Orientador: Luiz de Paula do Nascimento / Banca: Vicente Lopes Junior / Banca: Domingos Alves Rade / Resumo: Este trabalho apresenta uma análise teórica do desempenho de um sistema de controle ativo de vibração de rotores utilizando mancais magnéticos. O esquema de controle ativo proposto utiliza a estratégia de controle ativo feedforward sobreposta ao sistema de controle feedback dos mancais magnéticos. O desempenho desse sistema de controle foi analisado em função da flexibilidade dos rotores considerando o impacto do número e da localização dos atuadores e dos sensores de erro sobre a redução dos níveis de vibração desses rotores, tanto em termos de vibração global quanto em termos de vibração local. O sistema de controle foi aplicado em um modelo teórico de rotor desenvolvido através do método da matriz de impedância. / Abstract: This work presents a theoretical analysis of the performance of a system of active control of rotor vibrations using magnetic bearings. The proposed scheme of active control uses a feedforward active control strategy superimposed on the feedback control system of the magnetic bearings. The performance of this control system was analyzed as a function of the rotor flexibility considering the impact and optimization of the actuators and error sensors placement on the reduction of vibration levels of these rotors, in terms of global vibration as well as in terms of local vibration of the rotor. The control system was applied to a theoretical rotor model developed by the matrix impedance method. / Mestre

Cette thèse commence avec un état de l’art des domaines d’études importants pour notre objectif (différentes techniques usuelles de réduction des vibrations en usinage, méthodes de contrôle actif) avant de valider le principe de contrôle actif du fraisage en se plaçant en repère fixe. On a alors développé un modèle d’état d’une poutre d’Euler Bernoulli perturbée en un point et corrigée en un autre via un actionneur piézoélectrique. Ce modèle a permis d’obtenir plusieurs compensateurs, suivant différentes stratégies de commande. Nous avons par la suite procédé, d’un point de vue expérimental, à l’étude sur un dispositif similaire à notre besoin d’un point de vue de l’actionnement et des ordres de grandeurs (amplification mécanique, gamme de fréquences etc.). Les stratégies de commande robustes que nous avons développé pour pouvoir atténuer les déplacements vibratoires de cette poutre ont conduit à des résultats concluants présentés dans le même chapitre, d’abord en simulation (qui nous a permis une étude comparative), avec ou sans la présence du processus d’usinage, puis expérimentalement. La robustesse de ces stratégies de commande a été étudiée (en simulation) en ajoutant des incertitudes au modèle étudié de différentes manières. Ensuite, nous avons identifié le modèle du système étudié, déterminé les correcteurs correspondants et testé ces derniers sur notre banc d’essai pour valider le bon fonctionnement des différentes stratégies de contrôle utilisées tout le long de cette thèse. Enfin, pour préparer un déploiement de ces stratégies en repère tournant (porte-outil de contrôle actif), nous avons modélisé et implémenté les mêmes démarches pour le cas où l’actionnement se situe en repère tournant et concerne deux axes simultanément, situés dans le plan XY du porte-outil. Nous avons d’abord étudié les vibrations transversales d’une poutre en rotation dans le cas général avant de négliger les phénomènes d’inertie et gyroscopique. En effet, on s’intéresse au contrôle actif du fraisage particulièrement dans les applications de finition, là où on utilise des outils longs de faibles diamètres. Les nouvelles expressions des deux fonctions de transfert de notre système usinant ont été déterminées pour obtenir sa représentation d’état, clé du contrôle actif. La projection du processus de coupe sur le repère tournant est indispensable pour effectuer les simulations du fraisage via le porte outil actif. Ce dernier chapitre met en relief les perspectives de cette thèse, à savoir le contrôle actif du fraisage quelque soit le type de l’opération ou du diamètre de l’outil avec un porte outil mécatronique destiné pour ce genre d’opérations. / This thesis deals with the fields of study which are important for our objective (different usual vibration reduction techniques in machining, active control methods) before validating the principle of active control of milling in a fixed reference. We then developed a state space model of an Euler Bernoulli beam excited at one point and corrected in another one by a piezoelectric actuator. This model allowed us to obtain several compensators, according to different control strategies. We then proceeded from an experimental point of view to study a device similar to our need from an actuating point of view and levels of magnitude (mechanical amplification, frequency range, etc.). ). The robust control strategies that we have developed to attenuate the vibratory displacements of this beam have led to conclusive results presented in the same chapter, first in simulation (which allowed us a comparative study), with and without the cutting process and then experimentally. The robustness of these control strategies was studied (in simulation) by adding uncertainties to the model in different ways. Then we have identified the model of the system, calculated the corresponding compensators and tested them on the test bench in order to validate the good functioning of the different control strategies used in this thesis. Finally, in order to use these strategies in rotating reference (active control tool holder), we have modeled and implemented the same steps for the case where the actuation is located in rotating reference and concerns two axes simultaneously, located in the XY plane of the tool holder. We first studied the transverse vibrations of a rotating beam in the general case before neglecting the inertia and gyroscopic phenomena. Actually, we are interested in the active control of milling, particularly in finishing applications, where long tools of small diameters are used. The new expressions of the two transfer functions of the system have been determined to obtain its state space representation, key of the active control. Projection of the cutting process on the rotating reference is essential to perform milling simulations with the active tool holder. This last chapter highlights the prospects of this thesis,that is the active control of the milling for all kinds of milling operations as well as for different tools with a mechatronic tool holder aimed for this kind of operation.

Le travail de thèse porte sur la conception et la réalisation de deux modulateurs optiques assistés par phonon-polaritons de surface fonctionnant en réflectivité, autour de 8.5 THz, à température ambiante. Nous avons dans un premier temps validé expérimentalement la description théorique du couplage du champ propagatif aux phonons polaritons de surface pour un réseau de GaAs grâce à des mesures de réflectivité THz résolues angulairement. Nous montrons l'importance de la géométrie de la structure pour une description quantitative du couplage. Nous avons réalisé un modulateur de réflectivité THz contrôlé optiquement. La structure est un réseau lamellaire de GaAs dopé , de période inférieure à la longueur d'onde supportant un mode composé de plasmon-phonon-polaritons de surface se propageant le long des murs du réseau. L'éclairement de la structure dans le visible modifie la fréquence de résonance THz de ce mode en créant des photo-porteurs dans les murs du réseau et permet ainsi un contrôle actif de la réflectivité.Enfin nous étudions et réalisons un modulateur de réflectivité THz contrôlé électriquement. Nous proposons une structure permettant d'exciter un mode de phonon-polaritons d'interface dans un puits quantique. Ce mode est très confiné dans le puits et présente une forte sur-intensité de champ. Cet effet original est lié à la permittivité du puits proche de zéro à la fréquence du mode d'interface. La perturbation engendrée par des transitions intersous-bandes dans le puits quantique unique permet, en appliquant une tension de l'ordre du volt, de contrôler l'intensité du couplage du champ propagatif au mode du puits, ce qui donne un contrôle actif de la réflectivité de la structure. / In this work we report the design and fabrication of two THz modulators, assisted by surface phonons polaritons. Both devices work around 8.5 THz at room temperature.We first validate experimentally the coupling of the propagating field to surface-phonons polaritons on a GaAs grating by angular resolved THz reflectivity measurements. We show that a good knowledge of the grating geometry is necessary to have a quantitative description of the coupling.We have fabricated an optically controled THz modulator made of a doped GaAs lamellar grating with subwavelength dimensions. This grating supports surface-plasmon-phonons polaritons along the grating walls. The THz resonance frequency is then modified by shining visible light on the grating, which creates photo-electrons. This allows a dynamic optical control of the THz reflectivity.Finally we present an electrically controlled THz modulator. We design a structure that allows the coupling of the propagating field to an interface-phonon polaritons in a single quantum well. This mode is confined inside the quantum well and gives a high field enhancement. This original effect is due to a near-zero dielectric function of the well at the interface-mode frequency. The perturbation introduced by intersubband transitions in the single quantum well allows, by applying a voltage of about one volt, a control of the coupling intensity between the propagating field and the interface mode, leading to a change in the structure reflectivity.

A crescente demanda por reduções nos níveis de ruído gerados por veículos, e, mais recentemente, pela melhoria na qualidade sonora, aliada às penalidades associadas ao espaço e peso das soluções passivas, sugerem o uso de técnicas de controle ativo de ruído. O projeto de sistemas ativos deve fazer parte do desenvolvimento de produto desde sua fase de concepção para que tais soluções sejam aplicadas em nível industrial. Portanto, propõem-se metodologias de simulação para o projeto de sistemas de controle de ruído. Modelos vibroacústicos em elementos finitos são reduzidos e formulados em espaço de estados para permitir a simulação do sistema em malha fechada. Os modelos envolvidos permitem a inclusão da dinâmica de sensores e atuadores para que o desempenho seja previsto de forma acurada. As vantagens do uso de simulação de sistema de controle de ruído, além da redução de custo e tempo de projeto, permite o desenvolvimento de sistemas ativos onde estrutura e controle são desenvolvidos de forma simultânea. O procedimento de simulação é validado experimentalmente, tanto para malha aberta quanto para malha fechada, com o uso de uma geometria simplificada de veículo. Graças à redução dos modelos originais, é possível utilizar técnicas de otimização, onde a interação entre a estrutura e o controle são considerados de forma simultânea, resultando em um sistema ativo com desempenho superior a sistemas desenvolvidos separadamente. Através dos resultados obtidos com a otimização observam-se os parâmetros conflitantes e as decisões de compromisso envolvendo o controle de transmissão de ruído em veículos. Demonstra-se, que um sistema de controle estrutural, descentralizado, de alimentação de velocidade, oferece praticidade de implementação e desempenho satisfatório. Finalmente, o impacto do controle ativo na percepção dos ocupantes é avaliado por meio de métricas objetivas de qualidade sonora, como tonalidade e nível de pressão sonora. / The demands for improvement in sound quality and noise reduction generated by vehicles are steadily increasing, as are the penalties for space and weight of passive control solutions. This scenario suggests the use of active noise control. In order to bring active solutions to industrial level applications, the design of such systems should be part of the product development cycle. Therefore, methodologies for simulating and designing such active solutions are proposed. These models should allow the inclusion of sensors and actuators models, if accurate performance indexes are to be accessed. The challenge thus resides in deriving reasonable sized models that integrate structural, acoustical, and even sensor/actuator models in the controller algorithm simulation. The proposed modelling procedure coupe with this challenge, and besides the advantages on the cost and time reduction in the development phase, it allows the development of active systems with structure and controllers being designed concurrently. An experimental validation is performed using data obtained from simplified car geometry. Thanks to the reduced models, it is possible to run optimization routines in which the interaction of structure and control is considered, thus resulting in an improved system when compared to conventional stepwise procedure. The optimization results presented give some insights on the problem of designing active noise controllers for transmission loss in vehicles. It is shown that, a purely structural decentralized velocity feedback controller can offer both, easy practical implementation and satisfactory noise reduction. Also, the impact of the active control on the perceived noise reduction is evaluated with objective sound quality metrics, such as sound pressure level and specific loudness.

A crescente demanda por reduções nos níveis de ruído gerados por veículos, e, mais recentemente, pela melhoria na qualidade sonora, aliada às penalidades associadas ao espaço e peso das soluções passivas, sugerem o uso de técnicas de controle ativo de ruído. O projeto de sistemas ativos deve fazer parte do desenvolvimento de produto desde sua fase de concepção para que tais soluções sejam aplicadas em nível industrial. Portanto, propõem-se metodologias de simulação para o projeto de sistemas de controle de ruído. Modelos vibroacústicos em elementos finitos são reduzidos e formulados em espaço de estados para permitir a simulação do sistema em malha fechada. Os modelos envolvidos permitem a inclusão da dinâmica de sensores e atuadores para que o desempenho seja previsto de forma acurada. As vantagens do uso de simulação de sistema de controle de ruído, além da redução de custo e tempo de projeto, permite o desenvolvimento de sistemas ativos onde estrutura e controle são desenvolvidos de forma simultânea. O procedimento de simulação é validado experimentalmente, tanto para malha aberta quanto para malha fechada, com o uso de uma geometria simplificada de veículo. Graças à redução dos modelos originais, é possível utilizar técnicas de otimização, onde a interação entre a estrutura e o controle são considerados de forma simultânea, resultando em um sistema ativo com desempenho superior a sistemas desenvolvidos separadamente. Através dos resultados obtidos com a otimização observam-se os parâmetros conflitantes e as decisões de compromisso envolvendo o controle de transmissão de ruído em veículos. Demonstra-se, que um sistema de controle estrutural, descentralizado, de alimentação de velocidade, oferece praticidade de implementação e desempenho satisfatório. Finalmente, o impacto do controle ativo na percepção dos ocupantes é avaliado por meio de métricas objetivas de qualidade sonora, como tonalidade e nível de pressão sonora. / The demands for improvement in sound quality and noise reduction generated by vehicles are steadily increasing, as are the penalties for space and weight of passive control solutions. This scenario suggests the use of active noise control. In order to bring active solutions to industrial level applications, the design of such systems should be part of the product development cycle. Therefore, methodologies for simulating and designing such active solutions are proposed. These models should allow the inclusion of sensors and actuators models, if accurate performance indexes are to be accessed. The challenge thus resides in deriving reasonable sized models that integrate structural, acoustical, and even sensor/actuator models in the controller algorithm simulation. The proposed modelling procedure coupe with this challenge, and besides the advantages on the cost and time reduction in the development phase, it allows the development of active systems with structure and controllers being designed concurrently. An experimental validation is performed using data obtained from simplified car geometry. Thanks to the reduced models, it is possible to run optimization routines in which the interaction of structure and control is considered, thus resulting in an improved system when compared to conventional stepwise procedure. The optimization results presented give some insights on the problem of designing active noise controllers for transmission loss in vehicles. It is shown that, a purely structural decentralized velocity feedback controller can offer both, easy practical implementation and satisfactory noise reduction. Also, the impact of the active control on the perceived noise reduction is evaluated with objective sound quality metrics, such as sound pressure level and specific loudness.

In this thesis, three control methodologies are proposed for suppressing multi-mode vibration in flexible structures. Controllers developed using these methods are designed to (i) be able to cope with large and sudden changes in the system's parameters, (ii) be robust to unmodelled dynamics, and (iii) have a fast transient response. In addition, the controllers are designed to employ a minimum number of sensor-actuator pairs, and yet pose a minimum computational demand so as to allow real-time implementation. A cantilever beam with magnetically clamped loads is designed and constructed as the research vehicle for evaluation of the proposed controllers. Using this set-up, sudden and large dynamic variations of the beam loading can be tested, and the corresponding changes in the plant's parameters can be observed. Modal testing reveals that the first three modes of the plant are the most significant and need to be suppressed. It is also identified that the first and third modes are spaced more than a decade apart in frequency. The latter characteristic increases the difficulty of effectively controlling all three modes simultaneously using one controller. To overcome this problem, the resonant control method is chosen as the basis for the control methodologies discussed in this thesis. The key advantage of resonant control is that it can be tuned to provide specific attenuation only at and immediately close to the resonant frequency of concern. Consequently, it does not cause control spillover to other modes owing to unmodeled dynamics. Because of these properties, a resonant controller can be configured to form a parallel structure with the objective of targeting and cancelling multiple modes individually. This is possible regardless of the mode spacing. In addition, resonant control requires only a minimum number of collocated sensor-actuator pairs for multi-mode vibration cancellation. All these characteristics make resonant control a suitable candidate for multi-mode vibration cancellation of flexible structures. Since a resonant controller provides negligible attenuation away from the natural frequencies that it has been specifically designed for, it is very sensitive to changes of a system's natural frequencies and becomes ineffective when these mode frequencies change. Hence, for the case of a dynamically loaded structure with consequent variations in mode frequencies, the resonant control method must be modified to allow tracking of system parameter changes. This consideration forms the theme of this thesis, which is to allow adaptive multi-mode vibration control of dynamically-loaded flexible structures. Three controller design methodologies based on the resonant control principle are consequently proposed and evaluated. In the first approach, all possible loading conditions are assumed to be a priori known. Based on this assumption, a multi-model multi-mode resonant control (M4RC) method is proposed. The basis of the M4RC approach is that it comprises a bank of known loading models that are designed such that each model gives optimum attenuation for a particular loading condition. Conceptually, each model is implemented as a set of fixed-parameter controllers, one for each mode of concern. In reality, each mode controller is implemented as an adjustable resonant controller that is loaded with the fixed-model parameters of the corresponding mode. The M4RC method takes advantage of the highly frequency-sensitive nature of resonant control to allow simple and rapid selection of the optimum controller. Identification of the set of resonant frequencies is implemented using a bank of band-pass filters that correspond to the mode frequencies of the known models. At each time interval a supervisor scheme determines for each mode which model has the closest frequency to the observed vibration frequency and switches the corresponding model controller output to attenuate the mode. Selection is handled on a mode-by-mode basis, such that for each mode the closest model is selected. The proposed M4RC is relatively simple and less computationally complex compared to other multi-model methods reported in the literature. In particular, the M4RC uses a simple supervisor scheme and requires only a single controller per mode. Other multi-model methods use more complex supervision schemes and require one controller per model. The M4RC method is evaluated through both simulation and experimental studies. The results reveal that the proposed M4RC is very effective for controlling multi-mode vibration of a flexible structure with known loading conditions, but is ineffective for unmodeled loading conditions. In the second approach, the assumption that all loading conditions are a priori known is relaxed. An adaptive multi-mode resonant control (ARC) method is proposed to control the flexible structure for all possible (including unknown) loading conditions. On-line estimation of the structure's natural frequencies is used to update the adaptive resonant controller's parameters. The estimation of the natural frequencies is achieved using a parallel set of second-order recursive least-squares estimators, each of which is designed for a specific mode of concern. To optimise the estimation accuracy for each mode frequency, a different sampling rate suitable for that mode is used for the corresponding estimator. Simulation and experiment results show that the proposed adaptive method can achieve better performance, as measured by attenuation level, over its fixed-parameter counterpart for a range of unmodeled dynamics. The results also reveal that, for the same sequences of known loading changes, the transient responses of the ARC are slower than those of the M4RC. In the third approach, a hybrid multi-model and adaptive resonant control is utilized to improve the transient response of the ARC. The proposed multi-model multi-mode adaptive resonant control (M4ARC) method is designed as a combination of the M4RC and ARC methods. The basis of the proposed method is to use the M4RC fixed-parameter model scheme to deal with transient conditions while the ARC adaptive parameter estimator is still in a state of fluctuation. Then, once the estimator has reached the vicinity of its steady-state, the adaptive model is switched in place of the fixed model to achieve optimum control of the unforeseen loading condition. Whenever a loading change is experienced, the simple M4RC supervisor scheme is used to identify the closest model and to load the adjustable resonant controllers with the fixed parameters for that model. Meanwhile, the mode estimators developed for the ARC method are used to identify the exact plant parameters for the modes of concern. As soon as these parameters stop rapidly evolving and reach their steady-state, they are loaded into the respective adjustable controllers. The same process is repeated whenever a loading change occurs. Given the simplicity of the M4ARC method and its minimal computation demand, it is easily applicable for real-time implementation. Simulation and experiment results show that the proposed M4ARC outperforms both the ARC with respect to transient performance, and the M4RC with respect to unmodeled loading conditions. The outcomes of this thesis provide a basis for further development of the theory and application of active control for flexible structures with unforeseen configuration variations. Moreover, the basis for the proposed multi-model adaptive control can be used in other areas of control (not limited to vibration cancellation) where fast dynamic reconfiguration of the controller is necessary to accommodate structural changes and fluctuating external disturbances.

Bypass transition, i.e. transition of a boundary layer at subcritical Reynolds numbers, has been studied. Fundamental studies of the phenomenon as such have been performed side by side with experiments aimed at controlling, i.e. delaying, transition. The experiments have been performed in three different flow facilities, two with air as the working fluid (a plane channel flow and a wind-tunnel) and one with water (a water channel). From the water channel data the well known low-speed streaks appearing in a boundary layer under a turbulent free stream are found to be correlated with upward motion in the boundary layer. The streaks are found to scale in proportion to the boundary-layer thickness in both the streamwise and wall-normal directions. The streamwise length is around hundred boundary-layer thicknesses. It is found that the secondary instability of the streaks grows slower for disturbances consisting of less than four wavelengths, as compared to continuous wavetrains. Elongated low-speed structures are controlled, first in the plane channel flow and then by a reactive system in the wind-tunnel. In the channel, the breakdown of generated streaks is delayed by applying localized suction under the regions of low velocity. Measurements of the disturbance environment withand without control applied show that both the growth of the secondary instability and its spreading in the spanwise direction are reduced when applying the control. In order to be successful, the control has to be applied to a narrow region (about 1/10th of a streak width) around the position of minimum velocity. The reactive system in the windtunnel, comprising four upstream sensors and four suction ports downstream, inhibits the growth of the amplitude of the streaks for a certain distance downstream of the suction ports. After the inhibited growth the disturbances start to grow again and far downstream the streak amplitude returns to close to the uncontrolled values. / QC 20100527

Wind tunnel studies of the wake behind model wind turbines with one, two and three blades have been made in order to get a better understanding of wake development as well as the possibility to predict the power output from downstream turbines working in the wake of an upstream one. Both two-component hot-wire anemometry and particle image velocimetry (PIV) have been used to map the flow field downstream as well as upstream the turbine. All three velocity components were measured both for the turbine rotor normal to the oncoming flow as well as with the turbine inclined to the free stream direction (the yaw angle was varied from 0 to 30 degrees). The measurements showed, as expected, a wake rotation in the opposite direction to that of the turbine. A yawed turbine is found to clearly deflect the wake flow to the side showing the potential of controlling the wake position by yawing the turbine. The power output of a yawed turbine was found to depend strongly on the rotor. The possibility to use active wake control by yawing an upstream turbine was evaluated and was shown to have a potential to increase the power output significantly for certain configurations. An unexpected feature of the flow was that spectra from the time signals showed the appearance of a low frequency fluctuation both in the wake and in the flow outside. This fluctuation was found both with and without free stream turbulence and also with a yawed turbine. The non-dimensional frequency (Strouhal number) was independent of the freestream velocity and turbulence level but increases with the yaw angle. However the low frequency fluctuations were only observed when the tip speed ratio was high. Porous discs have been used to compare the meandering frequencies and the cause in wind turbines seems to be related to the blade rotational frequency. It is hypothesized that the observed meandering of wakes in field measurements is due to this shedding. / QC 20101018

The Reversed-Field Pinch (RFP) is one of the major alternatives for realizing energy production from thermonuclear fusion. Compared to alternative configurations (such as the tokamak and the stellarator) it has some advantages that suggest that an RFP reactor may be more economic. However, the conventional RFP is flawed with anomalously large energy and particle transport (which leads to unacceptably low energy confinement) due to a phenomenon called the "RFP dynam". The dynamo is driven by the gradient in the plasma current in the plasma core, and it has been shown that flattening of the plasma current profile quenches the dynamo and increases confinement. Various forms of current profile control schemes have been developed and tested in both numerical simulations and experiments. In this thesis an automatic current profile control routine has been developed for the three-dimensional, non-linear resistive magnetohydrodynamic computer code DEBSP. The routine utilizes active feedback of the dynamo associated fluctuating electric field, and is optimized for replacing it with an externally supplied field while maintaining field reversal. By introducing a semi-automatic feedback scheme, the number of free parameters is reduced, making a parameter scan feasible. A scaling study was performed and scaling laws for the confinement of the advanced RFP (an RFP with enhanced confinement due to current profile control) have been obtained. The conclusions from this research project are that energy confinement is enhanced substantially in the advanced RFP and that poloidal beta values are possible beyond the previous theoretical limit beta βΘ < ½. Scalings toward the reactor regime indicate strongly enhanced confinement as compared to conventional RFP scenarios, but the question of reactor viability remains open. / QC 20101101

This thesis describes the creation of a metrology system based upon an actively controlled diffraction grating interferometer, which measures relative linear distances. The dynamics of this sensor are estimated based on experimental testing, and a suitable controller is designed to maintain the position of the sensor in the most sensitive operating region. This controller is implemented on a field programmable gate array (FPGA) processor, which allows for flexible programming and real-time control. The sample under test is mounted atop a three axis linear stage system, which allows the diffraction grating interferometer to scan across the surface of the device, creating maps of the static and dynamic measurements. The controller is shown to maintain the sensitivity of the sensor during this operation. This insures all data are taken on the same scale, creating more accurate results. The controller increases the signal to noise ratio as compared to the system without the controller. The specifications of the entire metrology system are detailed including the sensor and controller bandwidth, the vertical and horizontal resolution, and the signal to noise ratio. A case study utilizing a capacitive micromachined ultrasonic transducer (cMUT) is presented. The sensor generates static and dynamic displacement maps of the surface of this MEMS device. The controller improves these measurements by maintaining a position of high sensitivity during operation. Finally, the preliminary results of a miniaturized version of this system are presented including the implementation of two fully independent parallel sensors. This allows for array implementation of these sensors, which is crucial for the batch fabrication photolithography techniques used to create many MEMS devices. Recommendations on the future work needed to complete the array implementation are given in conjunction with methods for increasing the resolution and robustness of the macroscale system described in this thesis.