Thesis (Ph. D.)--Michigan State University. Dept. of Electrical Engineering, 2008. / Title from PDF t.p. (viewed on July 2, 2009) Includes bibliographical references (p. 147-155). Also issued in print.

Thesis PlanB (M.S.)--University of Wisconsin--Stout, 2008. / Includes bibliographical references.

Thesis (doctoral)--Technische Universiteit Delft, 1997. / Includes bibliographical references (p. 133-137).

Thesis (doctoral)--Technische Universiteit Delft, 1997. / Includes bibliographical references (p. 133-137).

Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references (leaves [137]-142).

Thesis (M.S.)--Florida State University, 2006. / Advisor: Carl A. Moore, Florida State University, College of Engineering, Dept. of Mechanical Engineering. Title and description from dissertation home page (viewed June 8, 2006). Document formatted into pages; contains x, 107 pages. Includes bibliographical references.

A novel accelerometer based on light modulation has been designed and a prototype device manufactured. The device utilises the change in refractive index brought about by stress induced by the applied vibration. A detailed mathematical analysis of several feasible sensing designs has been performed to aid the design process. A mathematical model has been developed to assess the performance characteristics of the light modulated accelerometer the results of which were also used as a design tool. The prototype accelerometer was tested, from 1 g to 50 g between frequencies of 25 Hz to 2000 Hz, on a vibration system under three modulation schemes. The acceleration response of the device was seen to be linear over the testing range whilst the frequency response dropped off initially and levelled off at approximately 1 kHz. An experimental accelerometer was also assembled on the vibration table so that various materials could easily be tested without having to undergo precise machining. The acceleration and frequency responses showed similar behaviour to those obtained with the prototype accelerometer. However, the actual response levels varied with each material. To aid in the development of the accelerometer the stress-optic and thermo-optic coefficients have been determined for a range of polymeric materials. The stress optic coefficient was determined for polycarbonate, polymethyl methacrylate, polvinyl chloride and araldite epoxy resin using a circular polariscope and two interferometer configurations up to the yield stress of the materials tested. Each material showed a constant coefficient over the testing range. The results obtained using each technique were in good agreement with each other and the limited literature data available. The thermal variation of refractive index was also determined for the same materials. The Abbe refractometer was used for the determination between 5 and 140°C using five wavelength sources and two interferometer configurations using a HeNe laser from -50°C to approximately 30° above the glass transition temperatures. The change in index was found to be linear over the temperature range tested. However, at the glass transition temperature a change in gradient was observed with each material. Two simple mathematical relationships were used to predict the thermo-optic coefficient. These gave values reasonably close to those obtained in experiment.

Redox films are a broad class of electrochemically active films with many potential uses. In the present work, Prussian Blue and carbon coated electrodes have been investigated as possible electrochemical sensors for ascorbic acid and pH, respectively. The potential of Prussian Blue as an optical sensor has also been investigated. In the case of Prussian Blue, it has been discovered that up to 100 monolayers can be systematically deposited on gold electrodes by a new technique that we have called "directed assembly". This provides control of layer thickness with nanometer precision. In the case of carbon coated electrodes, we have developed a mechanical coating technique for quartz crystals, which allows them to be used in electrochemical cells, simultaneously as working electrodes and as mass sensors in a quartz crystal microbalance. This opens up the possibility of developing a variety of new sensor technologies, including pH-sensitive microelectrodes.

Phthalocyanines films have been noted for their use as chemical sensors by measuring changes in conductivity when a gas is adsorbed at the surface. The sensing mechanism is not well understood. This work uses iron phthalocyanine as a model in an attempt to understand the gas sensing mechanism of metal phthalocyanines. The alpha and beta polymorphs of iron phthalocyanine (FePc) have been synthesised and then studied using infra-red spectroscopy, scanning electron microscopy (SEM), gas sensing experiments and Mossbauer spectroscopy. Infra red spectroscopy indicates that a phase change occurs at 205°C and SEM work confirms this since the microcrystallite size changes at this temperature. Gas sensing work has shown that FePc responds to NO[2] and Cl[2] at room temperature. Variable temperature transmission mode Mossbauer spectroscopy of both phases showed that the alpha phase has a lower recoil free fraction at room temperature than the beta phase suggesting that the beta phase has a more rigid structure i.e. it is less free to vibrate in the lattice than the alpha phase. This also explains the difficulties experienced in attempts to collect backscatter spectra from alpha FePc. Backscatter Mossbauer spectroscopy has been used in vitro to show a difference at ambient temperature and pressure, of beta FePc before and after exposure to a gas. Conversion electron Mossbauer spectroscopy indicates that NO[2] adsorbs on to the surface of the FePc film preventing the escape of conversion electrons, and conversion x-ray experiments have shown that the NO[2] penetrates the near surface causing a chemical change.

abstract: The advancements in the technology of MEMS fabrication has been phenomenal in recent years. In no mean measure this has been the result of continued demand from the consumer electronics market to make devices smaller and better. MEMS inertial measuring units (IMUs) have found revolutionary applications in a wide array of fields like medical instrumentation, navigation, attitude stabilization and virtual reality. It has to be noted though that for advanced applications of motion tracking, navigation and guidance the cost of the IMUs is still pretty high. This is mainly because the process of calibration and signal processing used to get highly stable results from MEMS IMU is an expensive and time-consuming process. Also to be noted is the inevitability of using external sensors like GPS or camera for aiding the IMU data due to the error propagation in IMU measurements adds to the complexity of the system. First an efficient technique is proposed to acquire clean and stable data from unaided IMU measurements and then proceed to use that system for tracking human motion. First part of this report details the design and development of the low-cost inertial measuring system ‘yIMU’. This thesis intends to bring together seemingly independent techniques that were highly application specific into one monolithic algorithm that is computationally efficient for generating reliable orientation estimates. Second part, systematically deals with development of a tracking routine for human limb movements. The validity of the system has then been verified. The central idea is that in most cases the use of expensive MEMS IMUs is not warranted if robust smart algorithms can be deployed to gather data at a fraction of the cost. A low-cost prototype has been developed comparable to tactical grade performance for under $15 hardware. In order to further the practicability of this device we have applied it to human motion tracking with excellent results. The commerciality of device has hence been thoroughly established. / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2016