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Dissertations / Theses on the topic 'Microelectromechanical systems – Design and construction'

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Published: 4 June 2021

Last updated: 31 July 2024

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1

Li, Min 1977 Apr 2. "Continuum design sensitivity analysis based force calculation in EM devices." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=111523.

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The continuum design sensitivity analysis (CDSA) has been applied to the magnetostatic and electrostatic force calculation. This method allows the computation of the net loading force on a body as well as the force distribution on the surface of the body. An algorithm for force calculation combined with a standard field analysis software package is presented. The efficiency and accuracy of the method is proved through the numerical implementation applied to a set of test examples. In addition, the new approach has several advantages over the traditional methods based on the Maxwell Stress Tensor, such as no air gap or artificial interference with the original model is required. Particularly, the performance analysis of a MEMS micro-mirror using CDSA torque calculation is conducted for the first time.

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2

Wan, Weijie 1982. "Simulation and optimization of MEMS actuators and tunable capacitors." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99798.

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Micro-Electro-Mechanical Systems (MEMS) have played an important role in modern microelectronics, thermal, mechanical and hybrid systems. MEMS technology is a very promising means that might have a great impact on almost every corner of the society. Although many design methodology of MEMS already exists, not as much attention was given to the synthesis and optimization of MEMS devices. This thesis focuses on the optimization of MEMS actuators and MEMS tunable comb drive capacitors. The optimization is based on changing device geometry to achieve desired output parameter profile. For example in the design of MEMS tunable comb drive capacitors, the output parameter is the capacitance tuning range. Numerical experiments were performed to show the successful implementation of the optimization method.

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3

Zhang, Rui. "Mechanics of micromachined bridge-type accelerometer." Thesis, Cape Peninsula University of Technology, 2005. http://hdl.handle.net/20.500.11838/1285.

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Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2005
Having simple structure and high sensitivity, micro accelerometer is a type of popular transducer used to measure the acceleration in a great variety of conditions. The bridge-type micro accelerometer is a typical micro accelerometer and has many types. As one of research project of Kentron in South Africa, the thesis presented here analyzes the bridge-type capacitive nticro accelerometer (BTCMA) and the bridge-type micro accelerometer with two piezoelectric thin films read-out (BTPMA). In this thesis, the similar structures are used on BTCMA and BTPMA For proving the fundamental mode of the structure can measure acceleration and utilizing the structural and electric characteristic to avoid the effect of higher modes, the program CoventorWare for nticro-electric-mechanical system (MEMS) design and analysis is used here to analyze the modes of these two structures, The two group piezoelectric thin films of BTPMA can be connected in serial or parallel configurations. Integrating piezoelectric effect method, strength method and energy method, the analytical analysis of these two configurations has been done with particular emphasis on the elastic characteristics of the thin films. The analytical formulas of transducer, sensitivity, resonance frequency, noise, quality factor, ntinimum detectable signal and maximum detectable range are obtained. According to the comparison results between these two configurations, the charge output in parallel configuration is a little more than that in serial configuration and the sensitivity in serial configuration is much higher than that in parallel configuration. Finally, a calculation of certain practical nticro accelerometer size is used to prove the above conclusions. On the base of capacitance theory, strength method and energy method, the analytical analysis of the BTCMA has been done in this thesis.

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4

Wang, Lin. "Mechanics of micro capacitive accelerometer with u-shape cantilever beam." Thesis, Cape Peninsula University of Technology, 2005. http://hdl.handle.net/20.500.11838/2616.

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Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2005.
Due to an increasing in industrial micromation need in recent years, the use of micro accelerometers has been highly increased. Consecutively, this has promoted research activities in this field; capacitive accelerometers also have got high concern at large. As a research project of the Kentron in South Africa, this thesis deals with a theoretical model for a one-dimensional micro capacitive accelerometer with U-shape cantilever beam. The properties of the small angle tilted-plate capacitor have been analyzed; the capacitance equation and electrostatic force equation of this kind capacitor have been derived. The sensing element of this accelerometer consists of an inertial mass connected with two cantilever beams. The vibration modes analysis to the sensing element was accomplished by using CoventorWare2004's MemMech module, the result indicates that the main vibration mode can cause the capacitance change observably and the effect of the other modes to the capacitance can be ignored, which satisfied the purpose of the design. In the process of deriving the linearizing acceleration equation, the angle of the inertial mass caused by the deformation of the U-shape cantilever beam was taken into account as well as the electrostatic force between the two electrodes, thus the more precise acceleration linear equation was obtained. The sensitivity equation was derived through the acceleration linear equation, the relationship between the main parameters of the system and the sensitivity has been analyzed. The differential structure of this micro capacitive accelerometer was also analyzed; the linearizing acceleration equation and sensitivity equation of this kind structure were derived, it has been proven that the sensitivity of this structure is twice than the normal structure approximately. The maximum detectable signal was obtained in terms of the fracture strength of the cantilever beam and the maximum displacement of the inertial mass. The minimum detectable signal was obtained in terms of the thermal noise analysis. In the process of the dynamic analysis, the forced vibration produced by the sinusoidal periodic force and sinusoidal periodic moment was analyzed and the transient capacitance equation was derived, this proved the system has good dynamic character in theory. The system was simulated and analyzed by using CoventorWare2004's Saber module. The initial capacitance analysis indicates the relationship between the voltage and the initial capacitance, the result is close to the analytic model. The resonance frequencies analysis indicates that the main dimensions of the sensing element can determine the resonance frequencies and each vibration mode's sequence, the initial dimensions of the sensing element was proved reasonable by analyzing. Sensitivity analysis and Monte Carlo analysis indicate the effect of the sensing element's normal manufacturing tolerance to the system's frequency is small. Impact of plate curvature analysis indicates the effect of the inertial mass's deformation caused by the surface stress to the capacitance is small. Transient analysis obtained the system's transient displacement curve of six directions and transient capacitance curve in normal terms; this proved the system has good dynamic character in the simulating environment.

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5

Wu, Zhi Gang. "Design, analysis and experiment of novel compliant micromanipulators with grippers driven by PZT actuators." Thesis, University of Macau, 2017. http://umaclib3.umac.mo/record=b3691021.

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6

Neysmith, Jordan M. "A modular, direct chip attach, wafer level MEMS package : architecture and processing." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/17559.

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7

Creyts, Don Stafford IV. "Design and fabrication of a MEMS magnetic bistable valve." Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/17950.

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8

Mahdavi, Sareh. "RF power amplifiers and MEMS varactors." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112576.

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This thesis is concerned with the design and implementation of radio frequency (RF) power amplifiers and micro-electromechanical systems---namely MEMS varactors. This is driven by the many wireless communication systems which are constantly moving towards increased integration, better signal quality, and longer battery life.
The power amplifier consumes most of the power in a receiver/transmitter system (transceiver), and its output signal is directly transmitted by the antenna without further modification. Thus, optimizing the PA for low power consumption, increased linearity, and compact integration is highly desirable.
Micro-electromechanical systems enable new levels of performance in radio-frequency integrated circuits, which are not readily available via conventional IC technologies. They are good candidates to replace lossy, low Q-factor off-chip components, which have traditionally been used to implement matching networks or output resonator tanks in class AB, class F, or class E power amplifiers. The MEMS technologies also make possible the use of new architectures, with the possibility of flexible re-configurability and tunability for multi-band and/or multi-standard applications.
The major effort of this thesis is focused on the design and fabrication of an RF frequency class AB power amplifier in the SiGe BiCMOS 5HP technology, with the capability of being tuned with external MEMS varactors. The latter necessitated the exploration of wide-tuning range MEMS variable capacitors, with prototypes designed and fabricated in the Metal-MUMPS process.
An attempt is made to integrate the power amplifier chip and the MEMS die in the same package to provide active tuning of the power amplifier matching network, in order to keep the efficiency of the PA constant for different input power levels and load conditions.
Detailed simulation and measurement results for all circuits and MEMS devices are reported and discussed.

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9

Sivapurapu, Abhishek. "Piezoelectrically-Transduced Silicon Micromechanical Resonators." Thesis, Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7478.

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This thesis reports on the design and fabrication of micro-electro-mechanical (MEM) resonators on silicon that are piezoelectrically-transduced for operation in the very high frequency (VHF) range. These devices have a block-type or beam-type design, and are designed to resonate in their in-plane and out-of-plane bulk extensional modes. Two piezoelectric materials were taken into consideration, zinc-oxide (ZnO) and lead-zirconate-titanate (PZT). The resonators are fabricated on silicon-on-insulator (SOI) wafers and the metal/piezo/metal stack of layers forming the device is built and patterned on the device layer silicon via photolithography techniques, RF sputtering (for the piezo-layer) and electron-beam evaporation (for the metal layers). The designing aspect involved ANSYS simulations of the mode-shapes and estimation of frequencies, and these have correlated well with experimental results. Devices with RF sputtered ZnO were successfully fabricated and tested to give high quality factors at reasonably high frequencies. A gold ground plane was implemented to reduce the feed-through level and increase the signal-to-noise ratio. Extensive characterization of PZT was also done as a replacement for ZnO, as the former material has a much higher piezoelectric coefficient (~20X that of ZnO) and can therefore extend the operation of these MEM resonators into the UHF range. Although the basic design of the device remains the same, incorporation of PZT complicates the process flow considerably with respect to the chemistry now involved with the patterning of different layers. The frequency response for ZnO-based resonators as well as all the characterization data for PZT has been reported.

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10

Dusatko, Tomas A. "Silicon carbide RF-MEM resonators." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100250.

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A low-temperature (<300°C) method to fabricate electrostatically actuated microelectromechanical (MEM) clamped-clamped beam resonators has been developed. It utilizes an amorphous silicon carbide (SiC) structural layer and a thin polyimide spacer. The resonator beam is constructed by DC sputtering a tri-layer composite of low-stress SiC and aluminum over the thin polyimide sacrificial layer, and is then released using a microwave O 2 plasma etch. Deposition parameters have been optimized to yield low-stress films (<50MPa), in order to minimize the chance of stress-induced buckling or fracture in both the SiC and aluminum. Characterization of the deposited SiC was performed using several different techniques including scanning electron microscopy, EDX and XRD.
Several different clamped-clamped beam resonator designs were successfully fabricated and tested using a custom built vacuum system, with measured frequencies ranging from 5MHz to 25MHz. A novel thermal tuning method is also demonstrated, using integrated heaters directly on the resonant structure to exploit the temperature dependence of the Young's modulus and thermally induced stresses.

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11

Hashimura, Akinori. "Single-crystal silicon HARPSS capacitive beam resonators." Thesis, Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/15798.

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12

Solomon, Jose Enrique. "Study of a high-performance micropump : numerical analysis of flow and structural elements." Honors in the Major Thesis, University of Central Florida, 2001. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/246.

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This item is only available in print in the UCF Libraries. If this is your Honors Thesis, you can help us make it available online for use by researchers around the world by following the instructions on the distribution consent form at http://library.ucf.edu/Systems/DigitalInitiatives/DigitalCollections/InternetDistributionConsentAgreementForm.pdf You may also contact the project coordinator, Kerri Bottorff, at kerri.bottorff@ucf.edu for more information.
Bachelors
Engineering
Mechanical Engineering

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13

Williams, Frances R. "Monitoring and Control of Semiconductor Manufacturing Using Acoustic Techniques." Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/5278.

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Since semiconductor fabrication processes require numerous steps, cost and yield are critical concerns. In-situ monitoring is therefore vital for process control. However, this goal is currently restricted by the shortage of available sensors capable of performing in this manner. The goal of this research therefore, was to investigate the use of acoustic signals for monitoring and control of semiconductor fabrication equipment and processes. Currently, most methods for process monitoring (such as optical emission or interferometric techniques) rely on "looking" at a process to monitor its status. What was investigated here involved "listening" to the process. Using acoustic methods for process monitoring enhances the amount and sensitivity of data collection to facilitate process diagnostics and control. A silicon acoustic sensor was designed, fabricated, and implemented as a process monitor. Silicon acoustic sensors are favorable because of their utilization of integrated circuit and micromachining processing techniques; thus, enabling miniature devices with precise dimensions, batch fabrication of sensors, good reproducibility, and low costs. The fabricated sensor was used for in-situ monitoring of nickel-iron electrochemical deposition processes. During this process, changes occur in its plating bath as the alloy is being deposited. It is known that changes in the process medium affect the acoustic response. Thus, the sensor was implemented in an electroplating set-up and its response was observed during depositions. By mapping the sensor response received to the film thickness measured at certain times, a predictive model of the plated alloy thickness was derived as a function of sensor output and plating time. Such a model can lead to real-time monitoring of nickel-iron thickness.

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14

Sutanto, Bintoro Jemmy. "An Electromagnetic Actuated Microvalve Fabricated on a Single Wafer." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/4891.

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Microvalves are essential components of the miniaturization of the fluidic systems to control of fluid flow in a variety of applications as diverse as chemical analysis systems, micro-fuel cells, and integrated fluidic channel arrangements for electronic cooling. Using microvalves, these systems offer important advantages: they can operate using small sample volumes and provide rapid response time. This PhD dissertation presents the world first electromagnetically actuated microvalve fabricated on a single wafer with CMOS compatibility. In this dissertation, the design, fabrication, and testing results of two different types of electromagnetic microvalves are presented: the on/off microvalve and the bistable microvalve with latching mechanism. The microvalves operate with power consumption of less than 1.5 W and can control the volume flow rate of DI water, or a 50% diluted methanol solution in the range 1 - 50 µL in. The leaking rate of the on/off microvalve is the order of 30 nL/min. The microvalve demonstrated a response time for latching of 10 ms in water and 0.2 ms in air. This work has resulted in a US patent, application no. 10/699,210.Other inventions that have been developed as a result of this research are bidirectional, and bistable-bidirectional microactuators with latching mechanism, that can be utilized for optical switch, RF relay, micro mirror, nano indenter, or nano printings.

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15

Yoon, Yong-Kyu. "Micromachined Components for RF Systems." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5264.

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Several fabrication techniques for surface micromachined 3-D structures have been developed for RF components. The fabrication techniques all have in common the use of epoxy patterning and subsequent metallization. Techniques and structures such as embedded conductors, epoxy-core conductors, a reverse-side exposure technique, a multi-exposure scheme, and inclined patterning are presented. The epoxy-core conductor technique makes it easy to fabricate high-aspect-ratio (10-20:1), tall (~1mm) RF subelements as well as potentially very complex structures by taking advantage of advanced epoxy processes. To demonstrate feasibility and usefulness of the developed fabrication techniques for RF applications, two test vehicles are employed. One is a solenoid type RF inductor, and the other is a millimeter wave radiating structure such as a W-band quarter-wavelength monopole antenna. The embedded inductor approach provides mechanical robustness and package compatibility as well as good electrical performance. An inductor with a peak Q-factor of 21 and an inductance of 2.6nH at 4.5GHz has been fabricated on a silicon substrate. In addition, successful integration with a CMOS power amplifier has been demonstrated. A high-aspect-ratio inductor fabricated using epoxy core conductors shows a maximum Q-factor of 84 and an inductance of 1.17nH at 2.6GHz on a glass substrate with a height of 900um and a single turn. Successful W-band monopole antenna fabrication is demonstrated. A monopole with a height of 800um shows its radiating resonance at 85GHz with a return loss of 16dB. In addition to the epoxy-based devices, an advanced tunable ferroelectric device architecture is introduced. This architecture enables a low-loss conductor device; a reduced intermodulation distortion (IMD) device; and a compact tunable LC module. A single-finger capacitor having a low-loss conductor with an electrode gap of 1.2um and an electrode thickness of 2.2um has been fabricated using a reverse-side exposure technique, showing a tunability of 33% at 10V. It shows an improved Q-factor of 21.5. Reduced IMD capacitors consist of wide RF gaps and narrowly spaced high resistivity electrodes with a gap of 2um and a width of 2um within the wide gap. A 14um gap and a 20um gap capacitor show improved IMD performance compared to a 4um gap capacitor by 6dB and 15dB, respectively, while the tunability is approximately 21% at 30V for all three devices due to the narrowly spaced multi-pair high resistivity DC electrodes within the gap. Finally, a compact tunable LC module is implemented by forming the narrow gap capacitor in an inductor shape. The resonance frequency of this device is variable as a function of DC bias and a frequency tunability of 1.1%/V is achieved. The RF components developed in this thesis illustrate the usefulness of the application of micromachining technology to this application area, especially as frequencies of operation of RF systems continue to increase (and therefore wavelengths continue to shrink).

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16

Moore, Christopher Wayne. "Microfabricated Fuel Cells To Power Integrated Circuits." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7106.

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Microfabricated fuel cells have been designed and constructed on silicon integrated circuit wafers using many processes common in integrated circuit fabrication, including sputtering, polymer spin coating, reactive ion etching, and photolithography. Fuel delivery microchannels were made through the use of sacrificial polymers. The characteristics of different sacrificial polymers were studied to find the most suitable for this work. A polypropylene carbonate solution containing a photo-acid generator could be directly patterned with ultraviolet exposure and thermal decomposition. The material that would serve as the fuel cells proton exchange membrane (PEM) encapsulated the microchannels. Silicon dioxide deposited by plasma enhanced chemical vapor deposition (PECVD) at relatively low temperatures exhibited material properties that made it suitable as a thin-film PEM in these devices. By adding phosphorous to the silicon dioxide recipe during deposition, a phosphosilicate glass was formed that had an increased ionic conductivity. Various polymers were tested for use as the PEM or in combination with oxide to form a composite PEM. While it did not work well alone, using Nafion on top of the glass layer to form a dual-layer PEM greatly enhanced the fuel cell performance, including yield and long-term reliability. Platinum and platinum/ruthenium catalyst layers were sputter deposited. Experiments were performed to find a range of thicknesses that resulted in porous layers allowing contact between reactants, catalyst, and the PEM. When using the deposited glasses, multiple layers of catalyst could be deposited between thin layers of the electrolyte, resulting in higher catalyst loading while maintaining porosity. The current and power output were greatly improved with these additional catalyst layers.

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17

Vakili-Amini, Babak. "A Mixed-Signal Low-Noise Sigma-Delta Interface IC for Integrated Sub-Micro-Gravity Capacitive SOI Accelerometers." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/10437.

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This dissertation presents the design and development of a mixed-signal low noise second-order integrated circuit (IC) for the open-loop and closed-loop operation of integrated capacitive micro- and nano-gravity accelerometers. The micromechanical accelerometers are fabricated in thick (less than 100 m) silicon-on-insulator (SOI) substrates. The IC provides the 1-bit digital output stream and has the versatility of interfacing sensors with different sensitivities while maintaining minimum power consumption (less than 5 mW) and maximum dynamic range (90 dB). A fully-differential sampled-data scheme is deployed with the ability of low-frequency noise reduction through the use of correlated double sampling (CDS) scheme. In this work, the measured resolution of the closed-loop CMOS-SOI accelerometer system, in the presence of high background accelerations, is in the micro-g (g: gravity) range. In this design, a second-order SC modulator is cascaded with the accelerometer and the front-end amplifier. The accelerometer operates in air and is designed for non-peaking response with a BW-3dB of 500 Hz. A 22 dB improvement in noise and hence dynamic range is achieved with a sampling clock of 40 kHz corresponding to a low oversampling ratio (OSR) of 40. The interface IC consumed a current of 1.5 mA from a supply of 3 V.

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18

Morton, Matthew Allan. "Development of Monolithic SiGe and Packaged RF MEMS High-Linearity Five-bit High-Low Pass Phase Shifters for SoC X-band T/R Modules." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/16190.

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A comprehensive study of the High-pass/Low-pass topology has been performed, increasing the understanding of error sources arising from bit layout issues and fabrication tolerances. This included a detailed analysis of error sources in monolithic microwave phase shifters due to device size limitations, inductor parasitics, loading effects, and non-ideal switches. Each component utilized in the implementation of a monolithic high-low pass phase shifter was analyzed, with its influence on phase behavior shown in detail. An emphasis was placed on the net impact on absolute phase variation, which is critical to the system performance of a phased array radar system. The design of the individual phase shifter filter sections, and the influence of bit ordering on overall performance was also addressed. A variety of X-band four- and five-bit phase shifters were fabricated in a 200 GHz SiGe HBT BiCMOS technology platform, and further served to validate the analysis and design methodology. The SiGe phase shifter can be successfully incorporated into a single-chip T/R module forming a system-on-a-chip (SoC). Reduction in the physical size of transmission lines was shown to be a possibility with spinel magnetic nanoparticle films. The signal transmission properties of phase lines treated with nanoparticle thin films were examined, showing the potential for significant size reduction in both delay line and High-pass/Low-pass phase topologies. Wide-band, low-loss, and near-hermetic packaging techniques for RF MEMS devices were presented. A thermal compression bonding technique compatible with standard IC fabrication techniques was shown, that uses a low temperature thermal compression bonding method that avoids plastic deformations of the MEMS membrane. Ultimately, a system-on-a-package (SoP) approach was demonstrated that utilized packaged RF MEMS switches to maintain the performance of the SiGe phase shifter with much lower loss. The extremely competitive performance of the MEMS-based High-pass/Low-pass phase shifter, despite the lack of the extensive toolkits and commercial fabrication facilities employed with the active-based SiGe phase shifters, confirms both the effectiveness of the detailed phase error analysis presented in this work and the robust nature of the High-pass/Low-pass topology.

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19

McLean, Jeffrey John. "Interdigital Capacitive Micromachined Ultrasonic Transducers for Microfluidic Applications." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/7625.

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The goal of this research was to develop acoustic sensors and actuators for microfluidic applications. To this end, capacitive micromachined ultrasonic transducers (cMUTs) were developed which generate guided acoustic waves in fluid half-spaces and microchannels. An interdigital transducer structure and a phased excitation scheme were used to selectively excite guided acoustic modes which propagate in a single lateral direction. Analytical models were developed to predict the geometric dispersion of the acoustic modes and to determine the sensitivity of the modes to changes in material and geometric parameters. Coupled field finite element models were also developed to predict the effect of membrane spacing and phasing on mode generation and directionality. After designing the transducers, a surface micromachining process was developed which has a low processing temperature of 250C and has the potential for monolithically integrating cMUTs with CMOS electronics. The fabrication process makes extensive use of PECVD silicon nitride depositions for membrane formation and sealing. The fabricated interdigital cMUTs were placed in microfluidic channels and demonstrated to sense changes in fluid sound speed and flow rate using Scholte waves and other guided acoustic modes. The minimum detectable change in sound speed was 0.25m/s, and the minimum detectable change in flow rate was 1mL/min. The unique nature of the Scholte wave allowed for the measurement of fluid properties of a semi-infinite fluid using two transducers on a single substrate. Changes in water temperature, and thus sound speed, were measured and the minimum detectable change in temperature was found to be 0.1C. For fluid pumping, interdigital cMUTs were integrated into microchannels and excited with phase-shifted, continuous wave signals. Highly directional guided waves were generated which in turn generated acoustic streaming forces in the fluid. The acoustic streaming forces caused the fluid to be pumped in a single, electronically-controlled direction. For a power consumption of 43mW, a flow rate of 410nL/min was generated against a pressure of 3.4Pa; the thermodynamic efficiency was approximately 5x10-8%. Although the efficiency and pressure head are low, these transducers can be useful for precisely manipulating small amounts of fluid around microfluidic networks.

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20

Klaubert, Heather L. "Tiny design : a study of the design of microelectromechanical systems." Thesis, University of Cambridge, 1998. https://www.repository.cam.ac.uk/handle/1810/272160.

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21

Lusk, Craig P. "Ortho-Planar Mechanisms for Microelectromechanical Systems." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd902.pdf.

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22

Wittwer, Jonathan W. "Simulation-Based Design Under Uncertainty for Compliant Microelectromechanical Systems." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd723.pdf.

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23

Machiraju, Harita. "Thermal analysis and design of a MEMS-based safety and arming system." Diss., Online access via UMI:, 2007.

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24

Bolognini, Francesca. "An integrated simulation-based generative design method for microelectromechanical systems." Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611409.

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25

Cho, Jeong-Hyun. "Design, fabrication, and characterization of a MEMS thermal switch and integration with a dynamic micro heat engine." Online access for everyone, 2007. http://www.dissertations.wsu.edu/Dissertations/Fall2007/J_Cho_111607.pdf.

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26

Kusner, Michael Thomas. "Design of a 5 kw microturbine generator." Diss., Connect to online resource - MSU authorized users, 2006.

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Thesis (M.S.)--Michigan State University. Dept. of Mechanical Engineering, 2006.
Title from PDF t.p. (viewed on June 19, 2009) Includes bibliographical references (p. 123-125). Also issued in print.

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27

Tondapu, Karthik. "Design and fabrication of one and two axis nickel electroplated micromirror array." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/6037.

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Thesis (M.S.)--University of Missouri-Columbia, 2007.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on April 15, 2008) Includes bibliographical references.

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28

Pinto, Coelho Carlos (Carlos Freire da Silva). "Efficient tools for the design and simulation of microelectromechanical and microfluidic systems." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/42234.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.
Includes bibliographical references (p. 131-136).
In air-packaged surface micromachined devices and microfluidic devices the surface to volume ratio is such that drag forces play a very important role in device behavior and performance. Especially for surface micromachined devices, the amount of drag is greatly influenced by the presence of the nearby substrate. In this thesis a precorrected FFT accelerated boundary element method specialized for calculating the drag force on structures above a substrate is presented. The method uses the Green's function for Stokes flow bounded by an infinite plane to implicitly represent the device substrate, requiring a number of modifications to the precorrected FFT algorithm. To calculate the velocity due to force distribution on a panel near a substrate an analytical panel integration algorithm was also developed. Computational results demonstrate that the use of the implicit representation of the substrate reduces computation time and memory while increasing the solution accuracy. The results also demonstrate that surprisingly, and unfortunately, even though representing the substrate implicitly has many benefits it does not completely decouple discretization fineness from distance to the substrate. To simulate the time dependent behavior of micromechanical and microfluidic systems, a stable velocity implicit time stepping scheme coupling the precorrected FFT solver with rigid body dynamics was introduced and demonstrated. The ODE library was integrated with the solver to enable the simulation of systems with collisions, contacts and friction. Several techniques for speeding up the calculation of each time step were presented and tested. The time integration algorithm was successfully used to simulate the behavior of several real-world microfluidic devices.
by Carlos Pinto Coelho.
Ph.D.

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McCormick, William Brent. "Diffractive optical lens design and fabrication for integrated monitoring of microelectromechanical lateral comb resonators." Morgantown, W. Va. : [West Virginia University Libraries], 2004. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=3742.

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Thesis (M.S.)--West Virginia University, 2004.
Title from document title page. Document formatted into pages; contains viii, 118 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 117-118).

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Poreddy, Surender Reddy. "Design and dynamic analysis of MEMS gyroscopes /." free to MU campus, to others for purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p1422956.

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Ho, Gavin Kar-Fai. "Design and characterization of silicon micromechanical resonators." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/29634.

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Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009.
Committee Member: David R. Hertling; Committee Member: Farrokh Ayazi; Committee Member: Gary S. May; Committee Member: Oliver Brand; Committee Member: Paul A. Kohl. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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Ozmun, Phillip M. "Nonlinear control and design methodologies for electrostatic MEMS devices." Auburn, Ala., 2007. http://repo.lib.auburn.edu/07M%20Theses/OZMUN__16.pdf.

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Cannon, Bennion R. "Design and analysis of end-effector systems for scribing on silicon /." Diss., CLICK HERE for online access, 2003. http://contentdm.lib.byu.edu/ETD/image/etd259.pdf.

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Song, Yuanyuan. "Design, analysis and characterization of silicon microphones." Diss., Online access via UMI:, 2008.

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Thesis (Ph. D.)--State University of New York at Binghamton, Thomas J. Watson School of Engineering and Applied Science, Department of Mechanical Engineering, 2008.
Includes bibliographical references.

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Chen, Xi Gang. "Design and analysis of a new parallel micro-manipulator utilizing bridge amplifier structure and constant force mechanism for precise assembly system." Thesis, University of Macau, 2018. http://umaclib3.umac.mo/record=b3948884.

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Chang, Won Jae. "Design and fabrication of a novel electrostatic micromirror with high speed and large rotation angle." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0009060.

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Rogers, John E. Ramadoss Ramesh Hung John Y. "Design, fabrication, and dynamic modeling of a printed circuit based MEMS accelerometer." Auburn, Ala., 2007. http://repo.lib.auburn.edu/Send%2011-10-07/ROGERS_JOHN_58.pdf.

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Zhang, Peng. "Design and fabrication of chemiresistor type micro/nano hydrogen gas sensors using interdigitated electrodes." Orlando, Fla. : University of Central Florida, 2008. http://purl.fcla.edu/fcla/etd/CFE0002478.

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Lyon, Scott M. "The pseudo-rigid-body model for dynamic predictions of macro and micro compliant mechanisms /." Diss., CLICK HERE for online access, 2003. http://contentdm.lib.byu.edu/ETD/image/etd219.pdf.

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Kulkarni, Vinod Dilip. "Integration of micromachined thermal shear stress sensors with microchannels : design, fabrication and testing /." Online version of thesis, 2005. http://hdl.handle.net/1850/5201.

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Palasagaram, Jithendra N. Riggs Lloyd Stephen. "Efforts towards the design and development of an electromagnetic induction sensor optimized for detection and discrimination of unexploded ordnance." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Spring/master's/PALASAGARAM_NAGASANJEEVA_44.pdf.

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Park, Jong-Jin. "Design of a new arrayed temperature sensor system and thermal interface materials /." Thesis, Connect to this title online; UW restricted, 2004. http://hdl.handle.net/1773/7062.

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Beidaghi, Majid. "Design, Fabrication, and Evaluation of On-chip Micro-supercapacitors." FIU Digital Commons, 2012. http://digitalcommons.fiu.edu/etd/660.

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Due to the increasing demand for high power and reliable miniaturized energy storage devices, the development of micro-supercapacitors or electrochemical micro-capacitors have attracted much attention in recent years. This dissertation investigates several strategies to develop on-chip micro-supercapacitors with high power and energy density. Micro-supercapacitors based on interdigitated carbon micro-electrode arrays are fabricated through carbon microelectromechanical systems (C-MEMS) technique which is based on carbonization of patterned photoresist. To improve the capacitive behavior, electrochemical activation is performed on carbon micro-electrode arrays. The developed micro-supercapacitors show specific capacitances as high as 75 mFcm-2 at a scan rate of 5 mVs-1 after electrochemical activation for 30 minutes. The capacitance loss is less than 13% after 1000 cyclic voltammetry (CV) cycles. These results indicate that electrochemically activated C-MEMS micro-electrode arrays are promising candidates for on-chip electrochemical micro-capacitor applications. The energy density of micro-supercapacitors was further improved by conformal coating of polypyrrole (PPy) on C-MEMS structures. In these types of micro-devices the three dimensional (3D) carbon microstructures serve as current collectors for high energy density PPy electrodes. The electrochemical characterizations of these micro-supercapacitors show that they can deliver a specific capacitance of about 162.07 mFcm-2 and a specific power of 1.62mWcm-2 at a 20 mVs-1 scan rate. Addressing the need for high power micro-supercapacitors, the application of graphene as electrode materials for micro-supercapacitor was also investigated. The present study suggests a novel method to fabricate graphene-based micro-supercapacitors with thin film or in-plane interdigital electrodes. The fabricated micro-supercapacitors show exceptional frequency response and power handling performance and could effectively charge and discharge at rates as high as 50 Vs-1. CV measurements show that the specific capacitance of the micro-supercapacitor based on reduced graphene oxide and carbon nanotube composites is 6.1 mFcm-2 at scan rate of 0.01Vs-1. At a very high scan rate of 50 Vs-1, a specific capacitance of 2.8 mFcm-2 (stack capacitance of 3.1 Fcm-3) is recorded. This unprecedented performance can potentially broaden the future applications of micro-supercapacitors.

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Gupta, Raj K. Ph D. 1969. "Electrostatic pull-in test structure design for in-situ mechanical property measurements of microelectromechanical systems (MEMS)." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/10454.

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Rios, Erick E. "Design and manufacturing of plastic micro-cantilevers by injection molding." Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/18888.

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Maddela, Madhurima Ramadoss Ramesh. "Design of MEMS-based tunable antennas, organic transistors and MEMS-based organic control circuits." Auburn, Ala, 2008. http://repo.lib.auburn.edu/2007%20Fall%20Dissertations/Maddela_Madhurima_8.pdf.

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Aouad, Ghassan Fouad. "Integrated planning systems for the construction industry." Thesis, Loughborough University, 1991. https://dspace.lboro.ac.uk/2134/7199.

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This thesis reports on a CAD-based integrated model developed to aid the planning of the construction of in-situ concrete structures. The main aim of this model is to automate the planning process of in-situ concrete structures using data generated by CAD systems. In order to achieve this goal, the integration of a CAD system (AutoCAD 10) and a computerised planning system (Artemis 2000) via a database program (dBase IV) has been achieved on an IBM PS2 Model 70 microcomputer. This enables the generation of network plans in the AutoCAD system which are then automatically transferred to the Artemis system for time and cost analyses. Currently, the system can handle concreting, steel fixing and formwork activities associated with in-situ concrete design elements. However, further enhancement of the model is possible in order to automate the generation of most construction activities. In order to develop this CAD-based integrated planning model, it was necessary to undertake a questionnaire survey on the current status of planning techniques and information technology uses amongst the main UK and US contractors. This survey reveals that many of these contractors are now aware of the benefits that a CAD system can offer to the management and planning of in-situ concrete structures. It was also found that many aspects of information technology such as computer aided design and project management are well within the reach of most of the companies surveyed, and that many recent developments could be used to develop integrated systems as an aid to the planning of construction projects. These findings indicate that the application of such systems could soon become a reality. However, the practicality of these techniques has to be assessed on real life projects which could be the subject of a further research. The CAD-based integrated model described in this thesis offers many facilities for: modeling, drafting, materials and quantities scheduling, time and cost analyses and reporting which were all integrated and incorporated within such a single system. These facilities which have been fully customised within the developed package are easy to be run as the software is user friendly with pull-down and pop-up menus, and help facilities provided at almost all levels. This thesis demonstrates that current software and hardware technologies are more than sufficient to establish new approaches to the planning and management of in-situ concrete structures, particularly in the area of computer aided design. Such approaches can rectify many of the deficiencies found in traditional planning systems. For instance, a CAD-based system could eliminate the re-extraction of information from conventional drawings and documents which could be error prone as an access to the original electronic building model is provided within such a system. In addition, accurate quantities associated with sets of design elements and relevant to the planning process are automatically generated within the system.

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Lee, Chun Ming. "Design of two-axis capacitive accelerometer using MEMS." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Dec%5FLee%5Chun.pdf.

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Fritz, Nathan Tyler. "Materials, design and processing of air encapsulated MEMS packaging." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/43751.

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Air-gap structures are of particular interest for packaging of microelectromechanical systems (MEMS). In this work, an overcoat material is used to cover a sacrificial polymer, which protects the MEMS device during packaging. Once the overcoat is in place, the sacrificial polymer is thermally decomposed freeing the MEMS structure while the overcoat dielectric provides mechanical protection from the environment. An epoxy POSS dielectric was used as a high-selectivity etch mask for the PPC and a rigid overcoat for the structure leading to the process improvements. The packaging structures can be designed for a range of MEMS device sizes and operating environments. However, the air-cavity structures need additional rigidity to withstand chip-level packaging conditions. Metalized air cavity packages were molded under traditional lead frame molding pressures and tested for mechanical integrity. The experimental molding tests and mechanical models were used to establish processing conditions and physical designs for the cavities as a function of cavity size. A semi-hermetic package was created using an in-situ sacrificial decomposition/epoxy cure molding step for creating large cavity chip packages. Through the optimization of the air cavity, new materials and processes were tested for general microfabrication. The epoxy POSS dielectric provides a resilient, strong inorganic/organic hybrid dielectric for use in microfabrication and packaging applications. Polycarbonates can be used for low cost temporary adhesives in wafer-wafer bonding. An improved electroless deposition process for silver and copper was developed. The Sn/Pd activation was replaced by a cost efficient Sn/Ag catalyst. The process was shown to be able to deposit adherent copper on smooth POSS and silicon dioxide surfaces. Electroless copper was demonstrated on untreated silicon oxide wafers for TSV sidewall deposition.

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Martin, Jeremy Malcolm Randolph. "The design and construction of deadlock-free concurrent systems." Thesis, University of Buckingham, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.601333.

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Throughout our lives we take for granted the safety of complex structures that surround us. We live and work in buildings with scant regard for the lethal currents of electricity and flammable gas coarsing through their veins. We cross high bridges with little fear of them crumbling into the depths below. We are secure in the knowledge that these objects have been constructed using sound engineering principles. Now, increasingly, we are putting OUT lives into the hands of complex computer programs. One could cite aircraft control systems, railway signalling systems, and medical databases as examples. But whereas the disciplines of electrical and mechanical engineering have long been well understood, software engineering is in its infancy. Unlike other fields, there is no generally accepted certification of competence for its practitioners. Formal scientific methods for reliable software production have been developed, but these tend to require a level of mathematical knowledge beyond that of most programmers. Engineers, in general, are usually more concerned with practical issues than with the underlying scientific theory of their particular discipline. They want to get on with the business of building powerful systems. They rely on scientists to provide them with safety rules which they can incorporate into their designs. For instance, a bridge designer needs to know certain formulae to calculate how wide to set the span of an arch - he does not need to know why the formulae work. Software engineering is in need of a battery of similar rules to provide a bridge between theory and practice. The demand for increasing amounts of computing power makes parallel programming very appealing. However additional dangers lurk in this exciting field. In this thesis we explore ways to circumvent one particularly dramatic problem - deadlock. This is a state where none of the constituent processes of a system can agree on how to proceed, so nothing ever happens. Clearly we would desire that any sensible system we construct could never arrive at such a state, but what can we do to ensure that this is indeed the case? We might think to use a computer to check every posssible state of the system. But, given that the number of states of a parallel system usually grows exponentially with the number of processes, we would most likely find the task too great.

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