The electrostatic actuation with its several advantages is the main principle for micro-electro-mechanical systems (MEMS). One major drawback is the nonlinear behavior, which results into instability, known as the electrostatic pull-in effect. This effect might also push a closed-loop configuration into instability and thus makes a linear time-invariant control inapplicable to the system. The paper investigates the stability of an acceleration sensor in closed-loop operation with this setting. A simplified controller adjustment gives a first insight into this topic. Practical implementations saturate on the quantizer's full-scale value, which is also considered in the stability analysis. Numerical phase-plane analysis verifies the stability and shows further surprising results.

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The objective of this research is to apply micromachined silicon-based resonant gravimetric sensors to the detection of gas-phase volatile organic compounds (VOCs). This is done in two primary tasks: 1) the optimization and application of silicon disk resonators to the detection of gas-phase VOCs, and 2) the development and application of a novel gravimetric-capacitive multisensor platform for the detection of gas-phase VOCs. In the rst task, the design and fabrication of a silicon-based disk resonator structure utilizing an in-plane resonance mode is undertaken. The resonance characteristics of the disk resonator are characterized and optimized. The optimized characteristics include the resonator Q-factor as a function of geometric parameters, and the dynamic displacement of the in-plane resonance mode. The Q-factors of the disk resonators range from 2600 to 4360 at atmosphere for disk silicon thicknesses from 7 µm to 18 µm, respectively. The resonance frequency of the in-plane resonance mode ranges from 260 kHz up to 750 kHz. The disk resonators are applied to the sensing of gas-phase VOCs using (poly)isobutylene as a sensitive layer. Limits of detection for benzene, toluene and m-xylene vapors of 5.3 ppm, 1.2 ppm, and 0.6 ppm are respectively obtained. Finally, models for the limits of detection and chemical sensitivity of the resonator structures are developed for the case of the polymer layers used. In the second task, a silicon-based resonator is combined with a capacitive structure to produce a multisensor structure for the sensing of gas-phase VOCs. Fabrication of the multisensor structure is undertaken, and the sensor is theoretically modeled. The baseline capacitance of the capacitor component of the multisensor is estimated to be 170 fF. Finally, initial VOC detection results for the capacitive aspect of the sensor are obtained.

Basic resonator structures for frequency-selective capacitive vibration sensors which exploit their mechanical resonance peak for spectral selectivity are developed and analyzed. As an important capability, the stuctures offer voltage-controlled frequency tuning realized by electrostatic principles. Direct electrostatic tuning based on displacement-dependent electrostatic forces as well as tuning by stress-stiffening based on constant electrostatic forces are discussed. The sensor structures are designed for fabrication using common silicon surface microtechnologies. Experimental tests of both mentioned tuning principles are carried out at structures fabricated using a surface technology known as SCREAM. A considerable part of the work focusses on nonlinear oscillations of the mechanical resonator at large amplitudes arising in resonance. Dimensioning rules for minimum nonlinear disturbance are derived from a detailed analysis of the Duffing oscillator. Various capacitive principles for signal detection and electrostatic frequency tuning are evaluated in terms of nonlinearity. A novel type of specially shaped electrode systems offering linear properties within an amplitude range of 10 micrometers, so-called curved comb capacitors, is developed for fabrication in SCREAM technology. / In der vorliegenden Arbeit werden Grundstrukturen frequenzselektiver kapazitiver Vibrationssensoren entwickelt und analysiert, deren spektrale Selektionswirkung durch Ausnutzung ihrer mechanischen Resonanzüberhöhung entsteht. Wesentliches Merkmal der Strukturen ist ihre spannungsgesteuerte Abstimmbarkeit, die auf elektrostatischen Prinzipien beruht. Es werden die direkte elektrostatische Frequenzabstimmung, basierend auf positionsabhängigen Feldkräften, sowie das Prinzip des Stress-Stiffening, basierend auf einer konstanten elektrostatischen Kraft, diskutiert. Die Entwicklung konzentriert sich auf Sensorstrukturen, die in klassischen Oberflächentechnologien gefertigt werden können. Experimentelle Tests der beiden genannten Abstimmprinzipien werden anhand von Strukturen in oberflächennaher Silizium-bulk-Mikromechanik (SCREAM) durchgeführt. Schwerpunkt der Arbeit sind nichtlineare Schwingungen der mechanischen Resonatorkomponente bei großen Amplituden, die durch die Resonanzüberhöhung entstehen. Für den Sonderfall des Duffing-Schwingers werden Dimensionierungsregeln zur Minimierung der Nichtlinearitäten entwickelt. Kapazitive Prinzipien zur Detektion bzw. elektrostatischen Abstimmung werden hinsichtlich ihrer Linearität geprüft. Es werden neuartige Elektrodensysteme für die SCREAM-Technologie, sogenannte Kurvenkammsysteme entwickelt, die bei Schwingamplituden bis zu 10 Mikrometer linear arbeiten.

Over the last decade, electronics operating at high temperatures have been increasingly demanded to support in situ sensing applications such as automotive, deep-well drilling and aerospace. However, few of these applications have requirements above 460 °C, as the surface temperature of Venus, which is a specific target for the seismic sensing application in this thesis. Due to its wide bandgap, Silicon Carbide (SiC) is a promising candidate to implement integrated circuits (ICs) operating in such extreme environments. In this thesis, various analog and mixed-signal ICs in 4H-SiC bipolar technology for high-temperature sensing applications are explored, in which the device performance variation over temperatures are considered. For this purpose, device modeling, circuit design, layout design, and device/circuit characterization are involved. In this thesis, the circuits are fabricated in two batches using similar technologies. In Batch 1, the first SiC sigma-delta modulator is demonstrated to operate up to 500 °C with a 30 dB peak SNDR. Its building blocks including a fully-differential amplifier, an integrator and a comparator are characterized individually to investigate the modulator performance variation over temperatures. In the succeeding Batch 2, a SiC electromechanical sigma-delta modulator is designed with a chosen Si capacitive sensor for seismic sensing on Venus. Its building blocks including a charge amplifier, a multiplier and an oscillator are designed. Compared to Batch 1, a smaller transistor and two metal-interconnects are used to implement higher integration ICs in Batch 2. Moreover, the first VBIC-based compact model featured with continuous-temperature scalability from 27 to 500 °C is developed based on the SiC transistor in Batch 1, in order to optimize the design of circuits in Batch 2. The demonstrated performance of ICs in Batch 1 show the feasibility to further develop the SiC readout ICs for seismic sensor system operating on Venus. / <p>QC 20170911</p>

L’équipe Physique des Galaxies du Laboratoire d’Astrophysique de Marseille a développé un nouveau type d'interféromètre de Fabry-Perot, équipé de trois actionneurs piézoélectriques amplifiés et de trois capteurs capacitifs permettant le contrôle de l'espacement et du parallélisme des lames de verres de l'ordre de 200 µm avec une précision de positionnement du nm.L'objectif visé de ce manuscrit, composé de 3 parties, est le pilotage de cet interféromètre. La première partie, composée des chapitres 1 et 2, présente les généralités sur l'interférométrie de Fabry-Perot puis décrit les instruments 3DNTT et BTFI où seront installés l'interféromètre de nouvelle génération et son contrôleur associé. La conception et la réalisation d'un amplificateur hybride en vue de la réduction des non-linéarités des actionneurs piézoélectriques mettent fin à cette partie.La deuxième partie, chapitres 3 et 4, décrit le développement et la réalisation du contrôleur. Pour cela, une démarche basée sur le concept du Co-design a été adoptée.Le contrôleur ainsi réalisé est composé d'une carte de développement Microzed dont le cœur est un système sur puce de la série Zynq 7000 EPP et d'une carte d'interfaçage comportant des convertisseurs 3 ADC et 3 DAC et des circuits d'alimentation. La troisième et dernière partie, chapitres 5 et 6, traite de la modélisation d'état de l’interféromètre de Fabry-Perot et de son contrôle : un contrôle classique basé sur la régulation PID et un contrôle robuste et optimal basé sur le filtrage de KALMAN. Cette dernière partie conclut sur les perspectives pouvant découler des contributions de ce travail sur le contrôle et la commande Fabry-Perot. / The Physics of Galaxies Team of Laboratoire d'Astrophysique de Marseille (LAM) has developed a new type of Fabry-Perot, with three amplified piezoelectric actuators and three capacitive sensors to control the spacing and parallelism of mirror plates of approximately 200 µm with a positioning accuracy of 3 nm.The purpose of this manuscript, consisting of 3 parts is the control of this interferometer.The first part, consisting of Chapters 1 and 2 presents the general interferometry Fabry-Perot and then describes 3DNTT and BTFI instruments which will be installed the next generation interferometer and its associated controller. The design and implementation of a hybrid amplifier to reduce non-linearities of the piezoelectric actuators (hysteresis and creep) end this first part.The second part, Chapters 3 and 4, describes the development and implementation of the controller.For this, an approach based on codesign concept was adopted. The thus achieved controller consists of a Microzed development board whose heart is a system on chip of the 7000 series Zynq EPP (FPGA + Dual-Core ARM Cortex A9) and an interface card with converters (3 ADC and 3 DAC) and power supply circuits.For the finalization of the controller, two steps are necessary: hardware design in Xilinx Vivado and software design in Xilinx SDK.The third and final section, chapters 5 and 6 deals with the Fabry-Perot space-state modeling and its control: a classic control based on PID control and a robust and optimal control based on KALMAN filtering. This last part concludes the outlook may result from contributions of this work on the monitoring and control of the Fabry-Perot.

<p>Disertacija istražuje primenu fleksibilne elektronike za<br />kapacitivne senzore ugla i ugaone brzine tipa apsolutnog i<br />inkrementalnog enkodera cilindrične strukture. Razmatraju se dve<br />strukture, apsolutnog i inkrementalnog enkodera. Izvršena je analiza<br />uticaja mehaničkih nesavršenosti na funkciju kapacitivnosti.<br />Razvijena su dva prototipa kapacitivnih senzora za statičko i<br />dinamičko ispitivanje karakteristika senzora. Razvijena je<br />elektronika za obradu senzora inkrementalnog tipa sa<br />autokalibracijom senzora.</p> / <p>In this thesis a research on application of flexible electronics for capacitive<br />angular position and speed sensors, referred to as absolute and incremental<br />encoders, is done. It considers two structures of absolute and incremental<br />encoder type. An analysis of mechanical inaccuracies influence on a<br />capacitance function is conducted. Two prototypes are developed and used<br />for static and dynamic measurements of capacitive sensor&#39;s characteristics.<br />An electronics front-end for a capacitive two channel incremental encoder with<br />auto-calibration is developed.</p>

Basic resonator structures for frequency-selective capacitive vibration sensors which exploit their mechanical resonance peak for spectral selectivity are developed and analyzed. As an important capability, the stuctures offer voltage-controlled frequency tuning realized by electrostatic principles. Direct electrostatic tuning based on displacement-dependent electrostatic forces as well as tuning by stress-stiffening based on constant electrostatic forces are discussed. The sensor structures are designed for fabrication using common silicon surface microtechnologies. Experimental tests of both mentioned tuning principles are carried out at structures fabricated using a surface technology known as SCREAM. A considerable part of the work focusses on nonlinear oscillations of the mechanical resonator at large amplitudes arising in resonance. Dimensioning rules for minimum nonlinear disturbance are derived from a detailed analysis of the Duffing oscillator. Various capacitive principles for signal detection and electrostatic frequency tuning are evaluated in terms of nonlinearity. A novel type of specially shaped electrode systems offering linear properties within an amplitude range of 10 micrometers, so-called curved comb capacitors, is developed for fabrication in SCREAM technology. / In der vorliegenden Arbeit werden Grundstrukturen frequenzselektiver kapazitiver Vibrationssensoren entwickelt und analysiert, deren spektrale Selektionswirkung durch Ausnutzung ihrer mechanischen Resonanzüberhöhung entsteht. Wesentliches Merkmal der Strukturen ist ihre spannungsgesteuerte Abstimmbarkeit, die auf elektrostatischen Prinzipien beruht. Es werden die direkte elektrostatische Frequenzabstimmung, basierend auf positionsabhängigen Feldkräften, sowie das Prinzip des Stress-Stiffening, basierend auf einer konstanten elektrostatischen Kraft, diskutiert. Die Entwicklung konzentriert sich auf Sensorstrukturen, die in klassischen Oberflächentechnologien gefertigt werden können. Experimentelle Tests der beiden genannten Abstimmprinzipien werden anhand von Strukturen in oberflächennaher Silizium-bulk-Mikromechanik (SCREAM) durchgeführt. Schwerpunkt der Arbeit sind nichtlineare Schwingungen der mechanischen Resonatorkomponente bei großen Amplituden, die durch die Resonanzüberhöhung entstehen. Für den Sonderfall des Duffing-Schwingers werden Dimensionierungsregeln zur Minimierung der Nichtlinearitäten entwickelt. Kapazitive Prinzipien zur Detektion bzw. elektrostatischen Abstimmung werden hinsichtlich ihrer Linearität geprüft. Es werden neuartige Elektrodensysteme für die SCREAM-Technologie, sogenannte Kurvenkammsysteme entwickelt, die bei Schwingamplituden bis zu 10 Mikrometer linear arbeiten.

<div>A microheater and resistance temperature detector (RTD) are designed and fabricated for various applications. First, a hierarchical manifold microchannel heatsink with an integrated microheater and RTDs is demonstrated. Microfluidic cooling within the embedded heat sink improves heat dissipation, with two-phase operation offering the potential for dissipation of very high heat fluxes while maintaining moderate chip temperatures. To enable multi-chip stacking and other heterogeneous packaging approaches, it is important to densely integrate all fluid flow paths into the device. Therefore, the details of heatsink layouts and fabrication processes are introduced. Characterization of two-phase cooling as well as reliability of the microheater/RTDs are discussed. In addition, another application of microheater for mining particle detection using interdigitated capacitive sensor. While current personal monitoring devices are optimized for monitoring microscale particles, a higher resolution technique is required to detect sub-micron and nanoscale particulate matters (PM) due to smaller volume and mass of the particles. The detection capability of the capacitive sensor for sub-micron and nanoparticles are presented, and an incorporated microheater improved stable capacitive sensor reading under air flow and various humidity. </div><div>This paper also introduces the characterization of nanomaterials such as metallic nanowires (NWs) and single layer graphene. First, the copper nanowire (CuNW)/graphene hybrid networks for transparent conductors (TC) is investigated. Though indium tin oxide (ITO) has been widely used, demands for the next generation of TC is increasing due to a limited supply of indium. Thus, the optical and electrical properties of CuNW/graphene hybrid network are compared with other transparent conductive materials including ITO. Secondly, silver nanowire (AgNW) growth technique using electrodeposition is introduced. A vertically aligned branched AgNW arrays is made using a porous anodic alumina template and the optical properties of the structure are discussed.</div><div><br></div>