International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / It is tempting to conceive a program that is self-contained and to fiscally control the all the necessary developments. Such a path will lead to a program that is technically stovepiped and extremely expensive. For the test and evaluation (T&E) community, products are often developed only for single application. We do not exist in such times. The use of other program’s products and commercial products is basically required. This is the path that the Hardened Subminiature Telemetry and Sensor System (HSTSS) has taken. The HSTSS philosophy required that the technologies common to telemetry systems be examined for reduction in cost, size, ease of use, and above all the survivability under high-g or high shock environments. It was clear that HSTSS could not support all of these requirements for transmitters, batteries, electronic packaging, and sensors and be realistically affordable with a good return on investment. This paper describes how the HSTSS program has accomplished the development of new batteries, transmitters, and data acquisition devices based upon a leveraged acquisition strategy.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2009. / Nanoelectromechanical systems (NEMS) are the integration of nanotechnology and microelectromechanical systems (MEMS). The idea of this thesis is to give a basic preparation to approach NEMS, a subcategory of nanotechnology. This is performed by gaining knowledge of the two separate fields NEMS consist of, namely MEMS and nanotechnology. This document will discuss the basic theory and fabrication tools for microelectromechanical systems, as well as its limits as MEMS feature sizes decrease, reaching toward nanotechnology. It starts with an introduction that includes the history, giving a basic background. The essence is captured with theory of the equipment, the main material, some concepts of design and the creation of structures. To stimulate further interest, this thesis also illustrates practical design and fabrication methods. With the knowledge and skills that were discussed, one should be ready to get started with NEMS.

Metal Organic Frameworks (MOFs) are a new class of nanoporous materials with high surface area, thermal/chemical stability and a taylorable pore size. These properties make MOFs ideal for storage and gas separation applications. Piezoresistive microcantilever sensors are microfabricated devices that are highly sensitive to surface strain due to doped single crystal silicon regions. Changes in resistance generated by surface strain can be measured with a high degree of accuracy using a Wheatstone bridge and basic instrumentation. This thesis will discuss the use of piezoresistive microcantilever sensors as a transduction mechanism for detection of volatile organic compounds (VOC's) using MOF coatings. It will be shown that by coating a microcantilever with MOFs it is possible to detect low levels of different VOC's (hundreds of parts per million). Excellent sensitivity and a simple transduction mechanism make these devices low power and highly compact. Such devices would be capable of detecting a plethora of different analytes at low concentrations. Devices were engineered for maximum response and microfabricated in the cleanroom with high yield. A custom setup for testing the devices was designed and machined. A number of MOFs were selected and tested, their response was recorded and analyzed. Twelve different analytes including eleven VOC's and water were used to characterize the MOFs. Microcantilever sensors were shown to be durable, reliable and stable in long term testing despite being subjected to many different analytes. MOF coatings proved flexible, durable, stable and reversible. This work will show a promising new technology for a next generation gas sensor.

Neste trabalho é proposto um sensor capacitivo do tipo eletrodos interdigitados para avaliação da qualidade de combustíveis automotivos. Os eletrodos interdigitados apresentam algumas características adequadas ao sensor em questão. Entre elas o fato de elevar significativamente a capacitância por apresentar grande quantidade de capacitores em paralelo e de ser uma estrutura possível de se fabricar por processos convencionais de microfabricação. Além disso, esses eletrodos permitem que o combustível preencha seus espaçamentos funcionando como seu dielétrico. Foram feitas modelagens e simulações do sensor para verificação da influência de diversos parâmetros de projeto. Protótipos foram fabricados em substratos de alumina com eletrodos de níquel eletrodepositado. Os eletrodos têm larguras entre 50m e 100m, com espaçamento entre eletrodos tendo valores dessa mesma ordem. O comprimento dos eletrodos é de 800m. A altura dos eletrodos varia entre 20m e 40m. O sensor como um todo tem área em torno de 4cm². Foram realizadas medições com misturas álcool e água, gasolina e álcool, gasolina e querosene entre outras. As caracterizações mostraram bons resultados comprovando a validade do princípio proposto. O sensor se mostrou capaz de detectar os tipos de adulteração mais comuns no Brasil, adição de água ao álcool combustível e adição solventes orgânicos ou de álcool além do permitido à gasolina. / This work proposes a capacitive sensor with interdigitated electrodes in order to evaluate the quality of automotive fuel. Interdigitated electrodes have some interesting features for this type of sensor. Among them, they increase the capacitance by having several capacitors in parallel, and by having a structure feasible to be manufactured by conventional microfabrication processes. In addition, automotive fuel, serving as the dielectric material, fills the gaps of the electrodes. Modeling and computational simulations of the sensor were carried out in order to realize the influence of several design parameters. Samples were manufactured using alumina substrates with electroplated nickel electrodes. The width of the electrodes was chosen to be between 50m and 100m, with gaps of similar size. The paired length of the electrodes was 800m. The height of the electrodes varied between 20m and 40m. The whole sensor was around 4cm² in area. Several measurements were carried out using mixtures of alcohol and water, gasoline and alcohol, gasoline and kerosene, and others. Characterizations showed good results, validating the method. The sensor was capable of detecting the main types of fuel adulteration used in Brazil: addition of water to alcohol, and addition of organic solvents or alcohol to gasoline beyond the acceptable limit.

Autômatos celulares e suas variações são atualmente utilizados para simulação de diversos processos físicos. De especial interesse para o campo de simulação de processos de micro-fabricação são os autômatos celulares para evolução de frentes circulares e elípticas e os autômatos celulares para corrosão anisotrópica de Si. No presente trabalho é apresentado um autômato celular alternativo para uso na simulação da evolução topográfica de uma superfície. Este autômato celular apresenta diversas vantagens em relação aos autômatos celulares reportados na literatura, como menor vizinhança e melhores resultados para grandes redes de células. Também foi avaliada a viabilidade do uso de um autômato celular multipartículas para simulação de processos de dopagem e oxidação térmica do silício. Este autômato celular multipartículas se mostrou uma alternativa interessante para simulação da dopagem de Si por impurezas. Aqui é apresentado também detalhes do software desenvolvido, o simMEMS, para incorporar estes autômatos celulares em um único ambiente, permitindo assim a simulação do processo de fabricação completo de inúmeros dispositivos como MEMS, MOEMS e dispositivos e circuitos microeletrônicos. São também, como exemplo, o processo de fabricação de um microespelho para projeção digital de luz, uma porta lógica NOR e uma microagulha para uso em uma matriz de eletrodos com aplicações em biologia e medicina. / Cellular automata and their variations are currently used to simulate a large range of physical phenomena. Of special interest to the microfabrication field are cellular automata for the propagation of circular and elliptical fronts as well as cellular automata for the simulation of silicon wet etching. Here an alternative cellular automaton for use in surface propagation is presented. This cellular automaton has several advantages over those reported in the literature, such as a smaller neighborhood e better results in large grid simulations. The results on the study on the viability of using a multiparticle cellular automaton for simulation of reaction diffusion systems in microfabrication simulation are also reported. The multiparticle cellular automaton was used to simulate both dopant diffusion in silicon and silicon thermal oxidation. This multiparticle cellular automaton was found to be of interest to the simulation of dopant diffusion in silicon. Details of the implementation of the software developed to incorporate these cellular automata, called simMEMS, and allow for the simulation of complex MEMS, MOEMS and microelectronic circuits and devices are also presented. The fabrication processes of several complex devices, including a micromirror for digital light projection, a quad NOR logic gate IC and a microneedle for use in a medical electrode array, are presented as an example of the capabilities of the simMEMS software.

Autômatos celulares e suas variações são atualmente utilizados para simulação de diversos processos físicos. De especial interesse para o campo de simulação de processos de micro-fabricação são os autômatos celulares para evolução de frentes circulares e elípticas e os autômatos celulares para corrosão anisotrópica de Si. No presente trabalho é apresentado um autômato celular alternativo para uso na simulação da evolução topográfica de uma superfície. Este autômato celular apresenta diversas vantagens em relação aos autômatos celulares reportados na literatura, como menor vizinhança e melhores resultados para grandes redes de células. Também foi avaliada a viabilidade do uso de um autômato celular multipartículas para simulação de processos de dopagem e oxidação térmica do silício. Este autômato celular multipartículas se mostrou uma alternativa interessante para simulação da dopagem de Si por impurezas. Aqui é apresentado também detalhes do software desenvolvido, o simMEMS, para incorporar estes autômatos celulares em um único ambiente, permitindo assim a simulação do processo de fabricação completo de inúmeros dispositivos como MEMS, MOEMS e dispositivos e circuitos microeletrônicos. São também, como exemplo, o processo de fabricação de um microespelho para projeção digital de luz, uma porta lógica NOR e uma microagulha para uso em uma matriz de eletrodos com aplicações em biologia e medicina. / Cellular automata and their variations are currently used to simulate a large range of physical phenomena. Of special interest to the microfabrication field are cellular automata for the propagation of circular and elliptical fronts as well as cellular automata for the simulation of silicon wet etching. Here an alternative cellular automaton for use in surface propagation is presented. This cellular automaton has several advantages over those reported in the literature, such as a smaller neighborhood e better results in large grid simulations. The results on the study on the viability of using a multiparticle cellular automaton for simulation of reaction diffusion systems in microfabrication simulation are also reported. The multiparticle cellular automaton was used to simulate both dopant diffusion in silicon and silicon thermal oxidation. This multiparticle cellular automaton was found to be of interest to the simulation of dopant diffusion in silicon. Details of the implementation of the software developed to incorporate these cellular automata, called simMEMS, and allow for the simulation of complex MEMS, MOEMS and microelectronic circuits and devices are also presented. The fabrication processes of several complex devices, including a micromirror for digital light projection, a quad NOR logic gate IC and a microneedle for use in a medical electrode array, are presented as an example of the capabilities of the simMEMS software.

Fung, Kar Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 110-114). / Abstracts in English and Chinese. / 摘要 --- p.i / ABSTRACT --- p.ii / ACKNOWLEDGMENTS --- p.iii / TABLE OF CONTENTS --- p.iv / LIST OF FIGURES --- p.vi / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Background and Motivation --- p.1 / Chapter 1.2 --- Objective of the project --- p.4 / Chapter 1.3 --- Organization of the thesis --- p.5 / Chapter 2. --- Literature Review --- p.7 / Chapter 2.1 --- Control on Micro-Manipulation --- p.7 / Chapter 2.1.1 --- Visual Feedback Control --- p.8 / Chapter 2.1.2 --- Sensor-Based Feedback Control --- p.9 / Chapter 2.1.3 --- Bilateral Control --- p.9 / Chapter 2.2 --- Force Sensing System on Micro-Manipulation --- p.10 / Chapter 2.3 --- PVDF Sensor --- p.11 / Chapter 2.4 --- Summary of the Literature Review --- p.12 / Chapter 3. --- Micro-Manipulation --- p.14 / Chapter 3.1 --- Introduction of Micro-Manipulation --- p.14 / Chapter 3.2 --- Probe Station --- p.14 / Chapter 3.2.1 --- Micromanipulators --- p.15 / Chapter 3.2.2 --- Microscopes --- p.15 / Chapter 4. --- Piezoelectric Polyvinylidence Fluoride (PVDF) Sensor --- p.16 / Chapter 4.1 --- Charteristic of PVDF Sensor --- p.16 / Chapter 4.1.1 --- Piezoelectric Properties --- p.16 / Chapter 4.1.2 --- Dimensions of the PVDF Sensor --- p.18 / Chapter 4.2 --- Comparison of Piezoelectric Materials --- p.19 / Chapter 5. --- Theoretical Analysis of PVDF Sensor --- p.21 / Chapter 5.1 --- Sensitivity of PVDF Sensor --- p.21 / Chapter 5.2 --- Relationship between the Deflection and the Force of the PVDF --- p.22 / Chapter 5.3 --- Calculation of the Spring Constant K of the PVDF --- p.23 / Chapter 5.4 --- Simulation on the output from the PVDF Sensor --- p.23 / Chapter 6. --- Experimental Analysis of PVDF Sensor --- p.26 / Chapter 6.1 --- Force-Deflection Diagram --- p.26 / Chapter 6.2 --- Frequency Response of the PVDF Sensor --- p.27 / Chapter 7. --- 1-D PVDF-Based Sensing System --- p.30 / Chapter 7.1 --- Original Design of the Sensing System --- p.30 / Chapter 7.1.1 --- Plastic pipe and adapter --- p.31 / Chapter 7.1.2 --- PVDF Sensor --- p.32 / Chapter 7.1.3 --- Probe-tip holder --- p.32 / Chapter 7.2 --- Current Design of the Sensing System --- p.32 / Chapter 7.3 --- Analysis of the Sensing System --- p.34 / Chapter 7.3.1 --- Frequency Response of the Sensing System --- p.34 / Chapter 7.3.2 --- Sensitivity of the Sensing System --- p.41 / Chapter 8. --- Experiments on 1-D PVDF Sensing System --- p.49 / Chapter 8.1 --- Experimental Setup of the 1-D Sensing System --- p.49 / Chapter 8.1.1 --- Programmable Micromanipulator --- p.50 / Chapter 8.1.2 --- Charge Amplifier --- p.51 / Chapter 8.2 --- Calibration of the 1-D Sensing System --- p.53 / Chapter 8.2.1 --- Noise Signal from the system --- p.53 / Chapter 8.2.2 --- Signal from vibration --- p.55 / Chapter 8.3 --- Experimental Results on touching a substrate --- p.60 / Chapter 8.3.1 --- Description --- p.60 / Chapter 8.3.2 --- Results from touching a substrate --- p.62 / Chapter 8.3.3 --- Analysis of the deflection after touched a substrate --- p.67 / Chapter 8.4 --- Experimental Results on touching a micro mirror --- p.68 / Chapter 8.4.1 --- Description --- p.68 / Chapter 8.4.2 --- Results --- p.70 / Chapter 8.5 --- Experimental Results on lifting a mass platform --- p.74 / Chapter 8.5.1 --- Description --- p.74 / Chapter 8.5.2 --- Results --- p.76 / Chapter 9. --- Modification of 1-D Sensing System --- p.79 / Chapter 9.1 --- Design of the system --- p.79 / Chapter 9.2 --- Experimental Setup of the system --- p.80 / Chapter 9.3 --- Experimental Results on lifting a mass platform --- p.81 / Chapter 10. --- 2-D PVDF-Based Sensing System --- p.90 / Chapter 10.1 --- Design of the Sensing System --- p.90 / Chapter 10.2 --- Experimental Setup --- p.91 / Chapter 10.3 --- Calibration of the 2-D Sensing System --- p.92 / Chapter 10.3.1 --- Noise Signal from the system --- p.92 / Chapter 10.4 --- Experiments Results on touching a substrate --- p.94 / Chapter 11. --- Experimental Analysis --- p.97 / Chapter 11.1 --- Data Acquisition --- p.97 / Chapter 11.2 --- Spectrum Analysis of the Experimental Data --- p.101 / Chapter 12. --- Conclusion --- p.103 / Chapter 13. --- Future Work --- p.105 / Chapter 13.1 --- Control of the Sensing System --- p.105 / Chapter 13.2 --- Tele-operation System on force feedback sensing system --- p.107 / Chapter A. --- Appendix --- p.109 / Chapter A. 1 --- Procedures in using probe station --- p.109 / Bibliography --- p.110

The surface roughness of a few asperities and their influence on the work of adhesion is of scientific interest. Macroscale and nanoscale adhesion data have given seemingly inconsistent results. Despite the importance of bridging the gap between the two regimes, little experimental work has been done, presumably due to the difficulty of the experiment needed to determine how small amounts of surface roughness might influence adhesion data lying in between the two scales. To investigate the role of few-asperity contacts in adhesion, the pull-off force was measured between different sized AFM (Atomic-Force Microscope) tips that had different roughnesses and sample surfaces that had well-controlled material properties. The spring constant of the cantilever, the deflection of the cantilever, and the radius of the cantilever tip were measured before each experiment. There were seventeen tips of four different types, with radii from 200 nm to 60 ìm. The samples were unpatterned amorphous silicon dioxide die with two types of surface conditions: untreated and treated with a few angstroms of vapor deposited diphenylsiloxane. We observed that the pull-off force was independent of the radius of the AFM tip, which was contrary to all continuum-mechanics model predictions. To explain this behavior, we assumed that the interactions between the AFM tip and sample were additive, material properties were constant, and that the AFM tip, asperities, and sample surfaces were of uniform density. Based on these assumptions, we calculated a simple correction due to the measured Root Mean Square (RMS) surface roughness of the AFM tips. The simple correction for the RMS surface roughness resulted in the expected dependence of the pull-off force on radius, but the magnitudes were higher than expected. Commercial and heat-treated AFM tips had minimal surface roughness and result in magnitudes that were more reliable. The relative uncertainty for the pull-off force was estimated to be 10% and the work of adhesion was estimated to be 15%. In this thesis, we derive how the cantilever and tip parameters contribute to the measured pull-off force, show how the corrected results compare with theory, and demonstrate how the AFM probes were calibrated. Although much work is still needed, the work presented here should expand the understanding of adhesion between the nanoscale and macroscale.

The focus of this work is to present in detail the implementation of a three dimensional direct simulation Monte Carlo methodology on unstructured Delaunay meshes (U-DSMC). The validation and verification of the implementation are shown using a series of fundamental flow cases. The numerical error associated with the implementation is also studied using a fundamental flow configuration. Gas expansion from microtubes is studied using the U-DSMC code for tube diameters ranging from 100Æ’ÃÂ�m down to 100nm. Simulations are carried out for a range of inlet Knudsen numbers and the effect of aspect ratio and inlet Reynolds number on the plume structure is investigated. The effect of scaling the geometry is also examined. Gas expansion from a conical nozzle is studied using the U-DSMC code for throat diameters ranging from 250 Æ’ÃÂ�m down to 250 nm. Simulations are carried out for a range of inlet Knudsen numbers and the effect of inlet speed ratio and inlet Reynolds number on the plume structure is investigated. The effect of scaling the geometry is examined. Results of a numerical study using the U-DSMC code are employed to guide the design of a micropitot probe intended for use in analyzing rarefied gaseous microjet flow. The flow conditions considered correspond to anticipated experimental test cases for a probe that is currently under development. The expansion of nitrogen from an orifice with a diameter of 100Æ’ÃÂ�m is modeled using U-DSMC. From these results, local ¡¥free stream¡¦ conditions are obtained for use in U-DSMC simulations of the flow in the vicinity of the micropitot probe. Predictions of the pressure within the probe are made for a number of locations in the orifice plume. The predictions from the U-DSMC simulations are used for evaluating the geometrical design of the probe as well as aiding in pressure sensor selection. The effect of scale on the statistical fluctuation of the U-DSMC data is studied using Poiseuille flow. The error in the predicted velocity profile is calculated with respect to both first and second-order slip formulations. Simulations are carried out for a range of channel heights and the error between the U-DSMC predictions and theory are calculated for each case. From this error, a functional dependence is shown between the scale-induced statistical fluctuations and the decreasing channel height.

This Thesis proposes phase modulating interferometry as an alternative to phase stepping and phase-shifting interferometry for use in the shape and displacement characterization of microelectromechanical systems (MEMS) [Creath, 1988; de Groot, 1995a; Furlong and Pryputniewicz, 2003]. A phase modulating interferometer is developed theoretically with the use of a stroboscopic illumination source and implemented on a Linnik configured interferometer using a software control package developed in the LabVIEWâ„¢ programming environment. Optimization of the amplitude and phase of the sinusoidal modulation source is accomplished through the investigation and minimization of errors created by additive noise effects on the recovered optical phase. A spatial resolution of 2.762 µm over a 2.97x2.37 mm field of view has been demonstrated with 4x magnification objectives within the developed interferometer. The measurement resolution lays within the design tolerance of a 500Ã… ±2.5% thick NIST traceable gold film and within 0.2 nm of data acquired under low modulation frequency phase stepping interferometry on the same physical system. The environmental stability of the phase modulating interferometer is contrasted to the phase stepping interferometer, exhibiting a mean wrapped phase drift of 40.1 mrad versus 91 mrad under similar modulation frequencies. Shape and displacement characterization of failed µHexFlex devices from MIT's Precision Compliant Systems Laboratory is presented under phase modulating and phase stepping interferometry. Shape characterization indicates a central stage displacement of up to 7.6 µm. With a linear displacement rate of 0.75 Ã…/mV under time variant load conditions as compared to a nominal rate of 1.0 Ã…/mV in an undamaged structure [Chen and Culpepper, 2006].