with a differential readout scheme. With soft probe membranes, this low noise level would be suitable for direct force measurements without the need for a cantilever. Furthermore, the probe membranes were shown to have 0.5 µm actuation range with a flat response up to 100 kHz, enabling measurements at fast speeds.

Micromachining and dicing of sapphire, gallium nitride and micro LED devices with UV copper vapour laser

International Nuclear Information System (INIS)

Gu, E.; Jeon, C.W.; Choi, H.W.; Rice, G.; Dawson, M.D.; Illy, E.K.; Knowles, M.R.H.

2004-01-01

Gallium nitride (GaN) and sapphire are important materials for fabricating photonic devices such as high brightness light emitting diodes (LEDs). These materials are strongly resistant to wet chemical etching and also, low etch rates restrict the use of dry etching. Thus, to develop alternative high resolution processing and machining techniques for these materials is important in fabricating novel photonic devices. In this work, a repetitively pulsed UV copper vapour laser (255 nm) has been used to machine and dice sapphire, GaN and micro LED devices. Machining parameters were optimised so as to achieve controllable machining and high resolution. For sapphire, well-defined grooves 30 μm wide and 430 μm deep were machined. For GaN, precision features such as holes on a tens of micron length scale have been fabricated. By using this technique, compact micro LED chips with a die spacing 100 and a 430 μm thick sapphire substrate have been successfully diced. Measurements show that the performances of LED devices are not influenced by the UV laser machining. Our results demonstrate that the pulsed UV copper vapour laser is a powerful tool for micromachining and dicing of photonic materials and devices

Air plasma processing of poly(methyl methacrylate) micro-beads: Surface characterisations

International Nuclear Information System (INIS)

Liu Chaozong; Cui Naiyi; Osbeck, Susan; Liang He

2012-01-01

Highlights: ► PMMA micro-beads were processed using a rotary air plasma reactor. ► Surface chemistry and surface texture of PMMA micro-beads were characterised. ► Surface wettability was evaluated using “floating” water contact angle method. ► Surface oxidation and texture changes induced by air plasma attributed to the improvement of surface wettability. - Abstract: This paper reports the surface processing of poly(methyl methacrylate) (PMMA) micro-beads by using a rotary air plasma reactor, and its effects on surface properties. The surface properties, including surface wettability, surface chemistry and textures of the PMMA beads, were characterised. It was observed that the air plasma processing can improve the surface wettability of the PMMA microbeads significantly. A 15 min plasma processing can reduce the surface water contact angle of PMMA beads to about 50° from its original value of 80.3°. This was accompanied by about 8% increase in surface oxygen concentration as confirmed by XPS analysis. The optical profilometry examination revealed the air plasma processing resulted in a rougher surface that has a “delicate” surface texture. It is concluded that the surface chemistry and texture, induced by air plasma processing, co-contributed to the surface wettability improvement of PMMA micro-beads.

Electrolytic plasma processing of steel surfaces

International Nuclear Information System (INIS)

Bejar, M.A; Araya, R.N; Baeza, B

2006-01-01

The thermo-chemical treatments of steels with plasma is normally carried out in low-pressure ionized gaseous atmospheres. Among the treatments used most often are: nitruration, carburization and boronized. A plasma can also generate at atmospheric pressure. One way to produce it is with an electrochemical cell that works at a relatively high inter-electrode voltage and under conditions of heavy gas generation. This type of plasma is known as electrolytic plasma. This work studies the feasibility of using electrolytic plasma for the surface processing of steels. Two processes were selected: boronized and nitruration., for the hardening of two types of steel: one with low carbon (1020) and one with low alloy (4140). In the case of the nitruration, the 1020 steel was first aluminized. The electrolytes were aqueous solutions of borax for the boronizing and urea for the nitruration. The electrolytic plasmas were classified qualitatively, in relation with their luminosity by low, medium and high intensity. The boronizing was carried out with low intensity plasmas for a period of one hour. The nitruration was performed with plasmas of different intensities and for period of a few minutes to half an hour. The test pieces processed by electrolytic plasma were characterized by micro-hardness tests and X-ray diffraction. The maximum surface hardnesses obtained for the 1020 and 4140 steels were the following: 300 and 700 HV for the boronizing, and 1650 and 1200 HV for the nitruration, respectively. The utilization of an electrolytic plasma permits the surface processing of steels, noticeably increasing their hardness. With this type of plasma some thermo-chemical surface treatments can be done very rapidly as well (CW)

Electrostatic microactuators with integrated gear linkages for mechanical power transmission

NARCIS (Netherlands)

Legtenberg, R.; Legtenberg, Rob; Berenschot, Johan W.; Elwenspoek, Michael Curt; Fluitman, J.H.J.

1996-01-01

In this paper a surface micromachining process is presented which has been used to fabricate electrostatic microactuators that are interconnected with each other and linked to other movable microstructures by integrated gear linkages. The gear linkages consist of rotational and linear gear

An electrostatic lower stator axial gap wobble motor: design and fabrication

NARCIS (Netherlands)

Legtenberg, R.; Legtenberg, Rob; Berenschot, Johan W.; van Baar, J.J.J.; Lammerink, Theodorus S.J.; Elwenspoek, Michael Curt

1995-01-01

The fabrication, initial modelling and first results of an electrostatic lower stator axial gap wobble motor are presented. The four mask fabrication process is based on polysilicon surface micromachining techniques. Three to twelve stator pole wobble motor designs have been realized with rotor

Giant flexoelectric polarization in a micromachined ferroelectric diaphragm

KAUST Repository

Wang, Zhihong

2012-08-14

The coupling between dielectric polarization and strain gradient, known as flexoelectricity, becomes significantly large on the micro- and nanoscale. Here, it is shown that giant flexoelectric polarization can reverse remnant ferroelectric polarization in a bent Pb(Zr0.52Ti0.48) O3 (PZT) diaphragm fabricated by micromachining. The polarization induced by the strain gradient and the switching behaviors of the polarization in response to an external electric field are investigated by observing the electromechanical coupling of the diaphragm. The method allows determination of the absolute zero polarization state in a PZT film, which is impossible using other existing methods. Based on the observation of the absolute zero polarization state and the assumption that bending of the diaphragm is the only source of the self-polarization, the upper bound of flexoelectric coefficient of PZT film is calculated to be as large as 2.0 × 10-4 C m -1. The strain gradient induced by bending the diaphragm is measured to be on the order of 102 m-1, three orders of magnitude larger than that obtained in the bulk material. Because of this large strain gradient, the estimated giant flexoelectric polarization in the bent diaphragm is on the same order of magnitude as the normal remnant ferroelectric polarization of PZT film. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Receive-Noise Analysis of Capacitive Micromachined Ultrasonic Transducers.

Science.gov (United States)

Bozkurt, Ayhan; Yaralioglu, G Goksenin

2016-11-01

This paper presents an analysis of thermal (Johnson) noise received from the radiation medium by otherwise noiseless capacitive micromachined ultrasonic transducer (CMUT) membranes operating in their fundamental resonance mode. Determination of thermal noise received by multiple numbers of transducers or a transducer array requires the assessment of cross-coupling through the radiation medium, as well as the self-radiation impedance of the individual transducer. We show that the total thermal noise received by the cells of a CMUT has insignificant correlation, and is independent of the radiation impedance, but is only determined by the mass of each membrane and the electromechanical transformer ratio. The proof is based on the analytical derivations for a simple transducer with two cells, and extended to transducers with numerous cells using circuit simulators. We used a first-order model, which incorporates the fundamental resonance of the CMUT. Noise power is calculated by integrating over the entire spectrum; hence, the presented figures are an upper bound for the noise. The presented analyses are valid for a transimpedance amplifier in the receive path. We use the analysis results to calculate the minimum detectable pressure of a CMUT. We also provide an analysis based on the experimental data to show that output noise power is limited by and comparable to the theoretical upper limit.

Surface processing: existing and potential applications of ultraviolet light.

Science.gov (United States)

Manzocco, Lara; Nicoli, Maria Cristina

2015-01-01

Solid foods represent optimal matrices for ultraviolet processing with effects well beyond nonthermal surface disinfection. UV radiation favors hormetic response in plant tissues and degradation of toxic compound on the product surface. Photoinduced reactions can also provide unexplored possibilities to steer structure and functionality of food biopolymers. The possibility to extensively exploit this technology will depend on availability of robust information about efficacious processing conditions and adequate strategies to completely and homogeneously process food surface.

Enhancing structural integrity of adhesive bonds through pulsed laser surface micro-machining

KAUST Repository

Diaz, Edwin Hernandez

2015-01-01

of different kinds of heterogeneous surface properties that may replicate this behavior and the mechanisms at work. In order to do this, we used pulsed laser ablation on copper substrates (CuZn40) aiming to increase adhesion for bonding. A Yb-fiber laser

Precision laser processing for micro electronics and fiber optic manufacturing

Science.gov (United States)

Webb, Andrew; Osborne, Mike; Foster-Turner, Gideon; Dinkel, Duane W.

2008-02-01

The application of laser based materials processing for precision micro scale manufacturing in the electronics and fiber optic industry is becoming increasingly widespread and accepted. This presentation will review latest laser technologies available and discuss the issues to be considered in choosing the most appropriate laser and processing parameters. High repetition rate, short duration pulsed lasers have improved rapidly in recent years in terms of both performance and reliability enabling flexible, cost effective processing of many material types including metal, silicon, plastic, ceramic and glass. Demonstrating the relevance of laser micromachining, application examples where laser processing is in use for production will be presented, including miniaturization of surface mount capacitors by applying a laser technique for demetalization of tracks in the capacitor manufacturing process and high quality laser machining of fiber optics including stripping, cleaving and lensing, resulting in optical quality finishes without the need for traditional polishing. Applications include telecoms, biomedical and sensing. OpTek Systems was formed in 2000 and provide fully integrated systems and sub contract services for laser processes. They are headquartered in the UK and are establishing a presence in North America through a laser processing facility in South Carolina and sales office in the North East.

Complex three-dimensional structures in Si{1 0 0} using wet bulk micromachining

International Nuclear Information System (INIS)

Pal, Prem; Sato, Kazuo

2009-01-01

Complex three-dimensional structures for microelectromechanical systems (MEMS) are fabricated in Si{1 0 0} wafers using wet bulk micromachining. The structures are divided into two categories: fixed and freestanding. The fabrication processes for both types utilize single wafers with sequentially deposited nitride and oxide layers, local oxidation of silicon (LOCOS) and two steps of wet anisotropic etching. The fixed structures contain perfectly sharp edges. Thermally deposited oxide is used as the material for the freestanding structures. Wet etching is performed in tetramethyl ammonium hydroxide (TMAH) with and without Triton X-100 (C 14 H 22 O(C 2 H 4 O) n , n = 9–10). For the fixed structures, both etching steps are performed either in 25 wt% TMAH + Triton or pure TMAH or both, depending upon the type of the structures. In the case of freestanding systems, TMAH + Triton is utilized first, followed by pure TMAH. The fabrication methods enable densely arrayed structures, allowing the manufacture of corrugated diaphragms, compact size liquid (or gas) flow delivery systems, newly shaped mold for soft MEMS structures (e.g. PDMS (polydimethylsiloxane)) and other applications. The present research is an approach to fabricate advanced MEMS structures, extending the range of 3D structures fabricated by silicon anisotropic etching

Stability and spring constant investigation for micromachined inductive suspensions: theoretical analysis vs. experimental results

International Nuclear Information System (INIS)

Poletkin, K; Lu, Z; Wallrabe, U; Badilita, V; Den Hartogh, B

2014-01-01

We present a linear analytical model coupled with experimental analysis to discuss stability of a levitated proof mass (PM) in a micromachined inductive suspension (MIS), which has been previously introduced and characterized. The model is a function of the MIS geometry, describes the dynamics of a levitated disk-shaped PM near the equilibrium point, and predicts conditions for stable levitation. The experimental setup directly measures the lateral component of the Lorentz force, which has a stabilization role in the MIS structure, as well as the vertical levitation force. The experimental setup is further used to derive mechanical parameters such as stiffness values relative to lateral, vertical and angular displacements, proven to be in excellent agreement with the values predicted by the analytical model

PECVD silicon carbide surface micromachining technology and selected MEMS applications

NARCIS (Netherlands)

Rajaraman, V.; Pakula, L.S.; Yang, H.; French, P.J.; Sarro, P.M.

2011-01-01

Attractive material properties of plasma enhanced chemical vapour deposited (PECVD) silicon carbide (SiC) when combined with CMOS-compatible low thermal budget processing provides an ideal technology platform for developing various microelectromechanical systems (MEMS) devices and merging them with

Achievement report on commissioned research of R and D in fiscal 2000 on micromachine technologies. Development of microfactory technology; 2000 nendo kenkyu seika hokokusho. Maikuro fakutori gijutsu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-04-01

In order to achieve energy saving by miniaturizing the manufacturing process of small industrial products, R and D has been carried out on a micromachine system that puts together and assemble such devices as for processing, assembling, transportation and inspection used in the manufacturing process. This paper summarizes the achievements in fiscal 2000. In the research of a prototype micro-processing and assembling system, the secondary prototype system was fabricated, and verification was performed on its operation in processing and assembling works of a very small gear train. In the research of a micro liquid manipulating technology, high function liquid delivering device and holding device were developed, whereas the achievement of the targeted specifications was identified. In the research of a micro assembling technology, processing accuracy was improved on micro encoder disks. Furthermore, two second prototype micro arms were assembled into a microfactory to have performed verification on continuous operation to assemble trains of gears with a diameter of 10 mm. Other researches included the micro beam driving technology, micro electric power driving technology, micro transporting technology, and micro inspection technology. (NEDO)

A Three-Dimensional Enormous Surface Area Aluminum Microneedle Array with Nanoporous Structure

International Nuclear Information System (INIS)

Chen, P.Ch.; Zou, J.; Hsieh, Sh.J.; Chen, Ch.Ch.

2013-01-01

We proposed fabricating an aluminum micro needle array with a nano channel structure on the surface by combining micromachining, electrolyte polishing, and anodization methods. The micro needle array provides a three-dimensional (3D) structure that possesses several hundred times more surface area than a traditional nano channel template. Therefore, the micro needle array can potentially be used in many technology applications. This 3D micro needle array device can not only be used for painless injection or extraction, but also for storage, highly sensitive detection, drug delivery, and microelectrodes. From the calculation we made, the micro needle array not only increases surface area, but also enlarges the capacity of the device. Therefore, the micro needle array can further be used on many detecting, storing, or drug delivering applications.

An investigation of laser processing of silica surfaces

International Nuclear Information System (INIS)

Weber, A.J.; Stewart, A.F.; Exarhos, G.J.; Stowell, W.K.

1988-01-01

An initial set of experiments has been conducted to determine the practicality of laser processing of optical substrates. In contrast to earlier work, a high average power CO 2 laser was used to flood load the entire surface of each test sample. Fused silica substrates were laser polished on both surfaces at power densities ranging from 150 to 350 W/cm 2 . During each test sequence sample surface temperatures were recorded using a thermal imaging system. Extensive pre- and post-test characterization revealed that surface roughness and scattering of bare silica surfaces were reduced while internal stress increased. Laser damage thresholds were found to increase only for certain conditions. Changes in the microstructure were observed. These preliminary experiments demonstrate that laser processing can dramatically improve the optical properties of fused silica substrates

Chronic behavior evaluation of a micro-machined neural implant with optimized design based on an experimentally derived model.

Science.gov (United States)

Andrei, Alexandru; Welkenhuysen, Marleen; Ameye, Lieveke; Nuttin, Bart; Eberle, Wolfgang

2011-01-01

Understanding the mechanical interactions between implants and the surrounding tissue is known to have an important role for improving the bio-compatibility of such devices. Using a recently developed model, a particular micro-machined neural implant design aiming the reduction of insertion forces dependence on the insertion speed was optimized. Implantations with 10 and 100 μm/s insertion speeds showed excellent agreement with the predicted behavior. Lesion size, gliosis (GFAP), inflammation (ED1) and neuronal cells density (NeuN) was evaluated after 6 week of chronic implantation showing no insertion speed dependence.

Materials processing with superposed Bessel beams

Energy Technology Data Exchange (ETDEWEB)

Yu, Xiaoming [Department of Industrial and Manufacturing Systems Engineering, Kansas State University, Manhattan, KS 66506 (United States); Trallero-Herrero, Carlos A. [J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS 66506 (United States); Lei, Shuting, E-mail: lei@ksu.edu [Department of Industrial and Manufacturing Systems Engineering, Kansas State University, Manhattan, KS 66506 (United States)

2016-01-01

Graphical abstract: - Highlights: • Superpositions of Bessel beams can be generated with >50% efficiency using an SLM and an axicon. • These beams have orders-of-magnitude increase in depth-of-focus compared to Gaussian beams. • Multiple craters can be fabricated on glass with single-shot exposure. • The 1+(−1) superposition can reduce collateral damage caused by the rings in the zero-order Bessel beams. - Abstract: We report experimental results of femtosecond laser processing on the surface of glass and metal thin film using superposed Bessel beams. These beams are generated by a combination of a spatial light modulator (SLM) and an axicon with >50% efficiency, and they possess the long depth-of-focus (propagation-invariant) property as found in ordinary Bessel beams. Through micromachining experiments using femtosecond laser pulses, we show that multiple craters can be fabricated on glass with single-shot exposure, and the 1+(−1) superposed beam can reduce collateral damage caused by the rings in zero-order Bessel beams in the scribing of metal thin film.

Superhydrophobic coatings for aluminium surfaces synthesized by chemical etching process

Directory of Open Access Journals (Sweden)

Priya Varshney

2016-10-01

Full Text Available In this paper, the superhydrophobic coatings on aluminium surfaces were prepared by two-step (chemical etching followed by coating and one-step (chemical etching and coating in a single step processes using potassium hydroxide and lauric acid. Besides, surface immersion time in solutions was varied in both processes. Wettability and surface morphologies of treated aluminium surfaces were characterized using contact angle measurement technique and scanning electron microscopy, respectively. Microstructures are formed on the treated aluminium surfaces which lead to increase in contact angle of the surface (>150°. Also on increasing immersion time, contact angle further increases due to increase in size and depth of microstructures. Additionally, these superhydrophobic coatings show excellent self-cleaning and corrosion-resistant behavior. Water jet impact, floatation on water surface, and low temperature condensation tests assert the excellent water-repellent nature of coatings. Further, coatings are to be found mechanically, thermally, and ultraviolet stable. Along with, these coatings are found to be excellent regeneration ability as verified experimentally. Although aforesaid both processes generate durable and regenerable superhydrophobic aluminium surfaces with excellent self-cleaning, corrosion-resistant, and water-repellent characteristics, but one-step process is proved more efficient and less time consuming than two-step process and promises to produce superhydrophobic coatings for industrial applications.

Bending-induced electromechanical coupling and large piezoelectric response in a micromachined diaphragm

KAUST Repository

Wang, Zhihong

2013-11-04

We investigated the dependence of electromechanical coupling and the piezoelectric response of a micromachined Pb(Zr 0.52 Ti 0.48)O 3 (PZT) diaphragm on its curvature by observing the impedance spectrum and central deflection responses to a small AC voltage. The curvature of the diaphragm was controlled by applying air pressure to its back. We found that a depolarized flat diaphragm does not initially exhibit electromechanical coupling or the piezoelectric response. However, upon the application of static air pressure to the diaphragm, both electromechanical coupling and the piezoelectric response can be induced in the originally depolarized diaphragm. The piezoelectric response increases as the curvature increases and a giant piezoelectric response can be obtained from a bent diaphragm. The obtained results clearly demonstrate that a high strain gradient in a diaphragm can polarize a PZT film through a flexoelectric effect, and that the induced piezoelectric response of the diaphragm can be controlled by adjusting its curvature.

Plasma nitriding - an eco friendly surface hardening process

International Nuclear Information System (INIS)

Mukherjee, S.

2015-01-01

Surface hardening is a process of heating the metal such that the surface gets only hardened. This process is adopted for many components like gears, cams, and crankshafts, which desire high hardness on the outer surface with a softer core to withstand the shocks. So, to attain such properties processes like carburising, nitriding, flame hardening and induction hardening are employed. Amongst these processes nitriding is the most commonly used process by many industries. In nitriding process the steel material is heated to a temperature of around 550 C and then exposed to atomic nitrogen. This atomic nitrogen reacts with iron and other alloying elements and forms nitrides, which are very hard in nature. By this process both wear resistance and hardness of the product can be increased. The atomic nitrogen required for this process can be obtained using ammonia gas (gas nitriding), cyanide based salt bath (liquid nitriding) and plasma medium (plasma nitriding). However, plasma nitriding has recently received considerable industrial interest owing to its characteristic of faster nitrogen penetration, short treatment time, low process temperature, minimal distortion, low energy use and easier control of layer formation compared with conventional techniques such as gas and liquid nitriding. This process can be used for all ferrous materials including stainless steels. Plasma nitriding is carried out using a gas mixture of nitrogen and hydrogen gas at sub atmospheric pressures hence, making it eco-friendly in nature. Plasma nitriding allows modification of the surface layers and hardness profiles by changing the gas mixture and temperature. The wide applicable temperature range enables a multitude of applications, beyond the possibilities of gas or salt bath processes. This has led to numerous applications of this process in industries such as the manufacture of machine parts for plastics and food processing, packaging and tooling as well as pumps and hydraulic, machine

Diffusion processes in bombardment-induced surface topography

International Nuclear Information System (INIS)

Robinson, R.S.

1984-01-01

The bombardment of surfaces with moderate energy ions can lead to the development of various micron-sized surface structures. These structures include ridges, ledges, flat planes, pits and cones. The causal phenomena in the production of these features are sputtering, ion reflection, redeposition of sputtered material, and surface diffusion of both impurity and target-atom species. The authors concentrate on the formation of ion bombardment-induced surface topography wherein surface diffusion is a dominant process. The most thoroughly understood aspect of this topography development is the generation of cone-like structures during sputtering. The formation of cones during sputtering has been attributed to three effects. These are: (1) the presence of asperities, defects, or micro-inclusions in the surface layers, (2) the presence of impurities on the surfaces, and (3) particular crystal orientations. (Auth.)

Wafer-level packaged RF-MEMS switches fabricated in a CMOS fab

NARCIS (Netherlands)

Tilmans, H.A.C.; Ziad, H.; Jansen, Henricus V.; Di Monaco, O.; Jourdain, A.; De Raedt, W.; Rottenberg, X.; De Backer, E.; Decoussernaeker, A.; Baert, K.

2001-01-01

Reports on wafer-level packaged RF-MEMS switches fabricated in a commercial CMOS fab. Switch fabrication is based on a metal surface micromachining process. A novel wafer-level packaging scheme is developed, whereby the switches are housed in on-chip sealed cavities using benzocyclobutene (BCB) as

Process for cleaning radioactively contaminated metal surfaces

International Nuclear Information System (INIS)

Mihram, R.G.; Snyder, G.A.

1975-01-01

A process is described for removing radioactive scale from a ferrous metal surface, including the steps of initially preconditioning the surface by contacting it with an oxidizing solution (such as an aqueous solution of an alkali metal permanganate or hydrogen peroxide), then, after removal or decomposition of the oxidizing solution, the metallic surface is contacted with a cleaning solution which is a mixture of a mineral acid and a complexing agent (such as sulfuric acid and oxalic acid), and which preferably contains a corrosion inhibitor. A final step in the process is the treatment of the spent cleaning solution containing radioactive waste materials in solution by adding a reagent selected from the group consisting of calcium hydroxide or potassium permanganate and an alkali metal hydroxide to thereby form easily recovered metallic compounds containing substantially all of the dissolved metals and radioactivity. (auth)

3D Printing, Ink Casting and Micromachined Lamination (3D PICLμM: A Makerspace Approach to the Fabrication of Biological Microdevices

Directory of Open Access Journals (Sweden)

Avra Kundu

2018-02-01

Full Text Available We present a novel benchtop-based microfabrication technology: 3D printing, ink casting, micromachined lamination (3D PICLμM for rapid prototyping of lab-on-a-chip (LOC and biological devices. The technology uses cost-effective, makerspace-type microfabrication processes, all of which are ideally suited for low resource settings, and utilizing a combination of these processes, we have demonstrated the following devices: (i 2D microelectrode array (MEA targeted at in vitro neural and cardiac electrophysiology, (ii microneedle array targeted at drug delivery through a transdermal route and (iii multi-layer microfluidic chip targeted at multiplexed assays for in vitro applications. The 3D printing process has been optimized for printing angle, temperature of the curing process and solvent polishing to address various biofunctional considerations of the three demonstrated devices. We have depicted that the 3D PICLμM process has the capability to fabricate 30 μm sized MEAs (average 1 kHz impedance of 140 kΩ with a double layer capacitance of 3 μF, robust and reliable microneedles having 30 μm radius of curvature and ~40 N mechanical fracture strength and microfluidic devices having 150 μm wide channels and 400 μm fluidic vias capable of fluid mixing and transmitted light microparticle visualization. We believe our 3D PICLμM is ideally suited for applications in areas such as electrophysiology, drug delivery, disease in a dish, organ on a chip, environmental monitoring, agricultural therapeutic delivery and genomic testing.

MEMS: A new approach to micro-optics

Energy Technology Data Exchange (ETDEWEB)

Sniegowski, J.J.

1997-12-31

MicroElectroMechanical Systems (MEMS) and their fabrication technologies provide great opportunities for application to micro-optical systems (MOEMS). Implementing MOEMS technology ranges from simple, passive components to complicated, active systems. Here, an overview of polysilicon surface micromachining MEMS combined with optics is presented. Recent advancements to the technology, which may enhance its appeal for micro-optics applications are emphasized. Of all the MEMS fabrication technologies, polysilicon surface micromachining technology has the greatest basis in and leverages the most the infrastructure for silicon integrated circuit fabrication. In that respect, it provides the potential for very large volume, inexpensive production of MOEMS. This paper highlights polysilicon surface micromachining technology in regards to its capability to provide both passive and active mechanical elements with quality optical elements.

Nanoscale processes on insulating surfaces

National Research Council Canada - National Science Library

Gnecco, Enrico; Szymoński, Marek

2009-01-01

... the group of Prof. Ernst Meyer in Basel, where he investigated friction processes on alkali halide surfaces in ultra high vacuum (UHV). The main result was the observation of a logarithmic velocity dependence of atomic friction, which was interpreted within a combination of the classical Tomlinson and Eyring models. After his Ph.D. he joined the ...

Calculation of surface acoustic waves in a multilayered piezoelectric structure

International Nuclear Information System (INIS)

Zhang Zuwei; Wen Zhiyu; Hu Jing

2013-01-01

The propagation properties of the surface acoustic waves (SAWs) in a ZnO—SiO 2 —Si multilayered piezoelectric structure are calculated by using the recursive asymptotic method. The phase velocities and the electromechanical coupling coefficients for the Rayleigh wave and the Love wave in the different ZnO—SiO 2 —Si structures are calculated and analyzed. The Love mode wave is found to be predominantly generated since the c-axis of the ZnO film is generally perpendicular to the substrate. In order to prove the calculated results, a Love mode SAW device based on the ZnO—SiO 2 —Si multilayered structure is fabricated by micromachining, and its frequency responses are detected. The experimental results are found to be mainly consistent with the calculated ones, except for the slightly larger velocities induced by the residual stresses produced in the fabrication process of the films. The deviation of the experimental results from the calculated ones is reduced by thermal annealing. (semiconductor physics)

Review of piezoelectric micromachined ultrasonic transducers and their applications

International Nuclear Information System (INIS)

Jung, Joontaek; Lee, Wonjun; Kang, Woojin; Shin, Eunjung; Choi, Hongsoo; Ryu, Jungho

2017-01-01

In recent decades, micromachined ultrasonic transducers (MUTs) have been investigated as an alternative to conventional piezocomposite ultrasonic transducers, primarily due to the advantages that microelectromechanical systems provide. Miniaturized ultrasonic systems require ultrasonic transducers integrated with complementary metal-oxide-semiconductor circuits. Hence, piezoelectric MUTs (pMUTs) and capacitive MUTs (cMUTs) have been developed as the most favorable solutions. This paper reviews the basic equations to understand the characteristics of thin-film-based piezoelectric devices and presents recent research on pMUTs, including current approaches and limitations. Methods to improve the coupling coefficient of pMUTs are also investigated, such as device structure, materials, and fabrication techniques. The device structure improvements include multielectrode pMUTs, partially clamped boundary conditions, and 3D pMUTs (curved and domed types), where the latter can provide an electromechanical coupling coefficient of up to 45%. The piezoelectric coefficient ( e 31 ) can be increased by controlling the crystal texture (seed layer of γ -Al 2 O 3 ), using single-crystal (PMN-PT) materials, or control of residual stresses (using SiO 2 layer). Arrays of pMUTs can be implemented for various applications including intravascular ultrasound, fingerprint sensors, rangefinders in air, and wireless power supply systems. pMUTs are expected to be an ideal solution for applications such as mobile biometric security (fingerprint sensors) and rangefinders due to their superior power efficiency and compact size. (topical review)

Review of piezoelectric micromachined ultrasonic transducers and their applications

Science.gov (United States)

Jung, Joontaek; Lee, Wonjun; Kang, Woojin; Shin, Eunjung; Ryu, Jungho; Choi, Hongsoo

2017-11-01

In recent decades, micromachined ultrasonic transducers (MUTs) have been investigated as an alternative to conventional piezocomposite ultrasonic transducers, primarily due to the advantages that microelectromechanical systems provide. Miniaturized ultrasonic systems require ultrasonic transducers integrated with complementary metal-oxide-semiconductor circuits. Hence, piezoelectric MUTs (pMUTs) and capacitive MUTs (cMUTs) have been developed as the most favorable solutions. This paper reviews the basic equations to understand the characteristics of thin-film-based piezoelectric devices and presents recent research on pMUTs, including current approaches and limitations. Methods to improve the coupling coefficient of pMUTs are also investigated, such as device structure, materials, and fabrication techniques. The device structure improvements include multielectrode pMUTs, partially clamped boundary conditions, and 3D pMUTs (curved and domed types), where the latter can provide an electromechanical coupling coefficient of up to 45%. The piezoelectric coefficient (e 31) can be increased by controlling the crystal texture (seed layer of γ-Al2O3), using single-crystal (PMN-PT) materials, or control of residual stresses (using SiO2 layer). Arrays of pMUTs can be implemented for various applications including intravascular ultrasound, fingerprint sensors, rangefinders in air, and wireless power supply systems. pMUTs are expected to be an ideal solution for applications such as mobile biometric security (fingerprint sensors) and rangefinders due to their superior power efficiency and compact size.

Surface modification of the metal plates using continuous electron beam process (CEBP)

International Nuclear Information System (INIS)

Kim, Jisoo; Kim, Jin-Seok; Kang, Eun-Goo; Park, Hyung Wook

2014-01-01

Highlights: • We performed surface modification of SM20C, SUS303, and Al6061 using CEBP. • We analyzed surface properties and microstructure after electron-beam irradiation. • The surface quality was improved after electron-beam irradiation. • The surface hardness for SM20C was increased by ∼50% after CEBP irradiation. - Abstract: The finishing process is an important component of the quality-control procedure for final products in manufacturing applications. In this study, we evaluated the performance of continuous electron-beam process as the final process for finishing SM20C (steel alloy), SUS303 (stainless steel alloy), and Al6061 (aluminum alloy) surfaces both on the initially smooth and rough surfaces. Surface modification of the metals was carried out by varying the feed and frequency of the continuous electron-beam irradiation procedure. The resulting surface roughness was examined with respect to the initial surface roughness of the metals. SM20C and SUS303 experienced an improvement in surface roughness, particularly for initially rough surfaces. Continuous electron-beam process produced craters during the process and the effect of this phenomenon on the resulting surface roughness was relatively large with the initially smooth SM20C and SUS303 alloy surfaces. For Al6061, the continuous electron-beam process was effective at improving its surface roughness even with the initially smooth surface under the optimized conditions of process; this was attributed to its low melting point. Scanning electron microscopy was used to identify metallurgical variation within the thin melted and re-solidification layers of the tested alloys. Changes in the surface contact angle and hardness before and after electron-beam irradiation were also examined

Surface modification of the metal plates using continuous electron beam process (CEBP)

Energy Technology Data Exchange (ETDEWEB)

Kim, Jisoo, E-mail: kimjisu16@unist.ac.kr [School of Mechanical and Advanced Materials Engineering, Ulsan National Institute of Science and Technology, UNIST-gil 50, Eonyang-eup, Ulju-gun, Ulsan Metropolitan City 689-798 (Korea, Republic of); Kim, Jin-Seok, E-mail: totoro22@kitech.re.kr [Korea Institute of Industrial Technology (KITECH), KITECH Cheonan Headquarters 35-3 Hongcheon-ri, Ipjang-myeon, Cheonan-si, Chungcheongnam-do 330-825 (Korea, Republic of); Kang, Eun-Goo, E-mail: egkang@kitech.re.kr [Korea Institute of Industrial Technology (KITECH), KITECH Cheonan Headquarters 35-3 Hongcheon-ri, Ipjang-myeon, Cheonan-si, Chungcheongnam-do 330-825 (Korea, Republic of); Park, Hyung Wook, E-mail: hwpark@unist.ac.kr [School of Mechanical and Advanced Materials Engineering, Ulsan National Institute of Science and Technology, UNIST-gil 50, Eonyang-eup, Ulju-gun, Ulsan Metropolitan City 689-798 (Korea, Republic of)

2014-08-30

Highlights: • We performed surface modification of SM20C, SUS303, and Al6061 using CEBP. • We analyzed surface properties and microstructure after electron-beam irradiation. • The surface quality was improved after electron-beam irradiation. • The surface hardness for SM20C was increased by ∼50% after CEBP irradiation. - Abstract: The finishing process is an important component of the quality-control procedure for final products in manufacturing applications. In this study, we evaluated the performance of continuous electron-beam process as the final process for finishing SM20C (steel alloy), SUS303 (stainless steel alloy), and Al6061 (aluminum alloy) surfaces both on the initially smooth and rough surfaces. Surface modification of the metals was carried out by varying the feed and frequency of the continuous electron-beam irradiation procedure. The resulting surface roughness was examined with respect to the initial surface roughness of the metals. SM20C and SUS303 experienced an improvement in surface roughness, particularly for initially rough surfaces. Continuous electron-beam process produced craters during the process and the effect of this phenomenon on the resulting surface roughness was relatively large with the initially smooth SM20C and SUS303 alloy surfaces. For Al6061, the continuous electron-beam process was effective at improving its surface roughness even with the initially smooth surface under the optimized conditions of process; this was attributed to its low melting point. Scanning electron microscopy was used to identify metallurgical variation within the thin melted and re-solidification layers of the tested alloys. Changes in the surface contact angle and hardness before and after electron-beam irradiation were also examined.

Survey of practical application fields of micro-machine and micro-factory technologies in Japan; Nippon ni okeru maikuro machine oyobi maikuro factory gijutsu no jitsuyoka bun`ya chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-02-01

As for micro-machine and micro-factory technologies, research and development trends promoted by private companies were surveyed except for national projects. In the field of main technology development by private companies which do not participate in national projects, developments of micro-devices, such as micro-sensor, and micro-actuator, as well as basic technologies, such as machining, assembly, and material technology, are predominant. The applied fields of these aim at electronic industries for measurement and analysis equipment, motorcar sensors, information, communication, and home electric products. While, there are a few research and developments as to micro-robots. Research and developments aiming at application to medical field are widely promoted by private companies. In this field, micro-machining technology for micro-surgery and endoscopes is prospective. There is a photo-forceps technology for handling the micro-parts. However, there are few researches considering the micro-factory. 146 refs., 73 figs., 7 tabs.

Surface processing for bulk niobium superconducting radio frequency cavities

Science.gov (United States)

Kelly, M. P.; Reid, T.

2017-04-01

The majority of niobium cavities for superconducting particle accelerators continue to be fabricated from thin-walled (2-4 mm) polycrystalline niobium sheet and, as a final step, require material removal from the radio frequency (RF) surface in order to achieve performance needed for use as practical accelerator devices. More recently bulk niobium in the form of, single- or large-grain slices cut from an ingot has become a viable alternative for some cavity types. In both cases the so-called damaged layer must be chemically etched or electrochemically polished away. The methods for doing this date back at least four decades, however, vigorous empirical studies on real cavities and more fundamental studies on niobium samples at laboratories worldwide have led to seemingly modest improvements that, when taken together, constitute a substantial advance in the reproducibility for surface processing techniques and overall cavity performance. This article reviews the development of niobium cavity surface processing, and summarizes results of recent studies. We place some emphasis on practical details for real cavity processing systems which are difficult to find in the literature but are, nonetheless, crucial for achieving the good and reproducible cavity performance. New approaches for bulk niobium surface treatment which aim to reduce cost or increase performance, including alternate chemical recipes, barrel polishing and ‘nitrogen doping’ of the RF surface, continue to be pursued and are closely linked to the requirements for surface processing.

Design and fabrication of a GaAs/Al0.4Ga0.6As micro-accelerometer based on piezoresistive effect

International Nuclear Information System (INIS)

Liu Guowen; Zhang Binzhen; Zhang Kairui

2009-01-01

In this paper, a novel piezoresistive accelerometer based on the piezoresistive effect of GaAs/Al 0.4 Ga 0.6 As thin films was designed. The piezoresistive accelerometer contains four suspended flexural beams and a central proof mass configuration. The piezoresistive effect of a piezoresistor or thin film was used to make a resistor changing the output that is proportional to applied acceleration. The GaAs-based piezoresistive accelerometer was prepared with advanced surface micromachining processes, and bulk micromachining processes. Finally, the static pressure experiments were conducted on the sensing element. The experimental results showed that the combined semiconductor heterostructures and mechanical cantilevers have a good stress sensitive characteristic. The integration of these technologies promises to bring about a revolution in the applications of the semiconductor fine-structure devices.

Design and fabrication of a GaAs/Al{sub 0.4}Ga{sub 0.6}As micro-accelerometer based on piezoresistive effect

Energy Technology Data Exchange (ETDEWEB)

Liu Guowen; Zhang Binzhen; Zhang Kairui [National Key Laboratory for Electronic Measurement Technology, North University of China Taiyuan, Shanxi, 030051 (China)], E-mail: jacky.mucklow@iop.org

2009-03-01

In this paper, a novel piezoresistive accelerometer based on the piezoresistive effect of GaAs/Al{sub 0.4}Ga{sub 0.6}As thin films was designed. The piezoresistive accelerometer contains four suspended flexural beams and a central proof mass configuration. The piezoresistive effect of a piezoresistor or thin film was used to make a resistor changing the output that is proportional to applied acceleration. The GaAs-based piezoresistive accelerometer was prepared with advanced surface micromachining processes, and bulk micromachining processes. Finally, the static pressure experiments were conducted on the sensing element. The experimental results showed that the combined semiconductor heterostructures and mechanical cantilevers have a good stress sensitive characteristic. The integration of these technologies promises to bring about a revolution in the applications of the semiconductor fine-structure devices.

Double-section curvature tunable functional actuator with micromachined buckle and grid wire for electricity delivery

Science.gov (United States)

Feng, Guo-Hua; Hou, Sheng-You

2015-09-01

This paper presents an ionic polymer metal composite (IPMC)-driven tentacle-like biocompatible flexible actuator with double-section curvature tunability. This actuator, possessing an embedded electrical transmission ability that mimics skeletal muscle nerves in the human body, affords versatile device functions. Novel micromachined copper buckles and grid wires are fabricated and their superiority in electricity delivery and driving the IPMC component with less flexural rigidity is demonstrated. In addition, soft conductive wires realized on a polydimethylsiloxane structure function as electrical signal transmitters. A light-emitting diode integrated with the developed actuator offers directional guiding light ability while the actuator performs a snake-like motion. The electrical conductivity and Young’s modulus of the key actuator components are investigated, and flexural rigidity and dynamic behavior analyses of the actuator under electrical manipulation are elaborated.

Double-section curvature tunable functional actuator with micromachined buckle and grid wire for electricity delivery

International Nuclear Information System (INIS)

Feng, Guo-Hua; Hou, Sheng-You

2015-01-01

This paper presents an ionic polymer metal composite (IPMC)-driven tentacle-like biocompatible flexible actuator with double-section curvature tunability. This actuator, possessing an embedded electrical transmission ability that mimics skeletal muscle nerves in the human body, affords versatile device functions. Novel micromachined copper buckles and grid wires are fabricated and their superiority in electricity delivery and driving the IPMC component with less flexural rigidity is demonstrated. In addition, soft conductive wires realized on a polydimethylsiloxane structure function as electrical signal transmitters. A light-emitting diode integrated with the developed actuator offers directional guiding light ability while the actuator performs a snake-like motion. The electrical conductivity and Young’s modulus of the key actuator components are investigated, and flexural rigidity and dynamic behavior analyses of the actuator under electrical manipulation are elaborated. (paper)

Plasma assisted surface coating/modification processes: An emerging technology

Science.gov (United States)

Spalvins, T.

1986-01-01

A broad understanding of the numerous ion or plasma assisted surface coating/modification processes is sought. An awareness of the principles of these processes is needed before discussing in detail the ion nitriding technology. On the basis of surface modifications arising from ion or plasma energizing and interactions, it can be broadly classified as deposition of distinct overlay coatings (sputtering-dc, radio frequency, magnetron, reactive; ion plating-diode, triode) and surface property modification without forming a discrete coating (ion implantation, ion beam mixing, laser beam irradiation, ion nitriding, ion carburizing, plasma oxidation). These techniques offer a great flexibility and are capable in tailoring desirable chemical and structural surface properties independent of the bulk properties.

Plasma assisted surface coating/modification processes - An emerging technology

Science.gov (United States)

Spalvins, T.

1987-01-01

A broad understanding of the numerous ion or plasma assisted surface coating/modification processes is sought. An awareness of the principles of these processes is needed before discussing in detail the ion nitriding technology. On the basis of surface modifications arising from ion or plasma energizing and interactions, it can be broadly classified as deposition of distinct overlay coatings (sputtering-dc, radio frequency, magnetron, reactive; ion plating-diode, triode) and surface property modification without forming a discrete coating (ion implantation, ion beam mixing, laser beam irradiation, ion nitriding, ion carburizing, plasma oxidation. These techniques offer a great flexibility and are capable in tailoring desirable chemical and structural surface properties independent of the bulk properties.

Surface modification by electrolytic plasma processing for high Nb-TiAl alloys

Science.gov (United States)

Gui, Wanyuan; Hao, Guojian; Liang, Yongfeng; Li, Feng; Liu, Xiao; Lin, Junpin

2016-12-01

Metal surface modification by electrolytic plasma processing (EPP) is an innovative treatment widely commonly applied to material processing and pretreatment process of coating and galvanization. EPP involves complex processes and a great deal of parameters, such as preset voltage, current, solution temperature and processing time. Several characterization methods are presented in this paper for evaluating the micro-structure surfaces of Ti45Al8Nb alloys: SEM, EDS, XRD and 3D topography. The results showed that the oxide scale and other contaminants on the surface of Ti45Al8Nb alloys can be effectively removed via EPP. The typical micro-crater structure of the surface of Ti45Al8Nb alloys were observed by 3D topography after EPP to find that the mean diameter of the surface structure and roughness value can be effectively controlled by altering the processing parameters. The mechanical properties of the surface according to nanomechanical probe testing exhibited slight decrease in microhardness and elastic modulus after EPP, but a dramatic increase in surface roughness, which is beneficial for further processing or coating.

Modeling and evaluating of surface roughness prediction in micro-grinding on soda-lime glass considering tool characterization

Science.gov (United States)

Cheng, Jun; Gong, Yadong; Wang, Jinsheng

2013-11-01

The current research of micro-grinding mainly focuses on the optimal processing technology for different materials. However, the material removal mechanism in micro-grinding is the base of achieving high quality processing surface. Therefore, a novel method for predicting surface roughness in micro-grinding of hard brittle materials considering micro-grinding tool grains protrusion topography is proposed in this paper. The differences of material removal mechanism between convention grinding process and micro-grinding process are analyzed. Topography characterization has been done on micro-grinding tools which are fabricated by electroplating. Models of grain density generation and grain interval are built, and new predicting model of micro-grinding surface roughness is developed. In order to verify the precision and application effect of the surface roughness prediction model proposed, a micro-grinding orthogonally experiment on soda-lime glass is designed and conducted. A series of micro-machining surfaces which are 78 nm to 0.98 μm roughness of brittle material is achieved. It is found that experimental roughness results and the predicting roughness data have an evident coincidence, and the component variable of describing the size effects in predicting model is calculated to be 1.5×107 by reverse method based on the experimental results. The proposed model builds a set of distribution to consider grains distribution densities in different protrusion heights. Finally, the characterization of micro-grinding tools which are used in the experiment has been done based on the distribution set. It is concluded that there is a significant coincidence between surface prediction data from the proposed model and measurements from experiment results. Therefore, the effectiveness of the model is demonstrated. This paper proposes a novel method for predicting surface roughness in micro-grinding of hard brittle materials considering micro-grinding tool grains protrusion

Optical temperature sensor and thermal expansion measurement using a femtosecond micromachined grating in 6H-SiC.

Science.gov (United States)

DesAutels, G Logan; Powers, Peter; Brewer, Chris; Walker, Mark; Burky, Mark; Anderson, Gregg

2008-07-20

An optical temperature sensor was created using a femtosecond micromachined diffraction grating inside transparent bulk 6H-SiC, and to the best of our knowledge, this is a novel technique of measuring temperature. Other methods of measuring temperature using fiber Bragg gratings have been devised by other groups such as Zhang and Kahrizi [in MEMS, NANO, and Smart Systems (IEEE, 2005)]. This temperature sensor was, to the best of our knowledge, also used for a novel method of measuring the linear and nonlinear coefficients of the thermal expansion of transparent and nontransparent materials by means of the grating first-order diffracted beam. Furthermore the coefficient of thermal expansion of 6H-SiC was measured using this new technique. A He-Ne laser beam was used with the SiC grating to produce a first-order diffracted beam where the change in deflection height was measured as a function of temperature. The grating was micromachined with a 20 microm spacing and has dimensions of approximately 500 microm x 500 microm (l x w) and is roughly 0.5 microm deep into the 6H-SiC bulk. A minimum temperature of 26.7 degrees C and a maximum temperature of 399 degrees C were measured, which gives a DeltaT of 372.3 degrees C. The sensitivity of the technique is DeltaT=5 degrees C. A maximum deflection angle of 1.81 degrees was measured in the first-order diffracted beam. The trend of the deflection with increasing temperature is a nonlinear polynomial of the second-order. This optical SiC thermal sensor has many high-temperature electronic applications such as aircraft turbine and gas tank monitoring for commercial and military applications.

Array processing for seismic surface waves

Energy Technology Data Exchange (ETDEWEB)

Marano, S.

2013-07-01

This dissertation submitted to the Swiss Federal Institute of Technology ETH in Zurich takes a look at the analysis of surface wave properties which allows geophysicists to gain insight into the structure of the subsoil, thus avoiding more expensive invasive techniques such as borehole drilling. This thesis aims at improving signal processing techniques for the analysis of surface waves in various directions. One main contribution of this work is the development of a method for the analysis of seismic surface waves. The method also deals with the simultaneous presence of multiple waves. Several computational approaches to minimize costs are presented and compared. Finally, numerical experiments that verify the effectiveness of the proposed cost function and resulting array geometry designs are presented. These lead to greatly improved estimation performance in comparison to arbitrary array geometries.

Array processing for seismic surface waves

International Nuclear Information System (INIS)

Marano, S.

2013-01-01

This dissertation submitted to the Swiss Federal Institute of Technology ETH in Zurich takes a look at the analysis of surface wave properties which allows geophysicists to gain insight into the structure of the subsoil, thus avoiding more expensive invasive techniques such as borehole drilling. This thesis aims at improving signal processing techniques for the analysis of surface waves in various directions. One main contribution of this work is the development of a method for the analysis of seismic surface waves. The method also deals with the simultaneous presence of multiple waves. Several computational approaches to minimize costs are presented and compared. Finally, numerical experiments that verify the effectiveness of the proposed cost function and resulting array geometry designs are presented. These lead to greatly improved estimation performance in comparison to arbitrary array geometries

Estimation of surface absorptivity in laser surface heating process with experimental data

International Nuclear Information System (INIS)

Chen, H-T; Wu, X-Y

2006-01-01

This study applies a hybrid technique of the Laplace transform and finite-difference methods in conjunction with the least-squares method and experimental temperature data inside the test material to predict the unknown surface temperature, heat flux and absorptivity for various surface conditions in the laser surface heating process. In this study, the functional form of the surface temperature is unknown a priori and is assumed to be a function of time before performing the inverse calculation. In addition, the whole time domain is divided into several analysis sub-time intervals and then these unknown estimates on each analysis interval can be predicted. In order to show the accuracy of the present inverse method, comparisons are made among the present estimates, direct results and previous results, showing that the present estimates agree with the direct results for the simulated problem. However, the present estimates of the surface absorptivity deviate slightly from previous estimated results under the assumption of constant thermal properties. The effect of the surface conditions on the surface absorptivity and temperature is not negligible

Surface analytical techniques applied to minerals processing

International Nuclear Information System (INIS)

Smart, R.St.C.

1991-01-01

An understanding of the chemical and physical forms of the chemically altered layers on the surfaces of base metal sulphides, particularly in the form of hydroxides, oxyhydroxides and oxides, and the changes that occur in them during minerals processing lies at the core of a complete description of flotation chemistry. This paper reviews the application of a variety of surface-sensitive techniques and methodologies applied to the study of surface layers on single minerals, mixed minerals, synthetic ores and real ores. Evidence from combined XPS/SAM/SEM studies have provided images and analyses of three forms of oxide, oxyhydroxide and hydroxide products on the surfaces of single sulphide minerals, mineral mixtures and complex sulphide ores. 4 refs., 2 tabs., 4 figs

Micromachining of commodity plastics by proton beam writing and fabrication of spatial resolution test-chart for neutron radiography

International Nuclear Information System (INIS)

Sakai, T.; Yasuda, R.; Iikura, H.; Nojima, T.; Matsubayashi, M.; Kada, W.; Kohka, M.; Satoh, T.; Ohkubo, T.; Ishii, Y.; Takano, K.

2013-01-01

Proton beam writing is a direct-write technique and a promising method for the micromachining of commodity plastics such as acrylic resins. Herein, we describe the fabrication of microscopic devices made from a relatively thick (∼75 μm) acrylic sheet using proton beam writing. In addition, a software package that converts image pixels into coordinates data was developed, and the successful fabrication of a very fine jigsaw puzzle was achieved. The size of the jigsaw puzzle pieces was 50 × 50 μm. For practical use, a prototype of a line and space test-chart was also successfully fabricated for the determination of spatial resolution in neutron radiography

Surface quality in rapid prototype MMD process

Directory of Open Access Journals (Sweden)

Lisandro Vargas Henríquez

2004-09-01

Full Text Available This article summarises a Manufacturing Materials and Processes MSc thesis written for the Mechanical and Electrical Engineering Department. The paper shows the interaction of process, gap (deposition distance and extursion terminal velocity modelled process parameters for CEIF's (Centro de Equipos Interfacultades rapid prototype molten material deposit (MMD Titan SH-1 machine by analysing prototupes improved surface quality and resistence to tension and characterising material. The project applies experimental design criteria for orientating the selection of experimental process parameters. Acrylonitrile-buttadin-styrene (ABS had alredy been mechanically and physicochemically characterised (i.e the material used in the MMD process.

Zerodur polishing process for high surface quality and high efficiency

International Nuclear Information System (INIS)

Tesar, A.; Fuchs, B.

1992-08-01

Zerodur is a glass-ceramic composite importance in applications where temperature instabilities influence optical and mechanical performance, such as in earthbound and spaceborne telescope mirror substrates. Polished Zerodur surfaces of high quality have been required for laser gyro mirrors. Polished surface quality of substrates affects performance of high reflection coatings. Thus, the interest in improving Zerodur polished surface quality has become more general. Beyond eliminating subsurface damage, high quality surfaces are produced by reducing the amount of hydrated material redeposited on the surface during polishing. With the proper control of polishing parameters, such surfaces exhibit roughnesses of < l Angstrom rms. Zerodur polishing was studied to recommend a high surface quality polishing process which could be easily adapted to standard planetary continuous polishing machines and spindles. This summary contains information on a polishing process developed at LLNL which reproducibly provides high quality polished Zerodur surfaces at very high polishing efficiencies

THE PRODUCT DESIGN PROCESS USING STYLISTIC SURFACES

Directory of Open Access Journals (Sweden)

Arkadiusz Gita

2017-06-01

Full Text Available The increasing consumer requirements for the way what everyday use products look like, forces manufacturers to put more emphasis on product design. Constructors, apart from the functional aspects of the parts created, are forced to pay attention to the aesthetic aspects. Software for designing A-class surfaces is very helpful in this case. Extensive quality analysis modules facilitate the work and allow getting models with specific visual features. The authors present a design process of the product using stylistic surfaces based on the front panel of the moped casing. In addition, methods of analysis of the design surface and product technology are presented.

Tribological investigations of the applicability of surface functionalization for dry extrusion processes

Science.gov (United States)

Teller, Marco; Prünte, Stephan; Ross, Ingo; Temmler, André; Schneider, Jochen M.; Hirt, Gerhard

2017-10-01

Cold extrusion processes are characterized by large relative contact stresses combined with a severe surface enlargement of the workpiece. Under these process conditions a high risk for galling of workpiece material to the tool steel occurs especially in processing of aluminum and aluminum alloys. In order to reduce adhesive wear lubricants for separation of workpiece and tool surfaces are used. As a consequence additional process steps (e.g. preparation and cleaning of workpieces) are necessary. Thus, the realization of a dry forming process is aspired from an environmental and economic perspective. In this paper a surface functionalization with self-assembled-monolayers (SAM) of the tool steels AISI D2 (DIN 1.2379) and AISI H11 (DIN 1.2343) is evaluated by a process-oriented tribological test. The tribological experiment is able to resemble and scale the process conditions of cold extrusion related to relative contact stress and surface enlargement for the forming of pure aluminum (Al99.5). The effect of reduced relative contact stress, surface enlargement and relative velocity on adhesive wear and tool lifetime is evaluated. Similar process conditions are achievable by different die designs with decreased extrusion ratios and adjusted die angles. The effect of surface functionalization critically depends on the substrate material. The different microstructure and the resulting differences in surface chemistry of the two tested tool steels appear to affect the performance of the tool surface functionalization with SAM.

Porous siliconformation and etching process for use in silicon micromachining

Science.gov (United States)

Guilinger, Terry R.; Kelly, Michael J.; Martin, Jr., Samuel B.; Stevenson, Joel O.; Tsao, Sylvia S.

1991-01-01

A reproducible process for uniformly etching silicon from a series of micromechanical structures used in electrical devices and the like includes providing a micromechanical structure having a silicon layer with defined areas for removal thereon and an electrochemical cell containing an aqueous hydrofluoric acid electrolyte. The micromechanical structure is submerged in the electrochemical cell and the defined areas of the silicon layer thereon are anodically biased by passing a current through the electrochemical cell for a time period sufficient to cause the defined areas of the silicon layer to become porous. The formation of the depth of the porous silicon is regulated by controlling the amount of current passing through the electrochemical cell. The micromechanical structure is then removed from the electrochemical cell and submerged in a hydroxide solution to remove the porous silicon. The process is subsequently repeated for each of the series of micromechanical structures to achieve a reproducibility better than 0.3%.

Intracardiac ultrasound scanner using a micromachine (MEMS) actuator.

Science.gov (United States)

Zara, J M; Bobbio, S M; Goodwin-Johansson, S; Smith, S W

2000-01-01

Catheter-based intracardiac ultrasound offers the potential for improved guidance of interventional cardiac procedures. The objective of this research is the development of catheter-based mechanical sector scanners incorporating high frequency ultrasound transducers operating at frequencies up to 20 MHz. The authors' current transducer assembly consists of a single 1.75 mm by 1.75 mm, 20 MHz, PZT element mounted on a 2 mm by 2 mm square, 75 mum thick polyimide table that pivots on 3-mum thick gold plated polyimide hinges. The hinges also serve as the electrical connections to the transducer. This table-mounted transducer is tilted using a miniature linear actuator to produce a sector scan. This linear actuator is an integrated force array (IFA), which is an example of a micromachine, i.e., a microelectromechanical system (MEMS). The IFA is a thin (2.2 mum) polyimide membrane, which consists of a network of hundreds of thousands of micron scale deformable capacitors made from pairs of metallized polyimide plates. IFAs contract with an applied voltage of 30-120 V and have been shown to produce strains as large as 20% and forces of up to 8 dynes. The prototype transducer and actuator assembly was fabricated and interfaced with a GagePCI analog to digital conversion board digitizing 12 bit samples at a rate of 100 MSamples/second housed in a personal computer to create a single channel ultrasound scanner. The deflection of the table transducer in a low viscosity insulating fluid (HFE 7100, 3M) is up to +/-10 degrees at scan rates of 10-60 Hz. Software has been developed to produce real-time sector scans on the PC monitor.

Micromachined fiber optic Fabry-Perot underwater acoustic probe

Science.gov (United States)

Wang, Fuyin; Shao, Zhengzheng; Hu, Zhengliang; Luo, Hong; Xie, Jiehui; Hu, Yongming

2014-08-01

One of the most important branches in the development trend of the traditional fiber optic physical sensor is the miniaturization of sensor structure. Miniature fiber optic sensor can realize point measurement, and then to develop sensor networks to achieve quasi-distributed or distributed sensing as well as line measurement to area monitoring, which will greatly extend the application area of fiber optic sensors. The development of MEMS technology brings a light path to address the problems brought by the procedure of sensor miniaturization. Sensors manufactured by MEMS technology possess the advantages of small volume, light weight, easy fabricated and low cost. In this paper, a fiber optic extrinsic Fabry-Perot interferometric underwater acoustic probe utilizing micromachined diaphragm collaborated with fiber optic technology and MEMS technology has been designed and implemented to actualize underwater acoustic sensing. Diaphragm with central embossment, where the embossment is used to anti-hydrostatic pressure which would largely deflect the diaphragm that induce interferometric fringe fading, has been made by double-sided etching of silicon on insulator. By bonding the acoustic-sensitive diaphragm as well as a cleaved fiber end in ferrule with an outer sleeve, an extrinsic Fabry-Perot interferometer has been constructed. The sensor has been interrogated by quadrature-point control method and tested in field-stable acoustic standing wave tube. Results have been shown that the recovered signal detected by the sensor coincided well with the corresponding transmitted signal and the sensitivity response was flat in frequency range from 10 Hz to 2kHz with the value about -154.6 dB re. 1/μPa. It has been manifest that the designed sensor could be used as an underwater acoustic probe.

Micromachined silicon acoustic delay line with 3D-printed micro linkers and tapered input for improved structural stability and acoustic directivity

International Nuclear Information System (INIS)

Cho, Y; Kumar, A; Xu, S; Zou, J

2016-01-01

Recent studies have shown that micromachined silicon acoustic delay lines can provide a promising solution to achieve real-time photoacoustic tomography without the need for complex transducer arrays and data acquisition electronics. To achieve deeper imaging depth and wider field of view, a longer delay time and therefore delay length are required. However, as the length of the delay line increases, it becomes more vulnerable to structural instability due to reduced mechanical stiffness. In this paper, we report the design, fabrication, and testing of a new silicon acoustic delay line enhanced with 3D printed polymer micro linker structures. First, mechanical deformation of the silicon acoustic delay line (with and without linker structures) under gravity was simulated by using finite element method. Second, the acoustic crosstalk and acoustic attenuation caused by the polymer micro linker structures were evaluated with both numerical simulation and ultrasound transmission testing. The result shows that the use of the polymer micro linker structures significantly improves the structural stability of the silicon acoustic delay lines without creating additional acoustic attenuation and crosstalk. In addition, the improvement of the acoustic acceptance angle of the silicon acoustic delay lines was also investigated to better suppress the reception of unwanted ultrasound signals outside of the imaging plane. These two improvements are expected to provide an effective solution to eliminate current limitations on the achievable acoustic delay time and out-of-plane imaging resolution of micromachined silicon acoustic delay line arrays. (paper)

Novel CNC Grinding Process Control for Nanometric Surface Roughness for Aspheric Space Optical Surfaces

Directory of Open Access Journals (Sweden)

Jeong-Yeol Han

2004-06-01

Full Text Available Optics fabrication process for precision space optical parts includes bound abrasive grinding, loose abrasive lapping and polishing. The traditional bound abrasive grinding with bronze bond cupped diamond wheel leaves the machine marks of about 20 μm rms in height and the subsurface damage of about 1 μm rms in height to be removed by subsequent loose abrasive lapping. We explored an efficient quantitative control of precision CNC grinding. The machining parameters such as grain size, work-piece rotation speed and feed rate were altered while grinding the work-piece surfaces of 20-100 mm in diameter. The input grinding variables and the resulting surface quality data were used to build grinding prediction models using empirical and multi-variable regression analysis. The effectiveness of such grinding prediction models was then examined by running a series of precision CNC grinding operation with a set of controlled input variables and predicted output surface quality indicators. The experiment achieved the predictability down to ±20 nm in height and the surface roughness down to 36 nm in height. This study contributed to improvement of the process efficiency reaching directly the polishing and figuring process without the need for the loose abrasive lapping stage.

Acoustic emission-based in-process monitoring of surface generation in robot-assisted polishing

DEFF Research Database (Denmark)

Pilny, Lukas; Bissacco, Giuliano; De Chiffre, Leonardo

2016-01-01

The applicability of acoustic emission (AE) measurements for in-process monitoring of surface generation in the robot-assisted polishing (RAP) was investigated. Surface roughness measurements require interruption of the process, proper surface cleaning and measurements that sometimes necessitate...... automatic detection of optimal process endpoint allow intelligent process control, creating fundamental elements in development of robust fully automated RAP process for its widespread industrial application....... removal of the part from the machine tool. In this study, stabilisation of surface roughness during polishing rotational symmetric surfaces by the RAP process was monitored by AE measurements. An AE sensor was placed on a polishing arm in direct contact with a bonded abrasive polishing tool...

ENVISAT Land Surface Processes. Phase 2

Science.gov (United States)

vandenHurk, B. J. J. M.; Su, Z.; Verhoef, W.; Menenti, M.; Li, Z.-L.; Wan, Z.; Moene, A. F.; Roerink, G.; Jia, I.

2002-01-01

This is a progress report of the 2nd phase of the project ENVISAT- Land Surface Processes, which has a 3-year scope. In this project, preparative research is carried out aiming at the retrieval of land surface characteristics from the ENVISAT sensors MERIS and AATSR, for assimilation into a system for Numerical Weather Prediction (NWP). Where in the 1st phase a number of first shot experiments were carried out (aiming at gaining experience with the retrievals and data assimilation procedures), the current 2nd phase has put more emphasis on the assessment and improvement of the quality of the retrieved products. The forthcoming phase will be devoted mainly to the data assimilation experiments and the assessment of the added value of the future ENVISAT products for NWP forecast skill. Referring to the retrieval of albedo, leaf area index and atmospheric corrections, preliminary radiative transfer calculations have been carried out that should enable the retrieval of these parameters once AATSR and MERIS data become available. However, much of this work is still to be carried out. An essential part of work in this area is the design and implementation of software that enables an efficient use of MODTRAN(sub 4) radiative transfer code, and during the current project phase familiarization with these new components has been achieved. Significant progress has been made with the retrieval of component temperatures from directional ATSR-images, and the calculation of surface turbulent heat fluxes from these data. The impact of vegetation cover on the retrieved component temperatures appears manageable, and preliminary comparison of foliage temperature to air temperatures were encouraging. The calculation of surface fluxes using the SEBI concept,which includes a detailed model of the surface roughness ratio, appeared to give results that were in reasonable agreement with local measurements with scintillometer devices. The specification of the atmospheric boundary conditions

Scaling behaviour of randomly alternating surface growth processes

International Nuclear Information System (INIS)

Raychaudhuri, Subhadip; Shapir, Yonathan

2002-01-01

The scaling properties of the roughness of surfaces grown by two different processes randomly alternating in time are addressed. The duration of each application of the two primary processes is assumed to be independently drawn from given distribution functions. We analytically address processes in which the two primary processes are linear and extend the conclusions to nonlinear processes as well. The growth scaling exponent of the average roughness with the number of applications is found to be determined by the long time tail of the distribution functions. For processes in which both mean application times are finite, the scaling behaviour follows that of the corresponding cyclical process in which the uniform application time of each primary process is given by its mean. If the distribution functions decay with a small enough power law for the mean application times to diverge, the growth exponent is found to depend continuously on this power-law exponent. In contrast, the roughness exponent does not depend on the timing of the applications. The analytical results are supported by numerical simulations of various pairs of primary processes and with different distribution functions. Self-affine surfaces grown by two randomly alternating processes are common in nature (e.g., due to randomly changing weather conditions) and in man-made devices such as rechargeable batteries

Experimental Investigation of Laser Ablation Characteristics on Nickel-Coated Beryllium Copper

Directory of Open Access Journals (Sweden)

Dongkyoung Lee

2018-03-01

Full Text Available As electronic products are miniaturized, the components of the spring contact probe are made very fine. Current mechanical processing may make it difficult to perform micro-machining with a high degree of precision. A laser is often used for the high precision micro-machining due to its advantages such as a contact-free process, high energy concentration, fast processing time, and applicability to almost every material. The production of micro-electronics using nickel-coated copper is rapidly increasing and laser material processing is becoming a key processing technology owing to high precision requirements. Before applying laser material processing, it is necessary to understand the ablation characteristics of the materials. Therefore, this study systematically investigates the ablation characteristics of nickel-coated beryllium copper. Key laser parameters are pulse duration (4~200 ns and the total accumulated energy (1~1000 mJ. The processed workpiece is evaluated by analyzing the heat affected zone (HAZ, material removal zone (MRZ, and roundness. Moreover, the surface characteristics such as a burr, spatter, and roundness shapes are analyzed using scanning electron microscope (SEM.

Comparison between wire mesh and plate electrodes during Wide-pattern machining on invar fine sheet using through-mask electrochemical micromachining

Energy Technology Data Exchange (ETDEWEB)

Chun, Kwang-ho; Jin, Da-som; Kim, Seong-hyun; Lee, Eun-sang [Inha University, Incheon (Korea, Republic of)

2017-04-15

Many research on the fabrication of Organic light emitting diodes (OLED) shadow masks with high resolution have been carried out because of the development of the smart-display industry. It is the parts of display panel which has millions of micro holes on invar (Fe- Ni) fine sheet. Various techniques such as laser machining, chemical etching and Electrochemical micro-machining (EMM) are used to produce micro-hole arrays. In this study, Through-mask electrochemical machining (TMEMM) combine with portion of photolithography process was applied to fabricate micro-hole arrays on invar fine sheet. The sheet was coated with dry film photoresist. Two types of electrode, plate and mesh, was used to compare the influence of electrode type. The sheet was coated with dry film photoresist with micro- sized through holes. The results were compared in regard to uniformity and taper angle. Compared with the plate electrode, the mesh electrode has better uniformity and taper angle which is important criteria of OLED shadow mask. These results could be used to improve TMEMM for invar fine sheet when it is applied to fabricate micro-hole arrays and help to obtain optical uniformity and desired taper angles.

Dynamics of gas-surface interactions atomic-level understanding of scattering processes at surfaces

CERN Document Server

Díez Muniño, Ricardo

2013-01-01

This book gives a representative survey of the state of the art of research on gas-surface interactions. It provides an overview of the current understanding of gas surface dynamics and, in particular, of the reactive and non-reactive processes of atoms and small molecules at surfaces. Leading scientists in the field, both from the theoretical and the experimental sides, write in this book about their most recent advances. Surface science grew as an interdisciplinary research area over the last decades, mostly because of new experimental technologies (ultra-high vacuum, for instance), as well as because of a novel paradigm, the ‘surface science’ approach. The book describes the second transformation which is now taking place pushed by the availability of powerful quantum-mechanical theoretical methods implemented numerically. In the book, experiment and theory progress hand in hand with an unprecedented degree of accuracy and control. The book presents how modern surface science targets the atomic-level u...

SURFACE CAST IRON STRENGTHENING USING COMBINED LASER AND ULTRASONIC PROCESSING

Directory of Open Access Journals (Sweden)

O. G. Devojno

2013-01-01

Full Text Available The paper provides an analysis of ultrasonic surface plastic deformation and subsequent laser thermal strengthening of gray cast iron parts in the regime of hardening from a solid state with the purpose to obtain strengthened surface layers of bigger depth and less roughness of the processed surface. Program complex ANSYS 11.0 has been used for calculation of temperature fields induced by laser exposure.  The appropriate regime of laser processing without surface fusion has been selected on the basis of the applied complex. The possibility of displacement in the bottom boundary of α–γ-transformation temperature  for СЧ20 with 900 °С up to 800 °С is confirmed due to preliminary ultrasonic surface plastic deformation of the surface that allows to expand technological opportunities of laser quenching  of gray  cast iron from a solid state. 

On-chip micromachined dipole antenna with parasitic radiator for mm-wave wireless systems

KAUST Repository

Sallam, Mai O.; Serry, Mohamed; Shamim, Atif; Sedky, Sherif; Soliman, Ezzeldin A.

2016-01-01

In this paper, we present a micromachined dipole antenna with parasitic radiator. The antenna is designed for operation at 60 GHz. It consists of two Ig/2 dipole radiators fed by coplanar strips waveguide. Two slightly shorter dipoles are placed in proximity to the main radiators. They act as parasitic dipole arms which increase the bandwidth of the antenna. Two versions of the same antenna topology are presented in this paper in which one uses a high resistivity silicon substrate while the other uses a low resistivity one. The proposed antenna was optimized using HFSS and the final design was simulated using both HFSS and CST for verifying the obtained results. Both simulators are in good agreement. They show that the antenna has very good radiation characteristics where its directivity is around 7.5 dBi. The addition of the parasitic arms increased the bandwidth of the antenna from 1.3 GHz (3.62 GHz) to 4.3 GHz (7.44 GHz) when designed on high (low) resistivity silicon substrate.

To study the effect of different electrolytes and their concentrations on electrochemical micromachining

Science.gov (United States)

Singh, Ramandeep

2018-04-01

The machining of materials on micro-meter and sub-micrometre is considered the technology of future. Due to challenging applications of biomedical and aerospace industries, the traditional manufacturing techniques lacks in dimensional accuracy. Thus for such industries, the technique that can control micron tolerances is Electrochemical Micromachining (EMM). Hard metals and alloys can also be machined by this technique. Thus to develop a novel EMM system setup and to investigate the effect of three different electrolytes i.e NaCl, NaNO3 and HCl with their different concentrations, the current study was conducted. Stainless Steel-304 and copper were chosen as the work piece material in the present study. Taguchi L18 orthogonal array was used for the best combination of experiment. According to the present investigation most prominent factor affecting the material removal (MR) comes out was electrolyte. HCl provides the better MR among other electrolytes i.e. NaNO3 and NaCl. The amount of MR increased with the increase in the concentration of electrolyte.

On-chip micromachined dipole antenna with parasitic radiator for mm-wave wireless systems

KAUST Repository

Sallam, Mai O.

2016-12-19

In this paper, we present a micromachined dipole antenna with parasitic radiator. The antenna is designed for operation at 60 GHz. It consists of two Ig/2 dipole radiators fed by coplanar strips waveguide. Two slightly shorter dipoles are placed in proximity to the main radiators. They act as parasitic dipole arms which increase the bandwidth of the antenna. Two versions of the same antenna topology are presented in this paper in which one uses a high resistivity silicon substrate while the other uses a low resistivity one. The proposed antenna was optimized using HFSS and the final design was simulated using both HFSS and CST for verifying the obtained results. Both simulators are in good agreement. They show that the antenna has very good radiation characteristics where its directivity is around 7.5 dBi. The addition of the parasitic arms increased the bandwidth of the antenna from 1.3 GHz (3.62 GHz) to 4.3 GHz (7.44 GHz) when designed on high (low) resistivity silicon substrate.

Wireless Displacement Sensing of Micromachined Spiral-Coil Actuator Using Resonant Frequency Tracking

Directory of Open Access Journals (Sweden)

Mohamed Sultan Mohamed Ali

2014-07-01

Full Text Available This paper reports a method that enables real-time displacement monitoring and control of micromachined resonant-type actuators using wireless radiofrequency (RF. The method is applied to an out-of-plane, spiral-coil microactuator based on shape-memory-alloy (SMA. The SMA spiral coil forms an inductor-capacitor resonant circuit that is excited using external RF magnetic fields to thermally actuate the coil. The actuation causes a shift in the circuit’s resonance as the coil is displaced vertically, which is wirelessly monitored through an external antenna to track the displacements. Controlled actuation and displacement monitoring using the developed method is demonstrated with the microfabricated device. The device exhibits a frequency sensitivity to displacement of 10 kHz/µm or more for a full out-of-plane travel range of 466 µm and an average actuation velocity of up to 155 µm/s. The method described permits the actuator to have a self-sensing function that is passively operated, thereby eliminating the need for separate sensors and batteries on the device, thus realizing precise control while attaining a high level of miniaturization in the device.

Chemical vapor detection using a capacitive micromachined ultrasonic transducer.

Science.gov (United States)

Lee, Hyunjoo J; Park, Kwan Kyu; Kupnik, Mario; Oralkan, O; Khuri-Yakub, Butrus T

2011-12-15

Distributed sensing of gas-phase chemicals using highly sensitive and inexpensive sensors is of great interest for many defense and consumer applications. In this paper we present ppb-level detection of dimethyl methylphosphonate (DMMP), a common simulant for sarin gas, with a ppt-level resolution using an improved capacitive micromachined ultrasonic transducer (CMUT) as a resonant chemical sensor. The improved CMUT operates at a higher resonant frequency of 47.7 MHz and offers an improved mass sensitivity of 48.8 zg/Hz/μm(2) by a factor of 2.7 compared to the previous CMUT sensors developed. A low-noise oscillator using the CMUT resonant sensor as the frequency-selective device was developed for real-time sensing, which exhibits an Allan deviation of 1.65 Hz (3σ) in the presence of a gas flow; this translates into a mass resolution of 80.5 zg/μm(2). The CMUT resonant sensor is functionalized with a 50-nm thick DKAP polymer developed at Sandia National Laboratory for dimethyl methylphosphonate (DMMP) detection. To demonstrate ppb-level detection of the improved chemical sensor system, the sensor performance was tested at a certified lab (MIT Lincoln Laboratory), which is equipped with an experimental chemical setup that reliably and accurately delivers a wide range of low concentrations down to 10 ppb. We report a high volume sensitivity of 34.5 ± 0.79 pptv/Hz to DMMP and a good selectivity of the polymer to DMMP with respect to dodecane and 1-octanol.

Effect of different machining processes on the tool surface integrity and fatigue life

Energy Technology Data Exchange (ETDEWEB)

Cao, Chuan Liang [College of Mechanical and Electrical Engineering, Nanchang University, Nanchang (China); Zhang, Xianglin [School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan (China)

2016-08-15

Ultra-precision grinding, wire-cut electro discharge machining and lapping are often used to machine the tools in fine blanking industry. And the surface integrity from these machining processes causes great concerns in the research field. To study the effect of processing surface integrity on the fine blanking tool life, the surface integrity of different tool materials under different processing conditions and its influence on fatigue life were thoroughly analyzed in the present study. The result shows that the surface integrity of different materials was quite different on the same processing condition. For the same tool material, the surface integrity on varying processing conditions was quite different too and deeply influenced the fatigue life.

An Experimental Study of the Dropwise Condensation on Physically Processed Surface

International Nuclear Information System (INIS)

Choi, Jaeyoung; Chang, Soonheung; Watanabe, N.; Sambuichi, T.; Shiota, D.; Aritomi, M.

2013-01-01

Recent research by Kawakubo et al. derived empirical condensation heat transfer correlation suitable for wider range of operating condition in presence of non-condensable gas. However, their proposals of PCCS are focused on plane tube surface. To design better PCCS heat exchanger with high heat transfer coefficient new treatment on condensation surface can be considered in order to maintain dropwise condensation, the heat transfer coefficient of which has an order of magnitude larger than those of film condensation. Advanced research measure dropwise condensation heat transfer coefficient of Au and Cr coated surface based on number of droplet and droplet growth rate. However, coated surface is not desirable in power plant due to its duration of few years. On the other hand, physical processing (micro holes and patterns) on stainless steel and titanium surface is expected to perform better heat transfer, also is durable for the whole reactor lifetime. Since there is no published research about dropwise condensation for physically processed surface on SUS and Ti, the purposes of this research are to measure the condensation heat transfer coefficient and analyze its mechanism of enhanced heat transfer of treated SUS and Ti commonly used to nuclear plant. In the comparison of theoretical equation and experiment, it shows same result that heat transfer coefficient is proportional to maximum droplet diameter power to -0.321. Moreover, in the comparison of bare and processed surface, heat transfer coefficient decreases in processed surface

A simple process to achieve microchannels geometries able to produce hydrodynamic cavitation

Science.gov (United States)

Qiu, X.; Cherief, W.; Colombet, D.; Ayela, F.

2017-04-01

We present a simple process to perform microchannels in which cavitating two phase flows are easily producible. Up to now, hydrodynamic cavitation ‘on a chip’ was reached with small flow rates inside microchannels whose micromachining had involved a deep reactive ion etching (D-RIE). The process we present here does not require a D-RIE reactor, as it is only funded on a wet etching of silicon. It leads to a so-called microstep profile, and large cavitating flow rates become possible together with moderate pressure drops.

A simple process to achieve microchannels geometries able to produce hydrodynamic cavitation

International Nuclear Information System (INIS)

Qiu, X; Cherief, W; Colombet, D; Ayela, F

2017-01-01

We present a simple process to perform microchannels in which cavitating two phase flows are easily producible. Up to now, hydrodynamic cavitation ‘on a chip’ was reached with small flow rates inside microchannels whose micromachining had involved a deep reactive ion etching (D-RIE). The process we present here does not require a D-RIE reactor, as it is only funded on a wet etching of silicon. It leads to a so-called microstep profile, and large cavitating flow rates become possible together with moderate pressure drops. (technical note)

High surface area carbon and process for its production

Energy Technology Data Exchange (ETDEWEB)

Romanos, Jimmy; Burress, Jacob; Pfeifer, Peter; Rash, Tyler; Shah, Parag; Suppes, Galen

2016-12-13

Activated carbon materials and methods of producing and using activated carbon materials are provided. In particular, biomass-derived activated carbon materials and processes of producing the activated carbon materials with prespecified surface areas and pore size distributions are provided. Activated carbon materials with preselected high specific surface areas, porosities, sub-nm (<1 nm) pore volumes, and supra-nm (1-5 nm) pore volumes may be achieved by controlling the degree of carbon consumption and metallic potassium intercalation into the carbon lattice during the activation process.

Development of micro capacitive accelerometer for subsurface microseismic measurement. Second Report; Micromachining ni yoru chika danseiha kenshutsu no tame no silicone yoryogata kasokudo sensor no seisaku. 2

Energy Technology Data Exchange (ETDEWEB)

Nishizawa, M; Lim, G; Niitsuma, H; Esashi, M [Tohoku University, Sendai (Japan)

1997-10-22

Micromachining-aided manufacture is under way of a silicon capacitive accelerator sensor, high in sensitivity and broad in bandwidth, for detecting subsurface microseismic waves. The sensor detects acceleration by use of changes in capacities of the top and bottom capacitors generated when a spring-supported weight experiences displacement upon application of acceleration to the said weight. A diode bridge circuit is employed as the circuit for detecting acceleration. As for sensitivity of the sensor, when the virtual noise inputted into the electronic circuit is presumed at 1{mu}V and the circuit driving voltage at 5V, the sensor minimum detectability will be 2.5mgal in the presence of a 3{mu}m gap between the weight and an electrode plate. The natural vibration frequency is set at 1kHz. Such specifications may be realized using the current micromachining technology, and possibilities are that the bandwidth will be further expanded when the sensor is used in a servo-type configuration. The effort is still at the stage of acceleration sensor manufacturing, with a stopper just formed for the silicon weight. 9 refs., 6 figs., 1 tab.

Two photon processes in surface photovoltage spectroscopy

International Nuclear Information System (INIS)

Craig, R.P.; Thurgate, S.M.

1996-01-01

Full text: A significant mid-gap effect has been found in Surface Photovoltage Spectroscopy measurements of cleaved GaAs, InP and Si wafer which is normally interpreted as arising from transitions between surface states and band edges. This large mid-gap effect common to various materials is puzzling as such a high proportion of mid-gap states seems unlikely. Most theories of surface states predict states that tail from the band edges into the gap or states that have a well defined energy in the gap. None propose a large state exactly at E G /2. We recently investigated the variation in SPS spectra with flux density. We find a non-linear correlation in the magnitude of Band-Bending arising from mid-gap and band-gap photon energies. We suggest that the mid-gap feature is due to a two photon absorption process leading to carrier pair generation mediated by mid-gap states in the continuum of band-gap surface states

Quantification of chemical transport processes from the soil to surface runoff.

Science.gov (United States)

Tian, Kun; Huang, Chi-Hua; Wang, Guang-Qian; Fu, Xu-Dong; Parker, Gary

2013-01-01

There is a good conceptual understanding of the processes that govern chemical transport from the soil to surface runoff, but few studies have actually quantified these processes separately. Thus, we designed a laboratory flow cell and experimental procedures to quantify the chemical transport from soil to runoff water in the following individual processes: (i) convection with a vertical hydraulic gradient, (ii) convection via surface flow or the Bernoulli effect, (iii) diffusion, and (iv) soil loss. We applied different vertical hydraulic gradients by setting the flow cell to generate different seepage or drainage conditions. Our data confirmed the general form of the convection-diffusion equation. However, we now have additional quantitative data that describe the contribution of each individual chemical loading process in different surface runoff and soil hydrological conditions. The results of this study will be useful for enhancing our understanding of different geochemical processes in the surface soil mixing zone. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Surface topography of parallel grinding process for nonaxisymmetric aspheric lens

International Nuclear Information System (INIS)

Zhang Ningning; Wang Zhenzhong; Pan Ri; Wang Chunjin; Guo Yinbiao

2012-01-01

Workpiece surface profile, texture and roughness can be predicted by modeling the topography of wheel surface and modeling kinematics of grinding process, which compose an important part of precision grinding process theory. Parallel grinding technology is an important method for nonaxisymmetric aspheric lens machining, but there is few report on relevant simulation. In this paper, a simulation method based on parallel grinding for precision machining of aspheric lens is proposed. The method combines modeling the random surface of wheel and modeling the single grain track based on arc wheel contact points. Then, a mathematical algorithm for surface topography is proposed and applied in conditions of different machining parameters. The consistence between the results of simulation and test proves that the algorithm is correct and efficient. (authors)

Simulation of dynamic processes when machining transition surfaces of stepped shafts

Science.gov (United States)

Maksarov, V. V.; Krasnyy, V. A.; Viushin, R. V.

2018-03-01

The paper addresses the characteristics of stepped surfaces of parts categorized as "solids of revolution". It is noted that in the conditions of transition modes during the switch to end surface machining, there is cutting with varied load intensity in the section of the cut layer, which leads to change in cutting force, onset of vibrations, an increase in surface layer roughness, a decrease of size precision, and increased wear of a tool's cutting edge. This work proposes a method that consists in developing a CNC program output code that allows one to process complex forms of stepped shafts with only one machine setup. The authors developed and justified a mathematical model of a technological system for mechanical processing with consideration for the resolution of tool movement at the stages of transition processes to assess the dynamical stability of a system in the process of manufacturing stepped surfaces of parts of “solid of revolution” type.

The theory of development of surface morphology by sputter erosion processes

International Nuclear Information System (INIS)

Carter, G.; Nobes, M.J.

1984-01-01

When a surface is bombarded by an energetic ion flux a rich variety of surface structures are observed to develop at the atomic, microscopic and macroscopic scales. Such structures include elevated, with respect to the surrounding surface, features such as mesas or plateaux, ridges, cones and pyramids and depressed features such as etch pits and cavities. These elementary features may be isolated or in profusion and frequently repetitive patterns of coordinated pyramidal structures, etch pits, surface ledges or facets and ripple or wave-like structures occur. The majority of the features arise rather directly from the erosion action of the sputtering process, particularly from differential erosion processes at different surface localities. The authors outline a general approach to sputter erosion induced surface morphology development based on the concept of the surface as an advancing wave. (Auth.)

Electrolytic in process dressing (ELID) applied to double side grinding of ceramic materials

Science.gov (United States)

Spanu, Cristian E.

The objective of the present work is to design, optimize, and validate an electrolytic in-process dressing (ELID)-assisted double side grinding process for finishing advanced ceramic components. To attain this objective, an original ELID double side grinding system was designed, fabricated, and operated at Precision Micro-Machining Center at The University of Toledo, Ohio. The ELID technique was selected from among other options to assure the in-situ dressing of the metal-bonded superabrasive grinding wheel and to maintain its cutting ability throughout the operation, which is, otherwise, a challenging enterprise. Optimizing the ELID double side grinding process parameters is an important goal of the present study. To achieve this goal, a complex integrated model was developed and validated through extensive experimental testing. Four analytical computerized models were developed and integrated: (1) an improved kinematic model of double side grinding accounting for workpiece rotation, which is used to simulate the grinding trajectories; (2) a microscopic model of the interaction between a single diamond grit and the work surface, which is used to predict the volume of material removed; (3) a stochastic model for the topographical characterization of the superabrasive wheel, which leads to a new prediction method of depth of indentation; and (4) an electrolytic oxidation model, which explains the dynamics of the oxide layer. In order to validate the models and to confirm the optimized process, experimental tests were conducted under different conditions: with vitrified and metallic bond grinding wheels, with various average grain sizes of diamond grits, with different superabrasive concentrations, with different grinding fluids, with and without ELID assistance. Our findings show that an optimized ceramic double side grinding process using fine diamond grit is more efficient than lapping in producing very fine surfaces. The experiments confirmed the superiority of

CMOS Compatibility of a Micromachining Process Developed for Semiconductor Neural Probe

National Research Council Canada - National Science Library

An, S

2001-01-01

.... Test transistor patterns generated using standard CMOS fabrication line were exposed to a post-CMOS probe making process including dielectric deposition, gold metalization and the dry etching step...

Development of an SU-8 MEMS process with two metal electrodes using amorphous silicon as a sacrificial material

KAUST Repository

Ramadan, Khaled S.

2013-02-08

This work presents an SU-8 surface micromachining process using amorphous silicon as a sacrificial material, which also incorporates two metal layers for electrical excitation. SU-8 is a photo-patternable polymer that is used as a structural layer for MEMS and microfluidic applications due to its mechanical properties, biocompatibility and low cost. Amorphous silicon is used as a sacrificial layer in MEMS applications because it can be deposited in large thicknesses, and can be released in a dry method using XeF2, which alleviates release-based stiction problems related to MEMS applications. In this work, an SU-8 MEMS process was developed using ;-Si as a sacrificial layer. Two conductive metal electrodes were integrated in this process to allow out-of-plane electrostatic actuation for applications like MEMS switches and variable capacitors. In order to facilitate more flexibility for MEMS designers, the process can fabricate dimples that can be conductive or nonconductive. Additionally, this SU-8 process can fabricate SU-8 MEMS structures of a single layer of two different thicknesses. Process parameters were optimized for two sets of thicknesses: thin (5-10 m) and thick (130 m). The process was tested fabricating MEMS switches, capacitors and thermal actuators. © 2013 IOP Publishing Ltd.

Effect of the Detector Width and Gas Pressure on the Frequency Response of a Micromachined Thermal Accelerometer

Directory of Open Access Journals (Sweden)

Johann Courteaud

2011-05-01

Full Text Available In the present work, the design and the environmental conditions of a micromachined thermal accelerometer, based on convection effect, are discussed and studied in order to understand the behavior of the frequency response evolution of the sensor. It has been theoretically and experimentally studied with different detector widths, pressure and gas nature. Although this type of sensor has already been intensively examined, little information concerning the frequency response modeling is currently available and very few experimental results about the frequency response are reported in the literature. In some particular conditions, our measurements show a cut-off frequency at −3 dB greater than 200 Hz. By using simple cylindrical and planar models of the thermal accelerometer and an equivalent electrical circuit, a good agreement with the experimental results has been demonstrated.

Improving the work function of the niobium surface of SRF cavities by plasma processing

International Nuclear Information System (INIS)

Tyagi, P.V.; Doleans, M.; Hannah, B.; Afanador, R.; McMahan, C.; Stewart, S.; Mammosser, J.; Howell, M.; Saunders, J.; Degraff, B.; Kim, S.-H.

2016-01-01

Highlights: • An in situ plasma processing for SNS SRF cavities has been developed to remove hydrocarbons from cavity surface. • Reactive oxygen plasma is very effective to remove hydrocarbons from niobium top surface. • Reactive oxygen plasma processing increases the work function of niobium surface in the range of 0.5–1.0 eV. • It was observed that hydrocarbons can migrate at plasma cleaned top surface from near surface regions when waiting in vacuum at room temperature. • Multiple cycles of plasma processing with waiting periods in between was found beneficial to mitigate such hydrocarbons migration at plasma cleaned surface. - Abstract: An in situ plasma processing technique using chemically reactive oxygen plasma to remove hydrocarbons from superconducting radio frequency cavity surfaces at room temperature has been developed at the spallation neutron source, at Oak Ridge National Laboratory. To understand better the interaction between the plasma and niobium surface, surface studies on small samples were performed. In this article, we report the results from those surface studies. The results show that plasma processing removes hydrocarbons from top surface and improves the surface work function by 0.5–1.0 eV. Improving the work function of RF surface of cavities can help to improve their operational performance.

Monitoring tablet surface roughness during the film coating process

DEFF Research Database (Denmark)

Seitavuopio, Paulus; Heinämäki, Jyrki; Rantanen, Jukka

2006-01-01

The purpose of this study was to evaluate the change of surface roughness and the development of the film during the film coating process using laser profilometer roughness measurements, SEM imaging, and energy dispersive X-ray (EDX) analysis. Surface roughness and texture changes developing during...... the process of film coating tablets were studied by noncontact laser profilometry and scanning electron microscopy (SEM). An EDX analysis was used to monitor the magnesium stearate and titanium dioxide of the tablets. The tablet cores were film coated with aqueous hydroxypropyl methylcellulose, and the film...... coating was performed using an instrumented pilot-scale side-vented drum coater. The SEM images of the film-coated tablets showed that within the first 30 minutes, the surface of the tablet cores was completely covered with a thin film. The magnesium signal that was monitored by SEM-EDX disappeared after...

Photon technology. Laser process technology; Photon technology. Laser process gijutsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

For developing laser process technology by interaction between substance and photon, the present state, system, R and D issues and proposal of such technology were summarized. Development of the photon technology aims at the modification of bonding conditions of substances by quantum energy of photon, and the new process technology for generating ultra- high temperature and pressure fields by concentrating photon on a minute region. Photon technology contributes to not only the conventional mechanical and thermal forming and removal machining but also function added machining (photon machining) in quantum level and new machining technology ranging from macro- to micro-machining, creating a new industrial field. This technology extends various fields from the basis of physics and chemistry to new bonding technology. Development of a compact high-quality high-power high-efficiency photon source, and advanced photon transmission technology are necessary. The basic explication of an unsolved physicochemical phenomenon related to photon and substance, and development of related application technologies are essential. 328 refs., 147 figs., 13 tabs.

Development of optical interference-type micro accelerometer for subsurface microseismic measurement; Micromachining ni yoru chika danseiha keisoku no tame no hikari kanshogata kasokudo sensor no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Hirata, K; Niitsuma, H; Esashi, M [Tohoku University, Sendai (Japan). Faculty of Engineering

1997-10-22

Manufacture is under way of an optical interference-type micro accelerometer making use of the micromachining technology and an optical fiber measuring system for detecting microseismic waves in the ground. The sensor is required to be capable of detecting acceleration 0.1-1gal in amplitude, to be flat in amplitude characteristic in a frequency range of 10Hz-several kHz, to be ensured of straight phase characteristics to enable the measurement of transient phenomena, to be low in cross sensitivity, and to be high in resistance to water, pressure, and heat. The sensor is constructed in the following way. In the process for treating silicon, anisotropic etching is performed for the formation of a gap between the fiber end face and oscillator, boron is diffused, a stopper is formed, and then the silicon is subjected to penetrating etching. In the process for the optical fiber section, an optical fiber is inserted into a glass tube and fixed by an adhesive agent, and then the glass tube end face is polished, this together with the fiber end. Indium-tin oxide is sputtered onto the glass tube end. Finally, the sensor is assembled. 5 refs., 4 figs., 1 tab.

Micromachined sensor for stress measurement and micromechanical study of free-standing thin films for MEMS applications

Science.gov (United States)

Zhang, Ping

Microelectromechanical systems (MEMS) have a wide range of applications. In the field of wireless and microwave technology, considerable attention has been given to the development and integration of MEMS-based RF (radio frequency) components. An RF MEMS switch requires low insertion loss, high isolation, and low actuation voltage - electrical aspects that have been extensively studied. The mechanical requirements of the switch, such as low sensitivity to built-in stress and high reliability, greatly depend on the micromechanical properties of the switch materials, and have not been thoroughly explored. RF MEMS switches are typically in the form of a free-standing thin film structure. Large stress gradients and across-wafer stress variations developed during fabrication severely degrade their electrical performance. A micromachined stress measurement sensor has been developed that can potentially be employed for in-situ monitoring of stress evolution and stress variation. The sensors were micromachined using five masks on two wafer levels, each measuring 5x3x1 mm. They function by means of an electron tunneling mechanism, where a 2x2 mm silicon nitride membrane elastically deflects under an applied deflection voltage via an external feedback circuitry. For the current design, the sensors are capable of measuring tensile stresses up to the GPa range under deflection voltages of 50--100 V. Sensor functionality was studied by finite element modeling and a theoretical analysis of square membrane deflection. While the mechanical properties of thin films on substrates have been extensively studied, studies of free-standing thin films have been limited due to the practical difficulties in sample handling and testing. Free-standing Al and Al-Ti thin films specimens have been successfully fabricated and microtensile and stress relaxation tests have been performed using a custom-designed micromechanical testing apparatus. A dedicated TEM (transmission electron microscopy

Influence of Si wafer thinning processes on (sub)surface defects

Energy Technology Data Exchange (ETDEWEB)

Inoue, Fumihiro, E-mail: fumihiro.inoue@imec.be [Imec, Kapeldreef 75, 3001 Leuven (Belgium); Jourdain, Anne; Peng, Lan; Phommahaxay, Alain; De Vos, Joeri; Rebibis, Kenneth June; Miller, Andy; Sleeckx, Erik; Beyne, Eric [Imec, Kapeldreef 75, 3001 Leuven (Belgium); Uedono, Akira [Division of Applied Physics, Faculty of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan)

2017-05-15

Highlights: • Mono-vacancy free Si-thinning can be accomplished by combining several thinning techniques. • The grinding damage needs to be removed prior to dry etching, otherwise vacancies remain in the Si at a depth around 0.5 to 2 μm after Si wafer thickness below 5 μm. • The surface of grinding + CMP + dry etching is equivalent mono vacancy level as that of grinding + CMP. - Abstract: Wafer-to-wafer three-dimensional (3D) integration with minimal Si thickness can produce interacting multiple devices with significantly scaled vertical interconnections. Realizing such a thin 3D structure, however, depends critically on the surface and subsurface of the remaining backside Si after the thinning processes. The Si (sub)surface after mechanical grinding has already been characterized fruitfully for a range of few dozen of μm. Here, we expand the characterization of Si (sub)surface to 5 μm thickness after thinning process on dielectric bonded wafers. The subsurface defects and damage layer were investigated after grinding, chemical mechanical polishing (CMP), wet etching and plasma dry etching. The (sub)surface defects were characterized using transmission microscopy, atomic force microscopy, and positron annihilation spectroscopy. Although grinding provides the fastest removal rate of Si, the surface roughness was not compatible with subsequent processing. Furthermore, mechanical damage such as dislocations and amorphous Si cannot be reduced regardless of Si thickness and thin wafer handling systems. The CMP after grinding showed excellent performance to remove this grinding damage, even though the removal amount is 1 μm. For the case of Si thinning towards 5 μm using grinding and CMP, the (sub)surface is atomic scale of roughness without vacancy. For the case of grinding + dry etch, vacancy defects were detected in subsurface around 0.5–2 μm. The finished surface after wet etch remains in the nm scale in the strain region. By inserting a CMP step in

Air/surface exchange processes of mercury and their linkage to atmospheric pools

International Nuclear Information System (INIS)

Bahlmann, Enno; Ebinghaus, Ralf

2001-01-01

The atmospheric mercury cycle is strongly linked to the terrestrial, aquatic and biologic cycle of mercury via air/surface exchange processes. In order to quantify mercury fluxes from and to the atmosphere to predict local and regional source contributions the methods for flux measurements as well as the physicochemical factors controlling air/surface exchange processes must be assessed. We will describe methods for the determination of mercury and mercury species in ambient air which are basic for investigation of air/surface exchange processes. Further on we will describe approaches for studying the physicochemical factors controlling this processes by using a new laboratory flux measurement system. (author)

Dominant rate process of silicon surface etching by hydrogen chloride gas

International Nuclear Information System (INIS)

Habuka, Hitoshi; Suzuki, Takahiro; Yamamoto, Sunao; Nakamura, Akio; Takeuchi, Takashi; Aihara, Masahiko

2005-01-01

Silicon surface etching and its dominant rate process are studied using hydrogen chloride gas in a wide concentration range of 1-100% in ambient hydrogen at atmospheric pressure in a temperature range of 1023-1423 K, linked with the numerical calculation accounting for the transport phenomena and the surface chemical reaction in the entire reactor. The etch rate, the gaseous products and the surface morphology are experimentally evaluated. The dominant rate equation accounting for the first-order successive reactions at silicon surface by hydrogen chloride gas is shown to be valid. The activation energy of the dominant surface process is evaluated to be 1.5 x 10 5 J mol - 1 . The silicon deposition by the gaseous by-product, trichlorosilane, is shown to have a negligible influence on the silicon etch rate

Superhydrophobic Surface Coatings for Microfluidics and MEMs.

Energy Technology Data Exchange (ETDEWEB)

Branson, Eric D.; Singh, Seema [Sandia National Laboratories, Livermore, CA; Houston, Jack E.; van Swol, Frank B.; Brinker, C. Jeffrey

2006-11-01

Low solid interfacial energy and fractally rough surface topography confer to Lotus plants superhydrophobic (SH) properties like high contact angles, rolling and bouncing of liquid droplets, and self-cleaning of particle contaminants. This project exploits the porous fractal structure of a novel, synthetic SH surface for aerosol collection, its self-cleaning properties for particle concentration, and its slippery nature 3 to enhance the performance of fluidic and MEMS devices. We propose to understand fundamentally the conditions needed to cause liquid droplets to roll rather than flow/slide on a surface and how this %22rolling transition%22 influences the boundary condition describing fluid flow in a pipe or micro-channel. Rolling of droplets is important for aerosol collection strategies because it allows trapped particles to be concentrated and transported in liquid droplets with no need for a pre-defined/micromachined fluidic architecture. The fluid/solid boundary condition is important because it governs flow resistance and rheology and establishes the fluid velocity profile. Although many research groups are exploring SH surfaces, our team is the first to unambiguously determine their effects on fluid flow and rheology. SH surfaces could impact all future SNL designs of collectors, fluidic devices, MEMS, and NEMS. Interfaced with inertial focusing aerosol collectors, SH surfaces would allow size-specific particle populations to be collected, concentrated, and transported to a fluidic interface without loss. In microfluidic systems, we expect to reduce the energy/power required to pump fluids and actuate MEMS. Plug-like (rather than parabolic) velocity profiles can greatly improve resolution of chip-based separations and enable unprecedented control of concentration profiles and residence times in fluidic-based micro-reactors. Patterned SH/hydrophilic channels could induce mixing in microchannels and enable development of microflow control elements

Advancing MEMS Technology Usage through the MUMPS (Multi-User MEMS Processes) Program

Science.gov (United States)

Koester, D. A.; Markus, K. W.; Dhuler, V.; Mahadevan, R.; Cowen, A.

1995-01-01

In order to help provide access to advanced micro-electro-mechanical systems (MEMS) technologies and lower the barriers for both industry and academia, the Microelectronic Center of North Carolina (MCNC) and ARPA have developed a program which provides users with access to both MEMS processes and advanced electronic integration techniques. The four distinct aspects of this program, the multi-user MEMS processes (MUMP's), the consolidated micro-mechanical element library, smart MEMS, and the MEMS technology network are described in this paper. MUMP's is an ARPA-supported program created to provide inexpensive access to MEMS technology in a multi-user environment. It is both a proof-of-concept and educational tool that aids in the development of MEMS in the domestic community. MUMP's technologies currently include a 3-layer poly-silicon surface micromachining process and LIGA (lithography, electroforming, and injection molding) processes that provide reasonable design flexibility within set guidelines. The consolidated micromechanical element library (CaMEL) is a library of active and passive MEMS structures that can be downloaded by the MEMS community via the internet. Smart MEMS is the development of advanced electronics integration techniques for MEMS through the application of flip chip technology. The MEMS technology network (TechNet) is a menu of standard substrates and MEMS fabrication processes that can be purchased and combined to create unique process flows. TechNet provides the MEMS community greater flexibility and enhanced technology accessibility.

Gaussian process based intelligent sampling for measuring nano-structure surfaces

Science.gov (United States)

Sun, L. J.; Ren, M. J.; Yin, Y. H.

2016-09-01

Nanotechnology is the science and engineering that manipulate matters at nano scale, which can be used to create many new materials and devices with a vast range of applications. As the nanotech product increasingly enters the commercial marketplace, nanometrology becomes a stringent and enabling technology for the manipulation and the quality control of the nanotechnology. However, many measuring instruments, for instance scanning probe microscopy, are limited to relatively small area of hundreds of micrometers with very low efficiency. Therefore some intelligent sampling strategies should be required to improve the scanning efficiency for measuring large area. This paper presents a Gaussian process based intelligent sampling method to address this problem. The method makes use of Gaussian process based Bayesian regression as a mathematical foundation to represent the surface geometry, and the posterior estimation of Gaussian process is computed by combining the prior probability distribution with the maximum likelihood function. Then each sampling point is adaptively selected by determining the position which is the most likely outside of the required tolerance zone among the candidates and then inserted to update the model iteratively. Both simulationson the nominal surface and manufactured surface have been conducted on nano-structure surfaces to verify the validity of the proposed method. The results imply that the proposed method significantly improves the measurement efficiency in measuring large area structured surfaces.

Method for atmospheric pressure reactive atom plasma processing for surface modification

Science.gov (United States)

Carr, Jeffrey W [Livermore, CA

2009-09-22

Reactive atom plasma processing can be used to shape, polish, planarize and clean the surfaces of difficult materials with minimal subsurface damage. The apparatus and methods use a plasma torch, such as a conventional ICP torch. The workpiece and plasma torch are moved with respect to each other, whether by translating and/or rotating the workpiece, the plasma, or both. The plasma discharge from the torch can be used to shape, planarize, polish, and/or clean the surface of the workpiece, as well as to thin the workpiece. The processing may cause minimal or no damage to the workpiece underneath the surface, and may involve removing material from the surface of the workpiece.

Surface Nano Structures Manufacture Using Batch Chemical Processing Methods for Tooling Applications

DEFF Research Database (Denmark)

Tosello, Guido; Calaon, Matteo; Gavillet, J.

2011-01-01

The patterning of large surface areas with nano structures by using chemical batch processes to avoid using highenergy intensive nano machining processes was investigated. The capability of different surface treatment methods of creating micro and nano structured adaptable mould inserts for subse...

Surface processes during purification of InP quantum dots

Directory of Open Access Journals (Sweden)

Natalia Mordvinova

2014-08-01

Full Text Available Recently, a new simple and fast method for the synthesis of InP quantum dots by using phosphine as phosphorous precursor and myristic acid as surface stabilizer was reported. Purification after synthesis is necessary to obtain samples with good optical properties. Two methods of purification were compared and the surface processes which occur during purification were studied. Traditional precipitation with acetone is accompanied by a small increase in photoluminescence. It occurs that during the purification the hydrolysis of the indium precursor takes place, which leads to a better surface passivation. The electrophoretic purification technique does not increase luminescence efficiency but yields very pure quantum dots in only a few minutes. Additionally, the formation of In(OH3 during the low temperature synthesis was explained. Purification of quantum dots is a very significant part of postsynthetical treatment that determines the properties of the material. But this subject is not sufficiently discussed in the literature. The paper is devoted to the processes that occur at the surface of quantum dots during purification. A new method of purification, electrophoresis, is investigated and described in particular.

Large-area homogeneous periodic surface structures generated on the surface of sputtered boron carbide thin films by femtosecond laser processing

Energy Technology Data Exchange (ETDEWEB)

Serra, R., E-mail: ricardo.serra@dem.uc.pt [SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra (Portugal); Oliveira, V. [ICEMS-Instituto de Ciência e Engenharia de Materiais e Superfícies, Avenida Rovisco Pais no 1, 1049-001 Lisbon (Portugal); Instituto Superior de Engenharia de Lisboa, Avenida Conselheiro Emídio Navarro no 1, 1959-007 Lisbon (Portugal); Oliveira, J.C. [SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra (Portugal); Kubart, T. [The Ångström Laboratory, Solid State Electronics, P.O. Box 534, SE-751 21 Uppsala (Sweden); Vilar, R. [Instituto Superior de Engenharia de Lisboa, Avenida Conselheiro Emídio Navarro no 1, 1959-007 Lisbon (Portugal); Instituto Superior Técnico, Avenida Rovisco Pais no 1, 1049-001 Lisbon (Portugal); Cavaleiro, A. [SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra (Portugal)

2015-03-15

Highlights: • Large-area LIPSS were formed by femtosecond laser processing B-C films surface. • The LIPSS spatial period increases with laser fluence (140–200 nm). • Stress-related sinusoidal-like undulations were formed on the B-C films surface. • The undulations amplitude (down to a few nanometres) increases with laser fluence. • Laser radiation absorption increases with surface roughness. - Abstract: Amorphous and crystalline sputtered boron carbide thin films have a very high hardness even surpassing that of bulk crystalline boron carbide (≈41 GPa). However, magnetron sputtered B-C films have high friction coefficients (C.o.F) which limit their industrial application. Nanopatterning of materials surfaces has been proposed as a solution to decrease the C.o.F. The contact area of the nanopatterned surfaces is decreased due to the nanometre size of the asperities which results in a significant reduction of adhesion and friction. In the present work, the surface of amorphous and polycrystalline B-C thin films deposited by magnetron sputtering was nanopatterned using infrared femtosecond laser radiation. Successive parallel laser tracks 10 μm apart were overlapped in order to obtain a processed area of about 3 mm{sup 2}. Sinusoidal-like undulations with the same spatial period as the laser tracks were formed on the surface of the amorphous boron carbide films after laser processing. The undulations amplitude increases with increasing laser fluence. The formation of undulations with a 10 μm period was also observed on the surface of the crystalline boron carbide film processed with a pulse energy of 72 μJ. The amplitude of the undulations is about 10 times higher than in the amorphous films processed at the same pulse energy due to the higher roughness of the films and consequent increase in laser radiation absorption. LIPSS formation on the surface of the films was achieved for the three B-C films under study. However, LIPSS are formed under

Large-area homogeneous periodic surface structures generated on the surface of sputtered boron carbide thin films by femtosecond laser processing

International Nuclear Information System (INIS)

Serra, R.; Oliveira, V.; Oliveira, J.C.; Kubart, T.; Vilar, R.; Cavaleiro, A.

2015-01-01

Highlights: • Large-area LIPSS were formed by femtosecond laser processing B-C films surface. • The LIPSS spatial period increases with laser fluence (140–200 nm). • Stress-related sinusoidal-like undulations were formed on the B-C films surface. • The undulations amplitude (down to a few nanometres) increases with laser fluence. • Laser radiation absorption increases with surface roughness. - Abstract: Amorphous and crystalline sputtered boron carbide thin films have a very high hardness even surpassing that of bulk crystalline boron carbide (≈41 GPa). However, magnetron sputtered B-C films have high friction coefficients (C.o.F) which limit their industrial application. Nanopatterning of materials surfaces has been proposed as a solution to decrease the C.o.F. The contact area of the nanopatterned surfaces is decreased due to the nanometre size of the asperities which results in a significant reduction of adhesion and friction. In the present work, the surface of amorphous and polycrystalline B-C thin films deposited by magnetron sputtering was nanopatterned using infrared femtosecond laser radiation. Successive parallel laser tracks 10 μm apart were overlapped in order to obtain a processed area of about 3 mm 2 . Sinusoidal-like undulations with the same spatial period as the laser tracks were formed on the surface of the amorphous boron carbide films after laser processing. The undulations amplitude increases with increasing laser fluence. The formation of undulations with a 10 μm period was also observed on the surface of the crystalline boron carbide film processed with a pulse energy of 72 μJ. The amplitude of the undulations is about 10 times higher than in the amorphous films processed at the same pulse energy due to the higher roughness of the films and consequent increase in laser radiation absorption. LIPSS formation on the surface of the films was achieved for the three B-C films under study. However, LIPSS are formed under different

Thermal Diffusion Processes in Metal-Tip-Surface Interactions: Contact Formation and Adatom Mobility

DEFF Research Database (Denmark)

Sørensen, Mads Reinholdt; Jacobsen, Karsten Wedel; Jonsson, Hannes

1996-01-01

and the surface can occur by a sequence of atomic hop and exchange processes which become active on a millisecond time scale when the tip is about 3-5 Angstrom from the surface. Adatoms on the surface are stabilized by the presence of the tip and energy barriers for diffusion processes in the region under the tip......We have carried out computer simulations to identify and characterize various thermally activated atomic scale processes that can play an important role in room temperature experiments where a metal tip is brought close to a metal surface. We find that contact formation between the tip...

Finite Element Method in Machining Processes

CERN Document Server

Markopoulos, Angelos P

2013-01-01

Finite Element Method in Machining Processes provides a concise study on the way the Finite Element Method (FEM) is used in the case of manufacturing processes, primarily in machining. The basics of this kind of modeling are detailed to create a reference that will provide guidelines for those who start to study this method now, but also for scientists already involved in FEM and want to expand their research. A discussion on FEM, formulations and techniques currently in use is followed up by machining case studies. Orthogonal cutting, oblique cutting, 3D simulations for turning and milling, grinding, and state-of-the-art topics such as high speed machining and micromachining are explained with relevant examples. This is all supported by a literature review and a reference list for further study. As FEM is a key method for researchers in the manufacturing and especially in the machining sector, Finite Element Method in Machining Processes is a key reference for students studying manufacturing processes but al...

Electronic dissipation processes during chemical reactions on surfaces

CERN Document Server

Stella, Kevin

2012-01-01

Hauptbeschreibung Every day in our life is larded with a huge number of chemical reactions on surfaces. Some reactions occur immediately, for others an activation energy has to be supplied. Thus it happens that though a reaction should thermodynamically run off, it is kinetically hindered. Meaning the partners react only to the thermodynamically more stable product state within a mentionable time if the activation energy of the reaction is supplied. With the help of catalysts the activation energy of a reaction can be lowered. Such catalytic processes on surfaces are widely used in industry. A

Texturing in titanium grade 2 surface irradiate with ultrashort pulse laser; Texturizacao em superficies de titanio grau 2 irradiadas com laser com pulsos ultracurtos

Energy Technology Data Exchange (ETDEWEB)

Nogueira, Alessandro Francelino

2015-07-01

The texturing laser micromachining is an important alternative to improve the bonding adhesion between composites and titanium, which are applied to structural components in the aerospace industry. The texturing running on titanium plates is due to the fact that the preferred joining technique for many composite materials is the adhesive bonding. In this work, titanium plates were texturized using laser ultrashort pulses temporal widths of femtoseconds. This process resulted in minimal heat transfer to the material, avoiding deformation of the titanium plate surface as well as the formation of resolidified material in the ablated region. These drawbacks have occurred with the use of nanoseconds pulses. Were performed three types of texturing using laser with femtosecond pulses, with variations in the distances between the machined lines. The analysis of the obtained surfaces found that the wettability increases when there is the increased distance between the texturing lines. Advancing in the analysis by optical profilometry of textured surfaces was observed that there is substantial increase in the volume available for penetration of structural adhesive when the distances between the textured lines are diminished. In tensile tests conducted it was observed that there is an increase in shear strength of the adhesive joint by reducing the distance between the textured lines. (author)

A spherically-shaped PZT thin film ultrasonic transducer with an acoustic impedance gradient matching layer based on a micromachined periodically structured flexible substrate.

Science.gov (United States)

Feng, Guo-Hua; Liu, Wei-Fan

2013-10-09

This paper presents the microfabrication of an acoustic impedance gradient matching layer on a spherically-shaped piezoelectric ultrasonic transducer. The acoustic matching layer can be designed to achieve higher acoustic energy transmission and operating bandwidth. Also included in this paper are a theoretical analysis of the device design and a micromachining technique to produce the novel transducer. Based on a design of a lead titanium zirconium (PZT) micropillar array, the constructed gradient acoustic matching layer has much better acoustic transmission efficiency within a 20-50 MHz operation range compared to a matching layer with a conventional quarter-wavelength thickness Parylene deposition. To construct the transducer, periodic microcavities are built on a flexible copper sheet, and then the sheet forms a designed curvature with a ball shaping. After PZT slurry deposition, the constructed PZT micropillar array is released onto a curved thin PZT layer. Following Parylene conformal coating on the processed PZT micropillars, the PZT micropillars and the surrounding Parylene comprise a matching layer with gradient acoustic impedance. By using the proposed technique, the fabricated transducer achieves a center frequency of 26 MHz and a -6 dB bandwidth of approximately 65%.

Electrochemical and morphological analyses on the titanium surface modified by shot blasting and anodic oxidation processes

Energy Technology Data Exchange (ETDEWEB)

Szesz, Eduardo M., E-mail: eszesz@neoortho.com.br [Neoortho Research Institute, Rua Ângelo Domingos Durigan, 607-Cascatinha, CEP 82025-100 Curitiba, PR (Brazil); Pereira, Bruno L., E-mail: brnl7@hotmail.com [Physics Department, Universidade Federal do Paraná, 81531-980 Curitiba, PR (Brazil); Kuromoto, Neide K., E-mail: kuromoto@fisica.ufpr.br [Physics Department, Universidade Federal do Paraná, 81531-980 Curitiba, PR (Brazil); Marino, Claudia E.B., E-mail: claudiamarino@yahoo.com [Mechanical Engineering Department, Universidade Federal do Paraná, 81531-980 Curitiba, PR (Brazil); Souza, Gelson B. de, E-mail: gelsonbs@uepg.br [Physics Department, Universidade Estadual de Ponta Grossa, 84051-510 Ponta Grossa, PR (Brazil); Soares, Paulo, E-mail: pa.soares@pucpr.br [Mechanical Engineering Department, Pontifícia Universidade Católica do Paraná, 80215-901 Curitiba, PR (Brazil)

2013-01-01

In recent years, many surface modification processes have been developed in order to induce the osseointegration on titanium surface and thus to improve the implants' biocompatibility. In this work, Ti surface has been modified by shot blasting followed by anodic oxidation process in order to associate the good surface characteristics of both processes to obtain a rough and porous surface able to promote the titanium surface bioactivity. Commercially pure titanium (grade 2) plates were used on the surface treatments that were as follows: Shot blasting (SB) performed using alumina (Al{sub 2}O{sub 3}) particles, and anodic oxidation (AO) using NaOH electrolyte. The morphology, structural changes and the open-circuit potentials (OCP) of the surfaces were analyzed. It can be observed that an increase on the roughness of the blasted surface and a rough and porous surface happens after the AO process. The anodic film produced is thin and followed the blasted surface topography. It can be observed that there are small pores with regular shape covering the entire surface. X-ray diffraction results showed the presence of the anatase and rutile phases on the blasted and anodized surface after heat treatment at 600 °C/1 h. Concerning electrochemical measurements, when the different samples were submitted to open-circuit conditions in a physiological electrolyte, the protective effect increases with the oxidation process due to the oxide layer. When the surface was blasted, the OCP was more negative when compared with the Ti surface without surface treatments. - Highlights: ► A combination of shot blasting and anodic oxidation surface treatments is proposed. ► Both processes produced an increase in roughness compared to the polished surface. ► The combination of processes produced a rough and porous surface. ► Open circuit results show that the protective effect increases with oxidation process. ► The combination of processes presents the better results in this

Transformation of medical grade silicone rubber under Nd:YAG and excimer laser irradiation: First step towards a new miniaturized nerve electrode fabrication process

International Nuclear Information System (INIS)

Dupas-Bruzek, C.; Robbe, O.; Addad, A.; Turrell, S.; Derozier, D.

2009-01-01

Medical grade silicone rubber, poly-dimethylsiloxane (PDMS) is a widely used biomaterial. Like for many polymers, its surface can be modified in order to change one or several of its properties which further allow this surface to be functionalized. Laser-induced surface modification of PDMS under ambient conditions is an easy and powerful method for the surface modification of PDMS without altering its bulk properties. In particular, we profit from both UV laser inducing surface modification and of UV laser micromachining to develop a first part of a new process aiming at increasing the number of contacts and tracks within the same electrode surface to improve the nerve selectivity of implantable self sizing spiral cuff electrodes. The second and last part of the process is to further immerse the engraved electrode in an autocatalytic Pt bath leading in a selective Pt metallization of the laser irradiated tracks and contacts and thus to a functionalized PDMS surface. In the present work, we describe the different physical and chemical transformations of a medical grade PDMS as a function of the UV laser and of the irradiation conditions used. We show that the ablation depths, chemical composition, structure and morphology vary with (i) the laser wavelength (using an excimer laser at 248 nm and a frequency-quadrupled Nd:YAG laser at 266 nm), (ii) the conditions of irradiation and (iii) the pulse duration. These different modified properties are expected to have a strong influence on the nucleation and growth rates of platinum which govern the adhesion and the thickness of the Pt layer on the electrodes and thus the DC resistance of tracks.

Food-safe modification of stainless steel food processing surfaces to reduce bacterial biofilms.

Science.gov (United States)

Awad, Tarek Samir; Asker, Dalal; Hatton, Benjamin D

2018-06-11

Biofilm formation on stainless steel (SS) surfaces of food processing plants, leading to foodborne illness outbreaks, is enabled by the attachment and confinement within microscale cavities of surface roughness (grooves, scratches). We report Foodsafe Oil-based Slippery Coatings (FOSCs) for food processing surfaces that suppress bacterial adherence and biofilm formation by trapping residual oil lubricant within these surface cavities to block microbial growth. SS surfaces were chemically functionalized with alkylphosphonic acid to preferentially wet a layer of food grade oil. FOSCs reduced the effective surface roughness, the adhesion of organic food residue, and bacteria. FOSCs significantly reduced Pseudomonas aeruginosa biofilm formation on standard roughness SS-316 by 5 log CFU cm-2, and by 3 log CFU cm-2 for mirror-finished SS. FOSCs also enhanced surface cleanability, which we measured by bacterial counts after conventional detergent cleaning. Importantly, both SS grades maintained their anti-biofilm activity after erosion of the oil layer by surface wear with glass beads, which suggests there is a residual volume of oil that remains to block surface cavity defects. These results indicate the potential of such low-cost, scalable approaches to enhance the cleanability of SS food processing surfaces and improve food safety by reducing biofilm growth.

Surface roughening of ground fused silica processed by atmospheric inductively coupled plasma

International Nuclear Information System (INIS)

Xin, Qiang; Li, Na; Wang, Jun; Wang, Bo; Li, Guo; Ding, Fei; Jin, Huiliang

2015-01-01

Highlights: • The morphology evolution of ground fused silica, processed by atmospheric plasma, was investigated experimentally. • The roughness development results from opening and coalescing of the plasma-etched cracks. • The shapes of grain-like etched pits are the results of the adjacent cracks coalescing with one another. • The descent of the pits density is due to some smaller etched pits that are swallowed up by larger pits. • Leading role in surface smoothing is laterally etching away the side walls of the intersecting pits. - Abstract: Subsurface damage (SSD) is a defect that is inevitably induced during mechanical processes, such as grinding and polishing. This defect dramatically reduces the mechanical strength and the laser damage thresholds of optical elements. Compared with traditional mechanical machining, atmospheric pressure plasma processing (APPP) is a relatively novel technology that induces almost no SSD during the processing of silica-based optical materials. In this paper, a form of APPP, inductively coupled plasma (ICP), is used to process fused silica substrates with fluorocarbon precursor under atmospheric pressure. The surface morphology evolution of ICP-processed substrates was observed and characterized by confocal laser scanning microscope (CLSM), field emission scanning electron microscope (SEM), and atomic force microscopy (AFM). The results show that the roughness evolves with the etching depth, and the roughness evolution is a single-peaked curve. This curve results from the opening and the coalescing of surface cracks and fractures. The coalescence procedure of these microstructures was simulated with two common etched pits on a polished fused silica surface. Understanding the roughness evolution of plasma-processed surface might be helpful in optimizing the optical fabrication chain that contains APPP

Surface roughening of ground fused silica processed by atmospheric inductively coupled plasma

Energy Technology Data Exchange (ETDEWEB)

Xin, Qiang; Li, Na; Wang, Jun; Wang, Bo, E-mail: bradywang@hit.edu.cn; Li, Guo; Ding, Fei; Jin, Huiliang

2015-06-30

Highlights: • The morphology evolution of ground fused silica, processed by atmospheric plasma, was investigated experimentally. • The roughness development results from opening and coalescing of the plasma-etched cracks. • The shapes of grain-like etched pits are the results of the adjacent cracks coalescing with one another. • The descent of the pits density is due to some smaller etched pits that are swallowed up by larger pits. • Leading role in surface smoothing is laterally etching away the side walls of the intersecting pits. - Abstract: Subsurface damage (SSD) is a defect that is inevitably induced during mechanical processes, such as grinding and polishing. This defect dramatically reduces the mechanical strength and the laser damage thresholds of optical elements. Compared with traditional mechanical machining, atmospheric pressure plasma processing (APPP) is a relatively novel technology that induces almost no SSD during the processing of silica-based optical materials. In this paper, a form of APPP, inductively coupled plasma (ICP), is used to process fused silica substrates with fluorocarbon precursor under atmospheric pressure. The surface morphology evolution of ICP-processed substrates was observed and characterized by confocal laser scanning microscope (CLSM), field emission scanning electron microscope (SEM), and atomic force microscopy (AFM). The results show that the roughness evolves with the etching depth, and the roughness evolution is a single-peaked curve. This curve results from the opening and the coalescing of surface cracks and fractures. The coalescence procedure of these microstructures was simulated with two common etched pits on a polished fused silica surface. Understanding the roughness evolution of plasma-processed surface might be helpful in optimizing the optical fabrication chain that contains APPP.

ANFIS Modeling of the Surface Roughness in Grinding Process

OpenAIRE

H. Baseri; G. Alinejad

2011-01-01

The objective of this study is to design an adaptive neuro-fuzzy inference system (ANFIS) for estimation of surface roughness in grinding process. The Used data have been generated from experimental observations when the wheel has been dressed using a rotary diamond disc dresser. The input parameters of model are dressing speed ratio, dressing depth and dresser cross-feed rate and output parameter is surface roughness. In the experimental procedure the grinding conditions...

Upper Meter Processes: Short Wind Waves, Surface Flow, and Micro-Turbulence

National Research Council Canada - National Science Library

Jaehne, Bernd

2000-01-01

The primary goal of this project was to advance the knowledge of small-scale air-sea interaction processes at the ocean surface, focussing on the dynamics of short waves, the surface flow field and the micro-turbulence...

Scaling behaviour of randomly alternating surface growth processes

CERN Document Server

Raychaudhuri, S

2002-01-01

The scaling properties of the roughness of surfaces grown by two different processes randomly alternating in time are addressed. The duration of each application of the two primary processes is assumed to be independently drawn from given distribution functions. We analytically address processes in which the two primary processes are linear and extend the conclusions to nonlinear processes as well. The growth scaling exponent of the average roughness with the number of applications is found to be determined by the long time tail of the distribution functions. For processes in which both mean application times are finite, the scaling behaviour follows that of the corresponding cyclical process in which the uniform application time of each primary process is given by its mean. If the distribution functions decay with a small enough power law for the mean application times to diverge, the growth exponent is found to depend continuously on this power-law exponent. In contrast, the roughness exponent does not depe...

Mechanical and tribological properties of ion beam-processed surfaces

International Nuclear Information System (INIS)

Kodali, P.

1998-01-01

The intent of this work was to broaden the applications of well-established surface modification techniques and to elucidate the various wear mechanisms that occur in sliding contact of ion-beam processed surfaces. The investigation included characterization and evaluation of coatings and modified surfaces synthesized by three surface engineering methods; namely, beam-line ion implantation, plasma-source ion implantation, and DC magnetron sputtering. Correlation among measured properties such as surface hardness, fracture toughness, and wear behavior was also examined. This dissertation focused on the following areas of research: (1) investigating the mechanical and tribological properties of mixed implantation of carbon and nitrogen into single crystal silicon by beam-line implantation; (2) characterizing the mechanical and tribological properties of diamond-like carbon (DLC) coatings processed by plasma source ion implantation; and (3) developing and evaluating metastable boron-carbon-nitrogen (BCN) compound coatings for mechanical and tribological properties. The surface hardness of a mixed carbon-nitrogen implant sample improved significantly compared to the unimplanted sample. However, the enhancement in the wear factor of this sample was found to be less significant than carbon-implanted samples. The presence of nitrogen might be responsible for the degraded wear behavior since nitrogen-implantation alone resulted in no improvement in the wear factor. DLC coatings have low friction, low wear factor, and high hardness. The fracture toughness of DLC coatings has been estimated for the first time. The wear mechanism in DLC coatings investigated with a ruby slider under a contact stress of 1 GPa was determined to be plastic deformation. The preliminary data on metastable BCN compound coatings indicated high friction, low wear factor, and high hardness

Cold pressure welding of aluminium-steel blanks: Manufacturing process and electrochemical surface preparation

Science.gov (United States)

Schmidt, Hans Christian; Homberg, Werner; Orive, Alejandro Gonzalez; Grundmeier, Guido; Hordych, Illia; Maier, Hans Jürgen

2018-05-01

In this study the manufacture of aluminium-steel blanks by cold pressure welding and their preparation for a welding process through electrochemical surface treatment are investigated and discussed. The cold pressure welding process was done with an incremental rolling tool that allows for the partial pressure welding of two blanks along a prepared path. The influence of the surface preparation by electrochemical deposition of bond promoting organosilane-based agents and roughening on a nano-scale is investigated and compared to conventional surface treatments. Coating the surfaces with a thin organosilane-based film incorporating specific functional groups should promote additional bonding between the mating oxide layers; its influence on the total weld strength is studied. Pressure welding requires suitable process strategies, and the current advances in the proposed incremental rolling process for the combination of mild steel and aluminium are presented.

Fabricating Super-hydrophobic Polydimethylsiloxane Surfaces by a Simple Filler-Dissolved Process

Science.gov (United States)

Lin, Yung-Tsan; Chou, Jung-Hua

2010-12-01

The self-cleaning effect of super-hydrophobic surfaces has attracted the attention of researchers. Typical ways of manufacturing super-hydrophobic surfaces include the use of either dedicated equipment or a complex chemical process. In this study, a simple innovative filler-dissolved method is developed using mainly powder salt and rinsing to form hydrophobic surfaces. This method can produce large super-hydrophobic surfaces with porous and micro rib surface structures. It can also be applied to curved surfaces, including flexible membranes. The contact angle of the manufactured artificial hydrophobic surface is about 160°. Furthermore, water droplets roll off the surface readily at a sliding angle of less than 5°, resembling the nonwetting lotus like effect.

Surface enhancement of cold work tool steels by friction stir processing with a pinless tool

Science.gov (United States)

Costa, M. I.; Verdera, D.; Vieira, M. T.; Rodrigues, D. M.

2014-03-01

The microstructure and mechanical properties of enhanced tool steel (AISI D2) surfaces produced using a friction stir welding (FSW) related procedure, called friction stir processing (FSP), are analysed in this work. The surface of the tool steel samples was processed using a WC-Co pinless tool and varying processing conditions. Microstructural analysis revealed that meanwhile the original substrate structure consisted of a heterogeneous distribution of coarse carbides in a ferritic matrix, the transformed surfaces consisted of very small carbides, homogenously distributed in a ferrite- bainite- martensite matrix. The morphology of the surfaces, as well as its mechanical properties, evaluated by hardness and tensile testing, were found to vary with increasing tool rotation speed. Surface hardness was drastically increased, relative to the initial hardness of bulk steel. This was attributed to ferrite and carbide refinement, as well as to martensite formation during solid state processing. At the highest rotation rates, tool sliding during processing deeply compromised the characteristics of the processed surfaces.

A high volume cost efficient production macrostructuring process. [for silicon solar cell surface treatment

Science.gov (United States)

Chitre, S. R.

1978-01-01

The paper presents an experimentally developed surface macro-structuring process suitable for high volume production of silicon solar cells. The process lends itself easily to automation for high throughput to meet low-cost solar array goals. The tetrahedron structure observed is 0.5 - 12 micron high. The surface has minimal pitting with virtually no or very few undeveloped areas across the surface. This process has been developed for (100) oriented as cut silicon. Chemi-etched, hydrophobic and lapped surfaces were successfully texturized. A cost analysis as per Samics is presented.

Improvement in Surface Characterisitcs of Polymers for Subsequent Electroless Plating Using Liquid Assisted Laser Processing

DEFF Research Database (Denmark)

Marla, Deepak; Zhang, Yang; Jabbaribehnam, Mirmasoud

2016-01-01

Metallization of polymers is a widely used process in the electronic industry that involves their surface modification as a pre-treatment step. Laser-based surface modification is one of the commonly used techniques for polymers due to its speed and precision. The process involves laser heating...... of the polymer surface to generate a rough or porous surface. Laser processing in liquid generates superior surface characteristics that result in better metal deposition. In this study, a comparison of the surface characteristics obtained by laser processing in water vis-à-vis air along with the deposition...... characteristics are presented. In addition, a numerical model based on the finite volume method is developed to predict the temperature profile during the process. Based on the model results, it is hypothesized that physical phenomena such as vapor bubble generation and plasma formation may occur in the presence...

Two Novel Measurements for the Drive-Mode Resonant Frequency of a Micromachined Vibratory Gyroscope

Directory of Open Access Journals (Sweden)

Ancheng Wang

2013-11-01

Full Text Available To investigate the drive-mode resonance frequency of a micromachined vibratory gyroscope (MVG, one needs to measure it accurately and efficiently. The conventional approach to measure the resonant frequency is by performing a sweep frequency test and spectrum analysis. The method is time-consuming and inconvenient because of the requirements of many test points, a lot of data storage and off-line analyses. In this paper, we propose two novel measurement methods, the search method and track method, respectively. The former is based on the magnitude-frequency characteristics of the drive mode, utilizing a one-dimensional search technique. The latter is based on the phase-frequency characteristics, applying a feedback control loop. Their performances in precision, noise resistivity and efficiency are analyzed through detailed simulations. A test system is implemented based on a field programmable gate array (FPGA and experiments are carried out. By comparing with the common approach, feasibility and superiorities of the proposed methods are validated. In particular, significant efficiency improvements are achieved whereby the conventional frequency method consumes nearly 5,000 s to finish a measurement, while only 5 s is needed for the track method and 1 s for the search method.

Characterizing polycyclic aromatic hydrocarbon build-up processes on urban road surfaces

International Nuclear Information System (INIS)

Liu, Liang; Liu, An; Li, Dunzhu; Zhang, Lixun; Guan, Yuntao

2016-01-01

Reliable prediction models are essential for modeling pollutant build-up processes on urban road surfaces. Based on successive samplings of road deposited sediments (RDS), this study presents empirical models for mathematical replication of the polycyclic aromatic hydrocarbon (PAH) build-up processes on urban road surfaces. The contaminant build-up behavior was modeled using saturation functions, which are commonly applied in US EPA's Stormwater Management Model (SWMM). Accurate fitting results were achieved in three typical urban land use types, and the applicability of the models was confirmed based on their acceptable relative prediction errors. The fitting results showed high variability in PAH saturation value and build-up rate among different land use types. Results of multivariate data and temporal-based analyses suggested that the quantity and property of RDS significantly influenced PAH build-up. Furthermore, pollution sources, traffic parameters, road surface conditions, and sweeping frequency could synthetically impact the RDS build-up and RDS property change processes. Thus, changes in these parameters could be the main reason for variations in PAH build-up in different urban land use types. - Highlights: • Sufficient robust prediction models were established for analysis of PAH build-up on urban road surfaces. • PAH build-up processes showed high variability among different land use types. • Pollution sources as well as the quantity and property of RDS mainly influenced PAH build-up. - Sufficient robust prediction models were established for analysis of PAH build-up on urban road surfaces. Pollution sources as well as the quantity and property of RDS mainly influenced PAH build-up.

Improvement of Surface Properties of CP-Titanium by Thermo-Chemical Treatment (TCT) Process

International Nuclear Information System (INIS)

Jeong, Hyeon-Gyeong; Hur, Bo-Young; Lee, Dong-Geun; Lee, Yong-Tai; Yaskiv, O.

2011-01-01

The thermo-chemical treatment (TCT) process was applied to achieve surface hardening of CP titanium. The following three different surface modification conditions were tested so that the best surface hardening process could be selected:(a) PVD, (b) TCT+PVD, and (c) TCT+Aging+PVD. These specimens were tested and analyzed in terms of surface roughness, wear, friction coefficient, and the gradient of hardening from the surface of the matrix. The three test conditions were all beneficial to improve the surface hardness of CP titanium. Moreover, the TCT treated specimens, that is, (b) and (c), showed significantly improved surface hardness and low friction coefficients through the thickness up to 100um. This is due to the functionally gradient hardened surface improvement by the diffused interstitial elements. The hardened surface also showed improvement in bonding between the PVD and TCT surface, and this leads to improvement in wear resistance. However, TCT after aging treatment did not show much improvement in surface properties compared to TCT only. For the best surface hardening on CP titanium, TCT+PVD has advantages in surface durability and economics.

Facile preparation of self-healing superhydrophobic CeO2 surface by electrochemical processes

Science.gov (United States)

Nakayama, Katsutoshi; Hiraga, Takuya; Zhu, Chunyu; Tsuji, Etsushi; Aoki, Yoshitaka; Habazaki, Hiroki

2017-11-01

Herein we report simple electrochemical processes to fabricate a self-healing superhydrophobic CeO2 coating on Type 304 stainless steel. The CeO2 surface anodically deposited on flat stainless steel surface is hydrophilic, although high temperature-sintered and sputter-deposited CeO2 surface was reported to be hydrophobic. The anodically deposited hydrophilic CeO2 surface is transformed to hydrophobic during air exposure. Specific accumulation of contaminant hydrocarbon on the CeO2 surface is responsible for the transformation to hydrophobic state. The deposition of CeO2 on hierarchically rough stainless steel surface produces superhydrophobic CeO2 surface, which also shows self-healing ability; the surface changes to superhydrophilic after oxygen plasma treatment but superhydrophobic state is recovered repeatedly by air exposure. This work provides a facile method for preparing a self-healing superhydrophobic surface using practical electrochemical processes.

Effect of finishing process on the surface quality of Co-Cr-Mo dental alloys

Directory of Open Access Journals (Sweden)

Dorota Klimecka -Tatar

2016-09-01

Full Text Available Preparatory procedures for the material have a significant influence on the surface stereometry of the material. This study investigated the effect of the electropolishing process on the surface quality of metallic prosthetic constructions based on Co-Cr-Mo alloys. It has been found that the process of electropolishing prevents to excessive development of the surface of a material and consequently improves surface quality.

Fabrication of superhydrophobic wood surfaces via a solution-immersion process

Science.gov (United States)

Liu, Changyu; Wang, Shuliang; Shi, Junyou; Wang, Chengyu

2011-11-01

Superhydrophobic wood surfaces were fabricated from potassium methyl siliconate (PMS) through a convenient solution-immersion method. The reaction involves a hydrogen bond assembly and a polycondensation process. The silanol was formed by reacting PMS aqueous solution with CO2, which was assembled on the wood surface via hydrogen bonds with the wood surface -OH groups. The polymethylsilsesquioxane coating was obtained through the polycondensation reaction of the hydroxyl between wood and silanol. The morphology of products were characterized using a scanning electron microscope (SEM), the surface chemical composition was determined using energy dispersive X-ray analysis (EDXA), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry (TGA) and contact angle measurement. Analytical results revealed that rough protuberances uniformly covered the wood surface, thus transforming the wood surface from hydrophilic to superhydrophobic. The water contact angle of the superhydrophobic wood surface was about 153° and a sliding angle was 4.6°.

Apparatus and process for the surface treatment of carbon fibers

Science.gov (United States)

Paulauskas, Felix Leonard; Ozcan, Soydan; Naskar, Amit K.

2016-05-17

A method for surface treating a carbon-containing material in which carbon-containing material is reacted with decomposing ozone in a reactor (e.g., a hollow tube reactor), wherein a concentration of ozone is maintained throughout the reactor by appropriate selection of at least processing temperature, gas stream flow rate, reactor dimensions, ozone concentration entering the reactor, and position of one or more ozone inlets (ports) in the reactor, wherein the method produces a surface-oxidized carbon or carbon-containing material, preferably having a surface atomic oxygen content of at least 15%. The resulting surface-oxidized carbon material and solid composites made therefrom are also described.

Surface modification of food contact materials for processing and packaging applications

Science.gov (United States)

Barish, Jeffrey A.

This body of work investigates various techniques for the surface modification of food contact materials for use in food packaging and processing applications. Nanoscale changes to the surface of polymeric food packaging materials enables changes in adhesion, wettability, printability, chemical functionality, and bioactivity, while maintaining desirable bulk properties. Polymer surface modification is used in applications such as antimicrobial or non-fouling materials, biosensors, and active packaging. Non-migratory active packagings, in which bioactive components are tethered to the package, offer the potential to reduce the need for additives in food products while maintaining safety and quality. A challenge in developing non-migratory active packaging materials is the loss of biomolecular activity that can occur when biomolecules are immobilized. Polyethylene glycol (PEG), a biocompatible polymer, is grafted from the surface of ozone treated low-density polyethylene (LDPE) resulting in a surface functionalized polyethylene to which a range of amine-terminated bioactive molecules can be immobilized. The grafting of PEG onto the surface of polymer packaging films is accomplished by free radical graft polymerization, and to covalently link an amine-terminated molecule to the PEG tether, demonstrating that amine-terminated bioactive compounds (such as peptides, enzymes, and some antimicrobials) can be immobilized onto PEG-grafted LDPE in the development of non-migratory active packaging. Fouling on food contact surfaces during food processing has a significant impact on operating efficiency and can promote biofilm development. Processing raw milk on plate heat exchangers results in significant fouling of proteins as well as minerals, and is exacerbated by the wall heating effect. An electroless nickel coating is co-deposited with polytetrafluoroethylene onto stainless steel to test its ability to resist fouling on a pilot plant scale plate heat exchanger. Further

Achieving atomistic control in materials processing by plasma–surface interactions

International Nuclear Information System (INIS)

Chang, Jeffrey; Chang, Jane P

2017-01-01

The continuous down-scaling of electronic devices and the introduction of functionally improved novel materials require a greater atomic level controllability in the synthesis and patterning of thin film materials, especially with regards to deposition uniformity and conformality as well as etching selectivity and anisotropy. The richness of plasma chemistry and the corresponding plasma–surface interactions provide the much needed processing flexibility and efficacy. To achieve the integration of the novel materials into devices, plasma-enhanced atomic layer processing techniques are emerging as the enabling factors to obtain atomic scale control of complex materials and nanostructures. This review focuses on an overview of the role of respective plasma species involved in plasma–surface interactions, addressing their respective and synergistic effects, which is followed by two distinct applications: plasma-enhanced atomic layer deposition (ALD) and atomic layer etching (ALE). For plasma-enhanced ALD, this review emphasizes the use of plasma chemistry to enable alternative pathways to synthesize complex materials at low temperatures and the challenges associated with deposition conformality. For plasma enabled ALE processes, the review focuses on the surface-specific chemical reactions needed to achieve desirable selectivity and anisotropy. (topical review)

Modelling Periglacial Processes on Low-Relief High-Elevation Surfaces

DEFF Research Database (Denmark)

Andersen, Jane Lund; Knudsen, Mads Faurschou; Egholm, D.L.

history in many regions of the world. The glacial buzzsaw concept suggests that intense glacial erosion focused at the equilibrium-line altitude (ELA) leads to a concentration in surface area close to the ELA. However, even in predominantly glacial landscapes, such as the Scandinavian Mountains, the high...... as a function of mean annual air temperature and sediment thickness. This allows us to incorporate periglacial processes into a long-term landscape evolution model where surface elevation, sediment thickness, and climate evolve over time. With this model we are able to explore the slow feedbacks between...... evolution model can be used for obtaining more insight into the conditions needed for formation of low-relief surfaces at high elevation. Anderson, R. S. Modeling the tor-dotted crests, bedrock edges, and parabolic profiles of high alpine surfaces of the Wind River Range, Wyoming. Geomorphology, 46, 35...

Particle dry deposition to water surfaces: Processes and consequences

DEFF Research Database (Denmark)

Pryor, S.C.; Barthelmie, R.J.

2000-01-01

flux to coastal waters, atmosphere-surface exchange represents a significant component of the total flux and may be particularly critical during the summertime when both the riverine input and ambient nutrient concentrations are often at a minimum. In this chapter, we present an overview...... of the physical and chemical processes which dictate the quantity (and direction) of atmosphere-surface fluxes of trace chemicals to (and above) water surfaces with particular emphasis on the role of particles. Dry deposition (transfer to the surface in the absence of precipitation) of particles is determined...... efforts to simulate and measure fluxes close to the coastline. These arise in part from the complexity of atmospheric flow in this region where energy and chemical fluxes are highly inhomogeneous in space and time and thermally generated atmospheric circulations are commonplace. (C) 2000 Elsevier Science...

Improving the work function of the niobium surface of SRF cavities by plasma processing

Science.gov (United States)

Tyagi, P. V.; Doleans, M.; Hannah, B.; Afanador, R.; McMahan, C.; Stewart, S.; Mammosser, J.; Howell, M.; Saunders, J.; Degraff, B.; Kim, S.-H.

2016-04-01

An in situ plasma processing technique using chemically reactive oxygen plasma to remove hydrocarbons from superconducting radio frequency cavity surfaces at room temperature has been developed at the spallation neutron source, at Oak Ridge National Laboratory. To understand better the interaction between the plasma and niobium surface, surface studies on small samples were performed. In this article, we report the results from those surface studies. The results show that plasma processing removes hydrocarbons from top surface and improves the surface work function by 0.5-1.0 eV. Improving the work function of RF surface of cavities can help to improve their operational performance.

The esa earth explorer land surface processes and interactions mission

Science.gov (United States)

Labandibar, Jean-Yves; Jubineau, Franck; Silvestrin, Pierluigi; Del Bello, Umberto

2017-11-01

The European Space Agency (ESA) is defining candidate missions for Earth Observation. In the class of the Earth Explorer missions, dedicated to research and pre-operational demonstration, the Land Surface Processes and Interactions Mission (LSPIM) will acquire the accurate quantitative measurements needed to improve our understanding of the nature and evolution of biosphere-atmosphere interactions and to contribute significantly to a solution of the scaling problems for energy, water and carbon fluxes at the Earth's surface. The mission is intended to provide detailed observations of the surface of the Earth and to collect data related to ecosystem processes and radiation balance. It is also intended to address a range of issues important for environmental monitoring, renewable resources assessment and climate models. The mission involves a dedicated maneuvering satellite which provides multi-directional observations for systematic measurement of Land Surface BRDF (BiDirectional Reflectance Distribution Function) of selected sites on Earth. The satellite carries an optical payload : PRISM (Processes Research by an Imaging Space Mission), a multispectral imager providing reasonably high spatial resolution images (50 m over 50 km swath) in the whole optical spectral domain (from 450 nm to 2.35 μm with a resolution close to 10 nm, and two thermal bands from 8.1 to 9.1 μm). This paper presents the results of the Phase A study awarded by ESA, led by ALCATEL Space Industries and concerning the design of LSPIM.

Identification of soil erosion land surfaces by Landsat data analysis and processing

International Nuclear Information System (INIS)

Lo Curzio, S.

2009-01-01

In this paper, we outline the typical relationship between the spectral reflectance of aileron's on newly-formed land surfaces and the geo morphological features of the land surfaces at issue. These latter represent the products of superficial erosional processes due to the action of the gravity and/or water; thus, such land surfaces are highly representative of the strong soil degradation occurring in a wide area located on the boundary between Molise and Puglia regions (Southern Italy). The results of this study have been reported on thematic maps; on such maps, the detected erosional land surfaces have been mapped on the basis of their typical spectral signature. The study has been performed using Landsat satellite imagery data which have been then validated by means of field survey data. The satellite data have been processed using remote sensing techniques, such as: false colour composite, contrast stretching, principal component analysis and decorrelation stretching. The study has permitted to produce, in a relatively short time and at low expense, a map of the eroded land surfaces. Such a result represents a first and fundamental step in evaluating and monitoring the erosional processes in the study area [it

Micromachined silicon parallel acoustic delay lines as time-delayed ultrasound detector array for real-time photoacoustic tomography

Science.gov (United States)

Cho, Y.; Chang, C.-C.; Wang, L. V.; Zou, J.

2016-02-01

This paper reports the development of a new 16-channel parallel acoustic delay line (PADL) array for real-time photoacoustic tomography (PAT). The PADLs were directly fabricated from single-crystalline silicon substrates using deep reactive ion etching. Compared with other acoustic delay lines (e.g., optical fibers), the micromachined silicon PADLs offer higher acoustic transmission efficiency, smaller form factor, easier assembly, and mass production capability. To demonstrate its real-time photoacoustic imaging capability, the silicon PADL array was interfaced with one single-element ultrasonic transducer followed by one channel of data acquisition electronics to receive 16 channels of photoacoustic signals simultaneously. A PAT image of an optically-absorbing target embedded in an optically-scattering phantom was reconstructed, which matched well with the actual size of the imaged target. Because the silicon PADL array allows a signal-to-channel reduction ratio of 16:1, it could significantly simplify the design and construction of ultrasonic receivers for real-time PAT.

Micromachined silicon parallel acoustic delay lines as time-delayed ultrasound detector array for real-time photoacoustic tomography

International Nuclear Information System (INIS)

Cho, Y; Chang, C-C; Zou, J; Wang, L V

2016-01-01

This paper reports the development of a new 16-channel parallel acoustic delay line (PADL) array for real-time photoacoustic tomography (PAT). The PADLs were directly fabricated from single-crystalline silicon substrates using deep reactive ion etching. Compared with other acoustic delay lines (e.g., optical fibers), the micromachined silicon PADLs offer higher acoustic transmission efficiency, smaller form factor, easier assembly, and mass production capability. To demonstrate its real-time photoacoustic imaging capability, the silicon PADL array was interfaced with one single-element ultrasonic transducer followed by one channel of data acquisition electronics to receive 16 channels of photoacoustic signals simultaneously. A PAT image of an optically-absorbing target embedded in an optically-scattering phantom was reconstructed, which matched well with the actual size of the imaged target. Because the silicon PADL array allows a signal-to-channel reduction ratio of 16:1, it could significantly simplify the design and construction of ultrasonic receivers for real-time PAT. (paper)

Fiscal 1997 technological survey report. R and D on micromachine technology (Development of high functional maintenance technology for power station equipment); 1997 nendo micromachine gijutsu no kenkyu kaihatsu seika hokokusho. Hatsuden shisetsuyo kokino maintenance gijutsu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-03-01

Activities were conducted in search of micromachine technology for a high functional maintenance system that inspects and repairs abnormal conditions such as cracks in a heat exchanger or a piping system without disassembling it in a power generating station such as a thermal or nuclear power plant. The activities were proceeded in four areas of (1) experimental manufacturing of the system (an inline self-running environment recognizing system, an external inspection system for fine tube group, and a system capable of light internal operation such as welding), (2) R and D on sophistication technology for functional devices, (3) R and D on common basic technologies, and (4) comprehensive investigation and research. In (1), examination of detailed basic specifications was carried out, as were examination of element technologies, experimental manufacturing and operation test of element devices, and performance evaluation. Further, a part of element devices was made on an experimental basis, with the basic functions demonstrated. In the comprehensive investigation and research, a trend in the future maintenance technology in power generating equipment was obtained and pigeonholed. (NEDO)

A post-processing study on aluminum surface by fiber laser: Removing face milling patterns

Science.gov (United States)

Kayahan, Ersin

2018-05-01

The face milling process of the metal surface is a well-known machining process of using rotary cutters to remove material from a workpiece. Flat metal surfaces can be produced by a face milling process. However, in practice, visible, traced marks following the motion of points on the cutter's face are usually apparent. In this study, it was shown that milled patterns can be removed by means of 20 W fiber laser on the aluminum surface (AA7075). Experimental results also showed that roughened and hydrophobic surface can be produced with optimized laser parameters. It is a new approach to remove the patterns from the metal surface and can be explained through roughening by re-melting instead of ablation. The new method is a strong candidate to replace sandblasting the metal surface. It is also cheap and environmentally friendly.

Femtosecond laser 3D micromachining for microfluidic and optofluidic applications

CERN Document Server

Sugioka, Koji

2013-01-01

Femtosecond lasers opened up new avenue in materials processing due to its unique features of ultrashort pulse width and extremely high peak intensity. One of the most important features of femtosecond laser processing is that strong absorption can be induced even by materials which are transparent to the femtosecond laser beam due to nonlinear multiphoton absorption. The multiphoton absorption allows us to perform not only surface but also three-dimensionally internal microfabrication of transparent materials such as glass. This capability makes it possible to directly fabricate three-dimensi

Evaporation phase change processes of water/methanol mixtures on superhydrophobic nanostructured surfaces

Science.gov (United States)

Chiang, Cheng-Kun; Lu, Yen-Wen

2011-07-01

Evaporation phenomena are a critical and frequently seen phase change process in many heat transfer applications. In this paper, we study the evaporation process of a sessile droplet on two topologically different surfaces, including smooth and nanostructured surfaces. The nanostructured surface has an array of high-aspect-ratio nanowires (height/diameter ~ 125) and is implemented by using a simple template-based nanofabrication method. It possesses superhydrophobicity (>140°) and low contact angle hysteresis (1.2-2.1°), allowing the liquid droplets to remain in the 'fakir' state throughout the evaporation processes. Sessile droplets of deionized (DI) water and water/methanol binary mixture test liquids with their contact angles and base diameters are monitored. The results show that the nanostructures play a critical role in the droplet dynamics during evaporation.

Evaporation phase change processes of water/methanol mixtures on superhydrophobic nanostructured surfaces

International Nuclear Information System (INIS)

Chiang, Cheng-Kun; Lu, Yen-Wen

2011-01-01

Evaporation phenomena are a critical and frequently seen phase change process in many heat transfer applications. In this paper, we study the evaporation process of a sessile droplet on two topologically different surfaces, including smooth and nanostructured surfaces. The nanostructured surface has an array of high-aspect-ratio nanowires (height/diameter ∼ 125) and is implemented by using a simple template-based nanofabrication method. It possesses superhydrophobicity (>140°) and low contact angle hysteresis (1.2–2.1°), allowing the liquid droplets to remain in the 'fakir' state throughout the evaporation processes. Sessile droplets of deionized (DI) water and water/methanol binary mixture test liquids with their contact angles and base diameters are monitored. The results show that the nanostructures play a critical role in the droplet dynamics during evaporation

Report on achievements in fiscal 1999. Research and development of micro-machine technologies (development of micro-factory technologies); 1999 nendo micro machine gijutsu no kenkyu kaihatsu seika hokokusho. Micro factory gijutsu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

With an objective to achieve energy saving by micronizing the manufacturing processes of small industrial products, this research and development is intended to establish technologies to realize a micro-machine system, in which devices for processing, assembly, transportation and inspection used in the manufacturing processes are unified and incorporated in narrow spaces. Fiscal 1999 has performed, on the items of (1) research and development of the systematizing technologies and (2) comprehensive surveys and researches, with respect to the development of the first prototype system, and fabrication on the trial basis of devices to be mounted on the second prototype system, and discussions on further functional enhancement of the different devices. As a result in the research of the systematizing technology, the first prototype system was developed, that unifies the base unit fabricated in fiscal 1998, the electrolysis processing device, the fluid feeding device, the micro-arms, the coating device, the transportation device, and the environment recognizing device. The basic performances of the individual devices on the first prototype system were verified. Based on the result of this function verification, optimal design and fabrication on the trial basis of the devices mounted in the second prototype system were performed, and discussions were given on the further function enhancement in each functional device. (NEDO)

Gradient nanostructured surface of a Cu plate processed by incremental frictional sliding

DEFF Research Database (Denmark)

Hong, Chuanshi; Huang, Xiaoxu; Hansen, Niels

2015-01-01

The flat surface of a Cu plate was processed by incremental frictional sliding at liquid nitrogen temperature. The surface treatment results in a hardened gradient surface layer as thick as 1 mm in the Cu plate, which contains a nanostructured layer on the top with a boundary spacing of the order...

EXPERIMENTAL VALIDATION OF CUMULATIVE SURFACE LOCATION ERROR FOR TURNING PROCESSES

Directory of Open Access Journals (Sweden)

Adam K. Kiss

2016-02-01

Full Text Available The aim of this study is to create a mechanical model which is suitable to investigate the surface quality in turning processes, based on the Cumulative Surface Location Error (CSLE, which describes the series of the consecutive Surface Location Errors (SLE in roughing operations. In the established model, the investigated CSLE depends on the currently and the previously resulted SLE by means of the variation of the width of cut. The phenomenon of the system can be described as an implicit discrete map. The stationary Surface Location Error and its bifurcations were analysed and flip-type bifurcation was observed for CSLE. Experimental verification of the theoretical results was carried out.

Surface engineering of glazing materials and structures using plasma processes

International Nuclear Information System (INIS)

Anders, Andre; Monteiro, Othon R.

2003-01-01

A variety of coatings is commercially produced on a very large scale, including transparent conducting oxides and multi-layer silver-based low-emissivity and solar control coatings. A very brief review of materials and manufacturing process is presented and illustrated by ultrathin silver films and chevron copper films. Understanding the close relation between manufacturing processes and bulk and surface properties of materials is crucial for film growth and self-assembly processes

Detection of microbial biofilms on food processing surfaces: hyperspectral fluorescence imaging study

Science.gov (United States)

Jun, Won; Kim, Moon S.; Chao, Kaunglin; Lefcourt, Alan M.; Roberts, Michael S.; McNaughton, James L.

2009-05-01

We used a portable hyperspectral fluorescence imaging system to evaluate biofilm formations on four types of food processing surface materials including stainless steel, polypropylene used for cutting boards, and household counter top materials such as formica and granite. The objective of this investigation was to determine a minimal number of spectral bands suitable to differentiate microbial biofilm formation from the four background materials typically used during food processing. Ultimately, the resultant spectral information will be used in development of handheld portable imaging devices that can be used as visual aid tools for sanitation and safety inspection (microbial contamination) of the food processing surfaces. Pathogenic E. coli O157:H7 and Salmonella cells were grown in low strength M9 minimal medium on various surfaces at 22 +/- 2 °C for 2 days for biofilm formation. Biofilm autofluorescence under UV excitation (320 to 400 nm) obtained by hyperspectral fluorescence imaging system showed broad emissions in the blue-green regions of the spectrum with emission maxima at approximately 480 nm for both E. coli O157:H7 and Salmonella biofilms. Fluorescence images at 480 nm revealed that for background materials with near-uniform fluorescence responses such as stainless steel and formica cutting board, regardless of the background intensity, biofilm formation can be distinguished. This suggested that a broad spectral band in the blue-green regions can be used for handheld imaging devices for sanitation inspection of stainless, cutting board, and formica surfaces. The non-uniform fluorescence responses of granite make distinctions between biofilm and background difficult. To further investigate potential detection of the biofilm formations on granite surfaces with multispectral approaches, principal component analysis (PCA) was performed using the hyperspectral fluorescence image data. The resultant PCA score images revealed distinct contrast between

Manufacture of functional surfaces through combined application of tool manufacturing processes and Robot Assisted Polishing

DEFF Research Database (Denmark)

Eriksen, Rasmus Solmer; Arentoft, Mogens; Grønbæk, J.

2012-01-01

The tool surface topography is often a key parameter in the tribological performance of modern metal forming tools. A new generation of multifunctional surfaces is achieved by combination of conventional tool manufacturing processes with a novel Robot Assisted Polishing process. This novel surface...

Applications of Nd:YAG laser micromanufacturing in high temperature gas reactor research

International Nuclear Information System (INIS)

Rooyen, I.J. van; Smal, C.A.; Steyn, J.

2012-01-01

Highlights: ► Two innovative applications of Nd:YAG laser micromachining techniques demonstrated. ► Firstly an alumina jig to contain multiple 500 μm diameter ZrO 2 spheres. ► Secondly the manufacture of a sealing system using laser micromachining. ► ZrO 2 micro plugs isolate the openings of micro-machined cavities to produce a gas-tight seal. ► Manufacturing processes for both the tapered seating cavity and the plug are demonstrated. - Abstract: Two innovative applications of Nd:YAG laser micromachining techniques are demonstrated in this publication. Research projects to determine the fission product transport mechanisms in TRISO coated particles necessitate heat treatment studies as well as the manufacturing of a unique sealed system for experimentation at very high temperatures. This article describes firstly the design and creation of an alumina jig designed to contain 500 μm diameter ZrO 2 spheres intended for annealing experiments at temperatures up to 1600 °C. Functional requirements of this jig are the precision positioning of spheres for laser ablation, welding and post weld heat treatment in order to ensure process repeatability and accurate indexing of individual spheres. The design challenges and the performance of the holding device are reported. Secondly the manufacture of a sealing system using laser micromachining is reported. ZrO 2 micro plugs isolate the openings of micro-machined cavities to produce a gas-tight seal fit for application in a high temperature environment. The technique is described along with a discussion of the problems experienced during the sealing process. Typical problems experienced were seating dimensions and the relative small size (∼200 μm) of these plugs that posed handling challenges. Manufacturing processes for both the tapered seating cavity and the plug are demonstrated. In conclusion, this article demonstrates the application of Nd-YAG micromachining in an innovative way to solve practical research

The Fantastic Voyage of the Trypanosome: A Protean Micromachine Perfected during 500 Million Years of Engineering

Directory of Open Access Journals (Sweden)

Timothy Krüger

2018-02-01

Full Text Available The human body is constantly attacked by pathogens. Various lines of defence have evolved, among which the immune system is principal. In contrast to most pathogens, the African trypanosomes thrive freely in the blood circulation, where they escape immune destruction by antigenic variation and incessant motility. These unicellular parasites are flagellate microswimmers that also withstand the harsh mechanical forces prevailing in the bloodstream. They undergo complex developmental cycles in the bloodstream and organs of the mammalian host, as well as the disease-transmitting tsetse fly. Each life cycle stage has been shaped by evolution for manoeuvring in distinct microenvironments. Here, we introduce trypanosomes as blueprints for nature-inspired design of trypanobots, micromachines that, in the future, could explore the human body without affecting its physiology. We review cell biological and biophysical aspects of trypanosome motion. While this could provide a basis for the engineering of microbots, their actuation and control still appear more like fiction than science. Here, we discuss potentials and challenges of trypanosome-inspired microswimmer robots.

Integrated system of production information processing for surface mines

Energy Technology Data Exchange (ETDEWEB)

Li, K.; Wang, S.; Zeng, Z.; Wei, J.; Ren, Z. [China University of Mining and Technology, Xuzhou (China). Dept of Mining Engineering

2000-09-01

Based on the concept of geological statistic, mathematical program, condition simulation, system engineering, and the features and duties of each main department in surface mine production, an integrated system for surface mine production information was studied systematically and developed by using the technology of data warehousing, CAD, object-oriented and system integration, which leads to the systematizing and automating of the information management, data processing, optimization computing and plotting. In this paper, its overall object, system design, structure and functions and some key techniques were described. 2 refs., 3 figs.

Reduction of Surface Roughness by Means of Laser Processing over Additive Manufacturing Metal Parts.

Science.gov (United States)

Alfieri, Vittorio; Argenio, Paolo; Caiazzo, Fabrizia; Sergi, Vincenzo

2016-12-31

Optimization of processing parameters and exposure strategies is usually performed in additive manufacturing to set up the process; nevertheless, standards for roughness may not be evenly matched on a single complex part, since surface features depend on the building direction of the part. This paper aims to evaluate post processing treating via laser surface modification by means of scanning optics and beam wobbling to process metal parts resulting from selective laser melting of stainless steel in order to improve surface topography. The results are discussed in terms of roughness, geometry of the fusion zone in the cross-section, microstructural modification, and microhardness so as to assess the effects of laser post processing. The benefits of beam wobbling over linear scanning processing are shown, as heat effects in the base metal are proven to be lower.

Microscopic investigation of RF surfaces of 3 GHz niobium accelerator cavities following RF processing

International Nuclear Information System (INIS)

Graber, J.; Barnes, P.; Flynn, T.; Kirchgessner, J.; Knobloch, J.; Moffat, D.; Muller, H.; Padamsee, H.; Sears, J.

1993-01-01

RF processing of Superconducting accelerating cavities is achieved through a change in the electron field emission (FE) characteristics of the RF surface. The authors have examined the RF surfaces of several single-cell 3 GHz cavities, following RF processing, in a Scanning Electron Microscope (SEM). The RF processing sessions included both High Peak Power (P ≤ 50 kW) pulsed processing, and low power (≤ 20 W) continuous wave processing. The experimental apparatus also included a thermometer array on the cavity outer wall, allowing temperature maps to characterize the emission before and after RF processing gains. Multiple sites have been located in cavities which showed improvements in cavity behavior due to RF processing. Several SEM-located sites can be correlated with changes in thermometer signals, indicating a direct relationship between the surface site and emission reduction due to RF processing. Information gained from the SEM investigations and thermometry are used to enhance the theoretical model of RF processing

Thin film shape memory alloys for optical sensing applications

International Nuclear Information System (INIS)

Fu, Y Q; Luo, J K; Huang, W M; Flewitt, A J; Milne, W I

2007-01-01

Based on shape memory effect of the sputtered thin film shape memory alloys, different types of micromirror structures were designed and fabricated for optical sensing application. Using surface micromachining, TiNi membrane mirror structure has been fabricated, which can be actuated based on intrinsic two-way shape memory effect of the free-standing TiNi film. Using bulk micromachining, TiNi/Si and TiNi/Si 3 N 4 microcantilever mirror structures were fabricated

Decontamination Efficiency of Fish Bacterial Flora from Processing Surfaces

Directory of Open Access Journals (Sweden)

Birna Guðbjörnsdóttir

2009-01-01

Full Text Available There are numerous parameters that can influence bacterial decontamination during washing of machinery and equipment in a food processing establishment. Incomplete decontamination of bacteria will increase the risk of biofilm formation and consequently increase the risk of pathogen contamination or prevalence of other undesirable microorganisms such as spoilage bacteria in the processing line. The efficiency of a typical washing protocol has been determined by testing three critical parameters and their effects on bacterial decontamination. Two surface materials (plastic and stainless steel, water temperatures (7 and 25 °C and detergent concentrations (2 and 4 % were used for this purpose in combination with two types of detergents. Biofilm was prepared on the surfaces with undefined bacterial flora obtained from minced cod fillets. The bacterial flora of the biofilm was characterised by cultivation and molecular analysis of 16S rRNA genes. All different combinations of washing protocols tested were able to remove more than 99.9 % of the bacteria in the biofilm and reduce the cell number from 7 to 0 or 2 log units of bacteria/cm2. The results show that it is possible to use less diluted detergents than recommended with comparable success, and it is easier to clean surface material made of stainless steel compared to polyethylene plastic.

Linear and nonlinear post-processing of numerically forecasted surface temperature

Directory of Open Access Journals (Sweden)

M. Casaioli

2003-01-01

Full Text Available In this paper we test different approaches to the statistical post-processing of gridded numerical surface air temperatures (provided by the European Centre for Medium-Range Weather Forecasts onto the temperature measured at surface weather stations located in the Italian region of Puglia. We consider simple post-processing techniques, like correction for altitude, linear regression from different input parameters and Kalman filtering, as well as a neural network training procedure, stabilised (i.e. driven into the absolute minimum of the error function over the learning set by means of a Simulated Annealing method. A comparative analysis of the results shows that the performance with neural networks is the best. It is encouraging for systematic use in meteorological forecast-analysis service operations.