WorldWideScience

Sample records for surface micromachined smm

  1. Stiction in surface micromachining

    NARCIS (Netherlands)

    Tas, Niels Roelof; Sonnenberg, A.H.; Jansen, Henricus V.; Legtenberg, R.; Legtenberg, Rob; Elwenspoek, Michael Curt

    1996-01-01

    Due to the smoothness of the surfaces in surface micromachining, large adhesion forces between fabricated structures and the substrate are encountered. Four major adhesion mechanisms have been analysed: capillary forces, hydrogen bridging, electrostatic forces and van der Waals forces. Once contact

  2. Enhancing cavitation with micromachined surfaces

    Science.gov (United States)

    Fernandez Rivas, David; Stricker, Laura; Zijlstra, Aaldert G.; Gardeniers, Han; Lohse, Detlef; Prosperetti, Andrea; Mesoscale Chemical System Group Collaboration; Physics of Fluids Group Collaboration; Department of Mechanical Engineering Collaboration

    2012-11-01

    When a silicon surface with micromachined pits submerged in a liquid is exposed to continuous ultrasound at 200 kHz, bubbles are ejected from the air filled cavities. Depending on the pressure amplitude different scenarios are observed, as the bubbles ejected from the micropits interact in complex ways with each other, and with the silicon surface. We have determined the size distribution of bubbles ejected from one, two and three pits for three different electrical power settings, and correlated them with sonochemical OH* radical production. Numerical simulations of the sonochemical conversion reaction rates were obtained using the empirical bubble size distributions and are compared with experimental results. Experimental evidence of shock wave emission from the microbubble clusters, deformed microbubble shapes, jetting and surface erosion are also presented. Financially supported through the project 07391 of the Technology Foundation STW, The Netherlands.

  3. Integrated mold/surface-micromachining process

    Energy Technology Data Exchange (ETDEWEB)

    Barron, C.C.; Fleming, J.G.; Montague, S.; Sniegowski, J.J.; Hetherington, D.L.

    1996-03-01

    We detail a new monolithically integrated silicon mold/surface-micromachining process which makes possible the fabrication of stiff, high-aspect-ratio micromachined structures integrated with finely detailed, compliant structures. An important example, which we use here as our process demonstration vehicle, is that of an accelerometer with a large proof mass and compliant suspension. The proof mass is formed by etching a mold into the silicon substrate, lining the mold with oxide, filling it with mechanical polysilicon, and then planarizing back to the level of the substrate. The resulting molded structure is recessed into the substrate, forming a planar surface ideal for subsequent processing. We then add surface-micromachined springs and sense contacts. The principal advantage of this new monolithically integrated mold/surface-micromachining process is that it decouples the design of the different sections of the device: In the case of a sensitive accelerometer, it allows us to optimize independently the proof mass, which needs to be as large, stiff, and heavy as possible, and the suspension, which needs to be as delicate and compliant as possible. The fact that the high-aspect-ratio section of the device is embedded in the substrate enables the monolithic integration of high-aspect-ratio parts with surface-micromachined mechanical parts, and, in the future, also electronics. We anticipate that such an integrated mold/surface micromachining/electronics process will offer versatile high-aspect-ratio micromachined structures that can be batch-fabricated and monolithically integrated into complex microelectromechanical systems.

  4. Tribological issues of polysilicon surface-micromachining

    Energy Technology Data Exchange (ETDEWEB)

    Sniegowski, J.J.

    1997-12-01

    Polysilicon surface-micromachining is a Micro-Electro-Mechanical Systems (MEMS) manufacturing technology where the infrastructure for manufacturing silicon integrated circuits is used to fabricate micro-miniature mechanical devices. This presentation describes a multi-level mechanical polysilicon surface-micromachining technology and includes a discussion of the issues which affect device manufacture and performance. The multi-level technology was developed and is employed primarily to fabricate microactuated mechanisms. The intricate and complex motion offered by these devices is naturally accompanied by various forms of fraction and wear in addition to the classical stiction phenomena associated with micromechanical device fabrication and usage.

  5. Design of Surface Micromachined Compliant MEMS

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, Joe Anthony [Iowa State Univ., Ames, IA (United States)

    2002-12-31

    The consideration of compliant mechanisms as Microelectromechanical Systems (MEMS) is the focus of this research endeavor. MEMS are micron to millimeter devices that combine electrical, mechanical, and information processing capabilities on the same device. These MEMS need some mechanical motion or parts that move relative to each other. This relative motion, using multiple parts, is not desired because of the assembly requirement and the friction introduced. Compliant devices limits or eliminates friction and the need for multi-component assembly. Compliant devices improve designs by creating single piece mechanisms. The purpose of this research is to validate surface micromachining as a viable fabrication process for compliant MEMS designs. Specifically, this research has sought to fabricate a micro-compliant gripper and a micro-compliant clamp to illustrate the process. While other researchers have created compliant MEMs, most have used comb-drive actuation methods and bulk micromachining processes. This research focused on fully-compliant devices that use device flexibility for motion and actuation. Validation of these compliant MEMS is achieved by structural optimization of device design and functional performance testing. This research contributes to the ongoing research in MEMS by evaluating the potential of using surface micromachining as a process for fabricating compliant micro-mechanisms.

  6. Design of Surface micromachined Compliant MEMS

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, Joe Anthony [Iowa State Univ., Ames, IA (United States)

    2001-01-01

    The consideration of compliant mechanisms as Microelectromechanical Systems (MEMS) is the focus of this research endeavor. MEMS are micron to millimeter devices that combine electrical, mechanical, and information processing capabilities on the same device. These MEMS need some mechanical motion or parts that move relative to each other. This relative motion, using multiple parts, is not desired because of the assembly requirement and the friction introduced. Compliant devices limits or eliminates friction and the need for multi-component assembly. Compliant devices improve designs by creating single piece mechanisms. The purpose of this research is to validate surface micromachining as a viable fabrication process for compliant MEMS designs. Specifically, this research has sought to fabricate a micro-compliant gripper and a micro-compliant clamp to illustrate the process. While other researchers have created compliant MEMS, most have used comb-drive actuation methods and bulk micromachining processes. This research focuses on fully-compliant devices that use device flexibility for motion and actuation. Validation of these compliant MEMS is achieved by structural optimization of device design and functional performance testing. This research contributes to the ongoing research in MEMS by evaluating the potential of using surface micromachining as a process for fabricating compliant micro-mechanisms.

  7. Surface Micromachined Arrays of Transition-Edge Detectors, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — An innovative surface micromachining technique is described for the fabrication of closely-packed arrays of transition edge sensor (TES) x-ray microcalorimeters....

  8. Multi-layer enhancement to polysilicon surface-micromachining technology

    Energy Technology Data Exchange (ETDEWEB)

    Sniegowski, J.J.; Rodgers, M.S. [Sandia National Labs., Albuquerque, NM (United States). Intelligent Micromachine Dept.

    1997-10-01

    A multi-level polysilicon surface-micromachining technology consisting of 5 layers of polysilicon is presented. Surface topography and film mechanical stress are the major impediments encountered in the development of a multilayer surface-micromachining process. However, excellent mechanical film characteristics have been obtained through the use of chemical-mechanical polishing for planarization of topography and by proper sequencing of film deposition with thermal anneals. Examples of operating microactuators, geared power-transfer mechanisms, and optical elements demonstrate the mechanical advantages of construction with 5 polysilicon layers.

  9. Condensation of sodium on a micromachined surface for AMTEC

    International Nuclear Information System (INIS)

    Crowley, C.J.; Izenson, M.G.

    1993-01-01

    A novel condenser component is being developed to enable Alkali Metal Thermal to Electric Conversion (AMTEC) technology to achieve two critical goals: (1) optimization of conversion efficiency and (2) microgravity fluid management. The first goal is achieved by minimizing parasitic radiation heat transfer losses for condensers with a large view factor to the high-temperature β double-prime-alumina surface. The condenser geometry includes a specially designed, micromachined surface where large capillary forces are used to manage the fluid distribution to accomplish the second goal. We present and discuss the results of separate effects experiments investigating the wetting and condensation behavior of sodium on this capillary surface. Test results show that the micromachined surface maintains a smooth, high reflective film of liquid sodium on the surface, which implies reduced parasitic losses and increased conversion efficiencies in AMTEC cells. Accomplishing this in an adverse gravity gradient demonstrates the potential for management of the fluid even under spacecraft acceleration conditions

  10. 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

  11. Manufacturing microsystems-on-a-chip with 5-level surface micromachining technology

    Energy Technology Data Exchange (ETDEWEB)

    Sniegowski, J.; Rodgers, M.S.

    1998-05-01

    An agile microsystem manufacturing technology has been developed that provides unprecedented 5 levels of independent polysilicon surface-micromachine films for the designer. Typical surface-micromachining processes offer a maximum of 3 levels, making this the most complex surface-micromachining process technology developed to date. Leveraged from the extensive infrastructure present in the microelectronics industry, the manufacturing method of polysilicon surface-micromachining offers similar advantages of high-volume, high-reliability, and batch-fabrication to microelectromechanical systems (MEMS) as has been accomplished with integrated circuits (ICs). These systems, comprised of microscopic-sized mechanical elements, are laying the foundation for a rapidly expanding, multi-billion dollar industry 2 which impacts the automotive, consumer product, and medical industries to name only a few.

  12. Macrodesign for microdevices: Polysilicon surface-micromachining technology, applications and issues

    Energy Technology Data Exchange (ETDEWEB)

    Sniegowski, J.J. [Sandia National Labs., Albuquerque, NM (United States). Intelligent Micromachine Dept.

    1997-05-01

    The intent of this tutorial is to overview the technology of multi-level polysilicon surface micromachining, to present examples of devices which fully utilize this level of complexity, and to discuss what they believe to be significant issues which are not fully resolved. Following this intent, the tutorial consists of four sections. The first is an introduction and description of multi-level polysilicon surface micromachining and its potential benefits. Specifically, the inclusion of a third deposited layer of mechanical polysilicon greatly extends the degree of complexity available for micromechanism design. The second section introduces wafer planarization by CMP as a process tool for surface micromachining. The third section presents examples of actuated geared micromechanisms which require the multi-level fabrication process. Demonstration of actuation mechanisms coupled to external devices are illustrated. Finally, polysilicon surface micromachining fabrication technology has reached a level where many device designs, for the most part, can be embodied in the technology to produce a mechanical construct which provides the desired function. When designed properly, the fabricated mechanical element, if free to operate, will produce the desired function. However, one set of issues which can hinder or prevent operation are related to the post-fabricated device surfaces. These surface issues; namely, stiction, friction, and wear, are emphasized in the final section as a major hindrance to realizing the full potential of surface micromachined devices.

  13. 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...

  14. 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.

  15. Fabrication of surface micromachined ain piezoelectric microstructures and its potential apllication to rf resonators

    NARCIS (Netherlands)

    Saravanan, S.; Saravanan, S.; Berenschot, Johan W.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt

    2005-01-01

    We report on a novel microfabrication method to fabricate aluminum nitride (AlN) piezoelectric microstructures down to 2 microns size by a surface micromachining process. Highly c-axis oriented AlN thin films are deposited between thin Cr electrodes on polysilicon structural layers by rf reactive

  16. Surface micromachined fabrication of piezoelectric ain unimorph suspension devices for rf resonator applications

    NARCIS (Netherlands)

    Saravanan, S.; Saravanan, S.; Berenschot, Johan W.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt

    We report a surface micromachining process for aluminum nitride (AlN) thin films to fabricate piezoelectric unimorph suspension devices for actuator applications. Polysilicon is used as a structural layer. Highly c-axis oriented AlN thin films 1 /spl mu/m thick are deposited by rf reactive

  17. A manufacturing method for multi-layer polysilicon surface-micromachining technology

    Energy Technology Data Exchange (ETDEWEB)

    Sniegowski, J.J.; Rodgers, M.S.

    1998-01-01

    An advanced manufacturing technology which provides multi-layered polysilicon surface micromachining technology for advanced weapon systems is presented. Specifically, the addition of another design layer to a 4 levels process to create a 5 levels process allows consideration of fundamentally new architecture in designs for weapon advanced surety components.

  18. Thermal simulation of surface micromachined polysilicon hot plates of low power consumption

    NARCIS (Netherlands)

    Dumitrescu, Marius; Cobianu, Cornel; Lungu, Dan; Pascu, Adrian; Kolev, Spas; van den Berg, Albert

    1999-01-01

    A simple, IC compatible, surface micromachined polysilicon membrane was technologically designed and thermally simulated by 3D finite element ‘COSMOS' program in order to investigate its capability to work as a micro hot plate for a gas sensing test structure of low power consumption. For an

  19. Effect of fluorocarbon self-assembled monolayer films on sidewall adhesion and friction of surface micromachines with impacting and sliding contact interfaces

    International Nuclear Information System (INIS)

    Xiang, H.; Komvopoulos, K.

    2013-01-01

    A self-assembled monolayer film consisting of fluoro-octyltrichlorosilane (FOTS) was vapor-phase deposited on Si(100) substrates and polycrystalline silicon (polysilicon) surface micromachines. The hydrophobic behavior and structural composition of the FOTS film deposited on Si(100) were investigated by goniometry and X-ray photoelectron spectroscopy, respectively. The effects of contact pressure, relative humidity, temperature, and impact/sliding cycles on the adhesive and friction behavior of uncoated and FOTS-coated polysilicon micromachines (referred to as the Si and FOTS/Si micromachines, respectively) were investigated under controlled loading and environmental conditions. FOTS/Si micromachines demonstrated much lower and stable adhesion than Si micromachines due to the highly hydrophobic and conformal FOTS film. Contrary to Si micromachines, sidewall adhesion of FOTS/Si micromachines demonstrated a weak dependence on relative humidity, temperature, and impact cycles. In addition, FOTS/Si micromachines showed low and stable adhesion and low static friction for significantly more sliding cycles than Si micromachines. The adhesive and static friction characteristics of Si and FOTS/Si micromachines are interpreted in the context of physicochemical surface changes, resulting in the increase of the real area of contact and a hydrophobic-to-hydrophilic transition of the surface chemical characteristics caused by nanoscale surface smoothening and the removal of the organic residue (Si micromachines) or the FOTS film (FOTS/Si micromachines) during repetitive impact and oscillatory sliding of the sidewall surfaces.

  20. 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.

  1. 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.

  2. 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)

  3. 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 (micro-grooved surfaces could improve implant integration at the gingival site with respect to polished surfaces. Micro-grooved surfaces enhance early fibroblast adhesion and activation, which could be critical for the formation of a biological seal and finally promote tissue integration. Surfaces with wider grooves (≥50 μm) seem to be more

  4. Effects of Micromachining Processes on Electro-Osmotic Flow Mobility of Glass Surfaces

    Directory of Open Access Journals (Sweden)

    Norihisa Miki

    2013-03-01

    Full Text Available Silica glass is frequently used as a device material for micro/nano fluidic devices due to its excellent properties, such as transparency and chemical resistance. Wet etching by hydrofluoric acid and dry etching by neutral loop discharge (NLD plasma etching are currently used to micromachine glass to form micro/nano fluidic channels. Electro-osmotic flow (EOF is one of the most effective methods to drive liquids into the channels. EOF mobility is affected by a property of the micromachined glass surfaces, which includes surface roughness that is determined by the manufacturing processes. In this paper, we investigate the effect of micromaching processes on the glass surface topography and the EOF mobility. We prepared glass surfaces by either wet etching or by NLD plasma etching, investigated the surface topography using atomic force microscopy, and attempted to correlate it with EOF generated in the micro-channels of the machined glass. Experiments revealed that the EOF mobility strongly depends on the surface roughness, and therefore upon the fabrication process used. A particularly strong dependency was observed when the surface roughness was on the order of the electric double layer thickness or below. We believe that the correlation described in this paper can be of great help in the design of micro/nano fluidic devices.

  5. 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.

  6. A novel surface micromachining process to fabricate AlN unimorph suspensions and its application for RF resonators

    NARCIS (Netherlands)

    Saravanan, S.; Saravanan, S.; Berenschot, Johan W.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt

    2006-01-01

    A novel surface micromachining process is reported for aluminum nitride (AlN) thin films to fabricate piezoelectric unimorph suspension devices for micro actuator applications. Wet anisotropic etching of AlN thin film is used with a Cr metal mask layer in the microfabrication process. Tetra methyl

  7. Dependence of capillary forces on relative humidity and the surface properties of femtosecond laser micromachined titanium.

    Science.gov (United States)

    Lehr, Jorge; Kietzig, Anne-Marie

    2015-06-15

    Capillary forces were measured with colloidal atomic force microscopy at different levels of relative humidity on femtosecond laser micromachined titanium surfaces. After laser machining at different intensity levels, the titanium surfaces show a nanoscale ripple topology or microscopic bumpy structures. Different machining environments were chosen to influence the surface chemistry in addition to topology: while machining in pure oxygen and water resulted in surfaces consisting of TiO2, a composite surface of TiO2 and TiN was obtained after machining in pure nitrogen. All samples were subsequently exposed to pure oxygen, carbon dioxide or water, and showed different levels of wettability and capillary force. We have introduced the concept of humidity sensitivity as the relative increase of the capillary force with respect to the measured force at 0% humidity. We report that samples with a nanoscale ripple topology machined in pure oxygen exhibit the lowest level of capillary force and the lowest sensitivity towards humidity in the environment. Surfaces with low sensitivity towards changes of the relative humidity are good candidates for technical applications, where capillary forces have to be controlled. This study contributes to the development of such surfaces, to a better understanding of how capillary bridges are formed on rough surfaces and ultimately to the exploration of the relationship between surface wettability and capillary forces. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. The Development of Micromachined Gyroscope Structure and Circuitry Technology

    OpenAIRE

    Dunzhu Xia; Cheng Yu; Lun Kong

    2014-01-01

    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 electrostati...

  9. The Effect of Humidity on the Reliability of a Surface Micromachined Microengine

    Energy Technology Data Exchange (ETDEWEB)

    Dugger, M.T.; Eaton, W.P.; Irwin, L.W.; Miller, S.L.; Miller, W.M.; Smith, N.F.; Tanner, D.M.; Walraven, J.A.

    1999-02-02

    Humidity is shown to be a strong factor in the wear of rubbing surfaces in polysilicon micromachines. We demonstrate that very low humidity can lead to very high wear without a significant change in reliability. We show that the volume of wear debris generated is a function of the humidity in an air environment. As the humidity decreases, the wear debris generated increases. For the higher humidity levels, the formation of surface hydroxides may act as a lubricant. The dominant failure mechanism has been identified as wear. The wear debris has been identified as amorphous oxidized silicon. Large slivers (approximately 1 micron in length) of debris observed at the low humidity level were also amorphous oxidized silicon. Using transmission electron microscopy, we observed that the wear debris forms spherical and rod-like shapes. We compared two surface treatment processes: a fluorinated si- lane chain, (FITl) and supercritical C02 dried (SCC02). The microengines using the SCC02 process were found to be less reliable than those released with the FIX process under two humidity levels.

  10. Linkage design effect on the reliability of surface micromachined microengines driving a load

    Energy Technology Data Exchange (ETDEWEB)

    Tanner, D.M.; Peterson, K.A.; Irwin, L.W.; Tangyunyong, P.; Miller, W.M.; Eaton, W.P.; Smith, N.F.; Rodgers, M.S.

    1998-08-01

    The reliability of microengines is a function of the design of the mechanical linkage used to connect the electrostatic actuator to the drive. The authors have completed a series of reliability stress tests on surface micromachined microengines driving an inertial load. In these experiments, the authors used microengines that had pin mechanisms with guides connecting the drive arms to the electrostatic actuators. Comparing this data to previous results using flexure linkages revealed that the pin linkage design was less reliable. The devices were stressed to failure at eight frequencies, both above and below the measured resonance frequency of the microengine. Significant amounts of wear debris were observed both around the hub and pin joint of the drive gear. Additionally, wear tracks were observed in the area where the moving shuttle rubbed against the guides of the pin linkage. At each frequency, they analyzed the statistical data yielding a lifetime (t{sub 50}) for median cycles to failure and {sigma}, the shape parameter of the distribution. A model was developed to describe the failure data based on fundamental wear mechanisms and forces exhibited in mechanical resonant systems. The comparison to the model will be discussed.

  11. Surface Micromachining Process for the Integration of AlN Piezoelectric Microstructures

    NARCIS (Netherlands)

    Saravanan, S.; Berenschot, Johan W.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt

    2004-01-01

    We report a novel micromachining process to fabricate AlN (Aluminum Nitride) piezoelectric microstructures for actuator applications. Piezoelectric AlN thin films can be grown with (002) preferential orientation by means of RF reactive sputtering on various substrates. For this study, AlN was

  12. Micro-machining.

    Science.gov (United States)

    Brinksmeier, Ekkard; Preuss, Werner

    2012-08-28

    Manipulating bulk material at the atomic level is considered to be the domain of physics, chemistry and nanotechnology. However, precision engineering, especially micro-machining, has become a powerful tool for controlling the surface properties and sub-surface integrity of the optical, electronic and mechanical functional parts in a regime where continuum mechanics is left behind and the quantum nature of matter comes into play. The surprising subtlety of micro-machining results from the extraordinary precision of tools, machines and controls expanding into the nanometre range-a hundred times more precise than the wavelength of light. In this paper, we will outline the development of precision engineering, highlight modern achievements of ultra-precision machining and discuss the necessity of a deeper physical understanding of micro-machining.

  13. Safety and security monitoring of dams using nano-micromachined-based surface acoustic wave (SAW) sensors

    Science.gov (United States)

    Ross, Wayne, Jr.; Saafi, Mohamed; Romine, Peter; Xiao, Zhigang; Pett, Dave

    2006-03-01

    Concerns about the safety of concrete dams have increased during recent years, partly because the population at risk in locations downstream of major dams continues to expand and also because these old dams are experiencing long-term damage and the seismic design concepts used to build them were inadequate. Reliable techniques for continuous monitoring of certain key parameters affecting the dams' integrity are currently nonexistent and this is because of the lack of sensing technology capable to function in a hostile environment such as low temperatures and high moisture level. This paper presents new low cost, passive and wireless micro-machined SAW-based sensors to monitor the safety and security of dams. These SAW sensors are composed of MEMS transducers, Nano-polymer actuators and an antenna, and are deposited on a thin film substrate. The sensors are passive, do not require power on-board and can be interrogated wireless using a radar. When embedded into concrete dams, the devices will be able to detect and locate internal cracks and measure certain key parameters affecting the durability of dams such as temperature, moisture, pH, chloride and carbon dioxide.

  14. A row-column addressed micromachined ultrasonic transducer array for surface scanning applications.

    Science.gov (United States)

    Wong, Lawrence L P; Chen, Albert I H; Li, Zhenhao; Logan, Andrew S; Yeow, John T W

    2014-12-01

    Row-column addressed arrays for ultrasonic non-destructive testing (NDT) applications are analyzed and demonstrated in this paper. Simulation and experimental results of a row-column addressed 32 by 32 capacitive micromachined ultrasonic transducer (CMUT) array are presented. The CMUT array, which was designed for medical imaging applications, has a center frequency of 5.3MHz. The CMUT array was used to perform C-scans on test objects with holes that have diameters of 1.0mm and 0.5mm. The array transducer has an aperture size of 4.8mm by 4.8mm, and it was used to scan an area of 4.0mm by 4.0mm. Compared to an N by N fully addressed 2-D array, a row-column addressed array of the same number of elements requires fewer (N instead of N(2)) pairs of interconnection and supporting electronic components such as pulsers and amplifiers. Even though the resulting field of view is limit by the aperture size, row-column addressed arrays and the row-column addressing scheme can be an alternative option of 2-D arrays for NDT applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Micromachined silicon seismic transducers

    Energy Technology Data Exchange (ETDEWEB)

    Barron, C.C.; Fleming, J.G.; Sniegowski, J.J.; Armour, D.L.; Fleming, R.P.

    1995-08-01

    Batch-fabricated silicon seismic transducers could revolutionize the discipline of CTBT monitoring by providing inexpensive, easily depolyable sensor arrays. Although our goal is to fabricate seismic sensors that provide the same performance level as the current state-of-the-art ``macro`` systems, if necessary one could deploy a larger number of these small sensors at closer proximity to the location being monitored in order to compensate for lower performance. We have chosen a modified pendulum design and are manufacturing prototypes in two different silicon micromachining fabrication technologies. The first set of prototypes, fabricated in our advanced surface- micromachining technology, are currently being packaged for testing in servo circuits -- we anticipate that these devices, which have masses in the 1--10 {mu}g range, will resolve sub-mG signals. Concurrently, we are developing a novel ``mold`` micromachining technology that promises to make proof masses in the 1--10 mg range possible -- our calculations indicate that devices made in this new technology will resolve down to at least sub-{mu}G signals, and may even approach to 10{sup {minus}10} G/{radical}Hz acceleration levels found in the low-earth-noise model.

  16. 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.

  17. Surface-Micromachined Neural Sensors with Integrated Double Side Recordings on Dry-Etch Benzocyclobutene(BCB) Substrate.

    Science.gov (United States)

    Zhu, Haixin; He, Jiping; Kim, Bruce

    2005-01-01

    a neural sensor with novel structure and capable of double side recordings has been designed and fabricated using surface micromachining technique. Dry-etch Benzocyclobutene (BCB) was selected as the substrate and packaging material for its excellent electrical, mechanical and thermal properties. Positive photoresist (AZ4620) was used as the sacrificial layer during the formation of backside recording sites, and the lift-off process combined with BCB dry etch technique was developed to open the recording sites on the backside. The finished device has intracortical recording sites on both sides, and also epidural recording sites on the front side. The total channel number doubled compared to that of single side electrode structure. Three dry-etch BCB layers were applied to insulate the front side conduction traces from the backside trace layer, and package the entire devices. The developed process shows reliable and high fabrication yield, and results suggest that this newly developed neural sensor could improve the performance and efficiency of neural recording.

  18. Optimization of micropipette fabrication by laser micromachining for application in an ultrafine atmospheric pressure plasma jet using response surface methodology

    International Nuclear Information System (INIS)

    Wang, Tao; Liu, Jingquan; Yang, Bin; Chen, Xiang; Wang, Xiaolin; Yang, Chunsheng

    2016-01-01

    The optimization of the laser micromachining process for special tapered micropipettes was investigated using response surface methodology. Three process parameters for the CO 2 laser-based micropipette puller (P-2000, Sutter Instrument) were chosen as variables, namely heat, velocity and pull. The targeted length L TVS of the tapered variant section with a tip diameter of 10 μ m was taken as a response. The optimum process parameters with L TVS of 7.3 mm were determined by analyzing the response surface three-dimension surface plots. The central composite design was selected to optimize the process variables, and the experimental data were fitted into a reduced cubic polynomial model. The high R 2 value (99.66%) and low coefficient of variation (0.73%) indicated the statistical significance of the model and good precision for the experiment. The optimization result showed that the best parameters were with the heat, velocity and pull values of 850, 53 and 170, respectively. The result was verified by a CO 2 laser-based micropipette puller three times with length L TVS at 7.26 mm, 7.35 mm and 7.36 mm with the same optimized parameters. Then, the application to the ultrafine atmospheric pressure He/O 2 plasma jets was carried out and micro-hole etching of the parylene-C film was realized with length L TVS at 6.29 mm, 7.35 mm and 8.02 mm. The results showed that the micro-plasma jet with an L TVS of 7.35 mm had the minimum applied voltage of 12.7 kV and the minimum micro-etching diameter of 45 μ m with the deepest etching depth of 2.8 μ m. (paper)

  19. Sustainable Materials Management (SMM) Electronics Challenge Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — On September 22, 2012, EPA launched the SMM Electronics Challenge. The Challenge encourages electronics manufacturers, brand owners and retailers to strive to send...

  20. Sustainable Materials Management (SMM) Electronics Challenge

    Science.gov (United States)

    Learn how the SMM Electronics Challenge encourage electronic manufacturers to strive to send 100 percent of the used electronics they collect from the public and retailers to certified electronics refurbishers and recyclers.

  1. Surface micromachined MEMS deformable mirror based on hexagonal parallel-plate electrostatic actuator

    Science.gov (United States)

    Ma, Wenying; Ma, Changwei; Wang, Weimin

    2018-03-01

    Deformable mirrors (DM) based on microelectromechanical system (MEMS) technology are being applied in adaptive optics (AO) system for astronomical telescopes and human eyes more and more. In this paper a MEMS DM with hexagonal actuator is proposed and designed. The relationship between structural design and performance parameters, mainly actuator coupling, is analyzed carefully and calculated. The optimum value of actuator coupling is obtained. A 7-element DM prototype is fabricated using a commercial available standard three-layer polysilicon surface multi-user-MEMS-processes (PolyMUMPs). Some key performances, including surface figure and voltage-displacement curve, are measured through a 3D white light profiler. The measured performances are very consistent with the theoretical values. The proposed DM will benefit the miniaturization of AO systems and lower their cost.

  2. The development of micromachined gyroscope structure and circuitry technology.

    Science.gov (United States)

    Xia, Dunzhu; Yu, Cheng; Kong, Lun

    2014-01-14

    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.

  3. 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.

  4. The integration of surface micromachined devices with optoelectronics: Technology and applications

    Energy Technology Data Exchange (ETDEWEB)

    Warren, M.E.; Blum, O.; Sullivan, C.T.; Shul, R.J.; Rodgers, M.S.; Sniegowski, J.J.

    1998-04-01

    Sandia National Laboratories has a substantial effort in development of microelectromechanical system (MEMS) technologies. This miniaturization capability can lead to low-cost, small, high-performance systems-on-a-chip, and have many applications ranging from advanced military systems to large-volume commercial markets like automobiles, rf or land-based communications networks and equipment, or commercial electronics. One of the key challenges in realization of the microsystem is integration of several technologies including digital electronics; analog and rf electronics, optoelectronics, sensors and actuators, and advanced packaging technologies. In this work they describe efforts in integrating MEMS and optoelectronic or photonic functions and the fabrication constraints on both system components. the MEMS technology used in this work are silicon surface-machined systems fabricated using the SUMMiT (Sandia Ultraplanar Multilevel MEMS Technology) process developed at Sandia. This process includes chemical-mechanical polishing as an intermediate planarization step to allow the use of 4 or 5 levels of polysilicon.

  5. Acceleration of dormant storage effects to address the reliability of silicon surface micromachined Micro-Electro-Mechanical Systems (MEMS).

    Energy Technology Data Exchange (ETDEWEB)

    Cox, James V.; Candelaria, Sam A.; Dugger, Michael Thomas; Duesterhaus, Michelle Ann; Tanner, Danelle Mary; Timpe, Shannon J.; Ohlhausen, James Anthony; Skousen, Troy J.; Jenkins, Mark W.; Jokiel, Bernhard, Jr.; Walraven, Jeremy Allen; Parson, Ted Blair

    2006-06-01

    Qualification of microsystems for weapon applications is critically dependent on our ability to build confidence in their performance, by predicting the evolution of their behavior over time in the stockpile. The objective of this work was to accelerate aging mechanisms operative in surface micromachined silicon microelectromechanical systems (MEMS) with contacting surfaces that are stored for many years prior to use, to determine the effects of aging on reliability, and relate those effects to changes in the behavior of interfaces. Hence the main focus was on 'dormant' storage effects on the reliability of devices having mechanical contacts, the first time they must move. A large number ({approx}1000) of modules containing prototype devices and diagnostic structures were packaged using the best available processes for simple electromechanical devices. The packaging processes evolved during the project to better protect surfaces from exposure to contaminants and water vapor. Packages were subjected to accelerated aging and stress tests to explore dormancy and operational environment effects on reliability and performance. Functional tests and quantitative measurements of adhesion and friction demonstrated that the main failure mechanism during dormant storage is change in adhesion and friction, precipitated by loss of the fluorinated monolayer applied after fabrication. The data indicate that damage to the monolayer can occur at water vapor concentrations as low as 500 ppm inside the package. The most common type of failure was attributed to surfaces that were in direct contact during aging. The application of quantitative methods for monolayer lubricant analysis showed that even though the coverage of vapor-deposited monolayers is generally very uniform, even on hidden surfaces, locations of intimate contact can be significantly depleted in initial concentration of lubricating molecules. These areas represent defects in the film prone to adsorption of

  6. Surface micromachined scanning mirrors

    DEFF Research Database (Denmark)

    Mattsson, Kent Erik

    1992-01-01

    Both aluminum cantilever and torsional scanning mirrors have been fabricated and their static and dynamic properties are studied experimentally and theoretically. The experiments showed resonance frequencies in the range of 163 k-Hz - 632 kHz for cantilever beams with Q values between 5 and 11....... Torsional mirrors showed resonance frequencies in the range of 410 kHz - 667 kHz with Q values of 10 - 17. All measurements performed at atmospheric pressure. Both types of mechanical structures were deflected electrostatically at large angles (± 5°) more than 1011 times without breaking and without any...

  7. 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...

  8. Micromachined electrode array

    Science.gov (United States)

    Okandan, Murat; Wessendorf, Kurt O.

    2007-12-11

    An electrode array is disclosed which has applications for neural stimulation and sensing. The electrode array, in certain embodiments, can include a plurality of electrodes each of which is flexibly attached to a common substrate using a plurality of springs to allow the electrodes to move independently. In other embodiments of the electrode array, the electrodes can be fixed to the substrate. The electrode array can be formed from a combination of bulk and surface micromachining, and can include electrode tips having an electroplated metal (e.g. platinum, iridium, gold or titanium) or a metal oxide (e.g. iridium oxide) for biocompatibility. The electrode array can be used to form a part of a neural prosthesis, and is particularly well adapted for use in an implantable retinal prosthesis.

  9. Micromachined droplet ejector arrays

    Science.gov (United States)

    Perçin, Gökhan; Yaralioglu, Göksenin G.; Khuri-Yakub, Butrus T.

    2002-12-01

    In this article we present a micromachined flextensional droplet ejector array used to eject liquids. By placing a fluid behind one face of a vibrating circular plate that has an orifice at its center, we achieve continuous ejection of the fluid. We present results of ejection of water and isopropanol. The ejector is harmless to sensitive fluids and can be used to eject fuels, organic polymers, photoresists, low-k dielectrics, adhesives, and chemical and biological samples. Micromachined two-dimensional array flextensional droplet ejectors were realized using planar silicon micromachining techniques. Typical resonant frequency of the micromachined device ranges from 400 kHz to 4.5 MHz. The ejections of water through a 4 μm diameter orifice at 3.45 MHz and a 10 μm diameter orifice at 2.15 MHz were demonstrated by using the developed micromachined two-dimensional array ejectors.

  10. Micromachined patch-clamp apparatus

    Science.gov (United States)

    Okandan, Murat

    2012-12-04

    A micromachined patch-clamp apparatus is disclosed for holding one or more cells and providing electrical, chemical, or mechanical stimulation to the cells during analysis with the patch-clamp technique for studying ion channels in cell membranes. The apparatus formed on a silicon substrate utilizes a lower chamber formed from silicon nitride using surface micromachining and an upper chamber formed from a molded polymer material. An opening in a common wall between the chambers is used to trap and hold a cell for analysis using the patch-clamp technique with sensing electrodes on each side of the cell. Some embodiments of the present invention utilize one or more electrostatic actuators formed on the substrate to provide mechanical stimulation to the cell being analyzed, or to provide information about mechanical movement of the cell in response to electrical or chemical stimulation.

  11. 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

  12. 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.

  13. 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)

  14. 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.

  15. 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.

  16. 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.

  17. Sustainable Materials Management (SMM) Federal Green Challenge (FGC) Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Federal Green Challenge (FGC) is a national effort under EPA's Sustainable Materials Management (SMM) Program, challenging EPA and other federal agencies...

  18. 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)

  19. 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.

  20. Micromachining with Nanostructured Cutting Tools

    CERN Document Server

    Jackson, Mark J

    2013-01-01

    The purpose of the brief is to explain how nanostructured tools can be used to machine materials at the microscale.  The aims of the brief are to explain to readers how to apply nanostructured tools to micromachining applications. This book describes the application of nanostructured tools to machining engineering materials and includes methods for calculating basic features of micromachining. It explains the nature of contact between tools and work pieces to build a solid understanding of how nanostructured tools are made.

  1. Silicon-micromachined microchannel plates

    Energy Technology Data Exchange (ETDEWEB)

    Beetz, Charles P. E-mail: NanoSystem@aol.com; Boerstler, Robert; Steinbeck, John; Lemieux, Bryan; Winn, David R. E-mail: winn@fair1.fairfield.edu

    2000-03-11

    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 deposited or nucleated in the channels or the first strike surface. Results on resistivity, secondary emission and gain are presented.

  2. Silicon-micromachined microchannel plates

    Science.gov (United States)

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

    2000-03-01

    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°C, also compatible with high-temperture 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.

  3. 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

  4. Capacitive micromachined ultrasonic transducer based tilt sensing

    Science.gov (United States)

    Yu, Hongbin; Guo, Bin; Haridas, Kuruveettil; Lin, Tsu-Hui; Hao Cheong, Jia; Lin Tsai, Ming; Boon Yee, Tack

    2012-10-01

    In this paper, a tilt sensing mechanism based on the capacitive micromachined ultrasound transducers (CMUTs) is presented. By measuring the difference in the time of flight of various pulse-echo signals from different CMUT transmitting elements to one common receiving element in the oil bath, the tilt angle of the oil surface can be determined. With the proposed device, the maximum tilt angles of 20° and 28° have been measured in the clockwise and counterclockwise directions, respectively, and the difference between the measured and the theoretical values of the tilt angle was found to be within 0.05° during the whole test.

  5. Modeling Grinding Processes as Micro-Machining Operation ...

    African Journals Online (AJOL)

    A computational based model for surface grinding process as a micro-machined operation has been developed. In this model, grinding forces are made up of chip formation force and sliding force. Mathematical expressions for Modeling tangential grinding force and normal grinding force were obtained. The model was ...

  6. Sustainable Materials Management (SMM) WasteWise Data

    Science.gov (United States)

    EPA??s WasteWise encourages organizations and businesses to achieve sustainability in their practices and reduce select industrial wastes. WasteWise is part of EPA??s sustainable materials management efforts, which promote the use and reuse of materials more productively over their entire lifecycles. All U.S. businesses, governments and nonprofit organizations can join WasteWise as a partner, endorser or both. Current participants range from small local governments and nonprofit organizations to large multinational corporations. Partners demonstrate how they reduce waste, practice environmental stewardship and incorporate sustainable materials management into their waste-handling processes. Endorsers promote enrollment in WasteWise as part of a comprehensive approach to help their stakeholders realize the economic benefits to reducing waste. WasteWise helps organizations reduce their impact on global climate change through waste reduction. Every stage of a product's life cycle??extraction, manufacturing, distribution, use and disposal??indirectly or directly contributes to the concentration of greenhouse gases (GHGs) in the atmosphere and affects the global climate. WasteWise is part of EPA's larger SMM program (https://www.epa.gov/smm). Sustainable Materials Management (SMM) is a systemic approach to using and reusing materials more productively over their entire lifecycles. It represents a change in how our society thinks about the use of natural resources

  7. 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

  8. Bionics: prcise color tuning by interference in nature and technology-applications in surface-micromachined 1.55μm vertical air-cavity filters

    Science.gov (United States)

    Hillmer, Hartmut; Daleiden, Juergen; Prott, Cornelia; Irmer, Soeren; Roemer, Friedhard; Ataro, Edwin; Tarraf, Amer; Ruehling, H.; Maniak, Markus; Strassner, Martin

    2003-01-01

    Bionics transfers the principles of success of nature into natural science, engineering disciplines and applications. Often generation and detection of different spectral colors play key roles in communication in both, nature and technology. The latter one refers e.g. to dense wavelength division multiplex optical communication systems. This paper shows interesting parallels in tunable spectral light filtering by butterfly wings and by tunable optical filters used in optical communication systems. In both cases light interferes constructively and destructively with nano- and microstructures of appropriate shape, dimensions and materials. In this paper methodology is strongly emphasized. We demonstrate that tailored scaling allows the effectiveness of physical effects to be enhanced in nature and technology. These principles are rigorously applied in micromachined 1.55μm vertical-resonator-based filters, capable of wide, continuous, monotonic and kink-free tuning by a single control parameter. Tuning is achieved by mechanically actuating one or several membranes embedded by air-gaps in a vertical resonator including two ultra-highly reflective DBR mirrors. The layers of mirrors reveal a very strong refractive index contrast. Filters including InP/air-gap DBR's (3.5 periods) using GaInAs sacrificial layers reveal a continuous tuning of >9% of the absolute wavelength. Varying a reverse voltage (U=0 .. -3.2V) between the membranes, a tuning range up to 142nm was obtained due to electrostatic actuation. Appropriate miniaturization is shown to increase the mechanical stability and the effectiveness of spectral tuning by electrostatic actuation since the relative significance of the fundamental physical forces can be shifted considerably by appropriate scaling.

  9. Laser Micromachining of Glass, Silicon, and Ceramics

    Directory of Open Access Journals (Sweden)

    L. Rihakova

    2015-01-01

    Full Text Available A brief review is focused on laser micromachining of materials. Micromachining of materials is highly widespread method used in many industries, including semiconductors, electronic, medical, and automotive industries, communication, and aerospace. This method is a promising tool for material processing with micron and submicron resolution. In this paper micromachining of glass, silicon, and ceramics is considered. Interaction of these materials with laser radiation and recent research held on laser material treatment is provided.

  10. Fabrication of a novel quartz micromachined gyroscope

    Directory of Open Access Journals (Sweden)

    Liqiang Xie

    2015-04-01

    Full Text Available 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.

  11. Analysis and prediction of dimensions and cost of laser micro-machining internal channel fabrication process

    Directory of Open Access Journals (Sweden)

    Brabazon D.

    2010-06-01

    Full Text Available This paper presents the utilisation of Response Surface Methodology (RSM as the prediction tool for the laser micro-machining process. Laser internal microchannels machined using pulsed Nd:YVO4 laser in polycarbonate were investigated. The experiments were carried out according to 33 factorial Design of Experiment (DoE. In this work the three input process set as control parameters were laser power, P; pulse repetition frequency, PRF; and sample translation speed, U. Measured responses were the channel width and the micro-machining operating cost per metre of produced microchannels. The responses were sufficiently predicted within the set micro-machining parameters limits. Two factorial interaction (2FI and quadratic polynomial regression equations for both responses were constructed. It is proposed that the developed prediction equations can be used to find locally optimal micro-machining process parameters under experimental and operational conditions.

  12. Mechanical Micro-Machining and Laser Micro-Machining

    Science.gov (United States)

    Lou, Ning

    Ever since the 2000s, the manufacturing industry has gained tremendous development in terms of precision. Therefore, micro-machining as a cutting-edge technique has drawn more and more attention in precision-machining realm and been able to take on challenges brought by this. This doctoral program explores the micro-machining realm and results are consisted of two major parts. First, the machinability of "difficult-to-cut" materials is of interest where Inconel 718 is selected as its characteristics include outstanding strength and lackluster thermal conductivity. For its extraordinary hardness and sustainability, coated cemented carbide tools are selected for micro-endmilling processes on Inconel. The cutting forces along x and y axis, respectively, are analyzed to reveal any impact from the inputs. Moreover, the chip morphology is examined. Suggestions are made for future research guidance. As first part serves as preliminary work of the program, the research carries onto the second part - laser micro-machining which is considerably different from conventional machining. The laser being considered employs pulsewidth in realm of picosecond (10-12 s) and frequency of tens of kilohertz. This results in a very small energy distribution per pulse (microJ) and is called ultrafast or ultrashort laser machining. To study this type of technology, an all-new machining system needs to be built incorporating highly advanced apparatus such as laser head, scan head, attenuator, and beam expander, et al. From exit of laser head to workpiece, laser need to travel through all optical components and any deviation may leads to severe out-of-focus error as the depth of focus is within micron level. Thus, optical alignment along laser travelling route is key to successful machining results. This part of research focuses on the design and assembly of this system as a reliable structure offering both support and alignment to the laser delivery. 3-Dimentional (3D) Computer

  13. 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.

  14. Gamma ray detector for solar maximum mission (SMM) of NASA

    International Nuclear Information System (INIS)

    Brunner, W.; Brichzin, K.; Sach, E.

    1981-06-01

    For NASA's Project Solar Maximum Mission-SMM (launch 14.2.80) a Gamma Ray Detector was developed, manufactured and tested to measure solar high energetic Gamma rays and Neutron fluxes within the energy range 10-160 MeV, 4,43 MeV amd 2,23 MeV. The main components of the sensor are 7 NaI crystals 3 x 3 and a CsI crystal 30 cm diameter x 7,5 cm. The rejection of charged particles is done by two plasitc scintillators and 4 CsI-shields. From the beginning of the mission the experiment is working fully successfull. (orig.) [de

  15. 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.

  16. Micromachined Thermal Flow Sensors—A Review

    Directory of Open Access Journals (Sweden)

    Jonathan T. W. Kuo

    2012-07-01

    Full Text Available Microfabrication has greatly matured and proliferated in use amongst many disciplines. There has been great interest in micromachined flow sensors due to the benefits of miniaturization: low cost, small device footprint, low power consumption, greater sensitivity, integration with on-chip circuitry, etc. This paper reviews the theory of thermal flow sensing and the different configurations and operation modes available. Material properties relevant to micromachined thermal flow sensing and selection criteria are also presented. Finally, recent applications of micromachined thermal flow sensors are presented. Detailed tables of the reviewed devices are included.

  17. 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.

  18. 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...

  19. Development of a micromachined electrostatically suspended gyroscope

    OpenAIRE

    Damrongsak, Badin

    2009-01-01

    In this thesis, a new approach based on an electrostatically suspended gyroscope (ESG) was explored in order to improve the performance of micromachined gyroscopes. Typically, a conventional micromachined gyroscope consists of a vibrating mass suspended on elastic beams that are anchored to a substrate. It measures the rotation rate of a body of interest by detecting rotation-induced Coriolis acceleration of a vibrating structure. Such a gyro is sensitive to fabrication imperfections an...

  20. 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

  1. Sustainable Materials Management (SMM) Web Academy Webinar: Food Waste Reduction Alliance, a Unique Industry Collaboration

    Science.gov (United States)

    This is a webinar page for the Sustainable Management of Materials (SMM) Web Academy webinar titled Let’s WRAP (Wrap Recycling Action Program): Best Practices to Boost Plastic Film Recycling in Your Community

  2. Sustainable Materials Management (SMM) Web Academy Webinar: The Changing Waste Stream

    Science.gov (United States)

    This is a webinar page for the Sustainable Management of Materials (SMM) Web Academy webinar titled Let’s WRAP (Wrap Recycling Action Program): Best Practices to Boost Plastic Film Recycling in Your Community

  3. Sustainable Materials Management (SMM) Web Academy Webinar: Managing Wasted Food with Anaerobic Digestion: Incentives and Innovations

    Science.gov (United States)

    This is a webinar page for the Sustainable Management of Materials (SMM) Web Academy webinar titled Let’s WRAP (Wrap Recycling Action Program): Best Practices to Boost Plastic Film Recycling in Your Community

  4. Sustainable Materials Management (SMM) Web Academy Webinar: Reducing Wasted Food: How Packaging Can Help

    Science.gov (United States)

    This is a webinar page for the Sustainable Management of Materials (SMM) Web Academy webinar titled Let’s WRAP (Wrap Recycling Action Program): Best Practices to Boost Plastic Film Recycling in Your Community

  5. Acoustic lens for capacitive micromachined ultrasonic transducers

    Science.gov (United States)

    Chang, Chienliu; Firouzi, Kamyar; Park, Kwan Kyu; Sarioglu, Ali Fatih; Nikoozadeh, Amin; Yoon, Hyo-Seon; Vaithilingam, Srikant; Carver, Thomas; Khuri-Yakub, Butrus T.

    2014-08-01

    Capacitive micromachined ultrasonic transducers (CMUTs) have great potential to compete with traditional piezoelectric transducers in therapeutic ultrasound applications. In this paper we have designed, fabricated and developed an acoustic lens formed on the CMUT to mechanically focus ultrasound. The acoustic lens was designed based on the paraxial theory and made of silicone rubber for acoustic impedance matching and encapsulation. The CMUT was fabricated based on the local oxidation of silicon (LOCOS) and fusion-bonding. The fabricated CMUT was verified to behave like an electromechanical resonator in air and exhibited wideband response with a center frequency of 2.2 MHz in immersion. The fabrication for the acoustic lens contained two consecutive mold castings and directly formed on the surface of the CMUT. Applied with ac burst input voltages at the center frequency, the CMUT with the acoustic lens generated an output pressure of 1.89 MPa (peak-to-peak) at the focal point with an effective focal gain of 3.43 in immersion. Compared to the same CMUT without a lens, the CMUT with the acoustic lens demonstrated the ability to successfully focus ultrasound and provided a viable solution to the miniaturization of the multi-modality forward-looking endoscopes without electrical focusing.

  6. Acoustic lens for capacitive micromachined ultrasonic transducers

    International Nuclear Information System (INIS)

    Chang, Chienliu; Firouzi, Kamyar; Sarioglu, Ali Fatih; Nikoozadeh, Amin; Yoon, Hyo-Seon; Vaithilingam, Srikant; Carver, Thomas; Khuri-Yakub, Butrus T; Kyu Park, Kwan

    2014-01-01

    Capacitive micromachined ultrasonic transducers (CMUTs) have great potential to compete with traditional piezoelectric transducers in therapeutic ultrasound applications. In this paper we have designed, fabricated and developed an acoustic lens formed on the CMUT to mechanically focus ultrasound. The acoustic lens was designed based on the paraxial theory and made of silicone rubber for acoustic impedance matching and encapsulation. The CMUT was fabricated based on the local oxidation of silicon (LOCOS) and fusion-bonding. The fabricated CMUT was verified to behave like an electromechanical resonator in air and exhibited wideband response with a center frequency of 2.2 MHz in immersion. The fabrication for the acoustic lens contained two consecutive mold castings and directly formed on the surface of the CMUT. Applied with ac burst input voltages at the center frequency, the CMUT with the acoustic lens generated an output pressure of 1.89 MPa (peak-to-peak) at the focal point with an effective focal gain of 3.43 in immersion. Compared to the same CMUT without a lens, the CMUT with the acoustic lens demonstrated the ability to successfully focus ultrasound and provided a viable solution to the miniaturization of the multi-modality forward-looking endoscopes without electrical focusing. (paper)

  7. 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

  8. Acoustic mode converters micromachined in silicon by proton beam writing

    International Nuclear Information System (INIS)

    Scholz, U.; Menzel, F.; Pluta, M.; Grill, W.; Butz, T.

    2011-01-01

    Proton beam writing is a powerful tool for the production of microstructures for acoustic applications because it allows to create structures inclined to the original sample surface which therefore can act as acoustic mode converters. We report on experiments, finding optimal structure sizes in p-type 12 Ω cm silicon for this purpose. For the creation of the structures the proton beam at the LIPSION laboratory was used. Furthermore, by investigating the micromachined silicon with a phase sensitive acoustic microscope we give evidence that inclined structures such as rods and walls can be used to change the mode of acoustic waves in the crystal.

  9. Physics-based signal processing algorithms for micromachined cantilever arrays

    Science.gov (United States)

    Candy, James V; Clague, David S; Lee, Christopher L; Rudd, Robert E; Burnham, Alan K; Tringe, Joseph W

    2013-11-19

    A method of using physics-based signal processing algorithms for micromachined cantilever arrays. The methods utilize deflection of a micromachined cantilever that represents the chemical, biological, or physical element being detected. One embodiment of the method comprises the steps of modeling the deflection of the micromachined cantilever producing a deflection model, sensing the deflection of the micromachined cantilever and producing a signal representing the deflection, and comparing the signal representing the deflection with the deflection model.

  10. Micromachined gyroscopes: challenges, design solutions, and opportunities

    Science.gov (United States)

    Shkel, Andrei M.

    2001-08-01

    Micromachined gyroscopes are probably the most challenging type of transducers ever attempted to be designed in micro-world. A nail-size dynamic system integrated with control electronics on the same silicon chip is designed to be a very sensitive sensor which is potentially able to detect maneuvers and motions beyond human perception. Along with exciting opportunities which MEMS gyroscopes could bring to everyday life, the miniaturization introduces many new technical challenges. Multi-degree of freedom dynamics, sensitivity to fabrication imperfections, dynamic instability, limited control resources - all these raise a number of fundamentally challenging issues in the design, analysis, and control of micromachined gyroscopes. In this paper, we summarize principles of operation, review recent research and development efforts, and discuss potential applications and the future market of silicon based micromachined gyroscopes.

  11. Silicon Micromachining for Terahertz Component Development

    Science.gov (United States)

    Chattopadhyay, Goutam; Reck, Theodore J.; Jung-Kubiak, Cecile; Siles, Jose V.; Lee, Choonsup; Lin, Robert; Mehdi, Imran

    2013-01-01

    Waveguide component technology at terahertz frequencies has come of age in recent years. Essential components such as ortho-mode transducers (OMT), quadrature hybrids, filters, and others for high performance system development were either impossible to build or too difficult to fabricate with traditional machining techniques. With micromachining of silicon wafers coated with sputtered gold it is now possible to fabricate and test these waveguide components. Using a highly optimized Deep Reactive Ion Etching (DRIE) process, we are now able to fabricate silicon micromachined waveguide structures working beyond 1 THz. In this paper, we describe in detail our approach of design, fabrication, and measurement of silicon micromachined waveguide components and report the results of a 1 THz canonical E-plane filter.

  12. Simulation and optimization of a micromachined gyroscope using high-aspect-ratio micromachining fabrication process

    Science.gov (United States)

    Ruan, Aiwu Y.; Tse, Man S.; Chong, Gang Y.

    2001-11-01

    Micromachined gyroscopes rely on tuned vibration mode frequencies to measure rotation rates and typically have complex modes of vibration for the mechanical microstructures. Although there are many reports on how to exactly tune the drive and sense modes of vibration to maximize sensitivity of micromachined gyroscope, there are only few reports on the detailed analysis of modes of vibration. Modes of vibration are strongly dependent on the design parameters of the mechanical structure of the gyroscope including the dimension of the proof mass, types and dimensions of the suspension, and residual mechanical stress of the high aspect-ratio polysilicon film used to form the microstructures of the micromachined gyroscope. In this paper, an electrostatic drive and capacitive sense in-plane decoupled gyroscope for measuring vertical angular velocity is proposed to study the effects of the geometrical variables on modes of vibration. Finite-element analysis (FEA) simulation was performed on simplifiedmodel of the in-plane decoupled micromachined gyroscope microstructure. For optimal result the drive-mode and sense-mode suspensions of the micromachined gyroscope should be fabricated from thick polysilicon microstructure to give large aspect ratio suspension systems for the in-plane decoupled micromachined gyroscope. Folded-beam suspension design is recommended for the drive-mode suspension in order to relieve the residual stress of the thick polysilicon film for high aspect-ratio micromachine dgyroscope. It is critical to control the process variations of the suspension beam dimension, especially the beam width variation in order to achieve the goal of accurately control resonant frequencies of micromachined gyrocope.

  13. Planar silicon fabrication process for high-aspect-ratio micromachined parts

    Energy Technology Data Exchange (ETDEWEB)

    Barron, C.C.; Fleming, J.G. [Sandia National Labs., Albuquerque, NM (United States). Microelectronics Development Lab.

    1997-09-01

    Surface-micromachined silicon inertial sensors are limited to relatively high-G applications in part because of the fundamental limitations on proof mass imposed by the manufacturing technology. At the same time, traditional micromolding technologies such as LIGA do not lend themselves to integration with electronics, a capability which is equally necessary for high-performance inertial sensors. The silicon micromolding processes described in this report promise to offer both larger proof masses and integrability with on-chip electronics. In Sandia`s silicon micromolding process, the proof mass is formed using a mold which is first recessed into the substrate using a deep silicon trench etch, then lined with a sacrificial or etch-stop layer, and filled with mechanical polysilicon. Since the mold is recessed into the substrate, the whole micromechanical structure can be formed, planarized, and integrated with standard silicon microelectronic circuits before the release etch. In addition, unlike surface-micromachined parts, the thickness of the molded parts is limited by the depth of the trench etch (typically 10--50 {micro}m) rather than the thickness of deposited polysilicon (typically 2 {micro}m). The fact that the high-aspect-ratio section of the device is embedded in the substrate enables the monolithic integration of high-aspect-ratio parts with surface-micromachined mechanical parts, and, in the future, also electronics. The authors anticipate that such an integrated mold/surface micromachining/electronics process will offer versatile high-aspect-ratio micromachined structures that can be batch-fabricated and monolithically integrated into complex microelectromechanical systems including high-performance inertial sensing systems.

  14. Micromachined glass chips for ion analysis

    NARCIS (Netherlands)

    Gardeniers, Johannes G.E.; Mulder, Micha; Lüttge, Regina; van den Berg, Albert

    2002-01-01

    This article describes recent developments at Micronit Microfluidics B.V. and MESA+ in the field of "Lab-on-a-chip" systems for ion analysis. Glass chips with typical micromachined channel geometries for capillary electrophoresis and integrated conductivity detection were developed, with which

  15. Prediction of MHC class II binding affinity using SMM-align, a novel stabilization matrix alignment method

    DEFF Research Database (Denmark)

    Nielsen, Morten; Lundegaard, Claus; Lund, Ole

    2007-01-01

    BACKGROUND: Antigen presenting cells (APCs) sample the extra cellular space and present peptides from here to T helper cells, which can be activated if the peptides are of foreign origin. The peptides are presented on the surface of the cells in complex with major histocompatibility class II (MHC...... II) molecules. Identification of peptides that bind MHC II molecules is thus a key step in rational vaccine design and developing methods for accurate prediction of the peptide:MHC interactions play a central role in epitope discovery. The MHC class II binding groove is open at both ends making...... the correct alignment of a peptide in the binding groove a crucial part of identifying the core of an MHC class II binding motif. Here, we present a novel stabilization matrix alignment method, SMM-align, that allows for direct prediction of peptide:MHC binding affinities. The predictive performance...

  16. 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.

  17. Development of SMM wave laser scattering apparatus for the measurements of waves and turbulences in the tokamak plasma

    International Nuclear Information System (INIS)

    Saito, T.; Hamada, Y.; Yamashita, T.; Ikeda, M.; Nakamura, M.

    1980-01-01

    The SMM wave laser scattering apparatus has been developed for the measurement of the waves and turbulences in the plasma. This apparatus will help greatly to clarify the physics of RF heating of the tokamak plasma. The present status of main parts of the apparatus, the SMM wave laser and the Schottky barrier diode mixer for the heterodyne receiver, are described. (author)

  18. Sustainable Materials Management (SMM) - Materials and Waste Management in the United States Key Facts and Figures

    Science.gov (United States)

    Each year EPA produces a report called Advancing Sustainable Materials Management: Facts and Figures. It includes information on municipal solid waste (MSW) generation, recycling, composting, combustion with energy recovery and landfilling. The 2014 report provides information on historical tipping fees for MSW, and information on the construction and demolition debris generation, which is outside of the scope of MSW. The Facts and Figures website includes recent reports (2012 to 2014 as well as historical information on materials in the U.S. Municipal Waste Stream, 1960 to 2014 (in tons). The reports for both current and historical waste prevention can be accessed at EPA's SMM website. The recent Annual Facts and Figures reports are accessible at the following link: https://www.epa.gov/smm/advancing-sustainable-materials-management-facts-and-figures-report. Historical data as well as studies and summary tables related to the Advancing Sustainable Materials Management Report are accessible here: https://www.epa.gov/smm/studies-summary-tables-and-data-related-advancing-sustainable-materials-management-report. An excel file containing the data from 1960 - 2014 is located here: https://edg.epa.gov/data/PUBLIC/OLEM/Materials_Municipal_Waste_Stream_1960_to_2014.xlsx. EPA also maintains a list of state and local waste characterization studies (reports are not available for all states). You can search for your state at https://www.epa.gov/smm/advancing-

  19. SMM AS A PROMISING WAY TO PROMOTE GOODS AND SERVICES IN THE RUSSIAN MARKET

    Directory of Open Access Journals (Sweden)

    Ms. Elena V. Chepukhalina

    2016-06-01

    Full Text Available In this article definition to SMM is given (Social Media Marketing, types and tools of social media are classified, the marketing tasks solved by social media are listed, and the Russian audience of users of social media is analysed.

  20. Micromachining of AlN and Al2O3 Using Fiber Laser

    Directory of Open Access Journals (Sweden)

    Florian Preusch

    2014-11-01

    Full Text Available We report on high precision high speed micromachining of Al2O3 and AlN using pulsed near infrared fiber laser. Ablation thresholds are determined to be 30 J/cm2 for alumina and 18 J/cm2 for aluminum nitride. The factors influencing the efficiency and quality of 3D micromachining, namely the surface roughness, the material removal rate and the ablation depth accuracy are determined as a function of laser repetition rate and pulse overlap. Using a fluence of 64 J/cm², we achieve a material removal rate of up to 94 mm³/h in Al2O3 and 135 mm³/h in AlN for high pulse overlaps (89% and 84%. A minimum roughness of 1.5 μm for alumina and 1.65 μm for aluminum nitride can be accomplished for medium pulse overlaps (42% to 56%. In addition, ablation depth deviation of the micromachining process of smaller than 8% for alumina and 2% for aluminum nitride are achieved. Based on these results, by structuring exemplarily 3D structures we demonstrate the potential of high quality and efficient 3D micromachining using pulsed fiber laser.

  1. Novel silicon fabrication process for high-aspect-ratio micromachined parts

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, J.G.; Barron, C.C.

    1995-08-01

    Bulk micromachining generally refers to processes involving wet chemical etching of structures formed out of the silicon substrate and so is limited to fairly large, crude structures. Surface micromachining allows intricate patterning of thin films of polysilicon and other materials to form essentially two-dimensional layered parts (since the thickness of the parts is limited by the thickness of the deposited films). There is a third type of micromachining in which the part is formed by filling a mold which was defined by photolithographic means. Historically micromachining molds have been formed in some sort of photopolymer, be it with x-ray lithography (``LIGA``) or more conventional UV lithography, with the aim of producing piece parts. Recently, however, several groups including ours at Sandia have independently come up with the idea of forming the mold for mechanical parts by etching into the silicon substrate itself. In Sandia`s mold process, the mold is recessed into the substrate using a deep silicon trench etch, lined with a sacrificial or etch-stop layer, and then filled with any of a number of mechanical materials. The completed structures are not ejected from the mold to be used as piece parts rather, the mold is dissolved from around selected movable segments of the parts, leaving the parts anchored to the substrate. Since the mold is recessed into the substrate, the whole micromechanical structure can be formed, planarized, and integrated with standard silicon microelectronic circuits before the release etch. In addition, unlike surface-micromachined parts, the thickness of the molded parts is limited by the depth of the trench etch (typically 10--50 {mu}m) rather than the thickness of deposited polysilicon (typically 2 {mu}m). The capability of fabricating thicker (and therefore much stiffer and more massive) parts is critical for motion-sensing structures involving large gimballed platforms, proof masses, etc.

  2. 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.

  3. 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.

  4. 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,...

  5. In-pipe micromachine locomotion via the inertial stepping principle

    Energy Technology Data Exchange (ETDEWEB)

    Yum, Young Jin [University of Ulsan, Ulsan (Korea, Republic of); Hwang, Han Sub [Suweon Science College, Suweon (Korea, Republic of); Kelemen, Michal; Maxim, Vladislav; Frankovsky, Peter [Technical University of Kosice, Kosice (Slovakia)

    2014-08-15

    This paper discusses an in-pipe inspection micromachine intended for locomotion inside a small diameter pipe. The micromachine locomotion is based on the inertial stepping principle, which utilizes the drive force of the two-body impact. The in-pipe micromachine contacts the pipe through the elastic bristles installed on the in-pipe machine and in two lines and crossways with respect to the micromachine axle. The paper describes the principle of locomotion and the dynamics by which the unknown of both the parameters and the relations are experimentally identified. Based on the results, a simulation model was created, and the results of the simulations were compared with experimental results.

  6. 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.

  7. Resonant gravimetric immuno sensing based on capacitive micromachined ultrasound transducers

    International Nuclear Information System (INIS)

    Virzonis, Darius; Gailius Vanagas; Dovydas Barauskas; Ramanaviciene, Almira; Makaraviciute, Asta; Ramanavicius, Arunas; Wen, Weijia; Kodzius, Rimantas

    2014-01-01

    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. (author)

  8. 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.

  9. Temperature dependence of attitude sensor coalignments on the Solar Maximum Mission (SMM)

    Science.gov (United States)

    Pitone, D. S.; Eudell, A. H.; Patt, F. S.

    1990-01-01

    The temperature correlation of the relative coalignment between the fine-pointing sun sensor and fixed-head star trackers measured on the Solar Maximum Mission (SMM) is analyzed. An overview of the SMM, including mission history and configuration, is given. Possible causes of the misalignment variation are discussed, with focus placed on spacecraft bending due to solar-radiation pressure, electronic or mechanical changes in the sensors, uncertainty in the attitude solutions, and mounting-plate expansion and contraction due to thermal effects. Yaw misalignment variation from the temperature profile is assessed, and suggestions for spacecraft operations are presented, involving methods to incorporate flight measurements of the temperature-versus-alignment function and its variance in operational procedures and the spacecraft structure temperatures in the attitude telemetry record.

  10. 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.

  11. Results of a search for a new class of GRBS in the SMM data

    Science.gov (United States)

    Kouveliotou, C.; Cline, T. L.; Desai, U. D.; Dennis, B. R.; Orwig, L. E.

    1986-01-01

    The results of a search for the soft and short Gamma-Ray Bursts (GRBs) in the data of the Hard X-Ray Burst Spectrometer (HXRBS) on the Solar Maximum Mission (SMM) are presented. Data for four events are presented, including their time profiles and spectral characteristics. In one case the instrument time resolution reveals a total burst duration of 55 ms with rise and decay times of less than about 5 ms.

  12. Sustainable Materials Management (SMM) Web Academy Webinar: Building Collection Infrastructure for Composting: Success in the Greater Worcester, Massachusetts Area

    Science.gov (United States)

    This is a webinar page for the Sustainable Management of Materials (SMM) Web Academy webinar titled Let’s WRAP (Wrap Recycling Action Program): Best Practices to Boost Plastic Film Recycling in Your Community

  13. 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.

  14. Monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM): novel biological insights and development of early treatment strategies

    Science.gov (United States)

    Kristinsson, Sigurdur Y.

    2011-01-01

    Monoclonal gammopathy of unknown significance (MGUS) and smoldering multiple myeloma (SMM) are asymptomatic plasma cell dyscrasias, with a propensity to progress to symptomatic MM. In recent years there have been improvements in risk stratification models (involving molecular markers) of both disorders, which have led to better understanding of the biology and probability of progression of MGUS and SMM. In the context of numerous molecular events and heterogeneous risk of progression, developing individualized risk profiles for patients with MGUS and SMM represents an ongoing challenge that has to be addressed by prospective clinical monitoring and extensive correlative science. In this review we discuss the current standard of care of patients with MGUS and SMM, the use of risk models, including flow cytometry and free-light chain analyses, for predicting risk of progression. Emerging evidence from molecular studies on MGUS and SMM, involving cytogenetics, gene-expression profiling, and microRNA as well as molecular imaging is described. Finally, future directions for improving individualized management of MGUS and SMM patients, as well as the potential for developing early treatment strategies designed to delay and prevent development of MM are discussed. PMID:21441462

  15. Flexure-beam micromirror devices and potential expansion for smart micromachining

    Science.gov (United States)

    Lin, Tseng-Hwang

    1996-05-01

    Texas Instruments has been developing both digital and analog micromirror devices since the late 1970s. The analog flexure-beam micromirror devices are primarily targeted for imaging identification. Digital multiplexing mechanisms are used in column and row selection to address discretized analog signals into the array. Amplifiers and sample-and-hold circuits provide the appropriate signal range to control the micromirrors. Analog-to-digital and digital- to-analog conversions are currently built into the interface electronics, and will potentially be built into the chip. The micromirror devices are built on the top of the addressing circuits using sacrificial layers and two different metal layers. This concept of surface micromachining and mixed-signal circuit integration enables us to investigate the possibility of smart micromachining. Micromirror device applications can expand beyond optical applications into microsensor and other microactuator areas. The addressing circuits can be used in the interface of analog real-world and smart control circuits.

  16. Fabrication of three-dimensional microdisk resonators in calcium fluoride by femtosecond laser micromachining

    Science.gov (United States)

    Lin, Jintian; Xu, Yingxin; Tang, Jialei; Wang, Nengwen; Song, Jiangxin; He, Fei; Fang, Wei; Cheng, Ya

    2014-09-01

    We report on fabrication of on-chip calcium fluoride (CaF2) microdisk resonators using water-assisted femtosecond laser micromachining. Focused ion beam (FIB) milling is used to create ultra-smooth sidewalls. The quality ( Q) factors of the fabricated microresonators are measured to be 4.2 × 104 at wavelengths near 1,550 nm. The Q factor is mainly limited by the scattering from the bottom surface of the disk whose roughness remains high due to the femtosecond laser micromachining process. This technique facilitates the formation of on-chip microresonators on various kinds of bulk crystalline materials, which can benefit a wide range of applications such as nonlinear optics, quantum optics, and chip-level integration of photonic devices.

  17. Fiber laser micromachining of magnesium alloy tubes for biocompatible and biodegradable cardiovascular stents

    Science.gov (United States)

    Demir, Ali Gökhan; Previtali, Barbara; Colombo, Daniele; Ge, Qiang; Vedani, Maurizio; Petrini, Lorenza; Wu, Wei; Biffi, Carlo Alberto

    2012-02-01

    Magnesium alloys constitute an attractive solution for cardiovascular stent applications due to their intrinsic properties of biocompatibility and relatively low corrosion resistance in human-body fluids, which results in as a less intrusive treatment. Laser micromachining is the conventional process used to cut the stent mesh, which plays the key role for the accurate reproduction of the mesh design and the surface quality of the produced stent that are important factors in ensuring the mechanical and corrosion resistance properties of such a kind of devices. Traditionally continuous or pulsed laser systems working in microsecond pulse regime are employed for stent manufacturing. Pulsed fiber lasers on the other hand, are a relatively new solution which could balance productivity and quality aspects with shorter ns pulse durations and pulse energies in the order of mJ. This work reports the study of laser micromachining and of AZ31 magnesium alloy for the manufacturing of cardiovascular stents with a novel mesh design. A pulsed active fiber laser system operating in nanosecond pulse regime was employed for the micromachining. Laser parameters were studied for tubular cutting on a common stent material, AISI 316L tubes with 2 mm in diameter and 0.2 mm in thickness and on AZ31 tubes with 2.5 mm in diameter and 0.2 in thickness. In both cases process parameters conditions were examined for reactive and inert gas cutting solutions and the final stent quality is compared.

  18. Fabrication and simulation of glass micromachining using CO2 laser processing with PDMS protection

    Science.gov (United States)

    Chung, C. K.; Lin, S. L.; Wang, H. Y.; Tan, T. K.; Tu, K. Z.; Lung, H. F.

    2013-11-01

    Traditional glass micromachining using laser processing in air would produce many kinds of defects, such as bulges, debris, micro-cracks and scorches. In this article, a poly-dimethylsiloxane (PDMS) protection processing has been presented to reduce the temperature gradient and heat-affected zone (HAZ) to achieve crack-free Pyrex glass machining. A good quality of etched surface which is a clear and much-reduced bulge without crack and scorch is achieved using CO2 laser micromachining at 150 μm thick PDMS protection layer and the laser powers of 10-15 W and scanning speeds of 228-342 mm/s for five passes. The PDMS cover layer benefits feature size and bulge height reduction. The alpha-step measured profile shows that the much reduced bulge height around the rims of channel was about 1.2 μm at 150 μm thick PDMS about 13 times smaller than that in air. The ANSYS software was used to analyze the temperature distribution and thermal stress field of glass micromachining in air without and with PDMS cover layer. The smaller temperature gradient observed in PDMS protection processing has the smaller HAZ and diminishes the crack formation during the laser processing.

  19. 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...... capable of producing 62+62-element row-column addressed CMUT arrays with negligible charging issues. The arrays include an integrated apodization, which reduces the ghost echoes produced by the edge waves in such arrays by 15:8 dB. The acoustical cross-talk is measured on fabricated arrays, showing a 24 d...

  20. MEASUREMENT OF NANOSTRUCTURES WITH MICROMACHINED MICROSCOPES

    Energy Technology Data Exchange (ETDEWEB)

    G.S. KINO; W.E. MOERNER

    2005-04-30

    We have made reproducible scanning probes with high efficiency, and predictable and reproducible character-istics. We obtained good efficiency with dimensions well below the diffraction limit, so that rela-tively small laser powers in the milliwatt range can be used. For single frequency operation, only low power is necessary to obtain very high fields for the excitation of well-defined Raman scattering, and to work in a reflection mode with good scanning speeds; obtained predictable results with very high fields suitable for obtaining Raman scattering and two-photon scattering; made a scanning probe mounted on a micromachined cantilever to obtain high definition reflection mode images that can be scanned rapidly;and observed Raman scattering using bowtie antennas with CW excitation.

  1. 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

  2. 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.

  3. 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

  4. 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 (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.

  5. Development of a Novel Transparent Flexible Capacitive Micromachined Ultrasonic Transducer.

    Science.gov (United States)

    Pang, Da-Chen; Chang, Cheng-Min

    2017-06-20

    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.

  6. 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.

  7. Dust, ice and gas in time (DIGIT): Herschel and Spitzer spectro-imaging of SMM3 and SMM4 in Serpens

    Science.gov (United States)

    Dionatos, O.; Jørgensen, J. K.; Green, J. D.; Herczeg, G. J.; Evans, N. J.; Kristensen, L. E.; Lindberg, J. E.; van Dishoeck, E. F.

    2013-10-01

    Context. Mid- and far-infrared observations of the environment around embedded protostars reveal a plethora of high excitation molecular and atomic emission lines. Different mechanisms for the origin of these lines have been proposed, including shocks induced by protostellar jets and radiation or heating by the embedded protostar of its immediate surroundings. Aims: By studying of the most important molecular and atomic coolants, we aim at constraining the physical conditions around the embedded protostars SMM3 and SMM4 in the Serpens molecular cloud core and measuring the CO/H2 ratio in warm gas. Methods: Spectro-imaging observations from the Spitzer Infrared Spectrograph (IRS) and the Herschel Photodetector Array Camera and Spectrometer (PACS) provide an almost complete wavelength coverage between 5 and 200 μm. Within this range, emission from all major molecular (H2, CO, H2O and OH) and many atomic ([OI], [CII], [FeII], [SiII] and [SI]) coolants of excited gas are detected. Emission line maps reveal the morphology of the observed emission and indicate associations between the different species. The excitation conditions for molecular species are assessed through rotational diagrams. Emission lines from major coolants are compared to the results of steady-state C- and J-type shock models. Results: Line emission tends to peak at distances of ~10-20″ from the protostellar sources with all but [CII] peaking at the positions of outflow shocks seen in near-IR and sub-millimeter interferometric observations. The [CII] emission pattern suggests that it is most likely excited from energetic UV radiation originating from the nearby flat-spectrum source SMM6. Excitation analysis indicates that H2 and CO originate in gas at two distinct rotational temperatures of ~300 K and 1000 K, while the excitation temperature for H2O and OH is ~100-200 K. The morphological and physical association between CO and H2 suggests a common excitation mechanism, which allows direct

  8. Non-traditional micromachining processes fundamentals and applications

    CERN Document Server

    Bhattacharyya, B; Davim, J

    2017-01-01

    This book presents a complete coverage of micromachining processes from their basic material removal phenomena to past and recent research carried by a number of researchers worldwide. Chapters on effective utilization of material resources, improved efficiency, reliability, durability, and cost effectiveness of the products are presented. This book provides the reader with new and recent developments in the field of micromachining and microfabrication of engineering materials.

  9. In-fiber whispering-gallery-mode resonator fabricated by femtosecond laser micromachining.

    Science.gov (United States)

    Shi, Leilei; Zhu, Tao; Huang, Dongmei; Liu, Min; Deng, Ming; Huang, Wei

    2015-08-15

    An in-fiber whispering-gallery-mode resonator fabricated by femtosecond laser micromachining is demonstrated. The cylinder resonator cavity is fabricated by scanning the D-fiber cladding with infrared femtosecond pulses along a cylindrical trace with a radius of 25 μm and height of 20 μm. Quality factor on the order of 10(3) is achieved by smoothing the cavity surface with an ultrasonic cleaner, which is mainly limited by the surface roughness of several hundred nanometers. Resonant characteristics and polarization dependence of the proposed resonator are also studied in detail. Our method takes a step forward in the integration of whispering-gallery-mode resonators.

  10. Management of monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM).

    Science.gov (United States)

    Kyle, Robert A; Rajkumar, S Vincent

    2011-06-01

    Monoclonal gammopathy of undetermined significance (MGUS) is defined as a serum M protein level of less than 3 g/dL, less than 10% clonal plasma cells in the bone marrow, and the absence of end-organ damage. The prevalence of MGUS is 3.2% in the white population but is approximately twice that high in the black population. MGUS may progress to multiple myeloma, AL amyloidosis, Waldenström macroglobulinemia, or lymphoma. The risk of progression is approximately 1% per year, but the risk continues even after more than 25 years of observation. Risk factors for progression include the size of the serum M protein, the type of serum M protein, the number of plasma cells in the bone marrow, and the serum free light chain ratio. Smoldering (asymptomatic) multiple myeloma (SMM) is characterized by the presence of an M protein level of 3 g/dL or higher and/or 10% or more monoclonal plasma cells in the bone marrow but no evidence of end-organ damage. The overall risk of progression to a malignant condition is 10% per year for the first 5 years, approximately 3% per year for the next 5 years, and 1% to 2% per year for the following 10 years. Patients with both MGUS and SMM must be followed up for their lifetime.

  11. 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)

  12. Exploitation of capacitive micromachined transducers for nonlinear ultrasound imaging.

    Science.gov (United States)

    Novell, Anthony; Legros, Mathieu; Felix, Nicolas; Bouakaz, Ayache

    2009-12-01

    Capacitive micromachined ultrasonic transducers (CMUTs) present advantages such as wide frequency bandwidth, which could be further developed for nonlinear imaging. However, the driving electrostatic force induces a nonlinear behavior of the CMUT, thus generating undesirable harmonic components in the generated acoustic signal. Consequently, the use of CMUT for harmonic imaging (with or without contrast agents) becomes challenging. This paper suggests 2 compensation approaches, linear and nonlinear methods, to cancel unwanted nonlinear components. Furthermore, nonlinear responses from contrast agent were evaluated using CMUT in transmit before and after compensation. The results were compared with those obtained using a PZT transducer in transmit. Results showed that CMUT nonlinear behavior is highly influenced by the excitation to bias voltage ratio. Measurements of output pressure very close to the CMUT surface allow the estimation of optimal parameters for each compensation approach. Both methods showed a harmonic reduction higher than 20 dB when one element or several elements are excited. In addition, the study demonstrates that nonlinear approach seems to be more efficient because it is shown to be less sensitive to interelement variability and further avoids fundamental component deterioration. The results from contrast agent measurements showed that the responses obtained using CMUT elements in transmit with compensation were similar to those from PZT transducer excitation. This experimental study demonstrates the opportunity to use CMUT with traditional harmonic contrast imaging techniques.

  13. 3DX: a micromachined silicon crystallographic x-ray detector

    Science.gov (United States)

    Morse, John; Kenney, Christopher J.; Westbrook, Edwin M.; Naday, Istvan; Parker, Sherwood I.

    2003-01-01

    We are developing pixel detectors for macromolecular crystallography, in which diffracted X-rays are directly absorbed by high-resistivity, crystalline silicon that has been micro-machined by inductively-coupled plasma etching. Arrays of 64 × 64 holes at 150 μm pitch are first formed by etching through the entire silicon bulk, then backfilled with polysilicon that is doped to create conducting p and n type columnar electrodes. When reverse biased, these electrodes generate electric fields that define the individual pixels. By forming conducting polysilicon on the sides of the sensors, which are cut-out of the silicon wafer by plasma etching, the entire surface of the detector may be made active. CMOS readout integrated circuits are conductively bump bonded behind each 3D detector, providing a direct connection to every pixel. A large array will be assembled with no insensitive bands along the edges by overlapping these sensors, each of area 0.96cm2. This detector will measure X-ray signal intensities of up to 105 events/pixel/sec without any pile-up loss, by using an integration method that retains the benefits of discrete photon counting. The detector sensitivity will be highly uniform, it will not exhibit any dark signal or spurious noise, and no geometric distortion will occur within each sensor.

  14. Physical and chemical characteristics of L1689-SMM16, an oscillating prestellar core in Ophiuchus

    Energy Technology Data Exchange (ETDEWEB)

    Chitsazzadeh, S.; Di Francesco, J.; Sadavoy, S. I. [Department of Physics and Astronomy, The University of Victoria, Victoria, BC V8P 5C2 (Canada); Schnee, S. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Friesen, R. K. [The Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George St., Toronto, ON M5S 3H4 (Canada); Shimajiri, Y. [Laboratoire AIM, CEA/DSM-CNRS-Université Paris Diderot, IRFU/Service d' Astrophysique, CEA Saclay, F-91191 Gif-sur-Yvette (France); Langston, G. I. [National Radio Astronomy Observatory, P.O. Box 2, Green Bank, WV 24944 (United States); Bourke, T. L.; Keto, E. R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Pineda, J. E. [Institute for Astronomy, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich (Switzerland); Takakuwa, S. [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China); Tatematsu, K., E-mail: schitsaz@uvic.ca [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2014-08-01

    We present single-dish observations of the L1689-SMM16 core in the Ophiuchus molecular cloud in NH{sub 3} (1, 1) and (2, 2) emission using the Green Bank Telescope, in N{sub 2}H{sup +} (1-0) emission using the Nobeyama Radio Observatory, and in NH{sub 2}D (1{sub 1,1}{sup a}(--)1{sub 0,1}{sup s}), HCN (1-0), HNC (1-0), H{sup 13}CO{sup +} (1-0), and HCO{sup +} (1-0) emission using the Mopra telescope. The morphologies of the integrated NH{sub 3} (1, 1) and N{sub 2}H{sup +} (1-0) emission well match that of 250 μm continuum emission. Line widths of NH{sub 3} (1, 1) and N{sub 2}H{sup +} (1-0) show the presence of transonic turbulence across the core. Jeans and virial analyses made using updated measurements of core mass and size confirm that L1689-SMM16 is prestellar, i.e., gravitationally bound. It also has accumulated more mass compared to its corresponding Jeans mass in the absence of magnetic fields and therefore is a 'super-Jeans' core. The high levels of X(NH{sub 3})/X(N{sub 2}H{sup +}) and deuterium fractionation reinforce the idea that the core has not yet formed a protostar. Comparing the physical parameters of the core with those of a Bonnor-Ebert sphere reveals the advanced evolutionary stage of L1689-SMM16 and shows that it might be unstable to collapse. We do not detect any evidence of infall motions toward the core. Instead, red asymmetry in the line profiles of HCN (1-0) and HNC (1-0) indicates the expansion of the outer layers of the core at a speed of ∼0.2 km s{sup –1} to 0.3 km s{sup –1}. For a gravitationally bound core, expansion in the outer layers might indicate that the core is experiencing oscillations.

  15. Molecular-Scale Lubricants for Micromachine Applications: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Burns, A.R.; Dugger, M.T.; Houston, J.E.; Lopez, G.P.; Mayer, T.M.; Michalske, T.A.; Miller, S.L.; Sniegowski, J.J.; Stevens, M.J.; Zhou, Y.

    1998-12-01

    The nature of this work was to develop the physics and chemistry base for understanding molecular-scale lubricants used to reduce of friction- and adhesion-induced failure in silicon micromachines (MEMS). We acquired this new knowledge by tailoring the molecular properties of the lubricants, applying local probes that can directly monitor the response of lubricants in contact conditions, and evaluating the performance of model lubricants MEMS devices. Model lubricants under investigation were the silane coupling agents that form monolayer films on native oxide silicon surfaces, which is the substrate in MEMS. These molecules bind via strong surface bonds and produce a layer of hydro- or fluoro-carbon chains normal to the substrate. "Tailoring" the lubricants entails modifying the chain length, the chain chemical reactivity (H or F), and the density of chain structures. Thus much effort went into understanding the surface chemistry of silane-silicon oxide coupling. With proximal probes such as atomic force microscopy (AFM), interracial force microscopy (FM), and shear force microscopy in combination with IFM, we examined the frictional and adhesive properties of the silane films with very high spatial resolution (< 100 nm) and sensitivity. MEMS structures are treated with silanes under identical conditions, and examined for friction and adhesion under operating conditions. Proper assessment of the lubricants required quantitative analysis of MEMS performance at high speeds and long operating times. Our proximal probe measurements and WS performance analyses form a very important link for future molecular dynamics simulations, that, in turn, should be able to predict MEMS performance under all conditions.

  16. 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.

  17. Robust Design of an Optical Micromachine for an Ophthalmic Application

    Directory of Open Access Journals (Sweden)

    Ingo Sieber

    2016-05-01

    Full Text Available This article describes an approach to the robust design of an optical micromachine consisting of a freeform optics, an amplification linkage, and an actuator. The robust design approach consists of monolithic integration principles to minimize assembly efforts and of an optimization of the functional components with respect to robustness against remaining assembly and manufacturing tolerances. The design approach presented involves the determination of the relevant tolerances arising from the domains manufacturing, assembly, and operation of the micromachine followed by a sensitivity analysis with the objective of identifying the worst offender. Subsequent to the above-described steps, an optimization of the functional design of the freeform optics with respect to a compensation of the effects of the tolerances is performed. The result leads to a robust design of the freeform optics and hence ensures a defined and optimal minimum performance of the micromachine in the presence of tolerances caused by the manufacturing processes and the operation of the micromachine. The micromachine under discussion is the tunable optics of an ophthalmic implant, an artificial accommodation system recently realized as a demonstration model at a scale of 2:1. The artificial accommodation system will be developed to replace the human crystalline lens in the case of a cataract.

  18. Capacitive Micromachined Ultrasonic Transducers for Therapeutic Ultrasound Applications

    Science.gov (United States)

    Wong, Serena H.; Kupnik, Mario; Watkins, Ronald D.; Butts-Pauly, Kim; Khuri-Yakub, Butrus T.

    2014-01-01

    Therapeutic ultrasound guided by magnetic resonance imaging (MRI) is a noninvasive treatment that potentially reduces mortality, lowers medical costs, and widens accessibility of treatments for patients. Recent developments in the design and fabrication of capacitive micromachined ultrasonic transducers (CMUTs) have made them competitive with piezoelectric transducers for use in therapeutic ultrasound applications. In this paper, we present the first designs and prototypes of an 8-element, concentric-ring, CMUT array to treat upper abdominal cancers. This array was simulated and designed to focus 30–50 mm into tissue and ablate a 2–3 cm diameter tumor within 1 hour. Assuming a surface acoustic output pressure of 1 MPa peak to peak (8.5 W/cm2) at 2.5 MHz, we simulated an array that produced a focal intensity of 680 W/cm2 when focusing to 35 mm. CMUT cells were then designed to meet these frequency and surface acoustic intensity specifications. These cell designs were fabricated as 2.5 mm by 2.5 mm test transducers and used to verify our models. The test transducers were shown to operate at 2.5 MHz with an output pressure of 1.4 MPa peak to peak (16.3 W/cm2). With this CMUT cell design, we fabricated a full 8-element array. Due to yield issues, we only developed electronics to focus the four center elements of the array. The beam profile of the measured array deviated from the simulated because of crosstalk effects; the beamwidth matched within 10% and sidelobes increased by 2 times, which caused the measured gain to be 16.6 compared to 27.4. PMID:19628448

  19. Dual axis operation of a micromachined rate gyroscope

    Energy Technology Data Exchange (ETDEWEB)

    Juneau, T. [BSAC, Berkeley, CA (United States); Pisano, A.P. [Univ. California, Berkeley, CA (United States). Dept. of Mechanical Engineering; Smith, J. [Sandia National Lab., Albuquerque, NM (United States)

    1997-04-01

    Since micromachining technology has raised the prospect of fabricating high performance sensors without the associated high cost and large size, many researchers have investigated micromachined rate gyroscopes. The vast majority of research has focused on single input axis rate gyroscopes, but this paper presents work on a dual input axis micromachined rate gyroscope. The key to successful simultaneous dual axis operation is the quad symmetry of the circular oscillating rotor design. Untuned gyroscopes with mismatched modes yielded random walk as low as 10{degrees}/{radical}hour with cross sensitivity ranging from 6% to 16%. Mode frequency matching via electrostatic tuning allowed performance better than 2{degrees}/{radical}hour, but at the expense of excessive cross sensitivity.

  20. Development of Micromachine Gas Turbine for Portable Power Generation

    Science.gov (United States)

    Isomura, Kousuke; Tanaka, Shuji; Togo, Shinichi; Kanebako, Hideki; Murayama, Motohide; Saji, Nobuyoshi; Sato, Fumihiro; Esashi, Masayoshi

    Micromachine gas turbine with centrifugal impellers of 10mm diameter fabricated by 5-axis micro-milling is under development at Tohoku University, in conjunction with Ishikawajima-Harima Heavy Industries Co., Ltd. (IHI), Tohoku-Gakuin University, and Sankyo Seiki Mfg. Co., Ltd. The development is currently at the stage of proving the feasibility of the gas turbine cycle by component tests. Micro-combustors have been developed for both hydrogen and methane fuel. Over 99.9% of the combustion efficiency has been realized in both combustors and the baseline configuration of the combustor for the gas turbine is set. A compressor of 10mm diameter has been developed as a micromachined turbocharger. The performance test of the micromachined turbocharger has been started, and ran up to 566000rpm, which is approximately 65% of the design speed. Compressor performance has been successfully measured along a constant speed line at 55% of the design speed.

  1. Silicon bulk micromachined hybrid dimensional artifact.

    Energy Technology Data Exchange (ETDEWEB)

    Claudet, Andre A.; Tran, Hy D.; Bauer, Todd Marks; Shilling, Katherine Meghan; Oliver, Andrew David

    2010-03-01

    A mesoscale dimensional artifact based on silicon bulk micromachining fabrication has been developed and manufactured with the intention of evaluating the artifact both on a high precision coordinate measuring machine (CMM) and video-probe based measuring systems. This hybrid artifact has features that can be located by both a touch probe and a video probe system with a k=2 uncertainty of 0.4 {micro}m, more than twice as good as a glass reference artifact. We also present evidence that this uncertainty could be lowered to as little as 50 nm (k=2). While video-probe based systems are commonly used to inspect mesoscale mechanical components, a video-probe system's certified accuracy is generally much worse than its repeatability. To solve this problem, an artifact has been developed which can be calibrated using a commercially available high-accuracy tactile system and then be used to calibrate typical production vision-based measurement systems. This allows for error mapping to a higher degree of accuracy than is possible with a glass reference artifact. Details of the designed features and manufacturing process of the hybrid dimensional artifact are given and a comparison of the designed features to the measured features of the manufactured artifact is presented and discussed. Measurement results from vision and touch probe systems are compared and evaluated to determine the capability of the manufactured artifact to serve as a calibration tool for video-probe systems. An uncertainty analysis for calibration of the artifact using a CMM is presented.

  2. Monolithic Micromachined Quartz Resonator based Infrared Focal Plane Arrays

    Science.gov (United States)

    2012-05-05

    prototypes of integrated micromachined IR detectors consisting of 200 μm diameter QCM resonators, 241 MHz (6.9 μm) thick 5 x 5 resonator arrays from Y-cut...of small QCM devices. • A novel measurement method for the real-time tracking of the resonance frequency based on impedance measurement around the...miniaturize QCM ? • Micromachining Quartz • Evaluation of QCM MicroArrays • Adsorption Experiments – Human Serum Albumin, IgG, and Human Fibrinogen Adsorption

  3. The Cooling and Lubrication Performance of Graphene Platelets in Micro-Machining Environments

    Science.gov (United States)

    Chu, Bryan

    The research presented in this thesis is aimed at investigating the use of graphene platelets (GPL) to address the challenges of excessive tool wear, reduced part quality, and high specific power consumption encountered in micro-machining processes. There are two viable methods of introducing GPL into micro-machining environments, viz., the embedded delivery method, where the platelets are embedded into the part being machined, and the external delivery method, where graphene is carried into the cutting zone by jetting or atomizing a carrier fluid. The study involving the embedded delivery method is focused on the micro-machining performance of hierarchical graphene composites. The results of this study show that the presence of graphene in the epoxy matrix improves the machinability of the composite. In general, the tool wear, cutting forces, surface roughness, and extent of delamination are all seen to be lower for the hierarchical composite when compared to the conventional two-phase glass fiber composite. These improvements are attributed to the fact that graphene platelets improve the thermal conductivity of the matrix, provide lubrication at the tool-chip interface and also improve the interface strength between the glass fibers and the matrix. The benefits of graphene are seen to also carry over to the external delivery method. The platelets provide improved cooling and lubrication performance to both environmentally-benign cutting fluids as well as to semi-synthetic cutting fluids used in micro-machining. The cutting performance is seen to be a function of the geometry (i.e., lateral size and thickness) and extent of oxygen-functionalization of the platelet. Ultrasonically exfoliated platelets (with 2--3 graphene layers and lowest in-solution characteristic lateral length of 120 nm) appear to be the most favorable for micro-machining applications. Even at the lowest concentration of 0.1 wt%, they are capable of providing a 51% reduction in the cutting

  4. Capacitive micromachined ultrasonic transducers with through-wafer interconnects

    Science.gov (United States)

    Zhuang, Xuefeng

    Capacitive micromachined ultrasonic transducer (CMUT) is a promising candidate for making ultrasound transducer arrays for applications such as 3D medical ultrasound, non-destructive evaluation and chemical sensing. Advantages of CMUTs over traditional piezoelectric transducers include low-cost batch fabrication, wide bandwidth, and ability to fabricate arrays with broad operation frequency range and different geometric configurations on a single wafer. When incorporated with through-wafer interconnects, a CMUT array can be directly integrated with a front-end integrated circuit (IC) to achieve compact packaging and to mitigate the effects of the parasitic capacitance from the connection cables. Through-wafer via is the existing interconnect scheme for CMUT arrays, and many other types of micro-electro-mechanical system (MEMS) devices. However, to date, no successful through-wafer via fabrication technique compatible with the wafer-bonding method of making CMUT arrays has been demonstrated. The through-wafer via fabrication steps degrade the surface conditions of the wafer, reduce the radius of curvature, thus making it difficult to bond. This work focuses on new through-wafer interconnect techniques that are compatible with common MEMS fabrication techniques, including both surface-micromachining and direct wafer-to-wafer fusion bonding. In this dissertation, first, a through-wafer via interconnect technique with improved characteristics is presented. Then, two implementations of through-wafer trench isolation are demonstrated. The through-wafer trench methods differ from the through-wafer vias in that the electrical conduction is through the bulk silicon instead of the conductor in the vias. In the first implementation, a carrier wafer is used to provide mechanical support; in the second, mechanical support is provided by a silicon frame structure embedded inside the isolation trenches. Both implementations reduce fabrication complexity compared to the through

  5. 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)

  6. 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.

  7. A batch process micromachined thermoelectric energy harvester: Fabrication and characterization

    NARCIS (Netherlands)

    Su, J.; Leonov, V.; Goedbloed, M.; Andel, Y. van; Nooijer, M.C.de; Elfrink, R.; Wang, Z.; Vullers, R.J.M.

    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

  8. Micromachined palladium silver alloy membranes for hydrogen separation

    NARCIS (Netherlands)

    Tong, D.H.; Gielens, F.C.; Berenschot, Johan W.; de Boer, Meint J.; Gardeniers, Johannes G.E.; Jansen, Henricus V.; Nijdam, W.; van Rijn, C.J.M.; Elwenspoek, Michael Curt

    2002-01-01

    This paper presents wafer-scale palladium - silver alloy membranes, fabricated with a sequence of wellknown thin film and silicon micromachining techniques. The membranes have been tested in a gas permeation system to determine the hydrogen permeability and hydrogen selectivity. Typical flow rates

  9. 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

  10. The study of SMM as a virus strategy in the media space

    Directory of Open Access Journals (Sweden)

    V L Mouzykant

    2014-12-01

    Full Text Available The article describes the phenomenon of social marketing in the Internet that has changed the idea of the relationships between the addresser and the addressee in the social networks. The author analyzes the typology, genesis and consequences of the virus marketing in social networks from the perspective of the sociological analysis of media. The article considers the influence of the Internet on the behavior of the Russians, the methods of measuring the impact of the emerging new media. The author identifies different strategies in the SMM-market, such as creative content, digital-projects, media planning, simple content, government, close-to-government and educational projects. ROMIR within the GemuisAudience project conducted a research among 20 thousand Russian respondents to monitor their behavior in the sphere with the help of special sensors that identify Internet preferences of the Russians. The first results of the project revealed a trend - the more interesting the content the more likely the user is to share the app with his friends.

  11. DETECTION OF TWO CARBON-CHAIN-RICH CORES: CB130-3 AND L673-SMM4

    International Nuclear Information System (INIS)

    Hirota, Tomoya; Sakai, Takeshi; Sakai, Nami; Yamamoto, Satoshi

    2011-01-01

    We have found two dense cores, CB130-3 and L673-SMM4, where the carbon-chain molecules are extremely abundant relative to NH 3 , during a survey observation of radio emission lines of CCS, HC 3 N, HC 5 N, and NH 3 toward dark cloud cores. Judging from the low NH 3 /CCS ratios, they are possible candidates for 'Carbon-Chain-Producing Regions' (CCPRs) recognized as chemically young dark cloud cores. The deuterium fractionation ratios DNC/HN 13 C in CB130-3 and L673-SMM4 are found to be 1.28 +0.27 -0.05 and 1.96 +0.32 -0.01 , respectively, which are comparable to or slightly higher than those in CCPRs found previously. We suggest that the dense cores of CB130-3 and L673-SMM4 are analogous to CCPRs, but their chemical evolutionary phase would be slightly older than those of the dense cores in the Taurus region.

  12. Sustainable Materials Management (SMM) Web Academy Webinar: Let’s WRAP (Wrap Recycling Action Program): Best Practices to Boost Plastic Film Recycling in Your Community

    Science.gov (United States)

    This is a webinar page for the Sustainable Management of Materials (SMM) Web Academy webinar titled Let’s WRAP (Wrap Recycling Action Program): Best Practices to Boost Plastic Film Recycling in Your Community

  13. Sustainable Materials Management (SMM) Web Academy Webinar: How to Reduce Wasted Food: EPA’s Food Waste Reduction Tools for Food Services & Restaurants

    Science.gov (United States)

    This is a webinar page for the Sustainable Management of Materials (SMM) Web Academy webinar titled Let’s WRAP (Wrap Recycling Action Program): Best Practices to Boost Plastic Film Recycling in Your Community

  14. Sustainable Materials Management (SMM) Web Academy Webinar: Advancing Sustainable Materials Management: Facts and Figures 2013 - Assessing Trends in Materials Generation, Recycling and Disposal in the United States

    Science.gov (United States)

    This is a webinar page for the Sustainable Management of Materials (SMM) Web Academy webinar titled Let’s WRAP (Wrap Recycling Action Program): Best Practices to Boost Plastic Film Recycling in Your Community

  15. Sustainable Materials Management (SMM) Web Academy Webinar: Wasted Food to Energy: How 6 Water Resource Recovery Facilities are Boosting Biogas Production & the Bottom Line

    Science.gov (United States)

    This is a webinar page for the Sustainable Management of Materials (SMM) Web Academy webinar titled Let’s WRAP (Wrap Recycling Action Program): Best Practices to Boost Plastic Film Recycling in Your Community

  16. Sustainable Materials Management (SMM) Web Academy Webinar: Changing How We Think About Our Resources for a Better Tomorrow: How to Donate Surplus Food from K-12 Schools

    Science.gov (United States)

    This is a webinar page for the Sustainable Management of Materials (SMM) Web Academy webinar titled Changing How We Think About Our Resources for a Better Tomorrow: How to Donate Surplus Food from K-12 Schools

  17. Sustainable Materials Management (SMM) Web Academy Webinar Series: A Step-by-Step Guide to Conducting a Wasted Food Assessment with the Reducing Wasted Food & Packaging Toolkit

    Science.gov (United States)

    This is a webinar page for the Sustainable Management of Materials (SMM) Web Academy webinar titled Let’s WRAP (Wrap Recycling Action Program): Best Practices to Boost Plastic Film Recycling in Your Community

  18. Sustainable Materials Management (SMM) Web Academy Webinar: Compost from Food Waste: Understanding Soil Chemistry and Soil Biology on a College/University Campus

    Science.gov (United States)

    This page contains information about the Sustainable Materials Management (SMM) Web Academy Webinar Series titled Compost from Food Waste:Understanding Soil Chemistry and Soil Biology on a College/University Campus

  19. Sustainable Materials Management (SMM) Web Academy Webinar: An Introduction to Lithium Batteries and the Challenges that they Pose to the Waste and Recycling Industry

    Science.gov (United States)

    This is a webinar page for the Sustainable Management of Materials (SMM) Web Academy webinar titled, An Introduction to Lithium Batteries and the Challenges that they Pose to the Waste and Recycling Industry.

  20. 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

  1. DAMPAK PENERAPAN SMM ISO 9001:2000 TERHADAP KUALITAS LAYANAN AKADEMIK DAN LULUSAN FT UNY

    Directory of Open Access Journals (Sweden)

    Sugiyono Sugiyono

    2015-02-01

    Full Text Available ABSTRACT This research aims at revealing the impact of the implimentation of ISO 9001:2000 towards the academic service quality (the service quality of lecturers, staffs, technicians, and department orginizer and the graduates’ quality (GPA and period of study. This evaluation was conducted by using descriptive research method and document analysis to reveal the fact of academic service beforeand after the implementation of ISO 9001:2000. The sample technique was using cluster sampling technique as PTM and PTTB departments were chosen. The target sample was 83 students in the seventh semestser and the dacuments in ISO secretariat from those two deperatments. Data collection techniques were using questionnaire and documentation (syallabus and lesson plan, yusisum data, learning evaluation, attandence list and assessement document. Data analysis method was using quatitive descriptive analysis. The findings showed the mean scores of acedemic sevice quality in PTBB Department had been fulfilling the expectation (3,12 while for PTM can be categorized as moderate level (2.97. The lowest score was found in the area of academic administration service, i.e. 3,02 for PTBB and 2,83 for PTM. Furthermore, it was found that The quality of PTBB graduates improved 0,02 and the period of study for (S1/ Bachelor degree fluctuated in 5,16 while the GPA of PTM was not stable yet but the students had shorter period of study. By seeing the findings, it can concluded that the implementation of ISO 9001-2000 was able to improve the administration service of academic but it did not guarantee to create qualified acadmic service to support the fulfilment of high GPA and short period of study. Keywords: graduates’ quality, SMM-ISO 9001-2000, quality of academic service

  2. Technology trends in high temperature pressure transducers: The impact of micromachining

    Science.gov (United States)

    Mallon, Joseph R., Jr.

    1992-01-01

    This paper discusses the implications of micromachining technology on the development of high temperature pressure transducers. The introduction puts forth the thesis that micromachining will be the technology of choice for the next generation of extended temperature range pressure transducers. The term micromachining is defined, the technology is discussed and examples are presented. Several technologies for high temperature pressure transducers are discussed, including silicon on insulator, capacitive, optical, and vibrating element. Specific conclusions are presented along with recommendations for development of the technology.

  3. Capacitive Micromachined Ultrasonic Transducers (CMUTs for Underwater Imaging Applications

    Directory of Open Access Journals (Sweden)

    Jinlong Song

    2015-09-01

    Full Text Available A capacitive micromachined ultrasonic transducer structure for use in underwater imaging is designed, fabricated and tested in this paper. In this structure, a silicon dioxide insulation layer is inserted between the top electrodes and the vibration membrane to prevent ohmic contact. The capacitance-voltage (C-V characteristic curve shows that the transducer offers suitable levels of hysteresis and repeatability performance. The −6 dB center frequency is 540 kHz and the transducer has a bandwidth of 840 kHz for a relative bandwidth of 155%. Underwater pressure of 143.43 Pa is achieved 1 m away from the capacitive micromachined ultrasonic transducer under 20  excitation. Two-dimensional underwater ultrasonic imaging, which is able to prove that a rectangular object is present underwater, is achieved. The results presented here indicate that our work will be highly beneficial for the establishment of an underwater ultrasonic imaging system.

  4. Artificial intelligence: Collective behaviors of synthetic micromachines

    Science.gov (United States)

    Duan, Wentao

    Synthetic nano- and micromotors function through the conversion of chemical free energy or forms of energy into mechanical motion. Ever since the first reports, such motors have been the subject of growing interest. In addition to motility in response to gradients, these motors interact with each other, resulting in emergent collective behavior like schooling, exclusion, and predator-prey. However, most of these systems only exhibit a single type of collective behavior in response to a certain stimuli. The research projects in the disseratation aim at designing synthetic micromotors that can exhibit transition between various collective behaviors in response to different stimuli, as well as quantitative understanding on the pairwise interaction and propulsion mechanism of such motors. Chapter 1 offers an overview on development of synthetic micromachines. Interactions and collective behaviors of micromotors are also summarized and included. Chapter 2 presents a silver orthophosphate microparticle system that exhibits collective behaviors. Transition between two collective patterns, clustering and dispersion, can be triggered by shift in chemical equilibrium upon the addition or removal of ammonia, in response to UV light, or under two orthogonal stimuli (UV and acoustic field) and powering mechanisms. The transitions can be explained by the self-diffusiophoresis mechanism resulting from either ionic or neutral solute gradients. Potential applications of the reported system in logic gates, microscale pumping, and hierarchical assembly have been demonstrated. Chapter 3 introduces a self-powered oscillatory micromotor system in which active colloids form clusters whose size changes periodically. The system consists of an aqueous suspension of silver orthophosphate particles under UV radiation, in the presence of a mixture of glucose and hydrogen peroxide. The colloid particles first attract with each other to form clusters. After a lag time of around 5min, chemical

  5. High-speed Laser Micromachining with Copper Bromide Laser

    OpenAIRE

    Balchev, Ivaylo I.; Minkovski, Nikolai I.; Kostadinov, Ivan K.; Sabotinov, Nikola V.

    2006-01-01

    The application of the copper bromide (CuBr) laser as an attractive tool in the micro-machining of different materials has been demonstrated. High-quality drilling by trepanning and precision cutting was established on several materials with a negligible heat-affected zone (HAZ). That good performance was a result of the combination of high power visible radiation, short pulses, and close to the diffraction-limited laser beam quality with high-speed galvo scanner beam steering.

  6. 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.

  7. Fabrication of capacitive micromachined ultrasonic transducers based on adhesive wafer bonding technique

    International Nuclear Information System (INIS)

    Li, Zhenhao; Wong, Lawrence L P; Chen, Albert I H; Na, Shuai; Yeow, John T W; Sun, Jame

    2016-01-01

    This paper reports the fabrication process of wafer bonded capacitive micromachined ultrasonic transducers (CMUTs) using photosensitive benzocyclobutene as a polymer adhesive. Compared with direct bonding and anodic bonding, polymer adhesive bonding provides good tolerance to wafer surface defects and contamination. In addition, the low process temperature of 250 °C is compatible with standard CMOS processes. Single-element CMUTs consisting of cells with a diameter of 46 µ m and a cavity depth of 323 nm were fabricated. In-air and immersion acoustic characterizations were performed on the fabricated CMUTs, demonstrating their capability for transmitting and receiving ultrasound signals. An in-air resonance frequency of 5.47 MHz was measured by a vibrometer under a bias voltage of 300 V. (paper)

  8. Non-contact thermoacoustic detection of embedded targets using airborne-capacitive micromachined ultrasonic transducers

    Science.gov (United States)

    Nan, Hao; Boyle, Kevin C.; Apte, Nikhil; Aliroteh, Miaad S.; Bhuyan, Anshuman; Nikoozadeh, Amin; Khuri-Yakub, Butrus T.; Arbabian, Amin

    2015-02-01

    A radio frequency (RF)/ultrasound hybrid imaging system using airborne capacitive micromachined ultrasonic transducers (CMUTs) is proposed for the remote detection of embedded objects in highly dispersive media (e.g., water, soil, and tissue). RF excitation provides permittivity contrast, and ultra-sensitive airborne-ultrasound detection measures thermoacoustic-generated acoustic waves that initiate at the boundaries of the embedded target, go through the medium-air interface, and finally reach the transducer. Vented wideband CMUTs interface to 0.18 μm CMOS low-noise amplifiers to provide displacement detection sensitivity of 1.3 pm at the transducer surface. The carefully designed vented CMUT structure provides a fractional bandwidth of 3.5% utilizing the squeeze-film damping of the air in the cavity.

  9. High frequency ultrasonic imaging using thermal mechanical noise recorded on capacitive micromachined transducer arrays

    Science.gov (United States)

    Lani, Shane; Satir, Sarp; Gurun, Gokce; Sabra, Karim G.; Levent Degertekin, F.

    2011-11-01

    The cross-correlation of diffuse thermal-mechanical noise recorded by two sensors yields an estimate of the ultrasonic waves propagating between them. We used this approach at high frequencies (1-30 MHz) on a capacitive micromachined ultrasonic transducer (CMUT) ring array (d = 725 μm), monolithically integrated with low noise complementary metal oxide semiconductor electronics. The thermal-mechanical noise cross-correlations between the CMUT array elements in immersion reveal both evanescent surface waves (below 10 MHz) and waves propagating primarily in the fluid (above 10 MHz). These propagating waves may allow passive imaging of scatterers closer to the array as compared to conventional pulse-echo systems, providing potentially higher resolution.

  10. 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.

  11. Lead-Free Piezoelectric Diaphragm Biosensors Based on Micro-Machining Technology and Chemical Solution Deposition.

    Science.gov (United States)

    Li, Xiaomeng; Wu, Xiaoqing; Shi, Peng; Ye, Zuo-Guang

    2016-01-12

    In this paper, we present a new approach to the fabrication of integrated silicon-based piezoelectric diaphragm-type biosensors by using sodium potassium niobate-silver niobate (0.82KNN-0.18AN) composite lead-free thin film as the piezoelectric layer. The piezoelectric diaphragms were designed and fabricated by micro-machining technology and chemical solution deposition. The fabricated device was very sensitive to the mass changes caused by various targets attached on the surface of diaphragm. The measured mass sensitivity value was about 931 Hz/μg. Its good performance shows that the piezoelectric diaphragm biosensor can be used as a cost-effective platform for nucleic acid testing.

  12. Lead-Free Piezoelectric Diaphragm Biosensors Based on Micro-Machining Technology and Chemical Solution Deposition

    Directory of Open Access Journals (Sweden)

    Xiaomeng Li

    2016-01-01

    Full Text Available In this paper, we present a new approach to the fabrication of integrated silicon-based piezoelectric diaphragm-type biosensors by using sodium potassium niobate-silver niobate (0.82KNN-0.18AN composite lead-free thin film as the piezoelectric layer. The piezoelectric diaphragms were designed and fabricated by micro-machining technology and chemical solution deposition. The fabricated device was very sensitive to the mass changes caused by various targets attached on the surface of diaphragm. The measured mass sensitivity value was about 931 Hz/μg. Its good performance shows that the piezoelectric diaphragm biosensor can be used as a cost-effective platform for nucleic acid testing.

  13. Multi-Level Micromachined Systems-on-a-Chip: Technology and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Allen, J.J.; Krygowski, T.W.; Miller, S.L.; Montague, S.; Rodgers, M.S.; Smith, J.H.; Sniegowski, J.J.

    1998-10-27

    Researchers at Sandia have recently designed and built several research prototypes, which demonstrate that truly complex mechanical systems can now be realized in a surface micromachined technology. These MicroElectro- Mechanical Systems (MEMS) include advanced actuators, torque multiplying gear tmins, rack and pinion assemblies, positionable mirrors, and mechanical discriminators. All of tile mechanical components are batch fabricated on a single chip of silicon using the infrastructure origimdly developed to support today's highly reliabk; and robust microelectronics industry. Sand ia is also developing the technology 10 integrate microelectronic circuits onto the s,ime piece of silicon that is used to fabricate the MEMS devices. This significantly increases sensitivity and reliability, while fhrther reducing package size and fabrication costs. A review of the MEMS technology and capabilities available at Sandia National Laboratories is presented.

  14. 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.

  15. Freeform micromachining of an infrared Alvarez lens

    Science.gov (United States)

    Smilie, Paul J.; Dutterer, Brian S.; Lineberger, Jennifer L.; Davies, Matthew A.; Suleski, Thomas J.

    2011-02-01

    In 1967, Luis Alvarez introduced a novel concept for a focusing lens whereby two transmitting elements with cubic polynomial surfaces yield a composite lens of variable focal length with small lateral shifts. Computer simulations have demonstrated the behavior of these devices, but fabricating the refractive cubic surfaces of the types needed with adequate precision and depth modulation has proven to be challenging using standard methods, and, to the authors' knowledge, Alvarez lens elements have not been previously machined in infrared materials. Recent developments in freeform diamond machining capability have enabled the fabrication of such devices. In this paper, we discuss the fabrication of freeform refractive Alvarez elements in germanium using diamond micro-milling on a five-axis Moore Nanotech® 350FG Freeform Generator. Machining approaches are discussed, and measurements of surface figure and finish are presented. Initial experimental tests of optical performance are also discussed.

  16. Micromachining of inertial confinement fusion targets

    International Nuclear Information System (INIS)

    Gobby, P.L.; Salzer, L.J.; Day, R.D.

    1996-01-01

    Many experiments conducted on today's largest inertial confinement fusion drive lasers require target components with sub-millimeter dimensions, precisions of a micron or less and surface finishes measured in nanometers. For metal and plastic, techniques using direct machining with diamond tools have been developed that yield the desired parts. New techniques that will be discussed include the quick-flip locator, a magnetically held kinematic mount that has allowed the direct machining of millimeter-sized beryllium hemishells whose inside and outside surface are concentric to within 0.25 micron, and an electronic version of a tracer lathe which has produced precise azimuthal variations of less than a micron

  17. Effect of Ligand Field Tuning on the SMM Behavior for Three Related Alkoxide-Bridged Dysprosium Dimers.

    Science.gov (United States)

    Peng, Yan; Mereacre, Valeriu; Baniodeh, Amer; Lan, Yanhua; Schlageter, Martin; Kostakis, George E; Powell, Annie K

    2016-01-04

    The synthesis and characterization of three Dy2 compounds, [Dy2(HL1)2(NO3)4] (1), [Dy2(L2)2(NO3)4] (2), and [Dy2(HL3)2(NO3)4] (3), formed using related tripodal ligands with a central tertiary amine bearing picolyl and alkoxy arms, 2-[(2-hydroxy-ethyl)-pyridin-2-ylmethylamino]-ethanol (H2L1), 2-(bis-pyridin-2-ylmethylamino)-ethanol (HL2), and 2-(bis-pyridin-2-ylmethylamino)-propane-1,3-diol (H2L3), are reported. The compounds are rare examples of alkoxide-bridged {Dy2} complexes and display capped square antiprism coordination geometry around each Dy(III) ion. Changes in the ligand field environment around the Dy(III) ions brought about through variations in the ligand donors can be gauged from the magnetic properties, with compounds 1 and 2 showing antiparallel coupling between the Dy(III) ions and 3 showing parallel coupling. Furthermore, slow relaxation of the magnetization typical of SMM behavior could be observed for compounds 2 and 3, suggesting that small variations in the ligand field can have a significant influence on the slow relaxation processes responsible for SMM behavior of Dy(III)-based systems.

  18. Design, simulation and testing of capacitive micromachined ultrasound transducer-based phospholipidic biosensor elements

    International Nuclear Information System (INIS)

    Sapeliauskas, E; Vanagas, G; Barauskas, D; Mikolajunas, M; Pakenas, E; Pelenis, D; Sergalis, G; Jukna, T; Virzonis, D

    2015-01-01

    In this study we present theoretical proof of the principle of using interdigital capacitive micromachined ultrasound transducers (CMUT IDTs) for the detection of phospholipid membrane elasticity. Proof of principle was needed to find out whether the new type of microelectromechanical sensors of the toxins incorporated with the lipid membranes was feasible. CMUT IDTs for 10 MHz operation in water, with 146 µm spaced double fingers were designed and fabricated using the surface micromachining technique. Fabricated CMUTs were tested for their resonance in air and for Scholte-type wave transmission in deionized water and isopropanol solutions containing 0%, 10% and 20% water. The amplitude and phase velocity of the excited and received Scholte waves were measured in a 200 µm height microchannel, capped with a thick layer of soft polymer, which suppressed the production of non-informative guided waves. It was determined that the average sensitivity of Scholte wave phase velocity within the given range of solution concentrations is 2.9 m s −1 per one percent. Experimental data were also used to verify the adequacy of the finite element model, which was found to be suitable for reliable prediction of the phospholipid membrane elasticity impact on the Scholte wave phase velocity or the resonance frequency in the present IDT structure. It was determined that for the analyzed conditions (the elasticity of simulated phospholipid membrane changed from 1 to 5 GPa) the sensitivity of the measurement channel is expected to be no worse than 2 kHz GPa −1 in terms of the Scholte wave and CMUT IDT resonance frequency. This leads to a positive conclusion on the feasibility of the new sensor type. (paper)

  19. Design, simulation and testing of capacitive micromachined ultrasound transducer-based phospholipidic biosensor elements

    Science.gov (United States)

    Sapeliauskas, E.; Vanagas, G.; Barauskas, D.; Mikolajunas, M.; Pakenas, E.; Pelenis, D.; Sergalis, G.; Jukna, T.; Virzonis, D.

    2015-07-01

    In this study we present theoretical proof of the principle of using interdigital capacitive micromachined ultrasound transducers (CMUT IDTs) for the detection of phospholipid membrane elasticity. Proof of principle was needed to find out whether the new type of microelectromechanical sensors of the toxins incorporated with the lipid membranes was feasible. CMUT IDTs for 10 MHz operation in water, with 146 µm spaced double fingers were designed and fabricated using the surface micromachining technique. Fabricated CMUTs were tested for their resonance in air and for Scholte-type wave transmission in deionized water and isopropanol solutions containing 0%, 10% and 20% water. The amplitude and phase velocity of the excited and received Scholte waves were measured in a 200 µm height microchannel, capped with a thick layer of soft polymer, which suppressed the production of non-informative guided waves. It was determined that the average sensitivity of Scholte wave phase velocity within the given range of solution concentrations is 2.9 m s-1 per one percent. Experimental data were also used to verify the adequacy of the finite element model, which was found to be suitable for reliable prediction of the phospholipid membrane elasticity impact on the Scholte wave phase velocity or the resonance frequency in the present IDT structure. It was determined that for the analyzed conditions (the elasticity of simulated phospholipid membrane changed from 1 to 5 GPa) the sensitivity of the measurement channel is expected to be no worse than 2 kHz GPa-1 in terms of the Scholte wave and CMUT IDT resonance frequency. This leads to a positive conclusion on the feasibility of the new sensor type.

  20. Proton beam micromachining on PMMA, Foturan and CR-39 materials

    CERN Document Server

    Rajta, I; Kiss, A Z; Gomez-Morilla, I; Abraham, M H

    2003-01-01

    Proton Beam Micromachining was demonstrated at the Institute of Nuclear Research of the Hungarian Academy of Sciences using three different types of resists: PMMA, Foturan and CR-39 type Solid State Nuclear Track Detector material. Irradiations have been performed on the nuclear microprobe facility at ATOMKI. The beam scanning was done using a National Instruments (NI) card (model 6711), and the new C++ version of the program IonScan, developed specifically for PBM applications called IonScan 2.0. (R.P.)

  1. Capacitive micromachined ultrasonic transducer arrays as tunable acoustic metamaterials

    International Nuclear Information System (INIS)

    Lani, Shane W.; Sabra, Karim G.; Wasequr Rashid, M.; Hasler, Jennifer; Levent Degertekin, F.

    2014-01-01

    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

  2. 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.

  3. Development of capacitive Micromachined Ultrasonic Transducer (III) - Performance Test

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Bok; Ahn, Bong Young; Park, Hae Won; Kim, Young Joo; Lee, Seung Seok [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2004-12-15

    In this study, the capacitive micromachined ultrasonic transducer(cMUT) was developed based on the previous research results. The cross sectional image of the developed cMUT was characterized. To measure the membrane displacement of the cMUT, the Michelson phase modulation fiber interferometer was constructed. The measured membrane displacement was in good agreement with the result of the finite element analysis. To estimate the ultrasonic wave generated by the cMUT, an ultrasonic system including a pulser, receiver and charge amplifier was used. The cMUT developed in this study shows a good performance and hence will be widely used in the non-contact ultrasonic applications

  4. Capacitive micromachined ultrasonic transducer arrays as tunable acoustic metamaterials

    Science.gov (United States)

    Lani, Shane W.; Wasequr Rashid, M.; Hasler, Jennifer; Sabra, Karim G.; Levent Degertekin, F.

    2014-02-01

    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.

  5. Development of capacitive Micromachined Ultrasonic Transducer (III) - Performance Test

    International Nuclear Information System (INIS)

    Kim, Ki Bok; Ahn, Bong Young; Park, Hae Won; Kim, Young Joo; Lee, Seung Seok

    2004-01-01

    In this study, the capacitive micromachined ultrasonic transducer(cMUT) was developed based on the previous research results. The cross sectional image of the developed cMUT was characterized. To measure the membrane displacement of the cMUT, the Michelson phase modulation fiber interferometer was constructed. The measured membrane displacement was in good agreement with the result of the finite element analysis. To estimate the ultrasonic wave generated by the cMUT, an ultrasonic system including a pulser, receiver and charge amplifier was used. The cMUT developed in this study shows a good performance and hence will be widely used in the non-contact ultrasonic applications

  6. Photothermal self-excitation of the micromachined resonators

    Science.gov (United States)

    Churenkov, Alexander V.; Kozel, Stanislav M.; Listvin, Vladimir N.

    1990-07-01

    Recently interest has grown to the physical quantities fibre-optic sensors in which a micromachined resonator acts as a sensitive element. This resonator can change the resonant frequency when acted upon by an outside force. Energy supply necessary for the resonator excitation and transfer of information about the outer action are accomplished by optical fibres, that can be present in the zone of a higher aggressiveness, strong electromagnetic interferences atc. The frequency output of such sensors is easily processed by digital systems and is insensitive to signal level.

  7. Micromachined silicon grisms for infrared optics.

    Science.gov (United States)

    Mar, Douglas J; Marsh, Jasmina P; Deen, Casey P; Ling, Hao; Choo, Hosung; Jaffe, Daniel T

    2009-02-20

    We demonstrate the successful fabrication of large format (approximately 50 mm × 50 mm) gratings in monolithic silicon for use as high-efficiency grisms at infrared wavelengths. The substrates for the grisms were thick (8-16 mm) disks of precisely oriented single-crystal silicon (refractive index, n ~ 3.42). We used microlithography and chemical wet etching techniques to produce the diffraction gratings on one side of these substrates. These techniques permitted the manufacture of coarse grooves (as few as 7 grooves/mm) with precise control of the blaze angle and groove profile and resulted in excellent groove surface quality. Profilometric measurements of the groove structure of the gratings confirm that the physical dimensions of the final devices closely match their design values. Optical performance of these devices exceeds the specifications required for diffraction-limited performance (RMS wave surface error silicon transmits well, the blaze control and high index permit high-resolution, high-order dispersion in a compact space. The first application of these grisms is to provide FORCAST, a mid-infrared camera on NASA's airborne observatory, with a moderate resolution (R=100-1000) spectroscopic capability.

  8. 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.

  9. Capacitive micromachined ultrasonic resonator for ultra sensitive trace gas detection

    Science.gov (United States)

    Ge, Li-Feng

    2013-01-01

    The ultra-sensitive trace gas detection has become increasingly important due to the demand for environment and sci-tech progress. In recent years a capacitive micromachined ultrasonic transducer (CMUT) with circular diaphragms used for imaging has been successfully used to detect chemical gases, and shows promising results. However, its behavior is the same as that of CMUTs for ranging, imaging and therapy applications, where the acoustic radiation with a certain power, produced by the vibration of circular diaphragms operating at the first bending mode, is required but is undesirable for gas sensing since it disturbs inevitably the environment to be measured. This paper, therefore, presents to optimize its behavior after an ideal capacitive micromachined ultrasonic resonator (CMUR) and then to utilize second-order and high-order bending modes of the circular diaphragm to minimize its acoustic radiation and obtain higher resonance frequency also. Since the resonance frequencies of high-order modes much higher than the fundamental frequency, an ultra-high operating frequency of GHz can be reached so that raising greatly the sensitivity of the CMUR and being able to realize the ultra-sensitive trace gas detections.

  10. Parametric studies on the nanosecond laser micromachining of the materials

    Science.gov (United States)

    Tański, M.; Mizeraczyk, J.

    2016-12-01

    In this paper the results of an experimental studies on nanosecond laser micromachining of selected materials are presented. Tested materials were thin plates made of aluminium, silicon, stainless steel (AISI 304) and copper. Micromachining of those materials was carried out using a solid state laser with second harmonic generation λ = 532 nm and a pulse width of τ = 45 ns. The effect of laser drilling using single laser pulse and a burst of laser pulses, as well as laser cutting was studied. The influence of laser fluence on the diameter and morphology of a post ablation holes drilled with a single laser pulse was investigated. The ablation fluence threshold (Fth) of tested materials was experimentally determined. Also the drilling rate (average depth per single laser pulse) of holes drilled with a burst of laser pulses was determined for all tested materials. The studies of laser cutting process revealed that a groove depth increases with increasing average laser power and decreasing cutting speed. It was also found that depth of the laser cut grooves is a linear function of number of repetition of a cut. The quantitative influence of those parameters on the groove depth was investigated.

  11. 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

  12. Eye Vision Testing System and Eyewear Using Micromachines

    Directory of Open Access Journals (Sweden)

    Nabeel A. Riza

    2015-11-01

    Full Text Available Proposed is a novel eye vision testing system based on micromachines that uses micro-optic, micromechanic, and microelectronic technologies. The micromachines include a programmable micro-optic lens and aperture control devices, pico-projectors, Radio Frequency (RF, optical wireless communication and control links, and energy harvesting and storage devices with remote wireless energy transfer capabilities. The portable lightweight system can measure eye refractive powers, optimize light conditions for the eye under testing, conduct color-blindness tests, and implement eye strain relief and eye muscle exercises via time sequenced imaging. A basic eye vision test system is built in the laboratory for near-sighted (myopic vision spherical lens refractive error correction. Refractive error corrections from zero up to −5.0 Diopters and −2.0 Diopters are experimentally demonstrated using the Electronic-Lens (E-Lens and aperture control methods, respectively. The proposed portable eye vision test system is suited for children’s eye tests and developing world eye centers where technical expertise may be limited. Design of a novel low-cost human vision corrective eyewear is also presented based on the proposed aperture control concept. Given its simplistic and economical design, significant impact can be created for humans with vision problems in the under-developed world.

  13. Micromachined chemical sensor with integrated microelectronics

    International Nuclear Information System (INIS)

    Smith, J.; Sniegowski, J.; Koehler, D.; Ricco, T.; Martin, S.; McWhorter, P.

    1992-01-01

    With today's continued emphasis on environmental safety and health issues, a resurgence of interest has developed in the area of chemical sensors. These sensors would typically be used to monitor contamination hazards such as underground storage tanks or to assess previous contamination at waste disposal sites. Human exposure to chemical hazards can also be monitored. Additionally, these sensors can be used as part of a manufacturing process control loop. One type of sensor suitable for gas phase monitoring of chemicals is the quartz resonator or quartz crystal microbalance (QCM) sensor. In this type of sensor, a thickness shear mode (TSM) quartz resonator is coated with a film that interacts with the chemical species of interest. Changes in the mass and elasticity of this film are reflected as changes in the resonant properties of the device. Therefore, the presence of the species of interest can be detected by monitoring the frequency of an oscillator based on the resonance of the quartz. These QCM sensors compete with surface acoustic wave (SAW) devices as a means for monitoring gas phase species. SAW devices are typically more sensitive to small amounts of a species, but the instrumentation associated with a SAW device is an order of magnitude more expensive than the instrumentation associated with a TSM wave resonator since the SAW devices operate in the 100's of MHz frequency regime while quartz resonators operate in the 5--25 MHz regime. We are working to improve the sensitivity of the QCM sensor by increasing the frequency of the device to 25 MHz (compared to the typical 5 MHz crystal) and by increasing the frequency stability of the system to an ultimate goal of 0.1 Hz. The 25 MHz QCM has already been achieved and once the stability goal is achieved, the QCM will have the same sensitivity as a SAW device

  14. 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.

  15. Motor, Visual and Emotional Deficits in Mice after Closed-Head Mild Traumatic Brain Injury Are Alleviated by the Novel CB2 Inverse Agonist SMM-189

    Directory of Open Access Journals (Sweden)

    Anton Reiner

    2014-12-01

    Full Text Available We have developed a focal blast model of closed-head mild traumatic brain injury (TBI in mice. As true for individuals that have experienced mild TBI, mice subjected to 50–60 psi blast show motor, visual and emotional deficits, diffuse axonal injury and microglial activation, but no overt neuron loss. Because microglial activation can worsen brain damage after a concussive event and because microglia can be modulated by their cannabinoid type 2 receptors (CB2, we evaluated the effectiveness of the novel CB2 receptor inverse agonist SMM-189 in altering microglial activation and mitigating deficits after mild TBI. In vitro analysis indicated that SMM-189 converted human microglia from the pro-inflammatory M1 phenotype to the pro-healing M2 phenotype. Studies in mice showed that daily administration of SMM-189 for two weeks beginning shortly after blast greatly reduced the motor, visual, and emotional deficits otherwise evident after 50–60 psi blasts, and prevented brain injury that may contribute to these deficits. Our results suggest that treatment with the CB2 inverse agonist SMM-189 after a mild TBI event can reduce its adverse consequences by beneficially modulating microglial activation. These findings recommend further evaluation of CB2 inverse agonists as a novel therapeutic approach for treating mild TBI.

  16. 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.

  17. Two-dimensional capacitive micromachined ultrasonic transducer (CMUT) arrays for a miniature integrated volumetric ultrasonic imaging system

    Science.gov (United States)

    Zhuang, Xuefeng; Wygant, Ira O.; Yeh, David T.; Nikoozadeh, Amin; Oralkan, Omer; Ergun, Arif S.; Cheng, Ching-Hsiang; Huang, Yongli; Yaralioglu, Goksen G.; Khuri-Yakub, Butrus T.

    2005-04-01

    We have designed, fabricated, and characterized two-dimensional 16x16-element capacitive micromachined ultrasonic transducer (CMUT) arrays. The CMUT array elements have a 250-μm pitch, and when tested in immersion, have a 5 MHz center frequency and 99% fractional bandwidth. The fabrication process is based on standard silicon micromachining techniques and therefore has the advantages of high yield, low cost, and ease of integration. The transducers have a Si3N4 membrane and are fabricated on a 400-μm thick silicon substrate. A low parasitic capacitance through-wafer via connects each CMUT element to a flip-chip bond pad on the back side of the wafer. Each through wafer via is 20 μm in diameter and 400 μm deep. The interconnects form metal-insulator-semiconductor (MIS) junctions with the surrounding high-resistivity silicon substrate to establish isolation and to reduce parasitic capacitance. Each through-wafer via has less than 0.06 pF of parasitic capacitance. We have investigated a Au-In flip-chip bonding process to connect the 2D CMUT array to a custom integrated circuit (IC) with transmit and receive electronics. To develop this process, we fabricated fanout structures on silicon, and flip-chip bonded these test dies to a flat surface coated with gold. The average series resistance per bump is about 3 Ohms, and 100% yield is obtained for a total of 30 bumps.

  18. Fly's proprioception-inspired micromachined strain-sensing structure: idea, design, modeling and simulation, and comparison with experimental results

    Science.gov (United States)

    Wicaksono, D. H. B.; Zhang, L.-J.; Pandraud, G.; French, P. J.; Vincent, J. F. V.

    2006-04-01

    A new strain-sensing structure inspired from insect's (especially the Fly) propricoception sensor is devised. The campaniform sensillum is a strain-sensing microstructure with very high sensitivity despite its small dimension (diameter ~10 µm in a relatively stiff material of insect's exocuticle (E = ~109 Pa). Previous work shows that the high sensitivity of this structure towards strain is due to its membrane-in-recess- and strainconcentrating- hole- features. Based on this inspiration, we built similar structure using silicon micromachining technology. Then a simple characterisation setup was devised. Here, we present briefly, finite-element modeling and simulation based on this actual sample preparation for the characterisation. As comparison and also to understand mechanical features responsible for the strain-sensitivity, we performed the modeling on different mechanical structures: bulk chunk, blind-hole, thorugh-hole, surface membrane, and membrane-in-recess. The actual experimental characterisation was performed previously using optical technique to membranein- recess micromachined Si structure. The FEM simulation results confirm that the bending stress and strain are concentrated in the hole-vicinity. The membrane inside the hole acts as displacement transducer. The FEM is in conformity with previous analytical results, as well as the optical characterisation result. The end goal is to build a new type MEMS strain sensor.

  19. Compact Micromachined Infrared Bandpass Filters for Planetary Spectroscopy

    Science.gov (United States)

    Merrell, Willie C., II; Aslam, Shahid; Brown, Ari D.; Chervenak, James A.; Huang, Wei-Chung; Quijada, Manuel; Wollack, Edward

    2011-01-01

    The future needs of space based observational planetary and astronomy missions include low mass and small volume radiometric instruments that can operate in high radiation and low temperature environments. Here we focus on a central spectroscopic component, the bandpass filter. We model the bandpass response of the filters to target the wavelength of the resonance peaks at 20, 40, and 60 micrometers and report good agreement between the modeled and measured response. We present a technique of using common micromachining processes for semiconductor fabrication to make compact, free standing resonant metal mesh filter arrays with silicon support frames. The process can accommodate multiple detector array architectures and the silicon frame provides lightweight mechanical support with low form factor. We also present a conceptual hybridization of the filters with a detector array.

  20. 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.

  1. 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.

  2. 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)

  3. A Micro-Machined Gyroscope for Rotating Aircraft

    Directory of Open Access Journals (Sweden)

    Fuxue Zhang

    2012-07-01

    Full Text Available In this paper we present recent work on the design, fabrication by silicon micromachining, and packaging of a new gyroscope for stabilizing the autopilot of rotating aircraft. It operates based on oscillation of the silicon pendulum between two torsion girders for detecting the Coriolis force. The oscillation of the pendulum is initiated by the rolling and deflecting motion of the rotating carrier. Therefore, the frequency and amplitude of the oscillation are proportional to the rolling frequency and deflecting angular rate of the rotating carrier, and are measured by the sensing electrodes. A modulated pulse with constant amplitude and unequal width is obtained by a linearizing process of the gyroscope output signal and used to control the deflection of the rotating aircraft. Experimental results show that the gyroscope has a resolution of 0.008 °/s and a bias of 56.18 °/h.

  4. Capacitive micromachined ultrasonic transducers for medical imaging and therapy

    Science.gov (United States)

    Khuri-Yakub, Butrus T.; Oralkan, Ömer

    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 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.

  5. 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

  6. Compact Micromachined Bandpass Filters for Infrared Planetary Spectroscopy

    Science.gov (United States)

    Brown, Ari D.; Aslam, Shahid; Chervenak, James A.; Huang, Wei-Chung; Merrell, Willie; Quijada, Manuel

    2011-01-01

    The thermal instrument strawman payload of the Jupiter Europa Orbiter on the Europa Jupiter Science Mission will map out thermal anomalies, the structure, and atmospheric conditions of Europa and Jupiter within the 7-100 micron spectral range. One key requirement for the payload is that the mass cannot exceed 3.7 kg. Consequently, a new generation of light-weight miniaturized spectrometers needs to be developed. On the path toward developing these spectrometers is development of ancillary miniaturized spectroscopic components. In this paper, we present a strategy for making radiation hard and low mass FIR band pass metal mesh filters. Our strategy involves using MEMS-based fabrication techniques, which will permit the quasi-optical filter structures to be made with micron-scale precision. This will enable us to achieve tight control over both the pass band of the filter and the micromachined silicon support structure architecture, which will facilitate integration of the filters for a variety of applications.

  7. Micromachined Systems-on-a-Chip: Infrastructure, Technology and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Allen, J. J.; Krygowski, T. W.; Miller, S. L.; Montague, S.; Rodgers, M. S.; Schriner, H.; Smith, J. H.; Sniegowski, J. J.

    1998-10-09

    A review is made of the infrastructure, technology and capabilities of Sandia National Laboratories for the development of micromechanical systems that have potential space applications. By incorporating advanced fabrication processes, such as chemical mechanical polishing, and several mechanical polysilicon levels, the range' of rrticromechanical systems that can be fabricated in these technologies is virtually limitless. Representative applications include a micro- engine driven mirror, and a micromachined lock. Using a novel integrated MEM!YCMOS technology, a six degree-of-freedom accelerometer/gyroscope system has been designed by researchers at U.C. Berkeley and fabricated on the same silicon chip as the CMOS control circuits to produce an integrated micro-navigational unit.

  8. Sub-band-gap laser micromachining of lithium niobate

    DEFF Research Database (Denmark)

    Christensen, F. K.; Müllenborn, Matthias

    1995-01-01

    Laser processing of insulators and semiconductors is usually realized using photon energies exceeding the band-gap energy. This makes laser processing of insulators difficult since high photon energies typically require either a pulsed laser or a frequency-doubled continuous-wave laser. A new...... 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...... structures, or simple etching of grooves for precision positioning of optical fibers. ©1995 American Institute of Physics....

  9. Q-Switched Nd: YAG Laser Micro-Machining System

    International Nuclear Information System (INIS)

    Messaoud, S.; Allam, A.; Siserir, F.; Bouceta, Y.; Kerdja, T.; Ouadjaout, D.

    2008-01-01

    In this paper, we present the design of a low cost Q-switched Nd: YAG laser micro-machining system for photo masks fabrication. It consists of: Nd:YAG laser source, beam delivery system, X-Y table, PC, The CCD camera and TV monitor. The synchronization between the laser source and the X-Y table is realised by NI PCI-7342, the two axis MID-7602 and LabVIEW based program. The first step of this work consists of engraving continuous and discontinuous lines on a thin film metal with a 100 μm resolution by using the YG 980 Quantel Q-switched Nd:YAG laser.

  10. Micromachined hot-wire thermal conductivity probe for biomedical applications.

    Science.gov (United States)

    Yi, Ming; Panchawagh, Hrishikesh V; Podhajsky, Ronald J; Mahajan, Roop L

    2009-10-01

    This paper presents the design, fabrication, numerical simulation, and experimental validation of a micromachined probe that measures thermal conductivity of biological tissues. The probe consists of a pair of resistive line heating elements and resistance temperature detector sensors, which were fabricated by using planar photolithography on a glass substrate. The numerical analysis revealed that the thermal conductivity and diffusivity can be determined by the temperature response induced by the uniform heat flux in the heating elements. After calibrating the probe using a material (agar gel) of known thermal conductivity, the probe was deployed to calculate the thermal conductivity of Crisco. The measured value is in agreement with that determined by the macro-hot-wire probe method to within 3%. Finally, the micro thermal probe was used to investigate the change of thermal conductivity of pig liver before and after RF ablation treatment. The results show an increase in thermal conductivity of liver after the RF ablation.

  11. Characterization of a Silicon-Micromachined Thermal Shear-Stress Sensor

    National Research Council Canada - National Science Library

    Sheplak, Mark; Chandrasekaran, Venkataraman; Cain, Anthony; Nishida, Toshikazu; Cattafesta, Louis N

    2002-01-01

    A detailed characterization is presented of a silicon-micromachined thermal shear-stress sensor employing a thin-film platinum-sensing element on top of a silicon-nitride membrane that is stretched over a vacuum cavity...

  12. Laser micro-machined semi-slinky like MEMS structures: Novel interface coolers

    Science.gov (United States)

    Çelen, Serap

    2012-10-01

    Laser micro-machining has recently been considered a precision and reproducible manufacturing technique in MEMS fabrication because of the superior characteristics of a focused laser beam. It is not only a unique tool but also an invisible optical drill. The aim of the present paper is two-fold: to manufacture novel miniaturized titanium 3D MEMS surface structures in order to increase the cooling performance. Second is to find the behaviors of the operational parameters which controlling the laser-material interaction mechanisms and also suggest the best adjustments in order to achieve this novel semi-slinky like spiral MEMS surface structures with using a 20 W ytterbium fiber laser. Pure titanium micro-MEMS product which has novel interface coolers was manufactured using a ytterbium fiber laser (λ=1060 nm) with 40 ns pulse duration. Best adjustments were, respectively, the pulse duration: 40 ns, the pulse energy: 0.4 mJ, the laser scanning speed: 336.1 mm/s, the peak power density: 17.46 * 108 W/cm2.

  13. 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.

  14. Free-standing double-layer terahertz band-pass filters fabricated by femtosecond laser micro-machining.

    Science.gov (United States)

    Lin, Yanzhang; Yao, Haizi; Ju, Xuewei; Chen, Ying; Zhong, Shuncong; Wang, Xiangfeng

    2017-10-16

    We report on the fabrication and transmission properties of free-standing single-layer and double-layer THz bandpass filters. These filters are fabricated on aluminum foils using femtosecond laser micro-machining. The aluminum foils are periodically patterned with cross apertures with a total area of 1.75×1.75 cm 2 , also known as frequency-selective surfaces. Their terahertz transmission properties were simulated using the FDTD method and measured using a time-domain terahertz spectroscopy system. The simulation results agree with the measurements results very well. The performance of single-layer bandpass filters is as good as the commercial equivalents on the market. The double-layer filters show extraordinary transmission peaks with changing spacing between the two layers. We show the contour map of the electric field distribution across the apertures, and ascribe the new transmission peaks to the interference and coupling of surface plasmon polaritons between the two layers.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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)

  1. Immunogenicity and persistence of the 13-valent Pneumococcal Conjugate Vaccine (PCV13) in patients with untreated Smoldering Multiple Myeloma (SMM): A pilot study.

    Science.gov (United States)

    Bahuaud, Mathilde; Bodilis, Hélène; Malphettes, Marion; Maugard Landre, Anaïs; Matondo, Caroline; Bouscary, Didier; Batteux, Frédéric; Launay, Odile; Fermand, Jean-Paul

    2017-11-01

    Smoldering multiple myeloma (SMM) is an asymptomatic clonal plasma cell disorder that frequently progress to multiple myeloma (MM), a disease at high risk of pneumococcal infections. Moreover, if the polysaccharide vaccine is poorly immunogenic in MM, the 13-valent conjugated vaccine has never been tested in clonal plasma cell disorders. We evaluated its immunogenicity for 7 serotypes in 20 patients ≥ 50 years of age with smoldering multiple myeloma (SMM) pre and post routine-vaccination with PCV13. Concentrations of IgG specific for 7 serotypes were measured at baseline, 1, 6, and 12 months after vaccination by standardized ELISA and an Opsonophagocytic Assay (OPA). The primary endpoint was the proportion of patients responding to at least 5 of the 7 serotypes by ELISA at one month. At 1 month post vaccination, 12 patients (60%) were responders by ELISA, among whom 8 were also responders by OPA. At 6 months, 6 (30% of total) of the 12 responders had persistent immunity, and only 2 (10% of total) at 12 months. These results suggested a partial response in this population and a rapid decrease in antibody levels in the first months of vaccination. Although one injection of the 13-valent pneumococcal conjugate vaccine is immunogenic in some patients with SMM, the response is transient. Repeated injections are likely to be needed for effective and sustained protection.

  2. Immunogenicity and persistence of the 13-valent Pneumococcal Conjugate Vaccine (PCV13 in patients with untreated Smoldering Multiple Myeloma (SMM: A pilot study

    Directory of Open Access Journals (Sweden)

    Mathilde Bahuaud

    2017-11-01

    Full Text Available Smoldering multiple myeloma (SMM is an asymptomatic clonal plasma cell disorder that frequently progress to multiple myeloma (MM, a disease at high risk of pneumococcal infections. Moreover, if the polysaccharide vaccine is poorly immunogenic in MM, the 13-valent conjugated vaccine has never been tested in clonal plasma cell disorders. We evaluated its immunogenicity for 7 serotypes in 20 patients ≥ 50 years of age with smoldering multiple myeloma (SMM pre and post routine-vaccination with PCV13.Concentrations of IgG specific for 7 serotypes were measured at baseline, 1, 6, and 12 months after vaccination by standardized ELISA and an Opsonophagocytic Assay (OPA. The primary endpoint was the proportion of patients responding to at least 5 of the 7 serotypes by ELISA at one month.At 1 month post vaccination, 12 patients (60% were responders by ELISA, among whom 8 were also responders by OPA. At 6 months, 6 (30% of total of the 12 responders had persistent immunity, and only 2 (10% of total at 12 months. These results suggested a partial response in this population and a rapid decrease in antibody levels in the first months of vaccination.Although one injection of the 13-valent pneumococcal conjugate vaccine is immunogenic in some patients with SMM, the response is transient. Repeated injections are likely to be needed for effective and sustained protection. Keywords: Immunology, Vaccines, Infectious disease

  3. Sustainable Materials Management (SMM) Web Academy Webinar: State Policies to Increase Organics Diversion from Landfills: MA and VT one year in and CA the new kid on the block

    Science.gov (United States)

    This is a webinar page for the Sustainable Management of Materials (SMM) Web Academy webinar titled Changing How We Think About Our Resources for a Better Tomorrow: How to Donate Surplus Food from K-12 Schools

  4. 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.

  5. 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.

  6. Development of capacitive micromachined ultrasonic transducer for noncontact ultrasonic detection

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Bok; Ahn, Bong Young; Park, Hae Won; Kim, Young Joo; Lee, Seung Seok [Center for Environment and Safrty Measurement, KRISS, Daejeon (Korea, Republic of)

    2004-11-15

    In this study, the capacitive micromachined ultrasonic transducer (cMUT) was developed. Theoretical analysis and finite element analysis of the behavior of membrane (such as resonance frequency, membrane deflection, collapse deflection and collapse voltage) of the cMUT were performed. The design parameters of the cMUT were estimated and are the dimension and thickness of membrane, thickness of sacrificial layer, thickness and size of electrode, size of active element and so on. With the micro-fabrication process, the cMUT was fabricated on the silicon wafer. To measure the membrane displacement of cMUT, the Michelson phase modulation fiber interferometer was constructed. The measured membrane displacement was good agreed with the result of finite element analysis. To estimate the ultrasonic wave generated by the cMUT, the ultrasonic transceiver system was constructed. The developed cMUT shows a good performance and hence will be widely used to the filed of non-contact ultrasonic application.

  7. Capacitive micromachined ultrasonic transducers (CMUTs) for photoacoustic imaging

    Science.gov (United States)

    Vaithilingam, Srikant; Wygant, Ira O.; Kuo, Paulina S.; Zhuang, Xuefeng; Oralkan, Ömer; Olcott, Peter D.; Khuri-Yakub, Butrus T.

    2006-02-01

    In photoacoustic (optoacoustic) medical imaging, short laser pulses irradiate absorbing structures found in tissue, such as blood vessels, causing brief thermal expansions that in turn generate ultrasound waves. These ultrasound waves which correspond to the optical absorption distribution were imaged using a two dimensional array of capacitive micromachined ultrasonic transducers (CMUTs). Advantages of CMUT technology for photoacoustic imaging include the ease of integration with electronics, ability to fabricate large two dimensional arrays, arrays with arbitrary geometries, wide-bandwidth arrays and high-frequency arrays. In this study, a phantom consisting of three 0.86-mm inner diameter polyethylene tubes inside a tissue mimicking material was imaged using a 16 x 16 element CMUT array. The center tube was filled with India-ink to provide optical contrast. Traditional pulse-echo data as well as photoacoustic image data were taken. 2D cross-sectional slices and 3D volume rendered images are shown. Simple array tiling was attempted, whereby a 48 x 48 element array was simulated, to illustrate the advantages of larger arrays. Finally, the sensitivity of the photoacoustics setup to the concentration of ink in the tube was also explored. For the sensitivity experiment a different phantom consisting of only one 1.14-mm inner diameter polyethylene tube inside a tissue mimicking material was used. The concentration of the ink inside the tube was varied and images were taken.

  8. Capacitive micromachined ultrasound transducer (cMUT) for immunosensor design.

    Science.gov (United States)

    Ramanaviciene, Almira; Virzonis, Darius; Vanagas, Gailius; Ramanavicius, Arūnas

    2010-07-01

    An affinity sensor based on a capacitive micromachined ultrasound transducer (cMUT) is reported by this Communication. The cMUT micromembrane arrays modified with adsorbed bovine leukemia virus protein gp51 were applied as a biological recognition part. The cMUT-based sensor is shown to be sensitive to the antibodies against bovine leukemia virus protein gp51 (anti-gp51). Two different concentrations of anti-gp51-containing samples and one blank sample without anti-gp51 were tested. The sensitivity of cMUT-based immunosensor is comparable with the sensitivity of a quartz microbalance-based immunosensor. The cMUT array provides a multi-channel system for the measurement of analytical signal. Moreover, two different characteristics--the resonance frequency shift (Deltaf) and the shift of the real part of the electromechanical impedance (DeltaRe)--could have been evaluated simultaneously. Both analytical signals are informative and can be applied for the estimation of immune complex formation. We found the performance of such a system being potentially superior over some other immunosensing techniques. It is more rapid than electrochemical techniques and provides two different informative parameters.

  9. Singulation for imaging ring arrays of capacitive micromachined ultrasonic transducers

    International Nuclear Information System (INIS)

    Chang, Chienliu; Moini, Azadeh; Nikoozadeh, Amin; Sarioglu, Ali Fatih; Apte, Nikhil; Zhuang, Xuefeng; Khuri-Yakub, Butrus T

    2014-01-01

    Singulation of MEMS is a critical step in the transition from wafer-level to die-level devices. As is the case for capacitive micromachined ultrasound transducer (CMUT) ring arrays, an ideal singulation must protect the fragile membranes from the processing environment while maintaining a ring array geometry. The singulation process presented in this paper involves bonding a trench-patterned CMUT wafer onto a support wafer, deep reactive ion etching (DRIE) of the trenches, separating the CMUT wafer from the support wafer and de-tethering the CMUT device from the CMUT wafer. The CMUT arrays fabricated and singulated in this process were ring-shaped arrays, with inner and outer diameters of 5 mm and 10 mm, respectively. The fabricated CMUT ring arrays demonstrate the ability of this method to successfully and safely singulate the ring arrays and is applicable to any arbitrary 2D shaped MEMS device with uspended microstructures, taking advantage of the inherent planar attributes of DRIE. (technical note)

  10. Radiation impedance of collapsed capacitive micromachined ultrasonic transducers.

    Science.gov (United States)

    Ozgurluk, Alper; Atalar, Abdullah; Köymen, Hayrettin; Olçum, Selim

    2012-06-01

    The radiation impedance of a capacitive micromachined ultrasonic transducer (CMUT) array is a critical parameter to achieve high performance. In this paper, we present a calculation of the radiation impedance of collapsed, clamped, circular CMUTs both analytically and using finite element method (FEM) simulations. First, we model the radiation impedance of a single collapsed CMUT cell analytically by expressing its velocity profile as a linear combination of special functions for which the generated pressures are known. For an array of collapsed CMUT cells, the mutual impedance between the cells is also taken into account. The radiation impedances for arrays of 7, 19, 37, and 61 circular collapsed CMUT cells for different contact radii are calculated both analytically and by FEM simulations. The radiation resistance of an array reaches a plateau and maintains this level for a wide frequency range. The variation of radiation reactance with respect to frequency indicates an inductance-like behavior in the same frequency range. We find that the peak radiation resistance value is reached at higher kd values in the collapsed case as compared with the uncollapsed case, where k is the wavenumber and d is the center-to-center distance between two neighboring CMUT cells.

  11. Development of capacitive micromachined ultrasonic transducer for noncontact ultrasonic detection

    International Nuclear Information System (INIS)

    Kim, Ki Bok; Ahn, Bong Young; Park, Hae Won; Kim, Young Joo; Lee, Seung Seok

    2004-01-01

    In this study, the capacitive micromachined ultrasonic transducer (cMUT) was developed. Theoretical analysis and finite element analysis of the behavior of membrane (such as resonance frequency, membrane deflection, collapse deflection and collapse voltage) of the cMUT were performed. The design parameters of the cMUT were estimated and are the dimension and thickness of membrane, thickness of sacrificial layer, thickness and size of electrode, size of active element and so on. With the micro-fabrication process, the cMUT was fabricated on the silicon wafer. To measure the membrane displacement of cMUT, the Michelson phase modulation fiber interferometer was constructed. The measured membrane displacement was good agreed with the result of finite element analysis. To estimate the ultrasonic wave generated by the cMUT, the ultrasonic transceiver system was constructed. The developed cMUT shows a good performance and hence will be widely used to the filed of non-contact ultrasonic application.

  12. Diamond-based capacitive micromachined ultrasonic transducers in immersion.

    Science.gov (United States)

    Cetin, Ahmet M; Bayram, Baris

    2013-02-01

    Diamond is a superior membrane material for capacitive micromachined ultrasonic transducers (CMUTs). By using ultrananocrystalline diamond (UNCD) membrane and plasma-activated wafer bonding technology, a single diamond-based circular CMUT is demonstrated and operated in immersion for the first time. The diamond-based CMUT, biased at 100 V, is excited with a 10-cycle burst of 36 V(p-p) sine signal at 3.5 MHz. Pressure generated on a 2-D plane coincident with the normal of the CMUT is measured using a broadband hydrophone. Peak-to-peak hydrophone voltage measurements along the scan area clearly indicate the main lobe and the side lobes, as theoretically predicted by our directivity function calculations. The peak-to-peak hydrophone voltage on the axial direction of the CMUT is found to be in agreement with our theoretical calculations in the Fraunhofer region (-45 mm CMUT is measured for a dc bias of 100 V, and ac excitation with 30-cycle bursts of 9, 36, and 54 V(p-p) sine signal. A peak response at 5.6 MHz is measured for all ac amplitudes. Overall, diamond is shown to be an applicable membrane for CMUT devices and applications.

  13. 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.

  14. Encapsulation of Capacitive Micromachined Ultrasonic Transducers Using Viscoelastic Polymer

    Science.gov (United States)

    Lin, Der-Song; Zhuang, Xuefeng; Wong, Serena H.; Kupnik, Mario; Khuri-Yakub, Butrus Thomas

    2010-01-01

    The packaging of a medical imaging or therapeutic ultrasound transducer should provide protective insulation while maintaining high performance. For a capacitive micromachined ultrasonic transducer (CMUT), an ideal encapsulation coating would therefore require a limited and predictable change on the static operation point and the dynamic performance, while insulating the high dc and dc actuation voltages from the environment. To fulfill these requirements, viscoelastic materials, such as polydimethylsiloxane (PDMS), were investigated for an encapsulation material. In addition, PDMS, with a glass-transition temperature below room temperature, provides a low Young's modulus that preserves the static behavior; at higher frequencies for ultrasonic operation, this material becomes stiffer and acoustically matches to water. In this paper, we demonstrate the modeling and implementation of the viscoelastic polymer as the encapsulation material. We introduce a finite element model (FEM) that addresses viscoelasticity. This enables us to correctly calculate both the static operation point and the dynamic behavior of the CMUT. CMUTs designed for medical imaging and therapeutic ultrasound were fabricated and encapsulated. Static and dynamic measurements were used to verify the FEM and show excellent agreement. This paper will help in the design process for optimizing the static and the dynamic behavior of viscoelastic-polymer-coated CMUTs. PMID:21170294

  15. Singulation for imaging ring arrays of capacitive micromachined ultrasonic transducers

    Science.gov (United States)

    Chang, Chienliu; Moini, Azadeh; Nikoozadeh, Amin; Sarioglu, Ali Fatih; Apte, Nikhil; Zhuang, Xuefeng; Khuri-Yakub, Butrus T.

    2014-10-01

    Singulation of MEMS is a critical step in the transition from wafer-level to die-level devices. As is the case for capacitive micromachined ultrasound transducer (CMUT) ring arrays, an ideal singulation must protect the fragile membranes from the processing environment while maintaining a ring array geometry. The singulation process presented in this paper involves bonding a trench-patterned CMUT wafer onto a support wafer, deep reactive ion etching (DRIE) of the trenches, separating the CMUT wafer from the support wafer and de-tethering the CMUT device from the CMUT wafer. The CMUT arrays fabricated and singulated in this process were ring-shaped arrays, with inner and outer diameters of 5 mm and 10 mm, respectively. The fabricated CMUT ring arrays demonstrate the ability of this method to successfully and safely singulate the ring arrays and is applicable to any arbitrary 2D shaped MEMS device with uspended microstructures, taking advantage of the inherent planar attributes of DRIE.

  16. Towards a Casimir Force Measurement between Micromachined Parallel Plate Structures

    Directory of Open Access Journals (Sweden)

    Remco J. Wiegerink

    2012-11-01

    Full Text Available Ever since its prediction, experimental investigation of the Casimir force has been of great scientific interest. Many research groups have successfully attempted quantifying the force with different device geometries; however, measurement of the Casimir force between parallel plates with sub-micron separation distance is still a challenging task, since it becomes extremely difficult to maintain sufficient parallelism between the plates. The Casimir force can significantly influence the operation of micro devices and to realize reliable and reproducible devices it is necessary to understand and experimentally verify the influence of the Casimir force at sub-micron scale. In this paper, we present the design principle, fabrication and characterization of micromachined parallel plate structures that could allow the measurement of the Casimir force with tunable separation distance in the range of 100 to 1000 nm. Initially, a gold coated parallel plate structure is explored to measure the Casimir force, but also other material combinations could be investigated. Using gold-silicon eutectic bonding, a reliable approach to bond chips with integrated suspended plates together with a well-defined separation distance in the order of 1–2 μm is developed.

  17. 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.

  18. 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)

  19. Design and Simulation of a New Decoupled Micromachined Gyroscope

    Energy Technology Data Exchange (ETDEWEB)

    Sharaf, Abdelhameed [NCRRT, EAEA, 3 Ahmed Elzomer Street, Nasr City, Cairo (Egypt); STRC, AUC, 113 Kasr El Eini Street, 11215, Cairo (Egypt); Sedky, Sherif [STRC, AUC, 113 Kasr El Eini Street, 11215, Cairo (Egypt); Physics Department, AUC, 113 Kasr El Eini Street, 11215, Cairo (Egypt); Habib, S E-D [Electronics and Communication Department, Faculty of Engineering, Cairo University, 12613, Giza (Egypt)

    2006-04-01

    This paper reports on a new decoupled micromachined gyroscope. The proposed sensor is a dual mass type, electrostatically driven to primary mode oscillation and senses, capacitively, the output signal. Full decoupling between drive and sense modes minimizes the mechanical crosstalk. Three different designs are introduced in this work. Drive and sense amplitudes, mechanical and electrical sensitivities, quality factors and approximate bandwidths are extracted analytically and the results are confirmed using finite element analysis. The first design shows drive and sense modes resonance frequencies of 4077 Hz and 4081 Hz respectively; with a frequency mismatch lower than 0.1%. The drive and sense capacitance are 0.213 pF and 0.142 pF respectively. The mechanical and electrical sensitivities are 0.011 {mu}m/ ({sup 0}/s) and 2.75 mV/ ({sup 0}/s) respectively. The third design shows significantly improved mechanical and electrical sensitivities of 0.027 {mu}m/ ({sup 0}/s) and 6.85 mV/ ({sup 0}/s) respectively.

  20. 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

    The prime driving force for using microsystem and micromachine technologies in transport vehicles, such as spacecraft, aircraft, and automobiles, is to reduce the weight, power consumption, and volume of components and systems to lower costs and increase affordability and reliability. However, a number of specific issues need to be addressed with respect to using microsystems and micromachines in aerospace applications--such as the lack of understanding of material characteristics; methods for producing and testing the materials in small batches; the limited proven durability and lifetime of current microcomponents, packaging, and interconnections; a cultural change with respect to system designs; and the use of embedded software, which will require new product assurance guidelines. In regards to material characteristics, there are significant adhesion, friction, and wear issues in using microdevices. Because these issues are directly related to surface phenomena, they cannot be scaled down linearly and they become increasingly important as the devices become smaller. When microsystems have contacting surfaces in relative motion, the adhesion and friction affect performance, energy consumption, wear damage, maintenance, lifetime and catastrophic failure, and reliability. Ceramics, for the most part, do not have inherently good friction and wear properties. For example, coefficients of friction in excess of 0.7 have been reported for ceramics and ceramic composite materials. Under Alternate Fuels Foundation Technologies funding, two-phase oxide ceramics developed for superior high-temperature wear resistance in NASA's High Operating Temperature Propulsion Components (HOTPC) project and new two-layered carbon nanotube (CNT) coatings (CNT topcoat/iron bondcoat/quartz substrate) developed in NASA's Revolutionary Aeropropulsion Concepts (RAC) project have been chosen as a materials couple for aerospace applications, including micromachines, in the nanotechnology

  1. Micromachined Millimeter- and Submillimeter-Wave SIS Heterodyne Receivers for Remote Sensing

    Science.gov (United States)

    Hu, Qing

    1998-01-01

    A heterodyne mixer with a micromachined horn antenna and a superconductor -insulator-superconductor (SIS) tunnel junction as mixing element is tested in the W-band (75-115 GHz) frequency range. Micromachined integrated horn antennas consist of a dipole antenna suspended on a thin Si3N4 dielectric membrane inside a pyramidal cavity etched in silicon. The mixer performance is optimized by using a backing plane behind the dipole antenna to tune out the capacitance of the tunnel junction. The lowest receiver noise temperature of 30+/-3 K without any correction) is measured at 106 GHz with a 3-dB bandwidth of 8 GHz. This sensitivity is comparable to the state-of-the-art waveguide and quasi-optical SIS receivers, showing the potential use of micromachined horn antennas in imaging arrays.

  2. A Low-noise Micromachined Millimeter-Wave Heterodyne Mixer using Nb Superconducting Tunnel Junctions

    Science.gov (United States)

    DeLange, Gert; Jacobson, Brian R.; Hu, Qing

    1996-01-01

    A heterodyne mixer with a micromachined horn antenna and a superconductor-insulator-superconductor (SIS) tunnel junction as mixing element is tested in the W-band (75-115 GHz) frequency range. Micromachined integrated horn antennas consist of a dipole antenna suspended on a thin Si3N4 dielectric membrane inside a pyramidal cavity etched in silicon. The mixer performance is optimized by using a backing plane behind the dipole antenna to tune out the capacitance of the tunnel junction. The lowest receiver noise temperature of 30 +/- 3 K (without any correction) is measured at 106 GHz with a 3-dB bandwidth of 8 GHz. This sensitivity is comparable to the state-of-the-art waveguide and quasi-optical SIS receivers, showing the potential use of micromachined horn antennas in imaging arrays.

  3. Experimental Analysis of Bisbenzocyclobutene Bonded Capacitive Micromachined Ultrasonic Transducers.

    Science.gov (United States)

    Manwar, Rayyan; Chowdhury, Sazzadur

    2016-06-24

    Experimental measurement results of a 1.75 mm × 1.75 mm footprint area Capacitive Micromachined Ultrasonic Transducer (CMUT) planar array fabricated using a bisbenzocyclobutene (BCB)-based adhesive wafer bonding technique has been presented. The array consists of 40 × 40 square diaphragm CMUT cells with a cavity thickness of 900 nm and supported by 10 µm wide dielectric spacers patterned on a thin layer of BCB. A 150 µm wide one µm thick gold strip has been used as the contact pad for gold wire bonding. The measured resonant frequency of 19.3 MHz using a Polytec™ laser Doppler vibrometer (Polytec™ MSA-500) is in excellent agreement with the 3-D FEA simulation result using IntelliSuite™. An Agilent ENA5061B vector network analyzer (VNA) has been used for impedance measurement and the resonance and anti-resonance values from the imaginary impedance curve were used to determine the electromechanical coupling co-efficient. The measured coupling coefficient of 0.294 at 20 V DC bias exhibits 40% higher transduction efficiency as compared to a measured value published elsewhere for a silicon nitride based CMUT. A white light interferometry method was used to measure the diaphragm deflection profiles at different DC bias. The diaphragm center velocity was measured for different sub-resonant frequencies using a Polytec™ laser Doppler vibrometer that confirms vibration of the diaphragm at different excitation frequencies and bias voltages. Transmit and receive operations of CMUT cells were characterized using a pitch-catch method and a -6 dB fractional bandwidth of 23% was extracted from the received signal in frequency domain. From the measurement, it appears that BCB-based CMUTs offer superior transduction efficiency as compared to silicon nitride or silicon dioxide insulator-based CMUTs, and provide a very uniform deflection profile thus making them a suitable candidate to fabricate highly energy efficient CMUTs.

  4. 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.

  5. 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.

  6. Smooth transition between SMM and SCM-type slow relaxing dynamics for a 1-D assemblage of {Dy(nitronyl nitroxide)2} units.

    Science.gov (United States)

    Liu, Ruina; Li, Licun; Wang, Xiaoling; Yang, Peipei; Wang, Chao; Liao, Daizheng; Sutter, Jean-Pascal

    2010-04-21

    A model example for size effects on the dynamic susceptibility behavior is provided by the chain compound [{Dy(hfac)(3)NitPhIm(2)}Dy(hfac)(3)] (NitPhIm = 2-[4-(1-imidazole)phenyl]nitronyl nitroxide radical). The Arrhenius plot reveals two relaxation regimes attributed to SMM (Delta = 17.1 K and tau(0) = 17.5 x 10(-6) s) and SCM (Delta = 82.7 K and tau(0) = 8.8 x 10(-8) s) behaviors. The ferromagnetic exchange among the spin carriers has been established for the corresponding Gd derivative.

  7. Long-life micro vacuum chamber for a micromachined cryogenic cooler

    NARCIS (Netherlands)

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

    2015-01-01

    Micromachined cryogenic coolers can be used for cooling small electronic devices to improve their performance. However, for reaching cryogenic temperatures, they require a very good thermal insulation from the warm environment. This is established by a vacuum space that for adequate insulation has

  8. Angular Random Walk Estimation of a Time-Domain Switching Micromachined Gyroscope

    Science.gov (United States)

    2016-10-19

    TECHNICAL DOCUMENT 3308 September 2016 Angular Random Walk Estimation of a Time-Domain Switching Micromachined Gyroscope Andrew B. Sabater Paul...angular random walk (ARW), bias instability, and scale factor instability. While there are methods to address issues with bias and scale factor...8 4. ANGULAR RANDOM WALK CHARACTERIZATION

  9. 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

  10. 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.

  11. A micromachined silicon valve driven by a miniature bi-stable electro-magnetic actuator

    NARCIS (Netherlands)

    Bohm, S.; Burger, G.J.; Burger, G.J.; Korthorst, M.T.; Roseboom, F.

    2000-01-01

    In this paper a novel combination of a micromachined silicon valve with low dead volume and a bi-stable electromagnetic actuator produced by conventional machining is presented. The silicon valve part, 7×7×1 mm3 in dimensions, is a sandwich construction of two KOH etched silicon wafers with a layer

  12. 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...

  13. Unique Femtosecond Micromachining Methods in Semi-Insulating and Conducting Silicon Carbide (Preprint)

    National Research Council Canada - National Science Library

    Brewer, Chris; Dorsey, Don; Campbell, Angela; Juhl, Shane; DesAutels, G. L; Finet, Marc; Ristich, Scott; Whitaker, Matt; Powers, Peter E; Zhan, Qiwen

    2007-01-01

    ...); a wide bandgap semiconductor material provided by Wright-Patterson AFB AFRL/MLPS. Gratings were micro-machined into these materials using a novel anamorphic lens design and an automated x, y, z linear stage to control the sample position...

  14. Separation and Detection of Toxic Gases with a Silicon Micromachined Gas Chromatography System

    Science.gov (United States)

    Kolesar, Edward S.; Reston, Rocky R.

    1995-01-01

    A miniature gas chromatography (GC) system was designed and fabricated using silicon micromachining and integrated circuit (IC) processing techniques. The silicon micromachined gas chromatography system (SMGCS) is composed of a miniature sample injector that incorporates a 10 microliter sample loop; a 0.9 meter long, rectangular shaped (300 micrometer width and 10 micrometer height) capillary column coated with a 0.2 micrometer thick copper phthalocyanine (CuPc) stationary phase; and a dual detector scheme based upon a CuPc-coated chemiresistor and a commercially available 125 micrometer diameter thermal conductivity detector (TCD) bead. Silicon micromachining was employed to fabricate the interface between the sample injector and the GC column, the column itself, and the dual detector cavity. A novel IC thin-film processing technique was developed to sublime the CuPc stationary phase coating on the column walls that were micromachined in the host silicon wafer substrate and Pyrex (r) cover plate, which were then electrostatically bonded together. The SMGCS can separate binary gas mixtures composed of parts-per-million (ppm) concentrations of ammonia (NH3) and nitrogen dioxide (NO2) when isothermally operated (55-80 degrees C). With a helium carrier gas and nitrogen diluent, a 10 microliter sample volume containing ammonia and nitrogen dioxide injected at 40 psi ((2.8 x 10(exp 5)Pa)) can be separated in less than 30 minutes.

  15. Batch fabrication of scanning microscopy probes for thermal and magnetic imaging using standard micromachining

    NARCIS (Netherlands)

    Sarajlic, Edin; Vermeer, Rolf; Delalande, M.Y.; Siekman, Martin Herman; Huijink, R.; Fujita, H.; Abelmann, Leon

    2010-01-01

    We present a process for batch fabrication of a novel scanning microscopy probe for thermal and magnetic imaging using standard micromachining and conventional optical contact lithography. The probe features an AFM-type cantilever with a sharp pyramidal tip composed of four freestanding silicon

  16. Fly's proprioception-inspired micromachined strain-sensing structure: idea, design, modeling and simulation, and comparison with experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Wicaksono, D H B [Department of Microelectronics, Delft University of Technology, Mekelweg 4, Delft, Zuid-Holland 2628CD (Netherlands); Zhang, L-J [Department of Microelectronics, Delft University of Technology, Mekelweg 4, Delft, Zuid-Holland 2628CD (Netherlands); Pandraud, G [Department of Microelectronics, Delft University of Technology, Mekelweg 4, Delft, Zuid-Holland 2628CD (Netherlands); French, P J [Department of Microelectronics, Delft University of Technology, Mekelweg 4, Delft, Zuid-Holland 2628CD (Netherlands); Vincent, J F V [Department of Mech. Engineering, Bath University Bath, BA2 7AY (United Kingdom)

    2006-04-01

    A new strain-sensing structure inspired from insect's (especially the Fly) propricoception sensor is devised. The campaniform sensillum is a strain-sensing microstructure with very high sensitivity despite its small dimension (diameter {approx}10 {mu}m in a relatively stiff material of insect's exocuticle (E = {approx}10{sup 9} Pa). Previous work shows that the high sensitivity of this structure towards strain is due to its membrane-in-recess- and strainconcentrating-hole-features. Based on this inspiration, we built similar structure using silicon micromachining technology. Then a simple characterisation setup was devised. Here, we present briefly, finite-element modeling and simulation based on this actual sample preparation for the characterisation. As comparison and also to understand mechanical features responsible for the strain-sensitivity, we performed the modeling on different mechanical structures: bulk chunk, blind-hole, through-hole, surface membrane, and membrane-in-recess. The actual experimental characterisation was performed previously using optical technique to membrane in-recess micromachined Si structure. The FEM simulation results confirm that the bending stress and strain are concentrated in the hole-vicinity. The membrane inside the hole acts as displacement transducer. The FEM is in conformity with previous analytical results, as well as the optical characterisation result. The end goal is to build a new type MEMS strain sensor.

  17. Synthesis, Crystal Structures, Magnetic Properties, and Theoretical Investigation of a New Series of NiII-LnIII-WVHeterotrimetallics: Understanding the SMM Behavior of Mixed Polynuclear Complexes.

    Science.gov (United States)

    Vieru, Veacheslav; Pasatoiu, Traian D; Ungur, Liviu; Suturina, Elizaveta; Madalan, Augustin M; Duhayon, Carine; Sutter, Jean-Pascal; Andruh, Marius; Chibotaru, Liviu F

    2016-12-05

    The polynuclear compounds containing anisotropic metal ions often exhibit efficient barriers for blocking of magnetization at fairly arbitrary geometries. However, at variance with mononuclear complexes, which usually become single-molecule magnets (SMM) under the sole requirement of a highly axial crystal field at the metal ion, the factors influencing the SMM behavior in polynuclear complexes, especially, with weakly axial magnetic ions, still remain largely unrevealed. As an attempt to clarify these conditions, we present here the synthesis, crystal structures, magnetic behavior, and ab initio calculations for a new series of Ni II -Ln III -W V trimetallics, [(CN) 7 W(CN)Ni(H 2 O)(valpn)Ln(H 2 O) 4 ]·H 2 O (Ln = Y 1, Eu 2, Gd 3, Tb 4, Dy 5, Lu 6). The surprising finding is the absence of the magnetic blockage even for compounds involving strongly anisotropic Dy III and Tb III metal ions. This is well explained by ab initio calculations showing relatively large transversal components of the g-tensor in the ground exchange Kramers doublets of 1 and 4 and large intrinsic tunneling gaps in the ground exchange doublets of 3 and 5. In order to get more insight into this behavior, another series of earlier reported compounds with the same trinuclear [W V Ni II Ln III ] core structure, [(CN) 7 W(CN)Ni(dmf)(valdmpn)Ln(dmf) 4 ]·H 2 O (Ln = Gd III 7, Tb III 8a, Dy III 9, Ho III 10), [(CN) 7 W(CN)Ni(H 2 O)(valdmpn)Tb(dmf) 2.5 (H 2 O) 1.5 ]·H 2 O·0.5dmf 8b, and [(CN) 7 W(CN)Ni(H 2 O)(valdmpn)Er(dmf) 3 (H 2 O) 1 ]·H 2 O·0.5dmf 11, has been also investigated theoretically. In this series, only 8b exhibits SMM behavior which is confirmed by the present ab initio calculations. An important feature for the entire series is the strong ferromagnetic coupling between Ni(II) and W(V), which is due to an almost perfect trigonal dodecahedron geometry of the octacyano wolframate fragment. The reason why only 8b is an SMM is explained by positive zero-field splitting on the nickel

  18. Measurements of LET distribution and dose equivalent onboard the Space Shuttle IML-2 (STS-65) and S/MM#4 (STS-79)

    Science.gov (United States)

    Hayashi, T.; Doke, T.; Kikuchi, J.; Sakaguchi, T.; Takeuchi, R.; Takashima, T.; Kobayashi, M.; Terasawa, K.; Takahashi, K.; Watanabe, A.; hide

    1997-01-01

    Space radiation dosimetry measurements have been made onboard the Space Shuttle STS-65 in the Second International Microgravity Laboratory (IML-2: 28.5 degrees x 300 km: 14.68 days) and the STS-79 in the 4th Shuttle MIR mission (S/MM#4: 51.6 degrees x 300-400km: 10.2 days). In these measurements, three kinds of detectors were used; one is a newly developed active detector telescope called "Real-time Radiation Monitoring Device (RRMD-I for IML-2 and RRMD-II with improved triggering system for S/MM#4)" utilizing silicon semi-conductor detectors and the other detectors are conventional passive detectors of thermoluminescence dosimeters (TLDs) and CR-39 plastic track detectors. The main contribution to dose equivalent for particles with LET > 5.0 keV/micrometer (IML-2) and LET > 3.5 keV/micrometer (S/MM#4) is seen to be due to galactic cosmic rays (GCRs) and the contribution of the South Atlantic Anomaly (SAA) is less than 5% (IML-2: 28.5 degrees x 300 km) and 15% (S/MM#4: 51.6 degrees x 400 km) in the above RRMD LET detection conditions. For the whole LET range (> 0.2 kev/micrometer) obtained by TLDs and CR-39 in these two typical orbits (a small inclination x low altitude and a large inclination x high altitude), absorbed dose rates range from 94 to 114 microGy/day, dose equivalent rates from 186 to 207 microSv/day and average quality factors from 1.82 to 2.00 depending on the locations and directions of detectors inside the Spacelab at the highly protected IML-2 orbit (28.5 degrees x 300 km), and also, absorbed dose rates range from 290 to 367 microGy/day, dose equivalent rates from 582 to 651 microSv/day and average quality factors from 1.78 to 2.01 depending on the dosimeter packages around the RRMD-II "Detector Unit" at the S/MM#4 orbit (5l.6 degrees x 400km). In general, it is seen that absorbed doses depend on the orbit altitude (SAA trapped particles contribution dominant) and dose equivalents on the orbit inclination (GCR contribution dominant). The LET

  19. Fabrication of Super Hydrophobic Surfaces by fs Laser Pulses : How to Produce Self-Cleaning Surfaces

    NARCIS (Netherlands)

    Groenendijk, M.N.W.

    2008-01-01

    The chair of Applied Laser Technology of the University of Twente, The Netherlands, is performing research into applications of ultrashort pulsed lasers for micromachining. In a recent project, PhD student Max Groenendijk developed a method for the production of super water repellant surfaces by

  20. In-plane diffraction loss free optical cavity using coated optical fiber and silicon micromachined spherical mirror

    Science.gov (United States)

    Sabry, Yasser; Bourouina, Tarik; Saadany, Bassam; Khalil, Diaa

    2013-03-01

    Light trapping in optical cavities has many applications in optical telecommunications, biomedical optics, atomic studies, and chemical analysis. Efficient optical coupling in these cavities is an important engineering problem that affects greatly the cavity performance. One interesting way to form an optical cavity, while simultaneously connected to the rest of the optical systems, is to use an optical fiber surface as one of the cavity mirrors while the second mirror is fabricated by MEMS technology. In this way, cavity tuning with a MEMS actuator is a simple achievable task with low cost in mass production. The main problem in this solution is the high diffraction loss associated with the small spot size at the output of the standard single-mode fiber (SMF). Diffraction loss in the cavity is usually overcome by using an expensive lensed fiber or by inserting a coated lens in the cavity leading to a long cavity with small free spectral range (FSR). In this work, we report a Fabry-Perot cavity formed by a multilayer-coated cleaved-surface SMF inserted into a grove while facing a spherical micromirror; both are fabricated by silicon micromachining. The light is trapped inside the cavity while propagating in-plane of the wafer substrate. The light is injected in and collected from a Corning SMF-28 optical fiber with a coated surface reflectivity of about 98% at 1330 nm (O-band). The silicon mirror surface is aluminum metalized with a reflectivity of about 92%. The measured cavity has a line width of 0.45 nm around 1330 nm with a FSR of 26 nm. The obtained results indicate an almost diffraction-loss free optical cavity with a quality factor close to 3000, limited by the optical surfaces reflectivity that can be improved in future by an optimized mirror fabrication process and better matching of the fiber multilayer coating.

  1. 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

  2. Laser direct micro-machining with top-hat-converted single mode lasers

    Science.gov (United States)

    Homburg, O.; Toennissen, F.; Mitra, T.; Lissotschenko, V.

    2008-02-01

    Laser direct micro-machining processes are used in a variety of industries like inkjet printing, semiconductor processing, solar technology, flat-panel display production and medicine. Various kinds of materials, e.g. ceramics, metals, isolators, oxides, organics and semiconductors are being structured. In most cases pulsed single mode solid state lasers with an inhomogeneous Gaussian beam profile are employed, like YAG lasers and their harmonics. However, the quality and functionality of the generated structures and micro-systems as well as the speed of the process can be improved by the utilization of homogeneous top hat profiles. The beam shaping principle of refractive Gaussian-to-top-hat converters is shown. Compact beam shaper modules based on this principle have been developed - supporting most direct laser micro-machining applications. The resulting process advantages are demonstrated by selected application results, namely the drilling of holes and patterning of trenches for different kinds of materials.

  3. Femtosecond laser micro-machined polyimide films for cell scaffold applications.

    Science.gov (United States)

    Antanavičiūtė, Ieva; Šimatonis, Linas; Ulčinas, Orestas; Gadeikytė, Aušra; Abakevičienė, Brigita; Tamulevičius, Sigitas; Mikalayeva, Valeryia; Skeberdis, Vytenis Arvydas; Stankevičius, Edgaras; Tamulevičius, Tomas

    2018-02-01

    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 of commercially available 12.7 and 25.4 μm 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 2-6 μm 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. That was attributed to material modification around the micro-machined holes in the vicinity of the position of the focused laser beam track during trepanning drilling. We demonstrate that virgin PI films provide a suitable environment for the mobility, proliferation and intercellular communication of human bone marrow mesenchymal stem cells, and discuss how cell behaviour varies on the micro-machined PI films with holes of different diameters (3.1, 8.4 and 16.7 μm) and hole spacing (30, 35, 40 and 45 μm). We conclude that the holes of 3.1 μm diameter were sufficient for metabolic and genetic communication through membranous tunneling tubes between cells residing on the opposite sides of PI film, but prevented the trans-migration of cells through the holes. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  4. 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...

  5. Switching behavior of double-decker single molecule magnets on a metal surface

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Yingshuang; Schwoebel, Joerg; Hoffmann, Germar; Brede, Jens; Wiesendanger, Roland [University of Hamburg, Hamburg (Germany); Dillulo, Andrew [Ohio University, Athens (United States); Klyatskaya, Svetlana [Karlsruhe Institute of Technology, Karlsruhe (Germany); Ruben, Mario [Karlsruhe Institute of Technology, Karlsruhe (Germany); Universite de Strasbourg, Strasbourg (France)

    2011-07-01

    Single molecule magnets (SMM) are most promising materials for spin based molecular electronics. Due to their large magnetic anisotropy stabilized by inside chemical bonds, SMM can potentially be used for information storage at the single molecule level. For applications, it is of importance to adsorb the SMM onto surfaces and to study their subsequent conformational, electronic and magnetic properties. We have investigated the adsorption behavior of Tb and Dy based double-decker SMM on an Ir(111) surface with low temperature scanning tunneling microscopy and spectroscopy. It is found that Tb double-decker molecules bind tightly to the Ir(111) surface. By resonantly injecting tunneling electrons into its LUMO or HOMO state, the Tb double-decker molecule can be switched from a four-lobed structure to an eight-lobed structure. After switching, energy positions of the HOMO and LUMO states both shift closer to the Fermi level. Dy double-decker molecules also exhibit the same switching properties on the Ir(111) surface. The switching behavior of the molecules is tentatively attributed to a conformational change of the double-decker molecular frame.

  6. TOPICAL REVIEW: Capacitive micromachined ultrasonic transducer arrays for minimally invasive medical ultrasound

    Science.gov (United States)

    Chen, Jingkuang

    2010-02-01

    This paper reviews the minimally invasive capacitive micromachined ultrasonic transducer (CMUT) arrays for medical diagnosis and therapy. While piezoelectric transducers dominate today's medical ultrasound market, the capacitive micromachined ultrasonic transducer has recently emerged as a promising alternative which delivers a comparable device performance to its piezoelectric counterparts, is compatible with front-end circuit integration, allows high-density imager integration and is relative easy in miniaturization. Utilizing MEMS technology, the substrate of CMUT arrays can be micromachined into miniature platforms with various geometrical shapes, which include needles, three-dimensional prisms, as well as other flexible-substrate configurations. These arrays are useful for reaching deep inside the tissue or an organ with a minimally invasive approach. Due to the close proximity of the transducers to the target organ/tissue, a higher resolution/accuracy of diagnostic information can be achieved. In addition to pulse-echo and photoacoustic imaging, high-power CMUT devices capable of delivering ultrasounds with a pressure greater than 1.0 MPa have been monolithically integrated with imager CMUTs for image-guided therapy (IGT). Such miniature devices would facilitate diagnostic and therapy interventions not possible with conventional piezoelectric transducers.

  7. 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.

  8. A cellular-automata and particle-tracking simulation of abrasive jet micromachining of polymethyl-methacrylate

    International Nuclear Information System (INIS)

    Ciampini, D; Papini, M

    2011-01-01

    A cellular automaton simulation which is able to predict the geometry of micro-features etched into ductile erosive targets, as a result of abrasive jet micromachining (AJM), is presented. Similar to a previous simulation for the AJM of brittle erosive targets, the movement of individual erodent particles is tracked in a simulated environment, including their collisions with, and ricochet from, the mask and target substrate modeled as cellular-automatons. A new cell erosion algorithm is presented in order to allow the previous simulation to be applied to the AJM of ductile materials. A previously published empirical erosion rule, which related the erosion rate of ductile substrates caused by a jet, was also proven to be applicable, to a good approximation, to single particle impacts. With this new cell erosion algorithm, the predictions of the model compared well with measurements of the surface evolution of unmasked channels, masked micro-holes and micro-channels machined in polymethyl-methacrylate. The results also highlight the importance of modeling the effect of particle size on the prediction of the size and shape of features fabricated in ductile erosive materials using AJM

  9. Picosecond and nanosecond pulse delivery through a hollow-core Negative Curvature Fiber for micro-machining applications.

    Science.gov (United States)

    Jaworski, Piotr; Yu, Fei; Maier, Robert R J; Wadsworth, William J; Knight, Jonathan C; Shephard, Jonathan D; Hand, Duncan P

    2013-09-23

    We present high average power picosecond and nanosecond pulse delivery at 1030 nm and 1064 nm wavelengths respectively through a novel hollow-core Negative Curvature Fiber (NCF) for high-precision micro-machining applications. Picosecond pulses with an average power above 36 W and energies of 92 µJ, corresponding to a peak power density of 1.5 TWcm⁻² have been transmitted through the fiber without introducing any damage to the input and output fiber end-faces. High-energy nanosecond pulses (>1 mJ), which are ideal for micro-machining have been successfully delivered through the NCF with a coupling efficiency of 92%. Picosecond and nanosecond pulse delivery have been demonstrated in fiber-based laser micro-machining of fused silica, aluminum and titanium.

  10. 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)

  11. 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

  12. 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.

  13. 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.......5, which is only 11.6% from the predicted value. Earlier state-of-the-art fabrication of the CPC-shaped tip by fiber tapering was of so poor quality that the actual improvement was 43% lower than the predicted improvement of the ideal CPC shape....

  14. Wideband acoustic activation and detection of droplet vaporization events using a capacitive micromachined ultrasonic transducer

    Science.gov (United States)

    Novell, Anthony; Arena, Christopher B.; Oralkan, Omer; Dayton, Paul A.

    2016-01-01

    An ongoing challenge exists in understanding and optimizing the acoustic droplet vaporization (ADV) process to enhance contrast agent effectiveness for biomedical applications. Acoustic signatures from vaporization events can be identified and differentiated from microbubble or tissue signals based on their frequency content. The present study exploited the wide bandwidth of a 128-element capacitive micromachined ultrasonic transducer (CMUT) array for activation (8 MHz) and real-time imaging (1 MHz) of ADV events from droplets circulating in a tube. Compared to a commercial piezoelectric probe, the CMUT array provides a substantial increase of the contrast-to-noise ratio. PMID:27369143

  15. Non-Lithographic Silicon Micromachining Using Inkjet and Chemical Etching

    Directory of Open Access Journals (Sweden)

    Sasha Hoshian

    2016-12-01

    Full Text Available We introduce a non-lithographical and vacuum-free method to pattern silicon. The method combines inkjet printing and metal assisted chemical etching (MaCE; we call this method “INKMAC”. A commercial silver ink is printed on top of a silicon surface to create the catalytic patterns for MaCE. The MaCE process leaves behind a set of silicon nanowires in the shape of the inkjet printed micrometer scale pattern. We further show how a potassium hydroxide (KOH wet etching process can be used to rapidly etch away the nanowires, producing fully opened cavities and channels in the shape of the original printed pattern. We show how the printed lines (width 50–100 µm can be etched into functional silicon microfluidic channels with different depths (10–40 µm with aspect ratios close to one. We also used individual droplets (minimum diameter 30 µm to produce cavities with a depth of 60 µm and an aspect ratio of two. Further, we discuss using the structured silicon substrate as a template for polymer replication to produce superhydrophobic surfaces.

  16. 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

  17. 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.

  18. 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

  19. Fabrication of corrugated artificial insect wings using laser micromachined molds

    International Nuclear Information System (INIS)

    Tanaka, Hiroto; Wood, Robert J

    2010-01-01

    This paper describes the fabrication of an artificial insect wing with a rich set of topological features by micromolding a thermosetting resin. An example 12 mm long hoverfly-like wing is fabricated with 50–125 µm vein heights and 100 µm corrugation heights. The solid veins and membrane were simultaneously formed and integrated by a single molding process. Employing a layered laser ablation technique, three-dimensional molds were created with 5 µm resolution in height. Safe demolding of the wing was achieved with a water-soluble sacrificial layer on the mold. Measured surface profiles of the wing matched those of the molds, demonstrating the high replication accuracy of this molding process. Using this process, the morphological features of insect wings can be replicated at-scale with high precision, enabling parametric experiments of the functional morphology of insect wings. This fabrication capability also makes it possible to create a variety of wing types for micro air vehicles on scales similar to insects.

  20. First In Vivo Use of a Capacitive Micromachined Ultrasound Transducer Array–Based Imaging and Ablation Catheter

    Science.gov (United States)

    Stephens, Douglas N.; Truong, Uyen T.; Nikoozadeh, Amin; Oralkan, Ömer; Seo, Chi Hyung; Cannata, Jonathan; Dentinger, Aaron; Thomenius, Kai; de la Rama, Alan; Nguyen, Tho; Lin, Feng; Khuri-Yakub, Pierre; Mahajan, Aman; Shivkumar, Kalyanam; O’Donnell, Matt; Sahn, David J.

    2012-01-01

    Objectives The primary objective was to test in vivo for the first time the general operation of a new multifunctional intracardiac echocardiography (ICE) catheter constructed with a microlinear capacitive micromachined ultrasound transducer (ML-CMUT) imaging array. Secondarily, we examined the compatibility of this catheter with electroanatomic mapping (EAM) guidance and also as a radiofrequency ablation (RFA) catheter. Preliminary thermal strain imaging (TSI)-derived temperature data were obtained from within the endocardium simultaneously during RFA to show the feasibility of direct ablation guidance procedures. Methods The new 9F forward-looking ICE catheter was constructed with 3 complementary technologies: a CMUT imaging array with a custom electronic array buffer, catheter surface electrodes for EAM guidance, and a special ablation tip, that permits simultaneous TSI and RFA. In vivo imaging studies of 5 anesthetized porcine models with 5 CMUT catheters were performed. Results The ML-CMUT ICE catheter provided high-resolution real-time wideband 2-dimensional (2D) images at greater than 8 MHz and is capable of both RFA and EAM guidance. Although the 24-element array aperture dimension is only 1.5 mm, the imaging depth of penetration is greater than 30 mm. The specially designed ultrasound-compatible metalized plastic tip allowed simultaneous imaging during ablation and direct acquisition of TSI data for tissue ablation temperatures. Postprocessing analysis showed a first-order correlation between TSI and temperature, permitting early development temperature-time relationships at specific myocardial ablation sites. Conclusions Multifunctional forward-looking ML-CMUT ICE catheters, with simultaneous intracardiac guidance, ultrasound imaging, and RFA, may offer a new means to improve interventional ablation procedures. PMID:22298868

  1. First in vivo use of a capacitive micromachined ultrasound transducer array-based imaging and ablation catheter.

    Science.gov (United States)

    Stephens, Douglas N; Truong, Uyen T; Nikoozadeh, Amin; Oralkan, Omer; Seo, Chi Hyung; Cannata, Jonathan; Dentinger, Aaron; Thomenius, Kai; de la Rama, Alan; Nguyen, Tho; Lin, Feng; Khuri-Yakub, Pierre; Mahajan, Aman; Shivkumar, Kalyanam; O'Donnell, Matt; Sahn, David J

    2012-02-01

    The primary objective was to test in vivo for the first time the general operation of a new multifunctional intracardiac echocardiography (ICE) catheter constructed with a microlinear capacitive micromachined ultrasound transducer (ML-CMUT) imaging array. Secondarily, we examined the compatibility of this catheter with electroanatomic mapping (EAM) guidance and also as a radiofrequency ablation (RFA) catheter. Preliminary thermal strain imaging (TSI)-derived temperature data were obtained from within the endocardium simultaneously during RFA to show the feasibility of direct ablation guidance procedures. The new 9F forward-looking ICE catheter was constructed with 3 complementary technologies: a CMUT imaging array with a custom electronic array buffer, catheter surface electrodes for EAM guidance, and a special ablation tip, that permits simultaneous TSI and RFA. In vivo imaging studies of 5 anesthetized porcine models with 5 CMUT catheters were performed. The ML-CMUT ICE catheter provided high-resolution real-time wideband 2-dimensional (2D) images at greater than 8 MHz and is capable of both RFA and EAM guidance. Although the 24-element array aperture dimension is only 1.5 mm, the imaging depth of penetration is greater than 30 mm. The specially designed ultrasound-compatible metalized plastic tip allowed simultaneous imaging during ablation and direct acquisition of TSI data for tissue ablation temperatures. Postprocessing analysis showed a first-order correlation between TSI and temperature, permitting early development temperature-time relationships at specific myocardial ablation sites. Multifunctional forward-looking ML-CMUT ICE catheters, with simultaneous intracardiac guidance, ultrasound imaging, and RFA, may offer a new means to improve interventional ablation procedures.

  2. 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

  3. 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.

  4. Differential search algorithm-based parametric optimization of electrochemical micromachining processes

    Directory of Open Access Journals (Sweden)

    Debkalpa Goswami

    2014-01-01

    Full Text Available Electrochemical micromachining (EMM appears to be a very promising micromachining process for having higher machining rate, better precision and control, reliability, flexibility, environmental acceptability, and capability of machining a wide range of materials. It permits machining of chemically resistant materials, like titanium, copper alloys, super alloys and stainless steel to be used in biomedical, electronic, micro-electromechanical system and nano-electromechanical system applications. Therefore, the optimal use of an EMM process for achieving enhanced machining rate and improved profile accuracy demands selection of its various machining parameters. Various optimization tools, primarily Derringer’s desirability function approach have been employed by the past researchers for deriving the best parametric settings of EMM processes, which inherently lead to sub-optimal or near optimal solutions. In this paper, an attempt is made to apply an almost new optimization tool, i.e. differential search algorithm (DSA for parametric optimization of three EMM processes. A comparative study of optimization performance between DSA, genetic algorithm and desirability function approach proves the wide acceptability of DSA as a global optimization tool.

  5. Development of an electrochemical micromachining instrument for the confined etching techniques.

    Science.gov (United States)

    Zhou, Hang; Lai, Lei-Jie; Zhao, Xiang-Hui; Zhu, Li-Min

    2014-04-01

    This study proposes an electrochemical micromachining instrument for two confined etching techniques, namely, confined etchant layer technique (CELT) and electrochemical wet stamping (E-WETS). The proposed instrument consists of a granite bridge base, a Z-axis coarse/fine dual stage, and a force sensor. The Z-axis coarse/fine dual stage controls the vertical movement of the substrate with nanometer accuracy. The force sensor measures the contact force between the mold and the substrate. A contact detection method based on a digital lock-in amplifier is developed to make the mold-substrate contact within a five-nanometer range in CELT, and a force feedback controller is implemented to keep the contact force in E-WETS at a constant value with a noise of less than 0.2 mN. With the use of the confined etching techniques, a microlens array and a curvilinear ridge microstructure are successfully fabricated with high accuracy, thus demonstrating the promising performance of the proposed micromachining instrument.

  6. Optical waveguides fabricated in Cr:LiSAF by femtosecond laser micromachining

    Science.gov (United States)

    Biasetti, Demian A.; Di Liscia, Emiliano J.; Torchia, Gustavo A.

    2017-11-01

    In this work we present the fabrication of double-track type II waveguides written in 1% doped Cr:LiSrAlF6 (Cr:LiSAF) crystal by femtosecond laser micromachining. We studied waveguides fabricated at energies from 1 to 7 μJ per pulse at writing speeds of 15-45 μm/s. We found good wave-guiding performance for both, Transversal Magnetic (TM) and Transversal Electric (TE) polarization modes as well as acceptable losses according to the expected values addressed to technological applications. Also, we performed a high-resolution μ-luminescence waveguide cross-section mapping between the tracks, in order to identify possible spectral changes caused for active ions Cr3+ corresponding to the 4T2 →4A2 vibronic transition in the focal volume zone, due to induced anisotropic graded stress. Finally, their lifetimes were measured for bulk as well as for waveguide trapped ions. We found that for the range of parameters of ultra-short micromachining used, the Cr3+ ions embedded in the waveguides remained spectroscopically unchanged compared with those observed in bulk material.

  7. 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.

  8. 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

  9. A passive micromachined device for alignment of arrays of single-mode fibers for hermetic photonic packaging - the CLASP concept

    Energy Technology Data Exchange (ETDEWEB)

    Seigal, P.K.; Kravitz, S.H.; Word, J.C.; Bauer, T.M. [and others

    1997-02-01

    A micro-machined fiber alignment device, called CLASP (Capture and Locking Alignment Spring Positioner) has been fabricated. It uses a nickel leaf spring to passively capture vertical arrays of single-mode fibers with {approximately} 2 {mu}m accuracy.

  10. 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

  11. Electronic structure of surface-supported bis(phthalocyaninato) terbium(III) single molecular magnets.

    Science.gov (United States)

    Vitali, Lucia; Fabris, Stefano; Conte, Adriano Mosca; Brink, Susan; Ruben, Mario; Baroni, Stefano; Kern, Klaus

    2008-10-01

    The electronic structure of isolated bis(phthalocyaninato) terbium(III) molecules, a novel single-molecular-magnet (SMM), supported on the Cu(111) surface has been characterized by density functional theory and scanning tunneling spectroscopy. These studies reveal that the interaction with the metal surface preserves both the molecular structure and the large spin magnetic moment of the metal center. The 4f electron states are not perturbed by the adsorption while a strong molecular/metal interaction can induce the suppression of the minor spin contribution delocalized over the molecular ligands. The calculations show that the inherent spin magnetic moment of the molecule is only weakly affected by the interaction with the surface and suggest that the SMM character might be preserved.

  12. 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

  13. Study on vacuum packaging reliability of micromachined quartz tuning fork gyroscopes

    Science.gov (United States)

    Fan, Maoyan; Zhang, Lifang

    2017-09-01

    Packaging technology of the micromachined quartz tuning fork gyroscopes by vacuum welding has been experimentally studied. The performance of quartz tuning fork is influenced by the encapsulation shell, encapsulation method and fixation of forks. Alloy solder thick film is widely used in the package to avoid the damage of the chip structure by the heat resistance and hot temperature, and this can improve the device performance and welding reliability. The results show that the bases and the lids plated with gold and nickel can significantly improve the airtightness and reliability of the vacuum package. Vacuum packaging is an effective method to reduce the vibration damping, improve the quality factor and further enhance the performance. The threshold can be improved nearly by 10 times.

  14. 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)

  15. 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.

  16. Development of Capacitive Micromachined Ultrasonic Transducer (I) - Analysis of the Membrane Behavior

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Bok; Ahn, Bong Young; Park, Hae Won; Kim, Young Joo; Lee, Seung Seok [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2004-10-15

    This study was conducted to develop a capacitive micromachined ultrasonic transducer (cMUT) which enable to high efficient non-contact transmit and receive the ultrasonic wave in air. Theoretical analysis and finite element analysis of the behavior of membrane (such as resonance frequency, membrane deflection, collapse deflection and collapse voltage) of the cMUT were performed. The design parameters of the cMUT such as the dimension and thickness of membrane, thickness of sacrificial layer, thickness and size of electrode were estimated. The resonance frequency of the membrane increased as the thickness of the membrane increased but decreased as the diameter of the membrane increased. The deflection of the membrane increased as d-c bias voltage increased. The collapse voltage of the membrane was analyzed

  17. Modeling and analysis of the membrane-behavior in capacitive micromachined ultrasonic transducer

    International Nuclear Information System (INIS)

    Kim, Ki Bok; Ahn, Bong Young; Park, Hae Won; Kim, Young Joo; Kim, Kuk Jin; Lee, Seung Seok

    2003-01-01

    In this study, theoretical analysis and finite element analysis of the behavior of membrane (such as resonance frequency, membrane deflection, collapse deflection and collapse voltage) in the capacitive micromachined ultrasonic transducer (cMUT) were performed. The design parameters of the cMUT were estimated and are the dimension and thickness of membrane, thickness of sacrificial layer, thickness and size of electrode, size of active element and so on. The resonance frequency of the membrane increased as the thickness of the membrane increased but decreased as the diameter of the membrane increased. The deflection of the membrane increased as d-c bias voltage increased. The collapse voltage of the membrane was predicted.

  18. Low temperature capacitive micromachined ultrasonic transducers (cMUTs) on glass substrate

    International Nuclear Information System (INIS)

    Bahette, E; Michaud, J F; Certon, D; Gross, D; Perroteau, M; Alquier, D

    2016-01-01

    The possibility of fabricating capacitive micromachined ultrasonic transducers (cMUTs) on glass substrates may open the way for new fields of application in which the transparency of the substrate is advantageous. In this study, we demonstrate that a low-temperature process can be carried out to achieve cMUTs on glass substrates. Limited to temperatures lower than 400 °C, the process is based on the use of nickel as a sacrificial layer. The cMUT electromechanical behavior is studied and the performance compared to those obtained with silicon substrates. The cMUTs fabricated on glass substrate showed performance comparable with the Si ones. A slight shift in the resonance frequency and collapse voltage was observed. It is shown that these differences arise from the residual mechanical stresses in the substrate. (paper)

  19. Modeling and analysis of the membrane-behavior in capacitive micromachined ultrasonic transducer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Bok; Ahn, Bong Young; Park, Hae Won; Kim, Young Joo; Kim, Kuk Jin; Lee, Seung Seok [NDE Group, Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2003-05-15

    In this study, theoretical analysis and finite element analysis of the behavior of membrane (such as resonance frequency, membrane deflection, collapse deflection and collapse voltage) in the capacitive micromachined ultrasonic transducer (cMUT) were performed. The design parameters of the cMUT were estimated and are the dimension and thickness of membrane, thickness of sacrificial layer, thickness and size of electrode, size of active element and so on. The resonance frequency of the membrane increased as the thickness of the membrane increased but decreased as the diameter of the membrane increased. The deflection of the membrane increased as d-c bias voltage increased. The collapse voltage of the membrane was predicted.

  20. Modeling and analysis of the membrane-behavior in capacitive micromachined ultrasonic transducer

    International Nuclear Information System (INIS)

    Kim, Ki Bok; Ahn, Bong Young; Park, Hae Won; Kim, Young Joo; Kim, Kuk Jin; Lee, Seung Seok

    2003-01-01

    In this study, theoretical analysis and finite element analysis of the behavior of membrane (such as resonance frequency, membrane deflection, collapse deflection and collapse voltage) in the capacitive micromachined ultrasonic transducer (cMUT) were performed. The design parameter of the cMUT were estimated and are the dimension and thickness of membrane, thickness of sacrificed layer, thickness and size of electrode, size of active element and so on. The resonance frequency of the membrane increased as the thickness of the membrane increased but decreased as the diameter of the membrane increased. The deflection of the membrane increased as d-c bias voltage increased. The collapse voltage of the membrane was predicted.

  1. Low temperature capacitive micromachined ultrasonic transducers (cMUTs) on glass substrate

    Science.gov (United States)

    Bahette, E.; Michaud, J. F.; Certon, D.; Gross, D.; Perroteau, M.; Alquier, D.

    2016-11-01

    The possibility of fabricating capacitive micromachined ultrasonic transducers (cMUTs) on glass substrates may open the way for new fields of application in which the transparency of the substrate is advantageous. In this study, we demonstrate that a low-temperature process can be carried out to achieve cMUTs on glass substrates. Limited to temperatures lower than 400 °C, the process is based on the use of nickel as a sacrificial layer. The cMUT electromechanical behavior is studied and the performance compared to those obtained with silicon substrates. The cMUTs fabricated on glass substrate showed performance comparable with the Si ones. A slight shift in the resonance frequency and collapse voltage was observed. It is shown that these differences arise from the residual mechanical stresses in the substrate.

  2. Development of Capacitive Micromachined Ultrasonic Transducer (I) - Analysis of the Membrane Behavior

    International Nuclear Information System (INIS)

    Kim, Ki Bok; Ahn, Bong Young; Park, Hae Won; Kim, Young Joo; Lee, Seung Seok

    2004-01-01

    This study was conducted to develop a capacitive micromachined ultrasonic transducer (cMUT) which enable to high efficient non-contact transmit and receive the ultrasonic wave in air. Theoretical analysis and finite element analysis of the behavior of membrane (such as resonance frequency, membrane deflection, collapse deflection and collapse voltage) of the cMUT were performed. The design parameters of the cMUT such as the dimension and thickness of membrane, thickness of sacrificial layer, thickness and size of electrode were estimated. The resonance frequency of the membrane increased as the thickness of the membrane increased but decreased as the diameter of the membrane increased. The deflection of the membrane increased as d-c bias voltage increased. The collapse voltage of the membrane was analyzed

  3. Fabrication of Vacuum-Sealed Capacitive Micromachined Ultrasonic Transducer Arrays Using Glass Reflow Process

    Directory of Open Access Journals (Sweden)

    Nguyen Van Toan

    2016-04-01

    Full Text Available This paper presents a process for the fabrication of vacuum-sealed capacitive micromachined ultrasonic transducer (CMUT arrays using glass reflow and anodic bonding techniques. Silicon through-wafer interconnects have been investigated by the glass reflow process. Then, the patterned silicon-glass reflow wafer is anodically bonded to an SOI (silicon-on-insulator wafer for the fabrication of CMUT devices. The CMUT 5 × 5 array has been successfully fabricated. The resonant frequency of the CMUT array with a one-cell radius of 100 µm and sensing gap of 3.2 µm (distance between top and bottom electrodes is observed at 2.84 MHz. The Q factor is approximately 1300 at pressure of 0.01 Pa.

  4. Finite Element Analysis of Capacitive Micromachined Ultrasonic Transducer (CMUT) for NDE Applications

    Science.gov (United States)

    Singh, Manvinder; Kommareddy, Vamshi; Kumar, Manoj; Ramaswamy, Sivaramanivas; Fan, Ying; Barshinger, James; Tian, Wei-Cheng; Kishore, Kuna

    2006-03-01

    This paper presents a comparison of three Finite Element approaches for modeling the behavior of a Capacitive Micromachined Ultrasonic Transducer (CMUT). CMUTs have become very popular over the last decade because of the comparable bandwidth, sensitivity and dynamic range with its piezoelectric counterparts. The ease of fabrication is an added advantage. Modeling of CMUTs is a coupled physics problem, which involves solving Electrostatics and Structural interactions simultaneous. Finite Element models of the CMUT are constructed using the commercial code ANSYS (9.0). Three different approaches of solving the coupled field problem are discussed and the results are compared for resonance frequency, collapse voltage, capacitance and electromechanical coupling coefficient. The approaches discussed involve sequentially coupled-field analysis, direct coupled-field analysis and reduced order modeling. Detailed results have been presented for the effect of variation in geometrical factors as predicted by the three models.

  5. The influence of acoustic damping on the transformation efficiency of capacitive micromachined ultrasonic transducer in air

    Science.gov (United States)

    Lee, Seung-Mok; Cha, Bu-sang; Okuyama, Masanori

    2010-10-01

    Acoustic damping of a capacitive micromachined ultrasonic transducer (CMUT) in air causes mechanical impedance to the membrane vibration, which significantly influences the transformation efficiency of the device. We observed the effect of acoustic damping on the transformation efficiency of a CMUT under various external acoustic pressure and device structure conditions; the results were compared with other factors such as capacitance variations originating from the change in air-hole rate [area ratio (AR)] over the total membrane area. The damping ratio of the perforated membrane plate was computed for each acoustic pressure condition, and the results were introduced into calculations of the membrane displacement using the finite element method to take the squeeze-film damping effect into account. The Q factor and transformation efficiency of the CMUT under various AR for the membrane and dimension conditions of the device were studied; the acoustic damping effect is discussed in terms of design optimization.

  6. Deep Tissue Photoacoustic Imaging Using a Miniaturized 2-D Capacitive Micromachined Ultrasonic Transducer Array

    Science.gov (United States)

    Kothapalli, Sri-Rajasekhar; Ma, Te-Jen; Vaithilingam, Srikant; Oralkan, Ömer

    2014-01-01

    In this paper, we demonstrate 3-D photoacoustic imaging (PAI) of light absorbing objects embedded as deep as 5 cm inside strong optically scattering phantoms using a miniaturized (4 mm × 4 mm × 500 µm), 2-D capacitive micromachined ultrasonic transducer (CMUT) array of 16 × 16 elements with a center frequency of 5.5 MHz. Two-dimensional tomographic images and 3-D volumetric images of the objects placed at different depths are presented. In addition, we studied the sensitivity of CMUT-based PAI to the concentration of indocyanine green dye at 5 cm depth inside the phantom. Under optimized experimental conditions, the objects at 5 cm depth can be imaged with SNR of about 35 dB and a spatial resolution of approximately 500 µm. Results demonstrate that CMUTs with integrated front-end amplifier circuits are an attractive choice for achieving relatively high depth sensitivity for PAI. PMID:22249594

  7. Modeling and analysis of the membrane-behavior in capacitive micromachined ultrasonic transducer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Bok; Ahn, Bong Young; Park, Hae Won; Kim, Young Joo; Kim, Kuk Jin; Lee, Seung Seok [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2003-07-01

    In this study, theoretical analysis and finite element analysis of the behavior of membrane (such as resonance frequency, membrane deflection, collapse deflection and collapse voltage) in the capacitive micromachined ultrasonic transducer (cMUT) were performed. The design parameter of the cMUT were estimated and are the dimension and thickness of membrane, thickness of sacrificed layer, thickness and size of electrode, size of active element and so on. The resonance frequency of the membrane increased as the thickness of the membrane increased but decreased as the diameter of the membrane increased. The deflection of the membrane increased as d-c bias voltage increased. The collapse voltage of the membrane was predicted.

  8. 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)

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. CLASP (Capture and Locking alignment Spring Positioner): A micromachined fiber auto-positioning device

    Energy Technology Data Exchange (ETDEWEB)

    Kravitz, S.H.; word, J.C.; Bauer, T.M.; Seigal, P.K.; Armendariz, M.G.

    1996-03-01

    This work provides a method of mechanical alignment of an array of single mode fibers to an array of optical devices. The technique uses a micromachined metal spring, which captures a vertical, pre- positioned fiber, moves it into accurate alignment, and holds it for attachment. The spring is fabricated from electroplated mickel, using photodefined polyimide as a plating mask. The nickel is plated about 80 {mu}m thick, so that a large fiber depth is captured. In one application, the nickel springs can be aligned to optics on the back side of the substrate. This entire concept is referred to as CLASP (Capture and Locking Alignment Spring Positioner). These springs can be used for general alignment and capture of any fiber to any optical input or output device. Passive alignment of fiber arrays to {plus}/{minus} 2{mu}m accuracy has been demonstrated, with a clear path to improved accuracy.

  15. 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.

  16. 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

  17. A three-mask process for fabricating vacuum-sealed capacitive micromachined ultrasonic transducers using anodic bonding.

    Science.gov (United States)

    Yamaner, F Yalçın; Zhang, Xiao; Oralkan, Ömer

    2015-05-01

    This paper introduces a simplified fabrication method for vacuum-sealed capacitive micromachined ultrasonic transducer (CMUT) arrays using anodic bonding. Anodic bonding provides the established advantages of wafer-bondingbased CMUT fabrication processes, including process simplicity, control over plate thickness and properties, high fill factor, and ability to implement large vibrating cells. In addition to these, compared with fusion bonding, anodic bonding can be performed at lower processing temperatures, i.e., 350°C as opposed to 1100°C; surface roughness requirement for anodic bonding is more than 10 times more relaxed, i.e., 5-nm rootmean- square (RMS) roughness as opposed to 0.5 nm for fusion bonding; anodic bonding can be performed on smaller contact area and hence improves the fill factor for CMUTs. Although anodic bonding has been previously used for CMUT fabrication, a CMUT with a vacuum cavity could not have been achieved, mainly because gas is trapped inside the cavities during anodic bonding. In the approach we present in this paper, the vacuum cavity is achieved by opening a channel in the plate structure to evacuate the trapped gas and subsequently sealing this channel by conformal silicon nitride deposition in the vacuum environment. The plate structure of the fabricated CMUT consists of the single-crystal silicon device layer of a silicon-on-insulator wafer and a thin silicon nitride insulation layer. The presented fabrication approach employs only three photolithographic steps and combines the advantages of anodic bonding with the advantages of a patterned metal bottom electrode on an insulating substrate, specifically low parasitic series resistance and low parasitic shunt capacitance. In this paper, the developed fabrication scheme is described in detail, including process recipes. The fabricated transducers are characterized using electrical input impedance measurements in air and hydrophone measurements in immersion. A representative

  18. 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)

  19. 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

  20. Instanton calculus without equations of motion: semiclassics from monodromies of a Riemann surface

    Science.gov (United States)

    Gulden, Tobias; Janas, Michael; Kamenev, Alex

    2015-02-01

    Instanton calculations in semiclassical quantum mechanics rely on integration along trajectories which solve classical equations of motion. However in systems with higher dimensionality or complexified phase space these are rarely attainable. A prime example are spin-coherent states which are used e.g. to describe single molecule magnets (SMM). We use this example to develop instanton calculus which does not rely on explicit solutions of the classical equations of motion. Energy conservation restricts the complex phase space to a Riemann surface of complex dimension one, allowing to deform integration paths according to Cauchy’s integral theorem. As a result, the semiclassical actions can be evaluated without knowing actual classical paths. Furthermore we show that in many cases such actions may be solely derived from monodromy properties of the corresponding Riemann surface and residue values at its singular points. As an example, we consider quenching of tunneling processes in SMM by an applied magnetic field.

  1. 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.

  2. 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

  3. 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.

  4. Ultrawide continuously tunable 1.55-μm vertical air-cavity wavelength-selective elements for VCSELs using micromachined electrostatic actuation

    Science.gov (United States)

    Hillmer, Hartmut H.; Daleiden, Juergen; Prott, Cornelia; Roemer, Friedhard; Irmer, Soeren; Ataro, Edwin; Tarraf, Amer; Gutermuth, D.; Kommallein, I.; Strassner, Martin

    2003-08-01

    Surface-micromachined 1.55μm vertical-resonator-based devices, capable of wide, continuous, monotonic and kink-free tuning are designed, technologically implemented and characterized. Tuning is achieved by mechanically actuating one or several membranes in a vertical resonator including two ultra-highly reflective DBR mirrors. The tuning is controlled by a single parameter (actuation voltage). The two different layers composing the mirrors reveal a very strong refractive index contrast. Filters including InP/air-gap DBR's (3.5 periods) using GaInAs sacrificial layers reveal a continuous tuning of up to 9% of the absolute wavelength. Varying a reverse voltage (U=0 .. -3.2V) between the membranes, a tuning range up to 142nm was obtained by electrostatic actuation. The correlation of the wavelength and the applied voltage is accurately reproducible without any hysteresis. Theoretical model calculations are performed for symmetric and asymmetric device structures, varying layer thickness and compositions. Models of highly sophisticated color tuning can be found in nature, e.g. in tunable spectral light filtering by trogon and butterfly wings. Bionics transfers the principles of success of nature into natural science, engineering disciplines and applications (here filters and VCSELs for optical communication on the basis of WDM). Light interferes constructively and destructively with nano- and microstructures of appropriate shape, dimensions and materials, both in the artificial DBR structures fabricated in our labs as well as in the natural ones.

  5. Experimental characterization of micromilled surfaces by large range AFM

    DEFF Research Database (Denmark)

    Bariani, Paolo; Bissacco, Giuliano; Hansen, Hans Nørgaard

    2004-01-01

    of workpiece material, particularly when sub-micrometer chip thicknesses are considered and when machining hard materials. Quantification of surface topography is of fundamental importance for the evaluation of the generated surface; high resolution and wide measuring range being highly desirable...... for the evaluation of the distinctive behaviour of the ball end mill. The combination of the two demands is to date not matched by any measuring instrument. The paper describes an experimental investigation of surface topography of such micromachined surfaces. Accurate characterization of fine surface details...

  6. 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.

  7. A Micromachined Pressure Sensor with Integrated Resonator Operating at Atmospheric Pressure

    Directory of Open Access Journals (Sweden)

    Sen Ren

    2013-12-01

    Full Text Available A novel resonant pressure sensor with an improved micromechanical double-ended tuning fork resonator packaged in dry air at atmospheric pressure is presented. The resonator is electrostatically driven and capacitively detected, and the sensor is designed to realize a low cost resonant pressure sensor with medium accuracy. Various damping mechanisms in a resonator that is vibrating at atmospheric pressure are analyzed in detail, and a formula is developed to predict the overall quality factor. A trade-off has been reached between the quality factor, stress sensitivity and drive capability of the resonator. Furthermore, differential sense elements and the method of electromechanical amplitude modulation are used for capacitive detection to obtain a large signal-to-noise ratio. The prototype sensor chip is successfully fabricated using a micromachining process based on a commercially available silicon-on-insulator wafer and is hermetically encapsulated in a custom 16-pin Kovar package. Preliminary measurements show that the fundamental frequency of the resonant pressure sensor is approximately 34.55 kHz with a pressure sensitivity of 20.77 Hz/kPa. Over the full scale pressure range of 100–400 kPa and the whole temperature range of −20–60 °C, high quality factors from 1,146 to 1,772 are obtained. The characterization of the prototype sensor reveals the feasibility of a resonant pressure sensor packaged at atmospheric pressure.

  8. 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.

  9. Reverberation Reduction in Capacitive Micromachined Ultrasonic Transducers (CMUTs) by Front-face Reflectivity Minimization

    Science.gov (United States)

    Savoia, Alessandro Stuart; La Mura, Monica; Mauti, Barbara; Lamberti, Nicola; Caliano, Giosuè

    Front-face acoustic reflectivity of ultrasonic imaging transducers, due to acoustic impedance mismatch with the propagation medium, may cause reverberation phenomena during wideband pulse-echo operation. Front-face reflectivity may be reduced by promoting the transmission of the echoes, received from the medium, to the transducer backing, and by maximizing the mechanical-to-electrical energy conversion and dissipation by tuning the electrical load impedance connected to the transducer. In Capacitive Micromachined Ultrasonic Transducers (CMUTs), the energy transfer from the medium to the backing is very low due to the large impedance mismatch between the medium and the transducer substrate, typically made of silicon. Reverse Fabrication Process (RFP) makes it possible providing CMUTs with custom substrate materials, thus eliminating the original silicon microfabrication support. In this paper, we propose two methods for the front-face reflectivity reduction in RFP-CMUTs: the first one is based on the use of low-impedance, highly attenuating backing materials, and the second one is based on the maximization of the mechanoelectrical energy conversion and dissipation. We analyze the methods by finite element simulations and experimentally validate the obtained results by fabricating and characterizing single-element RFP-CMUTs provided with different backing materials and electrical loads.

  10. Capacitive micromachined ultrasonic transducers based on annular cell geometry for air-coupled applications.

    Science.gov (United States)

    Na, Shuai; Chen, Albert I H; Wong, Lawrence L P; Li, Zhenhao; Macecek, Mirek; Yeow, John T W

    2016-09-01

    A novel design of an air-coupled capacitive micromachined ultrasonic transducer (CMUT) with annular cell geometry (annular CMUT) is proposed. Finite element analysis shows that an annular cell has a ratio of average-to-maximum displacement (RAMD) of 0.52-0.58 which is 58-76% higher than that of a conventional circular cell. The increased RAMD leads to a larger volume displacement which results in a 48.4% improved transmit sensitivity and 127.3% improved power intensity. Single-cell annular CMUTs were fabricated with 20-μm silicon plates on 13.7-μm deep and 1.35-mm wide annular cavities using the wafer bonding technique. The measured RAMD of the fabricated CMUTs is 0.54. The resonance frequency was measured to be 94.5kHz at 170-V DC bias. The transmit sensitivity was measured to be 33.83Pa/V and 25.85Pa/V when the CMUT was excited by a continuous wave and a 20-cycle burst, respectively. The receive sensitivity at 170-V DC bias was measured to be 7.7mV/Pa for a 20-cycle burst, and 15.0mV/Pa for a continuous incident wave. The proposed annular CMUT design demonstrates a significant improvement in transmit efficiency, which is an important parameter for air-coupled ultrasonic transducers. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Development of capacitive Micromachined Ultrasonic Transducer (II) - Analysis of Microfabrication Process

    International Nuclear Information System (INIS)

    Kim, Ki Bok; Ahn, Bong Young; Park, Hae Won; Kim, Young Joo; Kim, Kuk Jin; Lee, Seung Seok

    2004-01-01

    The main goal of this study was to develop a micro-fabrication process for the capacitive micromachined ultrasonic transducer (cMUT). In order to achieve this goal, the former research results of the micro-electro-mechanical system (MEMS) process for the cMUT were analyzed. The membrane deposition, sacrificial layer deposition and etching were found to be a main process of fabricating the cMUT. The optimal conditions for those microfabrication were determined by the experiment. The thickness, uniformity, and residual stress of the Si 3 N 3 deposition which forms the membrane of the cMUT were characterized after growing the Si 3 N 3 on Si-wafer under various process conditions. As a sacrificial layer, the growth rate of the SiO 2 deposition was analyzed under several process conditions. The optimal etching conditions of the sacrificial layer were analyzed. The microfabrication process developed in this study will be used to fabricate the cMUT

  12. Capacitive micromachined ultrasonic transducer for ultra-low pressure measurement: Theoretical study

    Science.gov (United States)

    Li, Zhikang; Zhao, Libo; Jiang, Zhuangde; Akhbari, Sina; Ding, Jianjun; Zhao, Yihe; Zhao, Yulong; Lin, Liwei

    2015-12-01

    Ultra-low pressure measurement is necessary in many areas, such as high-vacuum environment monitoring, process control and biomedical applications. This paper presents a novel approach for ultra-low pressure measurement where capacitive micromachined ultrasonic transducers (CMUTs) are used as the sensing elements. The working principle is based on the resonant frequency shift of the membrane under the applied pressure. The membranes of the biased CMUTs can produce a larger resonant frequency shift than the diaphragms with no DC bias in the state-of-the-art resonant pressure sensors, which contributes to pressure sensitivity improvement. The theoretical analysis and finite element method (FEM) simulation were employed to study the relationship between the resonant frequency and the pressure. The results demonstrated excellent capability of the CMUTs for ultra-low pressure measurement. It is shown that the resonant frequency of the CMUT varies linearly with the applied pressure. A sensitivity of more than 6.33 ppm/Pa (68 kHz/kPa) was obtained within a pressure range of 0 to 100 Pa when the CMUTs were biased at a DC voltage of 90% of the collapse voltage. It was also demonstrated that the pressure sensitivity can be adjusted by the DC bias voltage. In addition, the effects of air damping and ambient temperature on the resonant frequency were also studied. The effect of air damping is negligible for the pressures below 1000 Pa. To eliminate the temperature effect on the resonant frequency, a temperature compensating method was proposed.

  13. Development of capacitive Micromachined Ultrasonic Transducer (II) - Analysis of Microfabrication Process

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Bok; Ahn, Bong Young; Park, Hae Won; Kim, Young Joo; Kim, Kuk Jin; Lee, Seung Seok [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2004-12-15

    The main goal of this study was to develop a micro-fabrication process for the capacitive micromachined ultrasonic transducer (cMUT). In order to achieve this goal, the former research results of the micro-electro-mechanical system (MEMS) process for the cMUT were analyzed. The membrane deposition, sacrificial layer deposition and etching were found to be a main process of fabricating the cMUT. The optimal conditions for those microfabrication were determined by the experiment. The thickness, uniformity, and residual stress of the Si{sub 3}N{sub 3} deposition which forms the membrane of the cMUT were characterized after growing the Si{sub 3}N{sub 3} on Si-wafer under various process conditions. As a sacrificial layer, the growth rate of the SiO{sub 2} deposition was analyzed under several process conditions. The optimal etching conditions of the sacrificial layer were analyzed. The microfabrication process developed in this study will be used to fabricate the cMUT

  14. Anodic bonding using SOI wafer for fabrication of capacitive micromachined ultrasonic transducers

    International Nuclear Information System (INIS)

    Bellaredj, M; Bourbon, G; Walter, V; Moal, P Le; Berthillier, M

    2014-01-01

    In medical ultrasound imaging, mostly piezoelectric crystals are used as ultrasonic transducers. Capacitive micromachined ultrasonic transducers (CMUTs) introduced around 1994 have been shown to be a good alternative to conventional piezoelectric transducers in various aspects, such as sensitivity, transduction efficiency or bandwidth. This paper focuses on a fabrication process for CMUTs using anodic bonding of a silicon on insulator wafer on a glass wafer. The processing steps are described leading to a good control of the mechanical response of the membrane. This technology makes possible the fabrication of large membranes and can extend the frequency range of CMUTs to lower frequencies of operation. Silicon membranes having radii of 50, 70, 100 and 150 µm and a 1.5 µm thickness are fabricated and electromechanically characterized using an auto-balanced bridge impedance analyzer. Resonant frequencies from 0.6 to 2.3 MHz and an electromechanical coupling coefficient around 55% are reported. The effects of residual stress in the membranes and uncontrolled clamping conditions are clearly responsible for the discrepancies between experimental and theoretical values of the first resonance frequency. The residual stress in the membranes is determined to be between 90 and 110 MPa. The actual boundary conditions are between the clamped condition and the simply supported condition and can be modeled with a torsional stiffness of 2.10 −7  Nm rad –1  in the numerical model. (paper)

  15. Optoacoustic characterization of broadband directivity patterns of capacitive micromachined ultrasonic transducers

    Science.gov (United States)

    Rebling, Johannes; Warshavski, Omri; Meynier, Cyril; Razansky, Daniel

    2017-04-01

    Frequency characteristics of ultrasound detectors used in optoacoustic tomography have a major impact on imaging performance. It is common practice to select transducers based on their sensitivity at the central frequency and under normal incidence. However, the bandwidth and angular sensitivity play an equally important role in establishing the quality and accuracy of the reconstructed images. Here, we developed a calibrated optoacoustic characterization method specifically tailored for broadband measurements of the angular transducer sensitivity (directivity). Ultrawideband omnidirectional optoacoustic responses were generated by uniformly illuminating thin absorbing sutures with nanosecond laser pulses and characterized with a needle hydrophone. This calibrated optoacoustic source was used to characterize the frequency dependence of the angular response by a conventional piezoelectric transducer (PZT) and a capacitive micromachined ultrasonic transducer (cMUT) with similar size and central frequency. Furthermore, both transducers had no preamplification electronics directly attached to the detection elements. While the PZT presented a 7.8 dB sensitivity advantage at normal incidence, it was able to provide detectable signal-to-noise levels only at incidence angles of up to 20 deg whereas the cMUT maintained reasonable sensitivity levels and broadband response at incidence angles of 40 deg and beyond. We further experimentally showcase a reduction in the limited-view image artifacts resulting from the broader acceptance angle of the cMUT.

  16. 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.

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

    Directory of Open Access Journals (Sweden)

    Gia Thinh Bui

    2016-06-01

    Full Text Available 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.

  18. 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.

  19. 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

  20. A novel deflection shape function for rectangular capacitive micromachined ultrasonic transducer diaphragms

    Directory of Open Access Journals (Sweden)

    Zhou Zheng

    2015-09-01

    Full Text Available A highly accurate analytical deflection shape function that describes the deflection profiles of capacitive micromachined ultrasonic transducers (CMUTs with rectangular membranes under electrostatic pressure has been formulated. The rectangular diaphragms have a thickness range of 0.6–1.5 μm and a side length range of 100–1000 μm. The new deflection shape function generates deflection profiles that are in excellent agreement with finite element analysis (FEA results for a wide range of geometry dimensions and loading conditions. The deflection shape function is used to analyze membrane deformations and to calculate the capacitances between the deformed membranes and the fixed back plates. In 50 groups of random tests, compared with FEA results, the calculated capacitance values have a maximum deviation of 1.486% for rectangular membranes. The new analytical deflection function can provide designers with a simple way of gaining insight into the effects of designed parameters for CMUTs and other MEMS-based capacitive type sensors.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. A Z-Axis Quartz Cross-Fork Micromachined Gyroscope Based on Shear Stress Detection

    Science.gov (United States)

    Xie, Liqiang; Wu, Xuezhong; Li, Shengyi; Wang, Haoxu; Su, Jianbin; Dong, Peitao

    2010-01-01

    Here we propose a novel quartz micromachined gyroscope. The sensor has a simple cross-fork structure in the x-y plane of quartz crystal. Shear stress rather than normal stress is utilized to sense Coriolis’ force generated by the input angular rate signal. Compared to traditional quartz gyroscopes, which have two separate sense electrodes on each sidewall, there is only one electrode on each sidewall of the sense beam. As a result, the fabrication of the electrodes is simplified and the structure can be easily miniaturized. In order to increase sensitivity, a pair of proof masses is attached to the ends of the drive beam, and the sense beam has a tapered design. The structure is etched from a z-cut quartz wafer and the electrodes are realized by direct evaporation using the aperture mask method. The drive mode frequency of the prototype is 13.38 kHz, and the quality factor is approximately 1,000 in air. Therefore, the gyroscope can work properly without a vacuum package. The measurement ability of the shear stress detection design scheme is validated by the Coriolis’ force test. The performance of the sensor is characterized on a precision rate table using a specially designed readout circuit. The experimentally obtained scale factor is 1.45 mV/°/s and the nonlinearity is 3.6% in range of ±200 °/s. PMID:22294887

  6. 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.

  7. 31-mode piezoelectric micromachined ultrasonic transducer with PZT thick film by granule spraying in vacuum process

    Science.gov (United States)

    Jung, Joontaek; Annapureddy, Venkateswarlu; Hwang, Geon-Tae; Song, Youngsup; Lee, Wonjun; Kang, Woojin; Ryu, Jungho; Choi, Hongsoo

    2017-05-01

    A piezoelectric micromachined ultrasonic transducer (pMUT) is an ideal device for portable medical diagnosis systems, intravascular ultrasound systems, and ultrasonic cameras because of its favorable characteristics including small size, acoustic impedance matching with the body, low power consumption, and simple integration with the systems. Despite these advantages, practical applications are limited because of insufficient acoustic pressure of the pMUT caused by the thin active piezoelectric layer. Here, we report the fabrication of a thick piezoelectric Pb(Zr,Ti)O3 (PZT) film-based pMUT device having high deflection at low driving voltage using the granule spraying in vacuum (GSV) process. Pre-patterned high-density thick (exceeding 8 μm) PZT films were grown on 6-inch-diameter Si/SiO2/Ti/Pt silicon-on-insulator wafers at room temperature at a high deposition rate of ˜5 μm min-1. The fabrication process using the proposed GSV process was simple and fast, and the deflection of the pMUT exhibited a high value of 0.8 μm.

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. Micromachined piezoresistive inclinometer with oscillator-based integrated interface circuit and temperature readout

    Science.gov (United States)

    Dalola, Simone; Ferrari, Vittorio; Marioli, Daniele

    2012-03-01

    In this paper a dual-chip system for inclination measurement is presented. It consists of a MEMS (microelectromechanical system) piezoresistive accelerometer manufactured in silicon bulk micromachining and a CMOS (complementary metal oxide semiconductor) ASIC (application specific integrated circuit) interface designed for resistive-bridge sensors. The sensor is composed of a seismic mass symmetrically suspended by means of four flexure beams that integrate two piezoresistors each to detect the applied static acceleration, which is related to inclination with respect to the gravity vector. The ASIC interface is based on a relaxation oscillator where the frequency and the duty cycle of a rectangular-wave output signal are related to the fractional bridge imbalance and the overall bridge resistance of the sensor, respectively. The latter is a function of temperature; therefore the sensing element itself can be advantageously used to derive information for its own thermal compensation. DC current excitation of the sensor makes the configuration unaffected by wire resistances and parasitic capacitances. Therefore, a modular system results where the sensor can be placed remotely from the electronics without suffering accuracy degradation. The inclination measurement system has been characterized as a function of the applied inclination angle at different temperatures. At room temperature, the experimental sensitivity of the system results in about 148 Hz/g, which corresponds to an angular sensitivity around zero inclination angle of about 2.58 Hz deg-1. This is in agreement with finite element method simulations. The measured output fluctuations at constant temperature determine an equivalent resolution of about 0.1° at midrange. In the temperature range of 25-65 °C the system sensitivity decreases by about 10%, which is less than the variation due to the microsensor alone thanks to thermal compensation provided by the current excitation of the bridge and the positive

  13. Capacitive micromachined ultrasonic transducer for ultra-low pressure measurement: Theoretical study

    Directory of Open Access Journals (Sweden)

    Zhikang Li

    2015-12-01

    Full Text Available Ultra-low pressure measurement is necessary in many areas, such as high-vacuum environment monitoring, process control and biomedical applications. This paper presents a novel approach for ultra-low pressure measurement where capacitive micromachined ultrasonic transducers (CMUTs are used as the sensing elements. The working principle is based on the resonant frequency shift of the membrane under the applied pressure. The membranes of the biased CMUTs can produce a larger resonant frequency shift than the diaphragms with no DC bias in the state-of-the-art resonant pressure sensors, which contributes to pressure sensitivity improvement. The theoretical analysis and finite element method (FEM simulation were employed to study the relationship between the resonant frequency and the pressure. The results demonstrated excellent capability of the CMUTs for ultra-low pressure measurement. It is shown that the resonant frequency of the CMUT varies linearly with the applied pressure. A sensitivity of more than 6.33 ppm/Pa (68 kHz/kPa was obtained within a pressure range of 0 to 100 Pa when the CMUTs were biased at a DC voltage of 90% of the collapse voltage. It was also demonstrated that the pressure sensitivity can be adjusted by the DC bias voltage. In addition, the effects of air damping and ambient temperature on the resonant frequency were also studied. The effect of air damping is negligible for the pressures below 1000 Pa. To eliminate the temperature effect on the resonant frequency, a temperature compensating method was proposed.

  14. Harmonic Reduction in Capacitive Micromachined Ultrasonic Transducers by Gap Feedback Linearization

    Science.gov (United States)

    Satir, Sarp; Degertekin, F. Levent

    2012-01-01

    The nonlinear relationship between the electrical input signal and electrostatic force acting on the capacitive micromachined ultrasonic transducer (CMUT) membrane limits its harmonic imaging performance. Several input shaping methods were proposed in order to compensate for the nonlinearity originating from the electrostatic force dependence on the square of the applied voltage. Here we analyze harmonic generation in CMUTs with a time domain model. The model explains the basis of the input shaping methods and suggests that the nonlinearity due to gap dependence of the electrostatic force is also significant. It also suggests that the harmonic distortion in the output pressure can be eliminated by subharmonic AC only excitation of the CMUT in addition to scaling the input voltage with the instantaneous gap. This gap feedback configuration can be approximated by the simple addition of a series impedance to the CMUT capacitance. We analyze several types of series impedance feedback topologies for gap feedback linearization. We show that for subharmonic AC excitation while resistive and capacitive impedances result in a trade-off between input voltage and harmonic distortion for a desired pressure output, harmonic generation can be suppressed while increasing the Pa/V transmit sensitivity for proper series inductance and resistance feedback. We experimentally demonstrate the feedback method by reducing harmonic generation by 10dB for the same output pressure at the fundamental frequency by using a simple series resistor feedback with a CMUT operating at a center frequency of 3 MHz. The proposed methods also allow for utilization of the full CMUT gap for transmit operation and hence should be useful in high intensity ultrasonic applications in addition to harmonic imaging. PMID:22293735

  15. Optical micromachined ultrasound transducers (OMUT) - a new approach for high resolution imaging

    Science.gov (United States)

    Tadayon, M. A.; Ashkenazi, S.

    2013-03-01

    Piezoelectric ultrasound (US) transducers are at the heart of almost any ultrasonic medical imaging probe. However, their sensitivity and reliability severely degrade in applications requiring high frequency (>20 MHz) and small element size (CMUT) and optical sensing and generation of ultrasound are being investigated. In this paper we present our first steps in developing optical micromachined ultrasound transducers (OMUT) technology. OMUTs rely on microfabrication techniques to construct micron-size air cavities capped by an elastic membrane. The membrane functions as the active ultrasound transmitter and receiver. We will describe the design and testing of prototype OMUT devices which implement a receive-only function. The cavity detector is an optical cavity which its top mirror is deflected under the application of pressure. The intensity of a reflected light beam is highly sensitive to displacement of the top membrane if the optical wavelength is at near-resonance condition. Therefore, US pulses can be detected by recording the reflected light intensity. The sensitivity of the device depends on the mechanical properties of the top membrane and optical characteristics of the optical cavity. The device was fabricated using SU8 as a structural material and gold as a mirror. We have developed a new bonding method to fabricate a sealed, low roughness, high quality optical cavity. The 60μm cavity with the 8.5 μm top membrane is tested in water with 25MHz ultrasound transducer. The NEP of the device for bandwidth of 28MHz was 9.25kPa. The optical cavity has a finesse of around 23.

  16. Air-coupled MUMPs capacitive micromachined ultrasonic transducers with resonant cavities.

    Science.gov (United States)

    Octavio Manzanares, Alberto; Montero de Espinosa, Francisco

    2012-04-01

    This work reports performance improvements of air-coupled capacitive micromachined ultrasonic transducers (CMUTs) using resonant cavities. In order to perform this work, we have designed and manufactured a CMUT employing multi-user microelectromechanical systems (MEMS) processes (MUMPs). The transducer was designed using Helmholtz resonator principles. This was characterised by the dimensions of the cavity and several acoustic ports, which had the form of holes in the CMUT plate. The MUMPs process has the advantage of being low cost which allows the manufacture of economic prototypes. In this paper we show the effects of the resonant cavities and acoustic ports in CMUTs using laser Doppler vibrometry and acoustical measurements. We also use Finite Element (FE) simulations in order to support experimental measurements. The results show that it is possible to enhance the output pressure and bandwidth in air by tuning the resonance frequency of the plate (f(p)) with that of the Helmholtz resonator (f(H)). The experimental measurements show the plate resonance along with an additional resonance in the output pressure spectrum. This appears due to the effect of the new resonant cavities in the transducer. FE simulations show an increase of 11 dB in the output pressure with respect to that of a theoretical vacuum-sealed cavity MUMPs CMUT by properly tuning the transducer. The bandwidth has been also analyzed by calculating the mechanical Q factor of the tuned CMUT. This has been estimated as 4.5 compared with 7.75 for the vacuum-sealed cavity MUMPs CMUT. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Microwave design and analysis of a micromachined self-heating power sensor based on matching thermocouples

    Science.gov (United States)

    Zhang, Zhiqiang; Liao, Xiaoping

    2017-08-01

    Microwave performance is a basic index of the sensors used at microwave frequencies, but also affects the sensing output. For the purpose of low-loss microwave applications, it is important for different microwave sensors to develop microwave design. This paper presents the microwave design and analysis of a micromachined self-heating microwave power sensor in the GaAs MMIC process, where the microwave power is dissipated and converted into output thermovoltages by two matching thermocouples. A dc-blocking capacitor is connected to the thermocouples in series and used to avoid the output short-circuit. In order to characterize the microwave performance, an S-parameter model of this self-heating power sensor is established. Using the model, the effects of the capacitor and the thermocouples on the reflection loss are investigated under different microwave frequencies. To demonstrate the validity of the microwave model, the microwave performance of the self-heating sensor is simulated using an electromagnetic software. In the simulation, the relationship between the substrate membrane underneath the thermocouples and the reflection loss is analyzed. Measured reflection losses of the self-heating sensor are between  -15.5 to  -15.9 dB at 8-12 GHz. The measured results show good agreement with the microwave model and simulation, and the source of small deviations is discussed. The proposed microwave design and analysis contributes to achieving low reflection loss for the sensor, with the fact that more power is used to convert into the thermovoltages.

  18. A smart fully integrated micromachined separator with soft magnetic micro-pillar arrays for cell isolation

    Science.gov (United States)

    Dong, Tao; Su, Qianhua; Yang, Zhaochu; Zhang, Yulong; Egeland, Eirik B.; Gu, Dan D.; Calabrese, Paolo; Kapiris, Matteo J.; Karlsen, Frank; Minh, Nhut T.; Wang, K.; Jakobsen, Henrik

    2010-11-01

    A smart fully integrated micromachined separator with soft magnetic micro-pillar arrays has been developed and demonstrated, which can merely employ one independent lab-on-chip to realize cell isolation. The simulation, design, microfabrication and test for the new electromagnetic micro separator were executed. The simulation results of the electromagnetic field in the separator show that special soft magnetic micro-pillar arrays can amplify and redistribute the electromagnetic field generated by the micro-coils. The separator can be equipped with a strong magnetic field to isolate the target cells with a considerably low input current. The micro separator was fabricated by micro-processing technology. An electroplating bath was hired to deposit NiCo/NiFe to fabricate the micro-pillar arrays. An experimental system was set up to verify the function of the micro separator by isolating the lymphocytes, in which the human whole blood mixed with Dynabeads® FlowComp Flexi and monoclonal antibody MHCD2704 was used as the sample. The results show that the electromagnetic micro separator with an extremely low input current can recognize and capture the target lymphocytes with a high efficiency, the separation ratio reaching more than 90% at a lower flow rate. For the electromagnetic micro separator, there is no external magnetizing field required, and there is no extra cooling system because there is less Joule heat generated due to the lower current. The magnetic separator is totally reusable, and it can be used to separate cells or proteins with common antigens.

  19. System Error Compensation Methodology Based on a Neural Network for a Micromachined Inertial Measurement Unit

    Science.gov (United States)

    Liu, Shi Qiang; Zhu, Rong

    2016-01-01

    Errors compensation of micromachined-inertial-measurement-units (MIMU) is essential in practical applications. This paper presents a new compensation method using a neural-network-based identification for MIMU, which capably solves the universal problems of cross-coupling, misalignment, eccentricity, and other deterministic errors existing in a three-dimensional integrated system. Using a neural network to model a complex multivariate and nonlinear coupling system, the errors could be readily compensated through a comprehensive calibration. In this paper, we also present a thermal-gas MIMU based on thermal expansion, which measures three-axis angular rates and three-axis accelerations using only three thermal-gas inertial sensors, each of which capably measures one-axis angular rate and one-axis acceleration simultaneously in one chip. The developed MIMU (100 × 100 × 100 mm3) possesses the advantages of simple structure, high shock resistance, and large measuring ranges (three-axes angular rates of ±4000°/s and three-axes accelerations of ±10 g) compared with conventional MIMU, due to using gas medium instead of mechanical proof mass as the key moving and sensing elements. However, the gas MIMU suffers from cross-coupling effects, which corrupt the system accuracy. The proposed compensation method is, therefore, applied to compensate the system errors of the MIMU. Experiments validate the effectiveness of the compensation, and the measurement errors of three-axis angular rates and three-axis accelerations are reduced to less than 1% and 3% of uncompensated errors in the rotation range of ±600°/s and the acceleration range of ±1 g, respectively. PMID:26840314

  20. 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.

  1. 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.

  2. Preclinical Testing of Frequency-Tunable Capacitive Micromachined Ultrasonic Transducer Probe Prototypes.

    Science.gov (United States)

    Pekař, Martin; Kolen, Alexander F; Belt, Harm; van Heesch, Frank; Mihajlović, Nenad; Hoefer, Imo E; Szili-Török, Tamas; Vos, Hendrik J; Bosch, Johan G; van Soest, Gijs; van der Steen, Antonius F W

    2017-09-01

    In intracardiac echocardiography (ICE) it may be beneficial to generate ultrasound images acquired at multiple frequencies, having the possibility of high penetration or high-resolution imaging in a single device. The objective of the presented work is to test two frequency-tunable probe prototypes in a preclinical setting: a rigid probe having a diameter of 11 mm and a new flexible and steerable 12-Fr ICE catheter. Both probes feature a forward-looking 32-element capacitive micromachined ultrasonic transducer array (aperture of 2 × 2 mm 2 ) operated in collapse mode, which allows for frequency tuning in the 6-MHz-18-MHz range. The rigid probe prototype is tested ex vivo in a passive heart platform. Images of an aortic valve acquired in high-penetration (6 MHz), generic (12 MHz) and high-resolution (18 MHz) mode combine satisfying image quality and penetration depth between 2.5 cm and 10 cm. The ICE catheter prototype is tested in vivo using a porcine animal model. Images of an aortic valve are acquired in the 3 imaging modes with the ICE catheter placed in an ascending aorta at multiple depths. It was found that the combination of the forward-looking design and frequency-tuning capability allows visualizing intracardiac structures of various sizes at different distances relative to the catheter tip, providing both wide overviews and detailed close-ups. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  3. 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

  4. 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.

  5. 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...

  6. 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.

  7. Heterometallic Zn3 Ln3 Ensembles Containing (μ6 -CO3 ) Ligand and Triangular Disposition of Ln3+ ions: Analysis of Single-Molecule Toroic (SMT) and Single-Molecule Magnet (SMM) Behavior.

    Science.gov (United States)

    Goura, Joydeb; Colacio, Enrique; Herrera, Juan Manuel; Suturina, Elizaveta A; Kuprov, Ilya; Lan, Yanhua; Wernsdorfer, Wolfgang; Chandrasekhar, Vadapalli

    2017-11-21

    Two new heterometallic Zn 3 Ln 3 (Ln 3+ =Dy, Tb) complexes, with a double triangular topology of the metal ions, have been assembled from the polytopic Mannich base ligand 6,6'-{[2-(dimethylamino)ethylazanediyl]bis(methylene)}bis(2-methoxy-4-methylphenol) (H 2 L) with the aid of an in situ generated carbonate ligand from atmospheric CO 2 fixation. Theoretical calculations indicate axial ground states for the Ln 3+ ions in these complexes, with their local magnetic moments being almost coplanar and tangential to the Ln 3+ atoms that define the equilateral triangle. Therefore, they can be considered as single-molecule toroics (SMTs) with almost zero total magnetic moment. Micro-SQUID measurements on the Dy 3+ counterpart show hysteresis loops below 3 K that have an S-shape, with large coercive fields opening upon cooling. This behavior is typical of a single molecule magnet (SMM) with very slow zero-field relaxation. At around ±0.35 T, the loops have a broad step, which is due to a direct relaxation process and corresponds to an acceleration of the relaxation of the magnetization, also observed at this magnetic field from ac susceptibility measurements. Simulations suggest that the broad step corresponds to two level avoidance of crossing points where the spin chiral Kramers doublet meets excited states of the coupled manifold, whose position is defined by exchange and dipole interactions. The Tb 3+ counterpart does not exhibit SMM behavior, which is due to the fact that the degeneracy of the ground state of the exchange coupled system is lifted at zero field, thus favoring quantum tunneling of magnetization (QTM). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. 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.

  9. Micromachined Silicon Stimulating Probes with CMOS Circuitry for Use in the Central Nervous System

    Science.gov (United States)

    Tanghe, Steven John

    1992-01-01

    Electrical stimulation in the central nervous system is a valuable technique for studying neural systems and is a key element in the development of prostheses for deafness and other disorders. This thesis presents a family of multielectrode probe structures, fulfilling the need for chronic multipoint stimulation tools essential for interfacing to the highly complex neural networks in the brain. These probes are batch-fabricated on silicon wafers, employing photoengraving techniques to precisely control the electrode site and array geometries and to allow the integration of on-chip CMOS circuitry for signal multiplexing and stimulus current generation. Silicon micromachining is used to define the probe shapes, which have typical shank dimensions of 3 mm in length by 100 mu m in width by 15 μm in thickness. Each shank supports up to eight planar iridium oxide electrode sites capable of delivering charge densities in excess of 3 mC/cm^2 during current pulse stimulation. Three active probe circuits have been designed with varied complexity and capability. All three can deliver biphasic stimulus currents through 16 sites using only 5 external leads, and they are all compatible with the same external control system. The most complex design interprets site addresses and stimulus current amplitudes from 16-bit words shifted into the probe at 4 MHz. Sixteen on-chip, biphasic, 8-bit digital-to-analog converters deliver analog stimulus currents in the range of +/- 254 muA to any combination of electrode sites. These DACs exhibit full-scale internal linearity to better than +/-1/2 LSB and can be calibrated by varying the positive power supply voltage. The entire probe circuit dissipates only 80 muW from +/-5 V supplies when not delivering stimulus currents, it includes several safety features, and is testable from the input pads. Test results from the fabricated circuits indicate that they all function properly at clocking frequencies as high as 10 MHz, meeting or exceeding

  10. Acoustical imaging using capacitive micromachined ultrasonic transducer arrays: Devices, circuits, and systems

    Science.gov (United States)

    Oralkan, Omer

    Integrated circuit technologies have had a great impact on the development of medical devices. Diagnostic imaging systems have benefited tremendously from the improvements in integrated circuits. One of the recent examples of this interaction between the two disciplines occurred in the area of ultrasonic imaging. The ability to build structures with dimensions in the submicron range enabled the realization of an almost a century old idea: Capacitive ultrasonic transducers. The major advantages of this transducer technology are ease of fabrication, potential for integration with supporting electronic circuits and improved bandwidth and sensitivity. This dissertation analyzes the viability of capacitive micromachined ultrasonic transducers (CMUTs) for practical imaging applications. This analysis is conducted by a detailed characterization effort, and by demonstrating both 2-D and 3-D images. Acoustical performance of 1-D and 2-D CMUT arrays fabricated using silicon integrated circuit technology has been experimentally characterized for transmit and receive modes, and the results are found to be in good agreement with the theoretical expectations. Both 2-D and 3-D images have been demonstrated. The distinctive features of CMUTs manifest themselves in the results of the characterization experiments and also in the resulting images. This dissertation also describes a general approach to design integrated front-end circuits for ultrasonic imaging and demonstrates basic circuit blocks for use in integrated systems along with CMUT arrays. The integration of the ultrasonic transducer arrays with supporting electronics not only reduces the cost and complexity of the system but also provides several advantages such as reduced parasitics, improved sensitivity, and a compact design with a reduced number of external interconnects. In this study, a custom integrated circuit comprising a pulse driver, a transmit/receive (T/R) switch and a wideband preamplifier has been fabricated

  11. Fabrication and characterization of a smart epitaxial piezoelectric micromachined ultrasonic transducer

    Energy Technology Data Exchange (ETDEWEB)

    Ozaki, Katsuya [Department of Electrical and Electronic Information Engg, Toyohashi University of Technology, Toyohashi, Aichi 441-8580 (Japan); Matin, Abdul, E-mail: matin.md.a@gmail.com [Department of Glass and Ceramic Engineering, Bangladesh University of Engg and Tech (BUET), Dhaka 1000 (Bangladesh); Numata, Yasuyuki [Department of Electrical and Electronic Information Engg, Toyohashi University of Technology, Toyohashi, Aichi 441-8580 (Japan); Akai, Daisuke [Electronics-Inspired Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology Toyohashi, Toyohahsi, Aichi 441-8580 (Japan); Sawada, Kazuaki; Ishida, Makoto [Department of Electrical and Electronic Information Engg, Toyohashi University of Technology, Toyohashi, Aichi 441-8580 (Japan); Electronics-Inspired Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology Toyohashi, Toyohahsi, Aichi 441-8580 (Japan)

    2014-12-15

    Highlights: • Highly [1 1 1] orientated functional PZT(1 1 1) thin film was grown on n-Si(1 1 1)/γ-Al{sub 2}O{sub 3}(1 1 1)/SrRuO{sub 3}(1 1 1). • Device performance of pMUT was studied using both experiment and modeling. • Material anisotropy played a significant role in the shifting of resonant frequency • pMUT shows high sensitivity for the transmission of ultrasonic pulses. • Successful realization of a piezoelectric ultrasonic transducer (pMUT) array. - Abstract: A novel piezoelectric micromachined ultrasonic transducer (pMUT) array was designed and fabricated using epitaxially grown functional Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3} (PZT) thin film on Si(1 1 1)/γ-Al{sub 2}O{sub 3}(1 1 1)/SrRuO{sub 3}(1 1 1) substrate for biomedical applications. The crystallographic orientation of PZT film was controlled by the incorporation of epitaxial γ-Al{sub 2}O{sub 3} film on Si substrate. Modal shape of pMUT was analyzed employing advanced 3D finite element modeling taking the crystallographic anisotropy of materials and the properties of immersed medium (air or water) into account. Eigenfrequency with mode shapes has shown to have significant influence on transmitting-receiving characteristics of pMUT. Modal shapes of pMUT were also quantitatively determined using Laser Doppler Vibratometry (LDV). An excellent correlation was obtained between computational and experimental results. A significantly high sensitivity of 3.9 μV/kPa was obtained in an under-water ultrasonic wave transmission experiment conducted using fabricated pMUT as wave transmitter and a commercial transducer as receiver at a fundamental frequency of 1.20 MHz. Advanced FE computation thus serves as a tool to a priori optimize device structure for the successful transmission of ultrasonic waves with sufficient power to generate high resolution 3D imaging.

  12. Spreading of thin-film metal patterns deposited on nonplanar surfaces using a shadow mask micromachined in si (110)

    NARCIS (Netherlands)

    Tiggelaar, Roald M.; Berenschot, Johan W.; Elwenspoek, Michael Curt; Gardeniers, Johannes G.E.; Dorsman, R.; Kleijn, C.R.

    The application of a three dimensional, self-aligning shadow mask in (110)-oriented silicon for thin-film metal deposition is discussed. This shadow mask is used for the deposition of metal tracks on the bottom of structures with vertical sidewalls, i.e., the patterning of metal catalytic patches

  13. 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)

  14. 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)

  15. High-performance micromachined vibratory rate- and rate-integrating gyroscopes

    Science.gov (United States)

    Cho, Jae Yoong

    The performance of vibratory micromachined gyroscopes has been continuously improving for the past two decades. However, to further improve performance of the MEMS gyroscope in harsh environment, it is necessary for gyros to reduce the sensitivity to environmental parameters, including vibration and temperature change. In addition, conventional rate-mode MEMS gyroscopes have limitation in performance due to tradeoff between resolution, bandwidth, and full-scale range. In this research, we aim to reduce vibration sensitivity by developing gyros that operate in the balanced mode. The balanced mode creates zero net momentum and reduces energy loss through an anchor. The gyro can differentially cancel measurement errors from external vibration along both sensor axes. The vibration sensitivity of the balanced-mode gyroscope including structural imbalance from microfabrication reduces as the absolute difference between in-phase parasitic mode and operating mode frequencies increases. The parasitic sensing mode frequency is designed larger than the operating mode frequency to achieve both improved vibration insensitivity and shock resistivity. A single anchor is used in order to minimize thermoresidual stress change. We developed two gyroscope based on these design principles. The Balanced Oscillating Gyro (BOG) is a quad-mass tuning-fork rate gyroscope. The relationship between gyro design and modal characteristics is studied extensively using finite element method (FEM). The gyro is fabricated using the planar Si-on-glass (SOG) process with a device thickness of 100microm. The BOG is evaluated using the first-generation analog interface circuitry. Under a frequency mismatch of 5Hz between driving and sense modes, the angle random walk (ARW) is measured to be 0.44°/sec/✓Hz. The performance is limited by quadrature error and low-frequency noise in the circuit. The Cylindrical Rate-Integrating Gyroscope (CING) operates in whole-angle mode. The gyro is completely

  16. Development of a multi-band photoacoustic tomography imaging system based on a capacitive micromachined ultrasonic transducer array.

    Science.gov (United States)

    Zhang, Jian; Pun, Sio Hang; Yu, Yuanyu; Gao, Duyang; Wang, Jiujiang; Mak, Peng Un; Lei, Kin Fong; Cheng, Ching-Hsiang; Yuan, Zhen

    2017-05-10

    Photoacoustic tomography (PAT) as a hybrid technology combines the high optical contrast and high acoustic resolution in a single imaging modality. However, most of the available PAT systems cannot comprehensively or accurately characterize biological systems at multiple length scales due to the use of narrow bandwidth commercial ultrasonic transducers. In this study, we fabricated a novel multi-band capacitive micromachined ultrasonic transducer (CMUT) array, and first developed a CMUT-based multi-band photoacoustic tomography (MBPAT) imaging system. The MBPAT imaging system was examined by the phantom experiment, and then was successfully applied to image the zebrafish in vivo. The imaging results indicated that CMUT-array-based MBPAT can provide a more comprehensive and accurate characterization of biological tissues, which exhibit the potential of MBPAT/CMUT in various areas of biomedical imaging.

  17. High energy green nanosecond and picosecond pulse delivery through a negative curvature fiber for precision micro-machining.

    Science.gov (United States)

    Jaworski, Piotr; Yu, Fei; Carter, Richard M; Knight, Jonathan C; Shephard, Jonathan D; Hand, Duncan P

    2015-04-06

    In this paper we present an anti-resonant guiding, low-loss Negative Curvature Fiber (NCF) for the efficient delivery of high energy short (ns) and ultrashort (ps) pulsed laser light in the green spectral region. The fabricated NCF has an attenuation of 0.15 dB/m and 0.18 dB/m at 532 nm and 515 nm respectively, and provided robust transmission of nanosecond and picosecond pulses with energies of 0.57 mJ (10.4 kW peak power) and 30 µJ (5 MW peak power) respectively. It provides single-mode, stable (low bend-sensitivity) output and maintains spectral and temporal properties of the source laser beam. The practical application of fiber-delivered pulses has been demonstrated in precision micro-machining and marking of metals and glass.

  18. 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.

  19. Fabrication of Mutilayered Microgear Using a Vertically Modularized and Sectioned Micromold System by X-ray Micromachining Process

    Science.gov (United States)

    Kim, Jong Hyun; Chang, Suk Sang; Lim, Geunbae; Lee, Bong-Kee

    2011-06-01

    In the present study, a vertically modularized and sectioned micromold system (v-MSMS) is proposed and developed by synchrotron X-ray micromachining process. The developed v-MSMS is a novel concept of constructing a micromold system by stacking several micromold modules. As one representative application of the present v-MSMS, micromold system with several kinds of spur gear patterns was fabricated using deep X-ray lithography and a subsequent nickel electroforming process. Then, the usefulness of v-MSMS was demonstrated by casting the microgear with multiple layers. The proposed technique can be a useful tool for the mass replication of multilayered mechanical components, various micro parts, complicated microstructures, and so on.

  20. 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.

  1. Achievement report on commissioned research of R and D in fiscal 2000 on micromachine technologies. Development of high function maintenance technology for power generation facilities; 2000 nendo kenkyu seika hokokusho. Hatsuden shisetsu you kokino mentenansu gijutsu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    R and D has been carried out on a high function maintenance system that performs inspection and repair of anomalies such as internal cracks by using micromachines without need of disassembling heat exchangers and piping systems in power generation facilities. This paper summarizes the achievements in fiscal 2000. In the research of a prototype self-propelled system to recognize environment in tubes, the secondary prototype system integrating all of the elemental devices was fabricated, and its functions were verified. In the research of a prototype system to inspect outer surface of fine tube groups, a plurality of single machines that perform movement in narrow spaces on flat surface, interlocking, separation and flaw detection were connected to execute a vertical movement experiment. In the research of a prototype system for works internal to devices, fabrication and functional verification were conducted on the final prototype system which is equipped with functions of measuring very small nicks and performing repair works, which are mounted on the tip of a curved tube unit with multiple degrees of freedom. In the research of a functional device improving technology, a device that puts together artificial muscles, micro-joints, and a suspension device with very low friction was fabricated, and a functional verification was implemented thereon. (NEDO)

  2. Micro-machining of optical glasses–A review of diamond-cutting ...

    Indian Academy of Sciences (India)

    In order to diamond-turn optical glasses to a nanometric surface finish, it is critical to determine the transition point from brittle mode to ductile mode. This paper presents various experimental techniques to study this transition and discusses the mechanism of the surface generation. It has been recognized that tool wear is a ...

  3. 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.

  4. Micro-machining of optical glasses – A review of diamond-cutting ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    , sometimes even upto 20–40 nm. When used with the preferred diamond turnable materials (copper, electrolysis nickel, and aluminium), surface roughness. Table 1. Diamond turning compared to conventional optical fabrication. Parameter.

  5. Toughness amplification in copper/epoxy joints through pulsed laser micro-machined interface heterogeneities

    KAUST Repository

    Hernandez Diaz, Edwin

    2017-11-21

    This work addresses the mechanics of debonding along copper/epoxy joints featuring patterned interfaces. Engineered surface heterogeneities with enhanced adhesion properties are generated through pulsed laser irradiation. Peel tests are carried out to ascertain the effect of patterns shape and area fraction on the mechanical response. Experimental results are evaluated with the support of three-dimensional finite element simulations based on the use of cohesive surfaces. Results discussion is largely framed in terms of effective peel force and energy absorbed to sever the samples. It is shown that surface heterogeneities act as sites of potential crack pinning able to trigger crack initiation, propagation and arrest. Surface patterns ultimately enable a remarkable increase in the effective peel force and dissipated energy with respect to baseline homogeneous sanded interface.

  6. 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)

  7. 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)

  8. 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)

  9. Fabrication of Micromachined SnO2 Based MOS Gas Sensor with Inbuilt Microheater for Detection of Methanol

    Directory of Open Access Journals (Sweden)

    Priyanka Kakoty

    2016-09-01

    Full Text Available This paper presents a simple method to fabricate a vertical closed membrane structured gas sensor on silicon substrate using micromachining technology for methanol detection at lower concentration. An undoped tin dioxide thin film is deposited by DC magnetron sputtering technique on a pair of gold interdigitated microelectrodes of dimension 820 µm ´ 925 µm. A meander shaped platinum micro heater of dimension 1025 µm ´ 1000 µm is incorporated to provide optimum operating temperature (about 350 0C for sensing operation. Energy dispersive X-ray spectroscopy is done to confirm the chemical composition of the sensor. Temperature coefficient of resistance of the inbuilt micro heater is found to be 0.0941 /0C. The sensor resistance shows significant change when micro heater voltage is varied from 1.5 V-3 V. I-V analysis of the sensor is carried out at 25 0C, 50 0C and 75 0C, and shifts in current through the sensor at different temperatures are observed. I-V characterization is also carried out at different methanol concentration levels (50-110 ppm and it is found that at minimum 80 ppm, the sensor exhibits promising result. The response time and recovery time of the sensor is found to be 160 s and 167 s respectively.

  10. Evaluation of bias voltage modulation sequence for nonlinear contrast agent imaging using a capacitive micromachined ultrasonic transducer array

    Science.gov (United States)

    Novell, Anthony; Legros, Mathieu; Grégoire, Jean-Marc; Dayton, Paul A.; Bouakaz, Ayache

    2014-09-01

    Many clinical diagnoses have now been improved thanks to the development of new techniques dedicated to contrast agent nonlinear imaging. Over the past few years, Capacitive Micromachined Ultrasonic Transducers (cMUTs) have emerged as a promising alternative to traditional piezoelectric transducers. One notable advantage of cMUTs is their wide frequency bandwidth. However, their use in nonlinear imaging approaches such as those used to detect contrast agents have been challenging due their intrinsic nonlinear character. We propose a new contrast imaging sequence, called bias voltage modulation (BVM), specifically developed for cMUTs to suppress their inherent nonlinear behavior. Theoretical and experimental results show that a complete cancellation of the nonlinear signal from the source can be reached when the BVM sequence is implemented. In-vitro validation of the sequence is performed using a cMUT probe connected to an open scanner and a flow phantom setup containing SonoVue microbubbles. Compared to the standard amplitude modulation imaging mode, a 6 dB increase of contrast-to-tissue ratio was achieved when the BVM sequence is applied. These results reveal that the problem of cMUT nonlinearity can be addressed, thus expanding the potential of this new transducer technology for nonlinear contrast agent detection and imaging.

  11. Evaluation of bias voltage modulation sequence for nonlinear contrast agent imaging using a capacitive micromachined ultrasonic transducer array

    International Nuclear Information System (INIS)

    Novell, Anthony; Grégoire, Jean-Marc; Bouakaz, Ayache; Legros, Mathieu; Dayton, Paul A

    2014-01-01

    Many clinical diagnoses have now been improved thanks to the development of new techniques dedicated to contrast agent nonlinear imaging. Over the past few years, Capacitive Micromachined Ultrasonic Transducers (cMUTs) have emerged as a promising alternative to traditional piezoelectric transducers. One notable advantage of cMUTs is their wide frequency bandwidth. However, their use in nonlinear imaging approaches such as those used to detect contrast agents have been challenging due their intrinsic nonlinear character. We propose a new contrast imaging sequence, called bias voltage modulation (BVM), specifically developed for cMUTs to suppress their inherent nonlinear behavior. Theoretical and experimental results show that a complete cancellation of the nonlinear signal from the source can be reached when the BVM sequence is implemented. In-vitro validation of the sequence is performed using a cMUT probe connected to an open scanner and a flow phantom setup containing SonoVue microbubbles. Compared to the standard amplitude modulation imaging mode, a 6 dB increase of contrast-to-tissue ratio was achieved when the BVM sequence is applied. These results reveal that the problem of cMUT nonlinearity can be addressed, thus expanding the potential of this new transducer technology for nonlinear contrast agent detection and imaging. (paper)

  12. A micromachined dual-axis beam steering actuator for use in a miniaturized optical space communication system

    International Nuclear Information System (INIS)

    Palmer, K; Lotfi, S; Berglund, M; Thornell, G; Kratz, H

    2010-01-01

    The design, fabrication and evaluation of an electrothermally actuated micromachined beam steering device for use in a free-space optical communication system intended for use on micro- and nanospacecraft in kilometer-sized formations are presented. SU-8 confined in v-grooves is heated to create bending movement in two orthogonal directions for two-axial steering with large static bending angles and low actuation voltages. Standard MEMS processing is used to fabricate the devices with square mirror side lengths of 1, 3.5 and 5 mm. In addition, a method to prevent thermal damage to SU-8 during deep reactive ion etching has been successfully developed. Characterization shows optical scan ranges larger than 40° in both directions with the maximum driving voltage of 16 V corresponding to a total power consumption of 1.14 W. Infrared imaging is used to investigate thermal cross-talk between actuators for the two scanning directions. It is found that a silicon backbone on the joint backside is crucial for device performance. Differences from expected performance are believed to arise from the SU-8 curing process and excessive heating during fabrication. A finite element method simulation is used to find the eigenfrequencies of the structures, and these are in good agreement with the measured frequency response

  13. A Si/Glass Bulk-Micromachined Cryogenic Heat Exchanger for High Heat Loads: Fabrication, Test, and Application Results.

    Science.gov (United States)

    Zhu, Weibin; White, Michael J; Nellis, Gregory F; Klein, Sanford A; Gianchandani, Yogesh B

    2010-02-01

    This paper reports on a micromachined Si/glass stack recuperative heat exchanger with in situ temperature sensors. Numerous high-conductivity silicon plates with integrated platinum resistance temperature detectors (Pt RTDs) are stacked, alternating with low-conductivity Pyrex spacers. The device has a 1 x 1-cm(2) footprint and a length of up to 3.5 cm. It is intended for use in Joule-Thomson (J-T) coolers and can sustain pressure exceeding 1 MPa. Tests at cold-end inlet temperatures of 237 K-252 K show that the heat exchanger effectiveness is 0.9 with 0.039-g/s helium mass flow rate. The integrated Pt RTDs present a linear response of 0.26%-0.30%/K over an operational range of 205 K-296 K but remain usable at lower temperatures. In self-cooling tests with ethane as the working fluid, a J-T system with the heat exchanger drops 76.1 K below the inlet temperature, achieving 218.7 K for a pressure of 835.8 kPa. The system reaches 200 K in transient state; further cooling is limited by impurities that freeze within the flow stream. In J-T self-cooling tests with an external heat load, the system reaches 239 K while providing 1 W of cooling. In all cases, there is an additional parasitic heat load estimated at 300-500 mW.

  14. Digital Micromirror Device (DMD-Based High-Cycle Torsional Fatigue Testing Micromachine for 1D Nanomaterials

    Directory of Open Access Journals (Sweden)

    Chenchen Jiang

    2016-03-01

    Full Text Available Fatigue behavior of nanomaterials could ultimately limit their applications in variable nano-devices and flexible nanoelectronics. However, very few existing nanoscale mechanical testing instruments were designed for dedicated fatigue experiments, especially for the challenging torsional cyclic loading. In this work, a novel high-cycle torsion straining micromachine, based on the digital micromirror device (DMD, has been developed for the torsional fatigue study on various one-dimensional (1D nanostructures, such as metallic and semiconductor nanowires. Due to the small footprint of the DMD chip itself and its cable-remote controlling mechanisms, it can be further used for the desired in situ testing under high-resolution optical or electron microscopes (e.g., scanning electron microscope (SEM, which allows real-time monitoring of the fatigue testing status and construction of useful structure-property relationships for the nanomaterials. We have then demonstrated its applications for testing nanowire samples with diameters about 100 nm and 500 nm, up to 1000 nm, and some of them experienced over hundreds of thousands of loading cycles before fatigue failure. Due to the commercial availability of the DMD and millions of micromirrors available on a single chip, this platform could offer a low-cost and high-throughput nanomechanical solution for the uncovered torsional fatigue behavior of various 1D nanostructures.

  15. A novel measurement method for the thermal properties of liquids by utilizing a bridge-based micromachined sensor

    International Nuclear Information System (INIS)

    Beigelbeck, Roman; Nachtnebel, Herbert; Kohl, Franz; Jakoby, Bernhard

    2011-01-01

    In recent decades, the demands for online monitoring of liquids in various applications have increased significantly. In this context, the sensing of the thermal transport parameters of liquids (i.e. thermal conductivity and diffusivity) may be an interesting alternative to well-established monitoring parameters like permittivity, mass density or shear viscosity. We developed a micromachined thermal property sensor, applicable to non-flowing liquids, featuring three in parallel microbridges, which carry either a heater or one of in total two thermistors. Its active sensing region was designed to achieve almost negligible spurious thermal shunts between heater and thermistors. This enables the adoption of a simple two-dimensional model to describe the heat transfer from the heater to the thermistors, which is mainly governed by the thermal properties of the sample liquid. Founded on this theoretical model, a novel measurement method for the thermal parameters was devised that relies solely on the frequency response of the measured peak temperature and allows simultaneous extraction of the thermal conductivity and diffusivity of liquids. In this contribution, we describe the device prototype, the model, the deduced measurement method and the experimental verification by means of test measurements carried out on five sample liquids

  16. Ultrasonic fingerprint sensor using a piezoelectric micromachined ultrasonic transducer array integrated with complementary metal oxide semiconductor electronics

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Y.; Fung, S.; Wang, Q.; Horsley, D. A. [Berkeley Sensor and Actuator Center, University of California, Davis, 1 Shields Avenue, Davis, California 95616 (United States); Tang, H.; Boser, B. E. [Berkeley Sensor and Actuator Center, University of California, Berkeley, California 94720 (United States); Tsai, J. M.; Daneman, M. [InvenSense, Inc., 1745 Technology Drive, San Jose, California 95110 (United States)

    2015-06-29

    This paper presents an ultrasonic fingerprint sensor based on a 24 × 8 array of 22 MHz piezoelectric micromachined ultrasonic transducers (PMUTs) with 100 μm pitch, fully integrated with 180 nm complementary metal oxide semiconductor (CMOS) circuitry through eutectic wafer bonding. Each PMUT is directly bonded to a dedicated CMOS receive amplifier, minimizing electrical parasitics and eliminating the need for through-silicon vias. The array frequency response and vibration mode-shape were characterized using laser Doppler vibrometry and verified via finite element method simulation. The array's acoustic output was measured using a hydrophone to be ∼14 kPa with a 28 V input, in reasonable agreement with predication from analytical calculation. Pulse-echo imaging of a 1D steel grating is demonstrated using electronic scanning of a 20 × 8 sub-array, resulting in 300 mV maximum received amplitude and 5:1 contrast ratio. Because the small size of this array limits the maximum image size, mechanical scanning was used to image a 2D polydimethylsiloxane fingerprint phantom (10 mm × 8 mm) at a 1.2 mm distance from the array.

  17. EFFECT OF MINIMUM QUANTITY LUBRICATION ON SURFACE ROUGHNESS IN TOOL-BASED MICROMILLING

    Directory of Open Access Journals (Sweden)

    Mohammad Yeakub Ali

    2017-05-01

    Full Text Available Cutting fluid plays an important role in machining processes to achieve dimensional accuracy in reducing tool wear and improving the tool life. Conventional flood cooling method in machining processes is not cost effective and consumption of huge amount of cutting fluids is not healthy and environmental friendly. In micromachining, flood cooling is not recommended to avoid possible damage of the microstructures. Therefore, one of the alternatives to overcome the environmental issues to use minimum quantity of lubrication (MQL in machining process. MQL is eco-friendly and has economical advantage on manufacturing cost. However, there observed lack of study on MQL in improving machined surface roughness in micromilling. Study of the effects of MQL on surface roughness should be carried out because surface roughness is one of the important issues in micromachined parts such as microfluidic channels. This paper investigates and compares surface roughness with the presence of MQL and dry cutting in micromilling of aluminium alloy 1100 using DT-110 milling machine. The relationship among depth of cut, feed rate, and spindle speed on surface roughness is also analyzed. All three machining parameters identified as significant for surface roughness with dry cutting which are depth of cut, feed rate, and spindle speed. For surface roughness with MQL, it is found that spindle speed did not give much influence on surface roughness. The presence of MQL provides a better surface roughness by decreasing the friction between tool and workpiece.

  18. Fresnel Lenses fabricated by femtosecond laser micromachining on Polymer 1D Photonic Crystal

    Directory of Open Access Journals (Sweden)

    Guduru Surya S.K.

    2013-11-01

    Full Text Available We report the fabrication of micro Fresnel lenses by femtosecond laser surface ablation on polymer 1D photonic crystals. This device is designed to focus the transmitted wavelength of the photonic crystal and filter the wavelengths corresponding to the photonic band gap region. Integration of such devices in a wavelength selective light harvesting and filtering microchip can be achieved.

  19. Advanced characterization of carrier profiles in germanium using micro-machined contact probes

    DEFF Research Database (Denmark)

    Clarysse, T.; Konttinen, M.; Parmentier, B.

    2012-01-01

    of new concepts based on micro machined, closely spaced contact probes (10 μm pitch). When using four probes to perform sheet resistance measurements, a quantitative carrier profile extraction based on the evolution of the sheet resistance versus depth along a beveled surface is obtained. Considering...

  20. Isotropic etching of silicon in fluoride containing solutions as a tool for micromachining

    OpenAIRE

    Tjerkstra, R.W.

    1999-01-01

    μTAS is hot in micromechanics today. All μTAS devices contain channels to connect the different components together. Channels can also be used as chromatography columns. Isotropic wet chemical etching of silicon can be a suitable process to construct (hemi)circular channels with very smooth surfaces. Wet etching of silicon can be done chemically, using aqueous solutions of HF and HNO , or electrochemically, using aqueous HF solutions. Both processes suffer from the loading-effect: due to extr...

  1. Fabrication of Capacitive Micromachined Ultrasonic Transducers Using a Boron Etch-Stop Method

    DEFF Research Database (Denmark)

    Diederichsen, Søren Elmin; Sandborg-Olsen, Filip; Engholm, Mathias

    2016-01-01

    etch-stop scheme for fabricating the flexible plate of a CMUT. The proposed fabrication method enables precise control of the plate thickness variation and is a low cost alternative to the SOI-based process. N-type silicon wafers are doped with boron to a surface concentration of > 1020 cm−3 using...... array is measured to 12MHz±2.5%. Furthermore, hydrophone measurements show that the fabricated devices can be used to emit sound pressure in the ultrasonic frequency domain....

  2. Ablation characteristics of aluminum oxide and nitride ceramics during femtosecond laser micromachining

    International Nuclear Information System (INIS)

    Kim, Sung Hoon; Sohn, Ik-Bu; Jeong, Sungho

    2009-01-01

    Femtosecond laser ablation of aluminum oxide (Al 2 O 3 ) and aluminum nitride (AlN) ceramics was performed under normal atmospheric conditions (λ = 785 nm, τ p = 185 fs, repetition rate = 1 kHz), and threshold laser fluencies for single- and multi-pulse ablation were determined. The ablation characteristics of the two ceramics showed similar trends except for surface morphologies, which revealed virtually no melting in Al 2 O 3 but clear evidence of melting for AlN. Based on subsequent X-ray photoelectron spectroscopy (XPS) analyses, the chemistry of these ceramics appeared to remain the same before and after femtosecond laser ablation.

  3. A comparison between conventional and collapse-mode capacitive micromachined ultrasonic transducers in 10-MHz 1-D arrays.

    Science.gov (United States)

    Park, Kwan Kyu; Oralkan, Omer; Khuri-Yakub, Butrus T

    2013-06-01

    This paper presents a comprehensive comparison between a collapse-mode and a conventional-mode capacitive micromachined ultrasonic transducer (CMUT); both devices have a 1-μm-thick silicon plate and operate at 10 MHz when biased at 100 V. The radii of the circular plates and the gap heights are modified to meet the design specifications required for a fair comparison. Finite element analysis (FEA) shows that the collapse-mode CMUT has higher output pressure sensitivity (46.5 kPa/V) than the conventional CMUT (13.1 kPa/V), and achieves a 3-dB fractional bandwidth (FBW) of 124% compared with 128% for the conventional mode. These results were validated by experiments performed on devices fabricated in a 1-D phased array configuration using the local oxidation of silicon (LOCOS)/wafer-bonding process. The measured output pressure sensitivity and the FBW of the collapse-mode and the conventional CMUTs at 100 V were 26.4 kPa/V and 103% and 12.7 kPa/V and 111%, respectively. The maximum output pressure of the collapse-mode CMUT was 1.19 MPa at 10 MHz, which was much higher than the conventional CMUT (0.44 MPa). However, the second harmonic distortion (SHD) level of the collapse-mode CMUT is higher than the conventional CMUT at the same excitation condition. Even with higher electric field in the cavity, the collapse-mode CMUT was as stable as the conventional CMUT in a long-term test. A 30-h test with a total of 3.2 × 10(9) cycles of 30 V ac excitation resulted in no significant degradation in the performance of the collapse-mode devices.

  4. Advanced characterization of carrier profiles in germanium using micro-machined contact probes

    DEFF Research Database (Denmark)

    Clarysse, T.; Konttinen, M.; Parmentier, B.

    2012-01-01

    of new concepts based on micro machined, closely spaced contact probes (10 μm pitch). When using four probes to perform sheet resistance measurements, a quantitative carrier profile extraction based on the evolution of the sheet resistance versus depth along a beveled surface is obtained. Considering...... the use of only two probes, a spreading resistance like setup is obtained with small spacing and drastically reduced electrical contact radii (~10 nm) leading to a substantial reduction of the correction factors which are normally required for converting spreading resistance profiles. We demonstrate......The accurate determination of the sheet resistance and carrier depth profile, i.e. active dopant profile, of shallow junction isolated structures involving new high mobility materials, such as germanium, is a crucial topic for future CMOS development. In this work, we discuss the capabilities...

  5. Improved photoelectrical properties of MoS(2) films after laser micromachining.

    Science.gov (United States)

    Lu, Junpeng; Lu, Jia Hui; Liu, Hongwei; Liu, Bo; Chan, Kim Xinhui; Lin, Jiadan; Chen, Wei; Loh, Kian Ping; Sow, Chorng Haur

    2014-06-24

    Direct patterning of ultrathin MoS2 films with well-defined structures and controllable thickness is appealing since the properties of MoS2 sheets are sensitive to the number of layer and surface properties. In this work, we employed a facile, effective, and well-controlled technique to achieve micropatterning of MoS2 films with a focused laser beam. We demonstrated that a direct focused laser beam irradiation was able to achieve localized modification and thinning of as-synthesized MoS2 films. With a scanning laser beam, microdomains with well-defined structures and controllable thickness were created on the same film. We found that laser modification altered the photoelectrical property of the MoS2 films, and subsequently, photodetectors with improved performance have been fabricated and demonstrated using laser modified films.

  6. Three-dimensional collimation of in-plane-propagating light using silicon micromachined mirror

    Science.gov (United States)

    Sabry, Yasser M.; Khalil, Diaa; Saadany, Bassam; Bourouina, Tarik

    2014-03-01

    We demonstrate light collimation of single-mode optical fibers using deeply-etched three-dimensional curved micromirror on silicon chip. The three-dimensional curvature of the mirror is controlled by a process combining deep reactive ion etching and isotropic etching of silicon. The produced surface is astigmatic with out-of-plane radius of curvature that is about one half the in-plane radius of curvature. Having a 300-μm in-plane radius and incident beam inplane inclined with an angle of 45 degrees with respect to the principal axis, the reflected beam is maintained stigmatic with about 4.25 times reduction in the beam expansion angle in free space and about 12-dB reduction in propagation losses, when received by a limited-aperture detector.

  7. Measurement of cell motility on proton beam micromachined 3D scaffolds

    International Nuclear Information System (INIS)

    Zhang, F.; Sun, F.; Kan, J.A. van; Shao, P.G.; Zheng, Z.; Ge, R.W.; Watt, F.

    2005-01-01

    Tissue engineering is a rapidly developing and highly interdisciplinary field that applies the principles of cell biology, engineering and material science. In natural tissues, the cells are arranged in a three-dimensional (3D) matrix which provides the appropriate functional, nutritional and spatial conditions. In scaffold guided tissue engineering 3D scaffolds provide the critical function of acting as extracellular matrices onto which cells can attach, grow, and form new tissue. The main focus of this paper is to understand cell behavior on micro-grooved and ridged substrates and to study the effects of geometrical constraints on cell motility and cell function. In this study, we found that BAE (Bovine Aortic Endothelial) cells naturally align with and are guided along 3D ridges and grooves machined into polymethylmethacrylate (PMMA) substrates. Average cell speed on micro-grooves and ridges ranged from 0.015 μm/s (for 12 μm wide and 10 μm deep ridges) to 0.025 μm/s (for 20 μm wide and 10 μm deep ridges). This compares with the cell motility rate on a flat PMMA surface where the average cell speed is around 0.012 μm/s. In this work we used scaffolds which were directly written with a focused proton beam, typically 1 MeV protons with a beam spot size of 1 x 1 μm 2

  8. Micromachined filter-chamber array with passive valves for biochemical assays on beads.

    Science.gov (United States)

    Andersson, H; van der Wijngaart, W; Stemme, G

    2001-01-01

    The filter-chamber array presented here enables a real-time parallel analysis of three different samples on beads in a volume of 3 nL, on a 1 cm2 chip. The filter-chamber array is a system containing three filter-chambers, three passive valves at the inlet channels and a common outlet. The design enables parallel sample handling and time-controlled analysis. The device is microfabricated in silicon and sealed with a Pyrex lid to enable real-time analysis. Single nucleotide polymorphism analysis by using pyrosequencing has successfully been performed in single filter-chamber devices. The passive valves consist of plasma-deposited octafluorocyclobutane and show a much higher resistance towards water and surface-active solutions than previous hydrophobic patches. The device is not sensitive to gas bubbles, clogging is rare and reversible, and the filter-chamber array is reusable. More complex (bio)chemical reactions on beads can be performed in the devices with passive valves than in the devices without valves.

  9. Mechanism and experimental study on three-dimensional facula shaping in femtosecond laser micromachining

    Science.gov (United States)

    Pan, Xuetao; Tu, Dawei; Cai, Jianwen

    2015-10-01

    Because of the laser beam waist and diffraction effect of the lens, the focal spot light field in femtosecond laser microprocessing has an ellipsoidal spatial distribution. This leads to the gap between two processing layers increasing along the axial direction, and the distribution density of processing points decreasing along the horizontal direction. This directly reduces the resolution of the microprocessing, and badly affects the machining accuracy and surface quality. We established a mathematical model for three-dimensional (3-D) laser beam shaping based on the Fresnel diffraction theory and designed a kind of four-ring complex amplitude transmittance phase plate by using a global optimization algorithm and genetic algorithm to simultaneously realize transverse and axial 3-D shaping. We numerically showed that the transverse and axial gains of the focal facula after 3-D shaping are 0.77 and 0.68, respectively, where the corresponding peak energy ratio is 0.36, the transverse and axial sidelobe energies are 0.28 and 0.62, respectively, and the defocusing amount is -0.08. We also constructed a confocal/two-photon microscope system to experimentally achieve a better shaping effect in the case of femtosecond laser fabrication at a point on the thin film of a photochromic material.

  10. Long-term outdoor reliability assessment of a wireless unit for air-quality monitoring based on nanostructured films integrated on micromachined platforms.

    Science.gov (United States)

    Leccardi, Matteo; Decarli, Massimiliano; Lorenzelli, Leandro; Milani, Paolo; Mettala, Petteri; Orava, Risto; Barborini, Emanuele

    2012-01-01

    We have fabricated and tested in long-term field operating conditions a wireless unit for outdoor air quality monitoring. The unit is equipped with two multiparametric sensors, one miniaturized thermo-hygrometer, front-end analogical and digital electronics, and an IEEE 802.15.4 based module for wireless data transmission. Micromachined platforms were functionalized with nanoporous metal-oxides to obtain multiparametric sensors, hosting gas-sensitive, anemometric and temperature transducers. Nanoporous metal-oxide layer was directly deposited on gas sensing regions of micromachined platform batches by hard-mask patterned supersonic cluster beam deposition. An outdoor, roadside experiment was arranged in downtown Milan (Italy), where one wireless sensing unit was continuously operated side by side with standard gas chromatographic instrumentation for air quality measurements. By means of a router PC, data from sensing unit and other instrumentation were collected, merged, and sent to a remote data storage server, through an UMTS device. The whole-system robustness as well as sensor dataset characteristics were continuously characterized over a run-time period of 18 months.

  11. 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.

  12. 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.

  13. 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)

  14. 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)

  15. Optical vibration measurements of cross coupling effects in capacitive micromachined ultrasonic transducer arrays

    Science.gov (United States)

    Leirset, Erlend; Aksnes, Astrid

    2011-05-01

    Optical vibration measurement systems are excellent tools for characterizing ultrasonic transducers. This paper presents measurements on immersed arrays of capacitive ultrasonic transducers (CMUTs) using a heterodyne interferometer. The interferometer allows measurements of vibrations from DC up to 1 GHz with a noise floor of ~1pm/√Hz. Previously CMUTs have been characterized in air. The transducer is intended for intravascular use. Therefore the CMUTs were characterized in the transparent fluids kerosene and rapeseed oil that have acoustic properties closer to blood. The optical measurements on immersed CMUTs were validated by assessing the measurement errors caused by the acousto optic effects in the fluid. When immersed there is significant cross coupling between individual CMUTs within an array. Simulations presented here indicate that this causes an acoustic wave mode that is bound to the interface between the CMUTs and the fluid. This is confirmed by measurements of the phase velocity and attenuation coefficient of this wave. The measurement results indicate that the wave exists up to a maximum frequency and that the attenuation constant increases with increasing frequency. Rapeseed oil causes a significantly larger attenuation coefficient than kerosene, which most probably is due to a considerable difference in fluid viscosities. There was a mismatch between the simulated and measured phase velocity for low frequencies. It is likely that the cause of this is coupling between the fluid CMUT interface waves and Lamb waves in the substrate of the CMUT array. Measurements performed with the heterodyne interferometer have confirmed the presence of dispersive waves bound to the surface of the transducer by directly showing their propagation along the array. The setup has also characterized the bound waves by measuring dispersion relations.

  16. Micromachined chemical jet dispenser

    Science.gov (United States)

    Swierkowski, S.P.

    1999-03-02

    A dispenser is disclosed for chemical fluid samples that need to be precisely ejected in size, location, and time. The dispenser is a micro-electro-mechanical systems (MEMS) device fabricated in a bonded silicon wafer and a substrate, such as glass or silicon, using integrated circuit-like fabrication technology which is amenable to mass production. The dispensing is actuated by ultrasonic transducers that efficiently produce a pressure wave in capillaries that contain the chemicals. The 10-200 {micro}m diameter capillaries can be arranged to focus in one spot or may be arranged in a larger dense linear array (ca. 200 capillaries). The dispenser is analogous to some ink jet print heads for computer printers but the fluid is not heated, thus not damaging certain samples. Major applications are in biological sample handling and in analytical chemical procedures such as environmental sample analysis, medical lab analysis, or molecular biology chemistry experiments. 4 figs.

  17. Micromachined hydraulic astable multivibrator

    NARCIS (Netherlands)

    Lammerink, Theodorus S.J.; Tas, Niels Roelof; Berenschot, Johan W.; Elwenspoek, Michael Curt; Fluitman, J.H.J.

    1995-01-01

    The paper presents a hydraulic astable multivibrator system. The system consists of hydraulic resistors, hydraulic capacitors and hydraulic pressure controlled valves. The system is designed, realised and tested. The measured system behaviour agrees well with the model simulations. The free running

  18. Silicon and Glass Micromachining

    NARCIS (Netherlands)

    Carlen, Edwin; Bomer, Johan G.; van Nieuwkasteele, Jan William; van den Berg, Albert; Herold, K.E.; Rasooly, A.

    The past two decades have seen rapid advancement of Lab on a Chip (LOC) systems with applications ranging from gas chromatography to capillary electrophoresis, and more recently to high-pressure chemistry and single cell analysis. For many applications in clinical medicine, biology and chemistry,

  19. 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.

  20. SummitView 1.0: a code to automatically generate 3D solid models of surface micro-machining based MEMS designs.

    Energy Technology Data Exchange (ETDEWEB)

    McBride, Cory L. (Elemental Technologies, American Fort, UT); Yarberry, Victor R.; Schmidt, Rodney Cannon; Meyers, Ray J. (Elemental Technologies, American Fort, UT)

    2006-11-01

    This report describes the SummitView 1.0 computer code developed at Sandia National Laboratories. SummitView is designed to generate a 3D solid model, amenable to visualization and meshing, that represents the end state of a microsystem fabrication process such as the SUMMiT (Sandia Ultra-Planar Multilevel MEMS Technology) V process. Functionally, SummitView performs essentially the same computational task as an earlier code called the 3D Geometry modeler [1]. However, because SummitView is based on 2D instead of 3D data structures and operations, it has significant speed and robustness advantages. As input it requires a definition of both the process itself and the collection of individual 2D masks created by the designer and associated with each of the process steps. The definition of the process is contained in a special process definition file [2] and the 2D masks are contained in MEM format files [3]. The code is written in C++ and consists of a set of classes and routines. The classes represent the geometric data and the SUMMiT V process steps. Classes are provided for the following process steps: Planar Deposition, Planar Etch, Conformal Deposition, Dry Etch, Wet Etch and Release Etch. SummitView is built upon the 2D Boolean library GBL-2D [4], and thus contains all of that library's functionality.

  1. Examination of returned solar-max surfaces for impacting orbital debris and meteoroids

    Science.gov (United States)

    Kessler, D. J.; Zook, H. A.; Potter, A. E.; Mckay, D. S.; Clanton, U. S.; Warren, J. L.; Watts, L. A.; Schultz, R. A.; Schramm, L. S.; Wentworth, S. J.

    1985-01-01

    Previous theoretical studies predicted that in certain regions of earth orbit, the man-made earth orbiting debris environment will soon exceed the interplanetary meteoroid environment for sizes smaller than 1 cm. The surfaces returned from the repaired Solar Max Mission (SMM) by STS 41-C on April 12, 1984, offered an excellent opportunity to examine both the debris and meteoroid environments. To date, approximately 0.7 sq. met. of the thermal insulation and 0.05 sq. met of the aluminum louvers have been mapped by optical microscope for crater diameters larger than 40 microns. Craters larger in diameter than about 100 microns found on the initial 75 micron thick Kapton first sheet on the MEB (Main Electronics Box) blanket are actually holes and constitute perforations through that blanket. The following populations have been found to date in impact sites on these blankets: (1) meteoritic material; (2) thermal paint particles; (3) aluminum droplets; and (4) waste particles.

  2. Micromachining and validation of the scanning acoustic microscope spatial resolution and sensitivity calibration block for 20–230 MHz frequency range

    International Nuclear Information System (INIS)

    Tamulevicius, Tomas; Simatonis, Linas; Ulcinas, Orestas; Tamulevicius, Sigitas; Zukauskas, Egidijus; Rekuviene, Regina; Mazeika, Liudas

    2016-01-01

    Scanning acoustic microscopy (SAM) is used as a routine non-destructive test tool for different diagnostic examinations: detection of defects such as microcracks, delamination, disbonding, inclusions, subsurface features in materials such as pores and cracks. SAM can be operated in a wide frequency range from Megahertz to Gigahertz. SAM measurement spatial resolution is diffraction limited by the wavelength of the acoustic wave in particular medium and also depends on individual transducers geometry. Actual SAM spatial resolution can be determined by measuring calibrated lithographically formed microstructures in high acoustic impedance materials. Numerical acoustic signal simulation method, based on the diffraction approach, was employed for the selection of the calibration block pattern geometry and linear dimensions of the elements. Universal calibration block for SAM operating in a 20–230 MHz frequency range was micromachined in high acoustic impedance ceramic substrates. Differently spaced (from 18 to 185 µm) lines of the same width and different widths (from 17 to 113 µm) but similar spacing lines were imposed in alumina ceramics employing one step lithography process, i.e. femtosecond laser ablation. Proposed SAM calibration pattern linear dimensions were characterized employing optical and scanning electron microscopy. Finally the samples were measured with SAM employing different frequency transducers and results were compared with the numerical simulations. It was obtained that resolution of SAM operating with 230 MHz transducer is not worse than 40 µm. (author)

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Phosphorene: Enhanced Photoresponse from Phosphorene-Phosphorene-Suboxide Junction Fashioned by Focused Laser Micromachining (Adv. Mater. 21/2016).

    Science.gov (United States)

    Lu, Junpeng; Carvalho, Alexandra; Wu, Jing; Liu, Hongwei; Tok, Eng Soon; Neto, Antonio H Castro; Özyilmaz, Barbaros; Sow, Chorng Haur

    2016-06-01

    On page 4090, B. Özyilmaz, C. H. Sow, and co-workers use a focused laser beam to modify the surface of a phosphorene device. With a simple focused laser beam, a part of the phosphorene can be scanned and converted into phosphorene-suboxide species, leaving behind a functional and active phosphorene-phosphorene suboxide junction in the device. Once the junction is formed, the photoresponsivity and photocurrent distribution of the device can be significantly altered with a qualitative difference in behavior. Photovoltaic-like behavior is observed, which is not found in the pristine sample. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. 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.

  9. Performance and characterisation of CVD diamond coated, sintered diamond and WC-Co cutting tools for dental and micromachining applications

    International Nuclear Information System (INIS)

    Sein, Htet; Ahmed, Waqar; Jackson, Mark; Woodwards, Robert; Polini, Riccardo

    2004-01-01

    Diamond coatings are attractive for cutting processes due to their high hardness, low friction coefficient, excellent wear resistance and chemical inertness. The application of diamond coatings on cemented tungsten carbide (WC-Co) tools was the subject of much attention in recent years in order to improve cutting performance and tool life. WC-Co tools containing 6% Co and 94% WC substrate with an average grain size 1-3 μm were used in this study. In order to improve the adhesion between diamond and WC substrates, it is necessary to etch away the surface Co and prepare the surface for subsequent diamond growth. Hot filament chemical vapour deposition with a modified vertical filament arrangement has been employed for the deposition of diamond films. Diamond film quality and purity have been characterised using scanning electron microscopy and micro-Raman spectroscopy. The performance of diamond coated WC-Co bur, uncoated WC-Co bur, and diamond embedded (sintered) bur have been compared by drilling a series of holes into various materials such as human teeth, borosilicate glass and porcelain teeth. Flank wear has been used to assess the wear rates of the tools. The materials subjected to cutting processes have been examined to assess the quality of the finish. Diamond coated WC-Co microdrills and uncoated microdrills were also tested on aluminium alloys. Results show that there was a 300% improvement when the drills were coated with diamond compared to the uncoated tools

  10. Geometrical profile of material surface ablated with highpower, short-pulse lasers in ambient gas media

    Science.gov (United States)

    Vatsya, S. R.; Nikumb, S. K.

    2007-04-01

    Finer and cleaner features are expected in micro-machining with high power, ultrashort pulse lasers as the melt and evaporation phases are considerably reduced. However, a high-intensity optical beam propagating through a gaseous medium can cause its breakdown generating plasma, which is enhanced further by the self focusing effect of the medium. Photon-plasma scattering compensates somewhat for the self-focusing, but it also distorts the beam profile with consequent impact on the fabricated surface. Plasma also continues to supply heat beyond the pulse duration, which may cause melting and thus distort the features further. In the present article, we show that suitable parameters can be determined to reduce the distortion to the beam profile and balance self-focusing and plasma defocusing resulting in plasma filamentation. Well-shaped beam and plasma filaments, both have favourable impact on the fabricated features. The calculated surface features are compared with the experimentally machined crater profiles with good agreement.

  11. 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.)

  12. Sclero-topometry Metrology in Valorisation of Waste Oil for Micro-machining of Ductile Cast Iron

    Directory of Open Access Journals (Sweden)

    Eymard S.

    2013-12-01

    Full Text Available During the time, the specific characteristics and the efficient lifetime of oil progressively decrease, due to complex pollution, ultimately making the oil unsuitable for the initial applications. The strategy to regenerate and to valorise waste oils is investigated using improved combinations of sclerometric and topometric tests on ductile nodular cast iron. Tribo-abrasive tests are performed in critical conditions, with base oil, waste oil and regenerated oil, of similar viscosities in order to discriminate their interfacial performances. The forms of the scratch traces indicate wear resistance and tendency to elasto-plastic deformation. The mechanisms of deformation and frictional behaviours were evaluated using optical and Scanning Electron Microscopy and measured for various tribological conditions with tactile and optical profilometry. The Energy Dispersive X ray Spectroscopy completes the chemical superficial distribution of pertinent elements. The surface topography metrology is used to characterize the scratch profiles and to determine the volume of the displaced and removed material, as well as maximum pit height. The originality of this paper is that it is a unique approach specifically devoted to transformer oil concerning tribological conditions.

  13. 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.

  14. Sustainable Materials Management (SMM) - Recycling Economic Information (REI) Report

    Science.gov (United States)

    The 2016 Recycling Economic Information (REI) Report aims to increase the understanding of the economic implications of material reuse and recycling. The report shows that recycling and reuse of materials creates jobs, while also generating local and state tax revenues. The 2016 REI Report covers the economic activities of nine sectors: ferrous metals, nonferrous metals (aluminum), glass, paper, plastics, rubber, construction and demolition, electronics and organics (including food and yard trimmings). The 2016 REI Report builds on work from a 2001 REI study. In 2001, to encourage the development of an economic market for recycling, EPA supported the creation of a national Recycling Economic Information (REI) Project and the related REI report, based upon the work of several states and regions. The REI report was a ground breaking national study demonstrating the economic value of recycling and reuse to the U.S. economy. Compiled through a cooperative agreement with the National Recycling Coalition, the study confirmed what many have known for decades: there are significant economic benefits in recycling. The 2016 report focuses on the economic impacts of recycling rather than the environmental benefits, as the environmental benefits have been researched in detail. Accurately estimating the impact that recycling has on jobs, wages and taxes is important because the results can influence policy decisions and provide a more robust picture of recycling by a

  15. Secondary mortgage market (SMM): Is it right for financing housing ...

    African Journals Online (AJOL)

    The formal housing finance system in Ghana is inadequate and highly underdeveloped. The formal finance institutions have provided very little mortgages particularly to the low and middle-income households. However, the fast growing capital market of Ghana offers an opportunity for sustainable housing finance in the ...

  16. Sustainable Materials Management (SMM) Food Recovery Challenge (FRC) Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — As part of EPA's Food Recovery Challenge (FRC), organizations pledge to improve their sustainable food management practices and report their results. The FRC is part...

  17. Secondary mortgage market (SMM): Is it right for financing housing ...

    African Journals Online (AJOL)

    Journal of Science and Technology (Ghana). Journal Home · ABOUT · Advanced Search · Current Issue · Archives · Journal Home > Vol 29, No 1 (2009) >. Log in or Register to get access to full text downloads.

  18. Transfer of knowledge in international cooperation: the Farmanguinhos - SMM case.

    Science.gov (United States)

    Silva, Samuel Araujo Gomes da; Duarte, Roberto Gonzalez; Castro, José Márcio de

    2017-01-01

    To analyze the influence of four mechanisms of knowledge transfer (training, technical visits, expatriation, and standard operating procedures) on the different dimensions (potential and realized) of absorptive capacity in international technical cooperation. We examine the case of implementation of the Sociedade Moçambicana de Medicamentos. Data have been collected using semi-structured interviews (applied to 21 professionals of the Sociedade Moçambicana de Medicamentos, Farmanguinhos, FIOCRUZ, and Itamaraty) and official documents. The data of the interviews have been submitted to content analysis, using the software NVivo. Training and technical visits directly influenced the acquisition and, partly, the assimilation of knowledge. Expatriation contributed with the transformation of this knowledge from the development and refinement of operational routines. Finally, the definition of standard operating procedures allowed the Mozambican technicians to be the actors of the transformation of the knowledge previously acquired and assimilated and, at the same time, it laid the foundations for a future exploration of the knowledge. Training and technical visits mainly influence the potential absorptive capacity, while expatriation and standard operating procedures most directly affect the realized absorptive capacity.

  19. Sustainable Materials Management (SMM) WasteWise Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — EPA’s WasteWise encourages organizations and businesses to achieve sustainability in their practices and reduce select industrial wastes. WasteWise is part of EPA’s...

  20. Sustainable Materials Management (SMM) - Recycling Economic Information (REI) Report

    Data.gov (United States)

    U.S. Environmental Protection Agency — The 2016 Recycling Economic Information (REI) Report aims to increase the understanding of the economic implications of material reuse and recycling. The report...

  1. Design and Analysis of a Micromechanical Three-Component Force Sensor for Characterizing and Quantifying Surface Roughness

    Directory of Open Access Journals (Sweden)

    Liang Q.

    2015-10-01

    Full Text Available Roughness, which can represent the trade-off between manufacturing cost and performance of mechanical components, is a critical predictor of cracks, corrosion and fatigue damage. In order to measure polished or super-finished surfaces, a novel touch probe based on three-component force sensor for characterizing and quantifying surface roughness is proposed by using silicon micromachining technology. The sensor design is based on a cross-beam structure, which ensures that the system possesses high sensitivity and low coupling. The results show that the proposed sensor possesses high sensitivity, low coupling error, and temperature compensation function. The proposed system can be used to investigate micromechanical structures with nanometer accuracy.

  2. Minimal surfaces

    CERN Document Server

    Dierkes, Ulrich; Sauvigny, Friedrich; Jakob, Ruben; Kuster, Albrecht

    2010-01-01

    Minimal Surfaces is the first volume of a three volume treatise on minimal surfaces (Grundlehren Nr. 339-341). Each volume can be read and studied independently of the others. The central theme is boundary value problems for minimal surfaces. The treatise is a substantially revised and extended version of the monograph Minimal Surfaces I, II (Grundlehren Nr. 295 & 296). The first volume begins with an exposition of basic ideas of the theory of surfaces in three-dimensional Euclidean space, followed by an introduction of minimal surfaces as stationary points of area, or equivalently

  3. 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

  4. Automated micromachining at the NSLS

    International Nuclear Information System (INIS)

    Ramotowski, Michelle; Johnson, Erik

    2000-01-01

    X14B, the newest beamline at the NSLS, saw its first light early this summer. Designed solely for deep x-ray lithography (DXRL), it is intended for processing large quantities of deep (up to a few mm), but essentially 2D in design, parts. It has an effective scan area of 637 cm2, and a hydraulic scan stage to move that area through the beam. In addition, work is being done at X27B for the development of in-the-round and true 3D lithography. The hydraulic scan stages, filter motors, and sample positioning motors on both beamlines are computer controlled. Scan time and speed are calculated based on beam current, and a beam monitor stops the scan if necessary (due to unexpected beam dump, etc) and re-starts it when appropriate. The user can start a scan to run overnight, and return the next morning to pick up a completed sample. In addition, scan progress can be checked remotely via a web page

  5. Rumble surfaces

    CSIR Research Space (South Africa)

    National Institute for Transport and Road

    1977-01-01

    Full Text Available Rumble surfaces are intermittent short lengths of coarse-textured road surfacings on which vehicle tyres produce a rumbling sound. used in conjunction with appropriate roadsigns and markings, they can reduce accidents on rural roads by alerting...

  6. Surface thermodynamics

    International Nuclear Information System (INIS)

    Garcia-Moliner, F.

    1975-01-01

    Basic thermodynamics of a system consisting of two bulk phases with an interface. Solid surfaces: general. Discussion of experimental data on surface tension and related concepts. Adsorption thermodynamics in the Gibbsian scheme. Adsorption on inert solid adsorbents. Systems with electrical charges: chemistry and thermodynamics of imperfect crystals. Thermodynamics of charged surfaces. Simple models of charge transfer chemisorption. Adsorption heat and related concepts. Surface phase transitions

  7. Adhesive Force of a Spider Mite, Tetranychus urticae, to a Flat Smooth Surface

    Science.gov (United States)

    Mizutani, Katsumi; Egashira, Kai; Toukai, Tadashi; Ogushi, Jun

    The adhesion of a spider mite to a surface of a flat smooth plate is investigated as a model for micromachine parts to adhere to and move on such surfaces. The measurement of adhesive force is carried out under various conditions in which plate material, surface roughness of a plate and environmental humidity are differed. The adhesion mechanism is also discussed. Of the forces acting between a spider mite and a surface, one from dispersion interaction is the most dominant because (1) there is a high correlation between the adhesive force and the dispersion force component of surface energy with adhesive forces of 8.2µN for glass, 9.7µN for mica, 9.9µN for silicon and 12.1µN for gold, and because (2) high humidity and high surface roughness reduce the adhesive force. For strong adhesion based on work of adhesion, spider mites have tenent hairs with a bell-shaped end.

  8. Superhydrophobic surfaces

    Science.gov (United States)

    Wang, Evelyn N; McCarthy, Matthew; Enright, Ryan; Culver, James N; Gerasopoulos, Konstantinos; Ghodssi, Reza

    2015-03-24

    Surfaces having a hierarchical structure--having features of both microscale and nanoscale dimensions--can exhibit superhydrophobic properties and advantageous condensation and heat transfer properties. The hierarchical surfaces can be fabricated using biological nanostructures, such as viruses as a self-assembled nanoscale template.

  9. Spherical Surfaces

    DEFF Research Database (Denmark)

    Brander, David

    2016-01-01

    We study surfaces of constant positive Gauss curvature in Euclidean 3-space via the harmonicity of the Gauss map. Using the loop group representation, we solve the regular and the singular geometric Cauchy problems for these surfaces, and use these solutions to compute several new examples. We give...

  10. Laser-induced novel patterns: As smart strain actuators for new-age dental implant surfaces

    International Nuclear Information System (INIS)

    Çelen, Serap; Özden, Hüseyin

    2012-01-01

    Highlights: ► It is time for that paradigm shift and for an exploration of novel surfaces. ► We developed novel 3D smart surfaces as strain actuators by nanosecond laser pulse energies. ► We analyzed these smart surface morphologies using FEM. ► We estimated their internal stiffness values which play a great role on stress shielding effect. ► We gave the optimum operation parameters. - Abstract: Surface morphologies of titanium implants are of crucial importance for long-term mechanical adaptation for following implantation. One major problem is the stress shielding effect which originates from the mismatch of the bone and the implant elasticity. It is time for a paradigm shift and for an exploration of novel smart surfaces to prevent this problem. Several surface treatment methods have traditionally been used to modify the surface morphology of titanium dental implants. The laser micro-machining can be considered as a unique and promising, non-contact, no media, contamination free, and flexible treatment method for modifying surface properties of materials in the biomedical industry. The aim of the present study is two folds; to develop novel 3D smart surfaces which can be acted as strain actuators by nanosecond laser pulse energies and irradiation strategies. And analyze these smart surface morphologies using finite element methods in order to estimate their internal stiffness values which play a great role on stress shielding effect. Novel 3D smart strain actuators were prepared using an ytterbium fiber laser (λ = 1060 nm) with 200–250 ns pulse durations on commercial pure titanium dental implant material specimen surfaces and optimum operation parameters were suggested.

  11. 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)

  12. A combination of CO2 laser and plasma surface modification of poly(etheretherketone) to enhance osteoblast response

    Science.gov (United States)

    Zheng, Yanyan; Xiong, Chengdong; Wang, Zhecun; Li, Xiaoyu; Zhang, Lifang

    2015-07-01

    Poly(etheretherketone) (PEEK) is a rigid semicrystalline polymer that combines excellent mechanical properties, broad chemical resistance and bone-like stiffness and is widely used in biomedical fields. However, the bio-inert surface of PEEK tends to hinder its biomedical applications when direct osteointegration between the implants and the host tissue is desired. In this work, we demonstrate a dual modification method, which combines the laser and plasma surface treatment to combine advantages of both chemical states and microstructures for osteoblasts responses. While the plasma treatment introduces surface carboxyl groups (sbnd COOH) onto PEEK surface, the laser treatment constructs microstructures over the PEEK surface. Our results indicated that sbnd COOH as well as microgrooves containing micropores or microcraters structure are constructed on PEEK surface and plasma treatment has no apparent effect on the morphology of microstructures produced by laser micromachining. Unexpectedly, the superior mechanical properties of PEEK were maintained irrespective of the treatment used. Compared to native PEEK and single treated PEEK, dual modified PEEK is more favorable for pre-osteoblasts (MC3T3-E1) adhesion, spreading and proliferation. Moreover, cell pseudopodia protrude into the micropores or microcraters, in favor of forming firmer bone-implant integration. Our study illustrates enhanced osteoblasts responses to dual treated PEEK surface, which gives beneficial information of its potential use in orthopedic or dental implants.

  13. Surface boxplots

    KAUST Repository

    Genton, Marc G.

    2014-01-22

    In this paper, we introduce a surface boxplot as a tool for visualization and exploratory analysis of samples of images. First, we use the notion of volume depth to order the images viewed as surfaces. In particular, we define the median image. We use an exact and fast algorithm for the ranking of the images. This allows us to detect potential outlying images that often contain interesting features not present in most of the images. Second, we build a graphical tool to visualize the surface boxplot and its various characteristics. A graph and histogram of the volume depth values allow us to identify images of interest. The code is available in the supporting information of this paper. We apply our surface boxplot to a sample of brain images and to a sample of climate model outputs.

  14. Convex surfaces

    CERN Document Server

    Busemann, Herbert

    2008-01-01

    This exploration of convex surfaces focuses on extrinsic geometry and applications of the Brunn-Minkowski theory. It also examines intrinsic geometry and the realization of intrinsic metrics. 1958 edition.

  15. Surface decontamination

    International Nuclear Information System (INIS)

    Silva, S. da; Teixeira, M.V.

    1986-06-01

    The general methods of surface decontamination used in laboratory and others nuclear installations areas, as well as the procedures for handling radioactive materials and surfaces of work are presented. Some methods for decontamination of body external parts are mentioned. The medical supervision and assistance are required for internal or external contamination involving or not lesion in persons. From this medical radiation protection decontamination procedures are determined. (M.C.K.) [pt

  16. Fabrication of microlens array on silicon surface using electrochemical wet stamping technique

    Science.gov (United States)

    Lai, Lei-Jie; Zhou, Hang; Zhu, Li-Min

    2016-02-01

    This paper focuses on the fabrication of microlens array (MLA) on silicon surface by taking advantage of a novel micromachining approach, the electrochemical we stamping (E-WETS). The E-WETS allows the direct imprinting of MLA on an agarose stamp into the substrate through a selective anodic dissolution process. The pre-patterned agarose stamp can direct and supply the solution preferentially on the contact area between the agarose stamp and the substrate, to which the electrochemical reaction is confined. The anodic potential vs. saturated calomel electrode is optimized and 1.5 V is chosen as the optimum value for the electrochemical polishing of p-Si. A refractive MLA on a PMMA mold is successfully transferred onto the p-Si surface. The machining deviations of the fabricated MLA from those on the mold are 0.44% in diameter and 2.1% in height respectively, and the machining rate in HF is around 1.1 μm/h. The surface roughness of the fabricated MLA is less than 12 nm owing to the electrochemical polishing process. The results demonstrate that E-WETS is a promising approach to fabricate MLA on p-Si surface with high accuracy and efficiency.

  17. Surface phonons

    CERN Document Server

    Wette, Frederik

    1991-01-01

    In recent years substantial progress has been made in the detection of surface phonons owing to considerable improvements in inelastic rare gas scattering tech­ niques and electron energy loss spectroscopy. With these methods it has become possible to measure surface vibrations in a wide energy range for all wave vectors in the two-dimensional Brillouin zone and thus to deduce the complete surface phonon dispersion curves. Inelastic atomic beam scattering and electron energy loss spectroscopy have started to play a role in the study of surface phonons similar to the one played by inelastic neutron scattering in the investigation of bulk phonons in the last thirty years. Detailed comparison between experimen­ tal results and theoretical studies of inelastic surface scattering and of surface phonons has now become feasible. It is therefore possible to test and to improve the details of interaction models which have been worked out theoretically in the last few decades. At this point we felt that a concise, co...

  18. Ice Surfaces

    Science.gov (United States)

    Shultz, Mary Jane

    2017-05-01

    Ice is a fundamental solid with important environmental, biological, geological, and extraterrestrial impact. The stable form of ice at atmospheric pressure is hexagonal ice, Ih. Despite its prevalence, Ih remains an enigmatic solid, in part due to challenges in preparing samples for fundamental studies. Surfaces of ice present even greater challenges. Recently developed methods for preparation of large single-crystal samples make it possible to reproducibly prepare any chosen face to address numerous fundamental questions. This review describes preparation methods along with results that firmly establish the connection between the macroscopic structure (observed in snowflakes, microcrystallites, or etch pits) and the molecular-level configuration (detected with X-ray or electron scattering techniques). Selected results of probing interactions at the ice surface, including growth from the melt, surface vibrations, and characterization of the quasi-liquid layer, are discussed.

  19. Surfacing Moves

    DEFF Research Database (Denmark)

    Lutz, Peter

    2013-01-01

    such as schedules, machines, and aging bodies. To this end, the article also experiments with ‘surfacing’ as an ethnographic heuristic for figuring these different ‘spatial-timings’. The article concludes that surfacing matters not only in senior home care but also in the field-desks of ethnographic analysis....

  20. Attack surfaces

    DEFF Research Database (Denmark)

    Gruschka, Nils; Jensen, Meiko

    2010-01-01

    The new paradigm of cloud computing poses severe security risks to its adopters. In order to cope with these risks, appropriate taxonomies and classification criteria for attacks on cloud computing are required. In this work-in-progress paper we present one such taxonomy based on the notion...... of attack surfaces of the cloud computing scenario participants....

  1. 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)

  2. 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.

  3. Surface-micromachined Bragg Reflectors Based on Multiple Airgap/SiO2 Layers for CMOS-compatible Fabry-perot Filters in the UV-visible Spectral Range

    NARCIS (Netherlands)

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

    2014-01-01

    In CMOS-compatible optical filter designs, SiO2 is often used as the low-index material, limiting the optical contrast (nHi/nLo) to about 2. Using the air as low-index material improves the optical contrast by about 50%, thus increasing the reflectivity and bandwidth at a given design complexity.

  4. A combination of CO{sub 2} laser and plasma surface modification of poly(etheretherketone) to enhance osteoblast response

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Yanyan [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Xiong, Chengdong [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); Wang, Zhecun [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Li, Xiaoyu [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Zhang, Lifang, E-mail: zhanglfcioc@163.com [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China)

    2015-07-30

    Highlights: • COOH and microgrooves containing micropores or microcraters structure were constructed on PEEK surface by a combination of CO{sub 2} laser and plasma treatment. • The mechanical properties of PEEK are maintained after single or dual surface treatment. • Pre-osteoblast cells (MC3T3-E1) adhesion, spreading and proliferation were improved remarkably on dual treated PEEK surface. • Cell pseudopodia protrude into the micropores or microcraters, in favor of forming firmer bone-implant integration. - Abstract: Poly(etheretherketone) (PEEK) is a rigid semicrystalline polymer that combines excellent mechanical properties, broad chemical resistance and bone-like stiffness and is widely used in biomedical fields. However, the bio-inert surface of PEEK tends to hinder its biomedical applications when direct osteointegration between the implants and the host tissue is desired. In this work, we demonstrate a dual modification method, which combines the laser and plasma surface treatment to combine advantages of both chemical states and microstructures for osteoblasts responses. While the plasma treatment introduces surface carboxyl groups (−COOH) onto PEEK surface, the laser treatment constructs microstructures over the PEEK surface. Our results indicated that −COOH as well as microgrooves containing micropores or microcraters structure are constructed on PEEK surface and plasma treatment has no apparent effect on the morphology of microstructures produced by laser micromachining. Unexpectedly, the superior mechanical properties of PEEK were maintained irrespective of the treatment used. Compared to native PEEK and single treated PEEK, dual modified PEEK is more favorable for pre-osteoblasts (MC3T3-E1) adhesion, spreading and proliferation. Moreover, cell pseudopodia protrude into the micropores or microcraters, in favor of forming firmer bone-implant integration. Our study illustrates enhanced osteoblasts responses to dual treated PEEK surface, which

  5. A combination of CO2 laser and plasma surface modification of poly(etheretherketone) to enhance osteoblast response

    International Nuclear Information System (INIS)

    Zheng, Yanyan; Xiong, Chengdong; Wang, Zhecun; Li, Xiaoyu; Zhang, Lifang

    2015-01-01

    Highlights: • COOH and microgrooves containing micropores or microcraters structure were constructed on PEEK surface by a combination of CO 2 laser and plasma treatment. • The mechanical properties of PEEK are maintained after single or dual surface treatment. • Pre-osteoblast cells (MC3T3-E1) adhesion, spreading and proliferation were improved remarkably on dual treated PEEK surface. • Cell pseudopodia protrude into the micropores or microcraters, in favor of forming firmer bone-implant integration. - Abstract: Poly(etheretherketone) (PEEK) is a rigid semicrystalline polymer that combines excellent mechanical properties, broad chemical resistance and bone-like stiffness and is widely used in biomedical fields. However, the bio-inert surface of PEEK tends to hinder its biomedical applications when direct osteointegration between the implants and the host tissue is desired. In this work, we demonstrate a dual modification method, which combines the laser and plasma surface treatment to combine advantages of both chemical states and microstructures for osteoblasts responses. While the plasma treatment introduces surface carboxyl groups (−COOH) onto PEEK surface, the laser treatment constructs microstructures over the PEEK surface. Our results indicated that −COOH as well as microgrooves containing micropores or microcraters structure are constructed on PEEK surface and plasma treatment has no apparent effect on the morphology of microstructures produced by laser micromachining. Unexpectedly, the superior mechanical properties of PEEK were maintained irrespective of the treatment used. Compared to native PEEK and single treated PEEK, dual modified PEEK is more favorable for pre-osteoblasts (MC3T3-E1) adhesion, spreading and proliferation. Moreover, cell pseudopodia protrude into the micropores or microcraters, in favor of forming firmer bone-implant integration. Our study illustrates enhanced osteoblasts responses to dual treated PEEK surface, which gives

  6. Micromachined, planar-geometry, atmospheric-pressure, battery-operated microplasma devices (MPDs) on chips for analysis of microsamples of liquids, solids, or gases by optical-emission spectrometry.

    Science.gov (United States)

    Karanassios, Vassili; Johnson, Kara; Smith, Andrea T

    2007-08-01

    Because of their desirable characteristics, for example small size, lightness, low power and gas consumption, and potential for portability, miniaturized plasma sources are receiving significant attention in the scientific literature. To take advantage of these characteristics we micromachined and fabricated new, planar-geometry, self-igniting, atmospheric-pressure microplasma devices (MPDs) on chips. These microplasmas required such low power for their operation they could be operated from a re-chargeable battery (of the type used in cordless power-tools). Despite their advantages, most miniaturized plasma sources reported in the literature have not performed well with liquid samples; analysis of powders or solids that can be converted to a powder (and processed and used as slurries) is even more difficult. To address these shortcomings we coupled an electrothermal, mini-in-torch vaporization (mini-ITV) "dry" sample-introduction system to the low-power planar microplasma devices we developed. In this preliminary investigation, absolute detection limits obtained from microsamples of single-element liquid standards and optical emission spectrometry with photomultiplier-tube detection and a spectral bandpass similar to that of portable, commercially available fiber-optic spectrometers were in the low-pg to ng range, for example 2 pg (for K) to 25 ng (for Pb). Mini-ITV also enabled (as far as we are aware, for the first time) measurement of analyte emission from microsamples of powdered solids (as slurries). In addition to the 3% H2 in Ar mixtures, the ac-operated microplasmas were sustained by use of a variety of electrode materials and different plasma-support gases (e.g. Ar, He and 3% H2 in He) thus indicating fabrication versatility and operational flexibility. Such flexibility has the potential to enable microplasmas to be tailored to analytical problems, and this is demonstrated by using a He MPD and chlorine emission measurements (837.594 nm) from gaseous

  7. Resonator structures on AlN ceramics surface treated by laser radiation

    Science.gov (United States)

    Koziol, Pawel E.; Antonczak, Arkadiusz J.; Stepak, Bogusz; Gorski, Przemyslaw A.; Walczakowski, Michal; Palka, Norbert; Abramski, Krzysztof M.

    2014-03-01

    In this paper a method for producing resonant structures using laser micromachining is presented. In the spot of laser beam impact on AlN ceramics surface a conductive aluminum layer is formed. Compilation of process parameters allows for the fabrication of structures with resistance at Rs ~ 0.01Ω/Rs. It has been also found out that the maximum value of resistance for which spiral resonator structures manifest their unique properties is at the level of Rs = 1.43 Ω. Furthermore, the occurrence of mutual capacity which value is dependent on the arrangement of individual SR structures with respect to each other was observed and examined. Based on satisfactory results for SR structures, it has been attempted to produce a resonant structures dedicated to the THz range based on the process of direct metallization of AlN ceramics surface. As a result, the Split Ring Resonator structure whose properties were verified by using the THz -TDS method was manufactured. In case of the field E perpendicular to SRR structure and one resonance area for 0.50 THz with field E parallel to the structure, two characteristic resonant dips for 0.22 THz and 0.46 THz were obtained. The studies confirmed that the method of direct metallization of AlN ceramics allows to produce resonant structures in the THz range.

  8. Surfaces of Building Practice

    OpenAIRE

    Surynková, Petra

    2009-01-01

    My diploma thesis Surfaces of Building Practice deals with the basic properties of surfaces, their mathematical description, categorization, and application in technical practice. Each studied surface is defined and its process of construction and parametrical description is listed. The thesis studies selected types of surfaces in details - these surfaces include surfaces of revolution, ruled surfaces, screw surfaces, and translational surfaces. An application of each studied surfaces is show...

  9. Electronic and magnetic properties of Mn{sub 12} single-molecule magnets on the Au(111) surface

    Energy Technology Data Exchange (ETDEWEB)

    Voss, Soenke; Burgert, Michael; Fonin, Mikhail; Groth, Ulrich; Ruediger, Ulrich [Universitaet Konstanz (Germany); Michaelis, Christian; Brihuega, Ivan; Kern, Klaus [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany); Dedkov, Yury S. [Institut fuer Festkoerperphysik, Technische Universitaet Dresden (Germany)

    2008-07-01

    The paramount interest in single-molecule magnets (SMMs) like Mn{sub 12}-acetate and its derivatives was inspired by numerous experimental and theoretical insights indicating the feasibility of addressing quantum effects of magnetism on a molecular scale. Due to its relatively high blocking temperature ({proportional_to}3 K) combined with the ability to identify well-defined spin states, Mn{sub 12} still remains the most favoured SMM possibly allowing the detection of magnetic fingerprints in transport properties of a single molecule. In this work, the electronic properties of Mn{sub 12} molecules chemically grafted on Au(111) surfaces have been studied by means of low temperature as well as room temperature scanning tunneling microscopy and spectroscopy (STS), X-ray absorption spectroscopy and photoelectron spectroscopy. The results revealed signatures from most probably intact Mn{sub 12} molecules while STS measurements in magnetic fields indicate the possibility to identify magnetic fingerprints in scanning tunneling spectra. The results will be discussed with respect to previous attempts to perform transport measurements on Mn{sub 12} SMMs.

  10. EFAB: A novel, high-aspect-ratio true three-dimensional microfabrication process for rapid, low-cost desktop micromachining of MEMS

    Science.gov (United States)

    Zhang, Gang

    1999-11-01

    Instant Masking, the core technique in EFAB (E&barbelow;lectrochemical FABrication), uses an Instant Mask to realize instant selective plating which speeds up present time-consuming 3-D fabrication processes. One method for fabrication of the silicone-base Instant Mask in presented in detail. Several basic performance characteristics of this Instant Mask were investigated. The major limitation of the Instant Mask is its short service lifetime due to delamination of the silicone rubber during Instant Masking plating. A BTA (Benzotriazole) surface modification method was proposed to extend the immersion lifetime of the Instant Mask in the plating bath. The electrochemical polarization method was used to study the cathodic and anodic processes in Instant Masking plating. Proper bath selection and modification are critical in Instant Masking plating. The performance of bulk nickel plating was investigated by DC electrochemical methods to adjust the related process parameters for meeting EFAB requirements. Internal stress in the deposits could cause failure of microstructures. The flexible strip method was employed to measure internal stresses in deposits produced under different conditions. The use of proper plating parameters and stress reducers can effectively reduce stress in the deposits. To obtain a layered microstructure, the adhesion between adjacent layers is very important. It was found that surface activation prior to plating is a critical step to achieve good adhesion. The effectiveness of several activation methods in increasing the adhesion of nickel deposits was evaluated by adhesion tests. Diamond lapping was chosen as the planarization process. Its operation procedure and limitations are described. Copper etching is the last step in the EFAB process. Both chemical and electrochemical etching were studied and it was found that a commercial chemical etching product worked well for copper etching. The electrochemical etching tests indicated that

  11. Rough surface

    International Nuclear Information System (INIS)

    Hudina, M.

    1982-08-01

    For the determination of the thermal-hydraulic performances of rough surfaces, the method of evaluation is particularly important. In order to increase confidence in the results, a new evaluation procedure was introduced. This procedure is based on the transformation of simple channel experimental results to equal boundary conditions, and on the suitable application and confirmation of these transformed values in more complicated flow channel geometries. Existing methods, applied to the results obtained in an annular channel, do not fulfil all the transformation requirements. Thus a new, more complete transformation method, which uses the turbulent eddy diffusivity model, was developed. To check the quality of this transformation, within the scope of the new evaluation procedure, the results of experimental investigation in annular channels and in a bundle of hexagonal geometry were used together with the predictions of benchmark calculations. The success of the new method was confirmed by extensive comparisons, with the results of different presently-acknowledged transformations being considered as well. Based on these comparisons an assessment of the individual transformations is given. (Auth.)

  12. 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.

  13. Fabrication of multi-scale periodic surface structures on Ti-6Al-4V by direct laser writing and direct laser interference patterning for modified wettability applications

    Science.gov (United States)

    Huerta-Murillo, D.; Aguilar-Morales, A. I.; Alamri, S.; Cardoso, J. T.; Jagdheesh, R.; Lasagni, A. F.; Ocaña, J. L.

    2017-11-01

    In this work, hierarchical surface patterns fabricated on Ti-6Al-4V alloy combining two laser micro-machining techniques are presented. The used technologies are based on nanosecond Direct Laser Writing and picosecond Direct Laser Interference Patterning. Squared shape micro-cells with different hatch distances were produced by Direct Laser Writing with depths values in the micro-scale, forming a well-defined closed packet. Subsequently, cross-like periodic patterns were fabricated by means of Direct Laser Interference Patterning using a two-beam configuration, generating a dual-scale periodic surface structure in both micro- and nano-scale due to the formation of Laser-Induced Periodic Surface Structure after the picosecond process. As a result a triple hierarchical periodic surface structure was generated. The surface morphology of the irradiated area was characterized with scanning electron microscopy and confocal microscopy. Additionally, static contact angle measurements were made to analyze the wettability behavior of the structures, showing a hydrophobic behavior for the hierarchical structures.

  14. Self-Calibration Method Based on Surface Micromaching of Light Transceiver Focal Plane for Optical Camera

    Directory of Open Access Journals (Sweden)

    Jin Li

    2016-10-01

    Full Text Available In remote sensing photogrammetric applications, inner orientation parameter (IOP calibration of remote sensing camera is a prerequisite for determining image position. However, achieving such a calibration without temporal and spatial limitations remains a crucial but unresolved issue to date. The accuracy of IOP calibration methods of a remote sensing camera determines the performance of image positioning. In this paper, we propose a high-accuracy self-calibration method without temporal and spatial limitations for remote sensing cameras. Our method is based on an auto-collimating dichroic filter combined with a surface micromachining (SM point-source focal plane. The proposed method can autonomously complete IOP calibration without the need of outside reference targets. The SM procedure is used to manufacture a light transceiver focal plane, which integrates with point sources, a splitter, and a complementary metal oxide semiconductor sensor. A dichroic filter is used to fabricate an auto-collimation light reflection element. The dichroic filter, splitter, and SM point-source focal plane are integrated into a camera to perform an integrated self-calibration. Experimental measurements confirm the effectiveness and convenience of the proposed method. Moreover, the method can achieve micrometer-level precision and can satisfactorily complete real-time calibration without temporal or spatial limitations.

  15. New Fabrication Method of Three-Electrode System on Cylindrical Capillary Surface as a Flexible Implantable Microneedle

    Science.gov (United States)

    Yang, Zhuoqing; Zhang, Yi; Itoh, Toshihiro; Maeda, Ryutaro

    2013-04-01

    In this present paper, a three-electrode system has been fabricated and integrated on the cylindrical polymer capillary surface by micromachining technology, which could be used as a flexible and implantable microneedle for glucose sensor application in future. A UV lithography system is successfully developed for high resolution alignment on cylindrical substrates. The multilayer alignment exposure for cylindrical polymer capillary substrate is for the first time realized utilizing the lithography system. The ±1 μm alignment precision has been realized on the 330 μm-outer diameter polymer capillary surface, on which the three-electrode structure consisting of two platinum electrodes and one Ag/AgCl reference electrode has been fabricated. The fabricated whole device as microneedle for glucose sensor application has been also characterized in 1 mol/L KCl and 0.02 mol/L K3Fe(CN)6 mix solution. The measured cyclic voltammetry curve shows that the prepared three-electrode system has a good redox property.

  16. On surface approximation using developable surfaces

    DEFF Research Database (Denmark)

    Chen, H. Y.; Lee, I. K.; Leopoldseder, s.

    1999-01-01

    We introduce a method for approximating a given surface by a developable surface. It will be either a G(1) surface consisting of pieces of cones or cylinders of revolution or a G(r) NURBS developable surface. Our algorithm will also deal properly with the problems of reverse engineering and produ...... robust approximation of given scattered data. The presented technique can be applied in computer aided manufacturing, e.g. in shipbuilding. (C) 1999 Academic Press....

  17. On surface approximation using developable surfaces

    DEFF Research Database (Denmark)

    Chen, H. Y.; Lee, I. K.; Leopoldseder, S.

    1998-01-01

    We introduce a method for approximating a given surface by a developable surface. It will be either a G_1 surface consisting of pieces of cones or cylinders of revolution or a G_r NURBS developable surface. Our algorithm will also deal properly with the problems of reverse engineering and produce...... robust approximation of given scattered data. The presented technique can be applied in computer aided manufacturing, e.g. in shipbuilding....

  18. Parametrization of translational surfaces

    OpenAIRE

    Perez-Diaz, Sonia; Shen, Liyong

    2014-01-01

    The algebraic translational surface is a typical modeling surface in computer aided design and architecture industry. In this paper, we give a necessary and sufficient condition for that algebraic surface having a standard parametric representation and our proof is constructive. If the given algebraic surface is translational, then we can compute a standard parametric representation for the surface.

  19. Micromachined Sensors for Hypersonic Flows, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Interdisciplinary Consulting Corporation proposes a sensor that offers the unique capability to make wall shear stress measurement and pressure measurements for time...

  20. Silicon Micromachined Sensor for Broadband Vibration Analysis

    Science.gov (United States)

    Gutierrez, Adolfo; Edmans, Daniel; Cormeau, Chris; Seidler, Gernot; Deangelis, Dave; Maby, Edward

    1995-01-01

    The development of a family of silicon based integrated vibration sensors capable of sensing mechanical resonances over a broad range of frequencies with minimal signal processing requirements is presented. Two basic general embodiments of the concept were designed and fabricated. The first design was structured around an array of cantilever beams and fabricated using the ARPA sponsored multi-user MEMS processing system (MUMPS) process at the Microelectronics Center of North Carolina (MCNC). As part of the design process for this first sensor, a comprehensive finite elements analysis of the resonant modes and stress distribution was performed using PATRAN. The dependence of strain distribution and resonant frequency response as a function of Young's modulus in the Poly-Si structural material was studied. Analytical models were also studied. In-house experimental characterization using optical interferometry techniques were performed under controlled low pressure conditions. A second design, intended to operate in a non-resonant mode and capable of broadband frequency response, was proposed and developed around the concept of a cantilever beam integrated with a feedback control loop to produce a null mode vibration sensor. A proprietary process was used to integrat a metal-oxide semiconductor (MOS) sensing device, with actuators and a cantilever beam, as part of a compatible process. Both devices, once incorporated as part of multifunction data acquisition and telemetry systems will constitute a useful system for NASA launch vibration monitoring operations. Satellite and other space structures can benefit from the sensor for mechanical condition monitoring functions.

  1. Hard turning micro-machine tool

    Science.gov (United States)

    DeVor, Richard E; Adair, Kurt; Kapoor, Shiv G

    2013-10-22

    A micro-scale apparatus for supporting a tool for hard turning comprises a base, a pivot coupled to the base, an actuator coupled to the base, and at least one member coupled to the actuator at one end and rotatably coupled to the pivot at another end. A tool mount is disposed on the at least one member. The at least one member defines a first lever arm between the pivot and the tool mount, and a second lever arm between the pivot and the actuator. The first lever arm has a length that is less than a length of the second lever arm. The actuator moves the tool mount along an arc.

  2. A case study of micromachined load cell

    Indian Academy of Sciences (India)

    The physical scales as well as the magnitude of signals of various subsystems vary widely. Known and proven integration techniques often lead to considerable loss in advantages the tiny MEMS sensors have to offer. Therefore, it becomes imper- ative to think of the entire system at the outset, at least in terms of the concept.

  3. A case study of micromachined load cell

    Indian Academy of Sciences (India)

    A basic signal conditioning circuit should address all these non-idealities. A typical block diagram of the signal conditioning unit (SCU) is shown in figure 7a. The differential signal from the piezo-resistive bridge sensor is amplified by the low noise, high. CMRR and high input impedance instrumentation amplifier (IA) ...

  4. Nanochannel Fabrication and characterization using bond micromachining

    NARCIS (Netherlands)

    Haneveld, J.; Haneveld, Jeroen

    2006-01-01

    This thesis deals with the fabrication and characterization of nanochannels (channels with at least one dimension in the sub-100 nm range). These channels are important for various areas of research, including DNA analysis systems and chemical sensors. In addition, the behavior of liquids in

  5. Micromachining of buried micro channels in silicon

    NARCIS (Netherlands)

    de Boer, Meint J.; Tjerkstra, R.W.; Berenschot, Johan W.; Jansen, Henricus V.; Burger, G.J.; Burger, G.J.; Gardeniers, Johannes G.E.; Elwenspoek, Michael Curt; van den Berg, Albert

    A new method for the fabrication of micro structures for fluidic applications, such as channels, cavities, and connector holes in the bulk of silicon wafers, called buried channel technology (BCT), is presented in this paper. The micro structures are constructed by trench etching, coating of the

  6. A review of micromachined thermal accelerometers

    Science.gov (United States)

    Mukherjee, Rahul; Basu, Joydeep; Mandal, Pradip; Guha, Prasanta Kumar

    2017-12-01

    A thermal convection based micro-electromechanical accelerometer is a relatively new kind of acceleration sensor that does not require a solid proof mass, yielding unique benefits like high shock survival rating, low production cost, and integrability with CMOS integrated circuit technology. This article provides a comprehensive survey of the research, development, and current trends in the field of thermal acceleration sensors, with detailed enumeration on the theory, operation, modeling, and numerical simulation of such devices. Different reported varieties and structures of thermal accelerometers have been reviewed highlighting key design, implementation, and performance aspects. Materials and technologies used for fabrication of such sensors have also been discussed. Further, the advantages and challenges for thermal accelerometers vis-à-vis other prominent accelerometer types have been presented, followed by an overview of associated signal conditioning circuitry and potential applications.

  7. Experimental Device for Electron Beam Micromachining

    Czech Academy of Sciences Publication Activity Database

    Dupák, Libor; Zobač, Martin; Dupák, Jan; Vlček, Ivan

    2006-01-01

    Roč. 41, 5-6 (2006), s. 272-275 ISSN 0861-4717. [EBT 2006 - International Conference on Electron Beam Technologies /8./. Varna, 05.06.2006-10.06.2006] Institutional research plan: CEZ:AV0Z20650511 Keywords : electron beam drilling * quartz glass Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  8. Dust, ice and gas in time (DIGIT) : Herschel and Spitzer spectro-imaging of SMM3 and SMM4 in Serpens

    NARCIS (Netherlands)

    Dionatos, O.; Jørgensen, J.; Green, J.; Herczeg, G.; Evans, N.; Kristensen, L.; Lindberg, J.; Dishoeck, van E.F.

    2013-01-01

    Context. Mid- and far-infrared observations of the environment around embedded protostars reveal a plethora of high excitation molecular and atomic emission lines. Different mechanisms for the origin of these lines have been proposed, including shocks induced by protostellar jets and radiation or

  9. Cryogenic Selective Surfaces

    Data.gov (United States)

    National Aeronautics and Space Administration — Selective surfaces have wavelength dependent emissivity/absorption. These surfaces can be designed to reflect solar radiation, while maximizing infrared emittance,...

  10. Characterization of solid surfaces

    National Research Council Canada - National Science Library

    Kane, Philip F; Larrabee, Graydon B

    1974-01-01

    .... A comprehensive review of surface analysis, this important volume surveys both principles and techniques of surface characterization, describes instrumentation, and suggests the course of future research...

  11. Open algebraic surfaces

    CERN Document Server

    Miyanishi, Masayoshi

    2000-01-01

    Open algebraic surfaces are a synonym for algebraic surfaces that are not necessarily complete. An open algebraic surface is understood as a Zariski open set of a projective algebraic surface. There is a long history of research on projective algebraic surfaces, and there exists a beautiful Enriques-Kodaira classification of such surfaces. The research accumulated by Ramanujan, Abhyankar, Moh, and Nagata and others has established a classification theory of open algebraic surfaces comparable to the Enriques-Kodaira theory. This research provides powerful methods to study the geometry and topology of open algebraic surfaces. The theory of open algebraic surfaces is applicable not only to algebraic geometry, but also to other fields, such as commutative algebra, invariant theory, and singularities. This book contains a comprehensive account of the theory of open algebraic surfaces, as well as several applications, in particular to the study of affine surfaces. Prerequisite to understanding the text is a basic b...

  12. 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)

  13. Surfaces with Natural Ridges

    DEFF Research Database (Denmark)

    Brander, David; Markvorsen, Steen

    2015-01-01

    We discuss surfaces with singularities, both in mathematics and in the real world. For many types of mathematical surface, singularities are natural and can be regarded as part of the surface. The most emblematic example is that of surfaces of constant negative Gauss curvature, all of which neces...

  14. Weyl nodal surfaces

    Science.gov (United States)

    Türker, Oǧuz; Moroz, Sergej

    2018-02-01

    We consider three-dimensional fermionic band theories that exhibit Weyl nodal surfaces defined as two-band degeneracies that form closed surfaces in the Brillouin zone. We demonstrate that topology ensures robustness of these objects under small perturbations of a Hamiltonian. This topological robustness is illustrated in several four-band models that exhibit nodal surfaces protected by unitary or antiunitary symmetries. Surface states and Nielsen-Ninomiya doubling of nodal surfaces are also investigated.

  15. Surface Topography Hinders Bacterial Surface Motility.

    Science.gov (United States)

    Chang, Yow-Ren; Weeks, Eric R; Ducker, William A

    2018-03-21

    We demonstrate that the surface motility of the bacterium, Pseudomonas aeruginosa, is hindered by a crystalline hemispherical topography with wavelength in the range of 2-8 μm. The motility was determined by the analysis of time-lapse microscopy images of cells in a flowing growth medium maintained at 37 °C. The net displacement of bacteria over 5 min is much lower on surfaces containing 2-8 μm hemispheres than on flat topography, but displacement on the 1 μm hemispheres is not lower. That is, there is a threshold between 1 and 2 μm for response to the topography. Cells on the 4 μm hemispheres were more likely to travel parallel to the local crystal axis than in other directions. Cells on the 8 μm topography were less likely to travel across the crowns of the hemispheres and were also more likely to make 30°-50° turns than on flat surfaces. These results show that surface topography can act as a significant barrier to surface motility and may therefore hinder surface exploration by bacteria. Because surface exploration can be a part of the process whereby bacteria form colonies and seek nutrients, these results help to elucidate the mechanism by which surface topography hinders biofilm formation.

  16. SURFACE PHOTOMETRY OF LOW SURFACE BRIGHTNESS GALAXIES

    NARCIS (Netherlands)

    DEBLOK, WJG; VANDERHULST, JM; BOTHUN, GD

    1995-01-01

    Low surface brightness (LSB) galaxies are galaxies dominated by an exponential disc whose central surface brightness is much fainter than the value of mu(B)(0) = 21.65 +/- 0.30 mag arcsec(-2) found by Freeman. In this paper we present broadband photometry of a sample of 21 late-type LSB galaxies.

  17. Computer aided surface representation

    Energy Technology Data Exchange (ETDEWEB)

    Barnhill, R E

    1987-11-01

    The aims of this research are the creation of new surface forms and the determination of geometric and physical properties of surfaces. The full sweep from constructive mathematics through the implementation of algorithms and the interactive computer graphics display of surfaces is utilized. Both three-dimensional and multi- dimensional surfaces are considered. Particular emphasis is given to the scientific computing solution of Department of Energy problems. The methods that we have developed and that we are proposing to develop allow applications such as: Producing smooth contour maps from measured data, such as weather maps. Modeling the heat distribution inside a furnace from sample measurements. Terrain modeling based on satellite pictures. The investigation of new surface forms includes the topics of triangular interpolants, multivariate interpolation, surfaces defined on surfaces and monotone and/or convex surfaces. The geometric and physical properties considered include contours, the intersection of surfaces, curvatures as a interrogation tool, and numerical integration.

  18. Mechanics of active surfaces

    Science.gov (United States)

    Salbreux, Guillaume; Jülicher, Frank

    2017-09-01

    We derive a fully covariant theory of the mechanics of active surfaces. This theory provides a framework for the study of active biological or chemical processes at surfaces, such as the cell cortex, the mechanics of epithelial tissues, or reconstituted active systems on surfaces. We introduce forces and torques acting on a surface, and derive the associated force balance conditions. We show that surfaces with in-plane rotational symmetry can have broken up-down, chiral, or planar-chiral symmetry. We discuss the rate of entropy production in the surface and write linear constitutive relations that satisfy the Onsager relations. We show that the bending modulus, the spontaneous curvature, and the surface tension of a passive surface are renormalized by active terms. Finally, we identify active terms which are not found in a passive theory and discuss examples of shape instabilities that are related to active processes in the surface.

  19. Description of a micro-mechanical testing system

    Energy Technology Data Exchange (ETDEWEB)

    Schmale, D.T.; Bourcier, R.J.; Buchheit, T.E. [Sandia National Labs., Albuquerque, NM (United States). Materials and Process Sciences Center

    1997-07-01

    In recent years, technological advances have significantly enhanced the capability to produce milli- and micro-sized components which may be incorporated into the design of small, less costly, reproducible and more reliable nuclear weapons components. Two promising micro-scale processing technologies are Silicon surface micromachining (SMM), a process derived from microelectronics fabrication, and LIGA, a process involving electrodeposition of metals into a polymeric mask containing very fine, sharp features. Complicated SMM structures with micron sized features such as microengines, gears and pop-up mirrors have already been successfully developed. As part of an overall broad effort to develop mechanical test capability of millisized and microsized structures, a mechanical test system has been designed and assembled with the primary goal of characterizing the mechanical properties of LIGA synthesized structures and materials. The current system utilizes many off-the-shelf items including an MTS 3,000 pound 1.0 inch travel hydraulic actuator and an Interface 100 pound load cell. Load, stroke and displacement control is provided by an MTS TestStar system and two 0.100 inch LVDT displacement gages situated in a parallel arrangement at the specimen. Load resolution is on the order of 50 {micro} oz. and displacement resolution less than 45 {micro} inch. The system can test dynamically up to 100 hz at 0.005 inch actuator displacement and loads of 100 lb., statically at up to 250 lb. (limited by the load cell). The scope and flexibility of the microscale test system extends far beyond simply testing LIGA synthesized parts. A detailed description of the machine and a diverse set of results are presented in this report.

  20. Advanced Surface Technology

    DEFF Research Database (Denmark)

    Møller, Per; Nielsen, Lars Pleht

    This new significant book on advanced modern surface technology in all its variations, is aimed at both teaching at engineering schools and practical application in industry. The work covers all the significant aspects of modern surface technology and also describes how new advanced techniques make...... of the components. It covers everything from biocompatible surfaces of IR absorbent or reflective surfaces to surfaces with specific properties within low friction, hardness, corrosion, colors, etc. The book includes more than 400 pages detailing virtually all analysis methods for examining at surfaces....