This work examined the design, fabrication, and testing of a bio-mimetic MEMS earthworm crawler with external actuators. The micro-earthworm consisted of a passive mobile shuttle with two flexible diamond shaped segments; each segment was independently squeezed by a pair of stationary chevron-shaped thermal actuators. By applying a specific sequence of squeezes to the earthworm segments, the shuttle could be driven backwards or forwards. Unlike existing inchworm drives, which use separate clamping and thrusting motors, the earthworm motor applies only clamping forces and lateral thrust is produced by the shuttle’s compliant geometry. A study of existing crawler work was performed; to the author’s knowledge, this was the first micro-crawler to achieve both clamping force and lateral motion using the same actuators. The earthworm assembly was fabricated using the POLYMUMPs process, with planar dimensions of 400 µm wide by 800 µm long. The stationary earthworm motors operated within the range of 4-9 V, and 0-10 kHz; these motors provided a maximum shuttle range of motion of 350 µm (~half the size of the device), a maximum shuttle speed of 17,000 µm /s at 10 kHz, and a maximum DC shuttle force of 80 µN. The shuttle speed was found to vary linearly with both input voltage and input frequency; the shuttle force was found to vary linearly with actuator voltage. The tested design had higher force, range, and speed (per device footprint) than most other existing designs. Future work recommendations included the implementation of multiple motors and a closed loop control system to allow an indefinite range of motion, as well as the investigation of a two degree of freedom crawler. / THE DESIGN AND TESTING OF A BIO-INSPIRED HIGH PRECISION, HIGH SPEED, LONG RANGE PERISTALTIC MICRO-MOTOR

The purpose of this thesis is to introduce a novel method of dry micro-object manipulation and to demonstrate predictable vision-based control. The Lift and slide conveyors presented utilize three main components: pads, lifters and a floating platform. The pads have a small planar displacement in the XY axis and lifters have a small Z axis displacement. Together they can be used to create minute displacements per cycle while carrying a floating platform that can hold the desired objects to be moved. These platforms can be handed off to other pad-lifter groups to create an unlimited planar envelope. Two degree of freedom control was established using LabView with open and closed loop routines. A model is presented that predicts the resonance frequencies with different loading and geometric characteristics to aid in design optimization for various applications. Parameters such as velocity, drift and traction are well characterized for different operating conditions.

Several free-free beam micro-resonators are designed and fabricated using two commercially available surface micromachining processes, the UW-MEMS process and PolyMUMPs. Theoretical derivations of the design parameters are presented and an electrical lumped behavior model is developed for a single resonator with direct mechanic-to-electric analogy. A finite-element analysis (FEA) tool, the COMSOL Multiphysics 4.2a, is utilized to simulate the effects of the critical structural dimensions and electromechanical coupling. A variety of analyses, such as modal, static and dynamic responses are performed in FEA and the results are compared with the analytical solutions. The static and dynamic performances of the fabricated UW-MEMS resonators are tested using the Vecco NT-9100 In-Motion System. The electrical testing is carried out to obtain the frequency characteristics in electrical domain of the device. Measured data are compared with the analytical and simulation results. Discrepancies are discussed and analyzed.

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This thesis describes the development of a MEMS repulsive actuator capable of producing a large out-of-plane force. Existing MEMS repulsive actuators are low out-of-plane force actuators that are unable to support or lift a mass of 1 mg. A high force MEMS repulsive actuator was developed to overcome this limitation. The design was optimized employing parameters of the actuator’s fingers to increase the out-of-plane force. A design was developed based on the analytical results derived from extending the mathematical model of an existing actuator. A commercial manufacturing process, PolyMUMPs, was used to fabricate a prototype which was tested to validate the analytical and computational results. The prototype achieved an out-of-plane displacement of 15 µm and a 0.2° angular rotation. The resonance frequency was 120 Hz, and the rise and fall times were measured as 14.5 ms and 3625 ms (3.6 sec), respectively. The estimated out-of-plane force is 40 µN.

This thesis describes the development of a MEMS repulsive actuator capable of producing a large out-of-plane force. Existing MEMS repulsive actuators are low out-of-plane force actuators that are unable to support or lift a mass of 1 mg. A high force MEMS repulsive actuator was developed to overcome this limitation. The design was optimized employing parameters of the actuator’s fingers to increase the out-of-plane force. A design was developed based on the analytical results derived from extending the mathematical model of an existing actuator. A commercial manufacturing process, PolyMUMPs, was used to fabricate a prototype which was tested to validate the analytical and computational results. The prototype achieved an out-of-plane displacement of 15 µm and a 0.2° angular rotation. The resonance frequency was 120 Hz, and the rise and fall times were measured as 14.5 ms and 3625 ms (3.6 sec), respectively. The estimated out-of-plane force is 40 µN.

Dans un contexte de développement durable et d’automatisation de notre environnement, l’utilisation de capteurs sans-fil distribués est croissante. Hors l’usage et le remplacement de piles s’avère coûteux. La consommation énergétique de plus en plus faible de l’électronique rend l’extraction énergétique de l’énergie ambiante envisageable. La chaleur résiduelle est une source d ’énergie intéressante puisqu’elle est la forme finale de la majeure partie de l’énergie utilisée par l’humain. Cependant, à petite échelle, seuls les éléments thermoélectriques sont disponibles. Les présents travaux s’intéressent donc à explorer et comparer des mécanismes de génération alternatifs. Puisque la majorité des mécanismes de transduction alternatifs sont dynamiques, leur utilisation requiert une transformation de l’énergie thermique continue en oscillations. Les mécanismes étudiés ont donc tous en commun de posséder un oscillateur thermique en plus d’un mécanisme de transduction vers la forme d ’énergie électrique. Parmi les divers mécanismes identifiés, deux sont étudiés en détails pour comprendre leurs comportements ainsi que connaître leur efficacité et leur puissance potentielle. Le premier générateur étudié théoriquement est basé sur le changement de ferromagnétisme d’une masse suspendue par des ressorts au-dessus d’un aimant. Les comportements du modèle développé correspondent aux comportements reportés dans la littérature. Deux paramètres de conception principaux ont été identifiés, perm ettant un contrôle de la fréquence, de la plage de températures d’opération. De plus le mécanisme peut opérer avec de faibles différences de température et des températures proches de l’ambiant, ouvrant la porte à des applications utilisant la chaleur du corps humain. L’utilisation de matériau pyroélectrique comme mécanisme de transduction pourrait offrir des densités de puissance électrique envisageables de l’ordre de 1 m W / c m 3. Le second générateur étudié expérimentalement est basé sur l’évaporation explosive d’un liquide surchauffé en absence de sites de nucléation. Un premier prototype a permis de démontrer, pour la première fois, le fonctionnement d’un tel cycle. Une étude de l’effet de la température de la source de chaleur et de l’effet du débit de liquide montre qu’une zone d’opération idéale est présente. La puissance de sortie maximale mesurée est de l’ordre de 1.6//W. Des améliorations sont proposées pour faire croître cette puissance de deux ordres de grandeur. Finalement, l’utilisation du pompage capillaire pour rendre le système autonome est démontré, mais reste sensible aux variations de conditions. Finalement, l’étude des dispositifs montre que les microgénérateurs à base d’oscillateurs thermiques peuvent présenter un intérêt, par rapport aux éléments thermoélectriques, dans les applications où les températures sont faibles ou incertaines. Cependant, ces mécanismes souffrnt d’une très faible efficacité causée par les multiples transformations énergétiques à faible couplage. [symboles non conforme]

The prospect of finding life outside Earth has fascinated mankind for ages, and new technology continuously pushes the boundary of how remote and how obscure evidence we can find. Employing smaller, or completely new, types of landers and robots, and equipping them with miniature instruments would indeed revolutionize exploration of other planets and moons. In this thesis, microsystems technology is used to create a miniature high-precision isotope-resolving molecular spectrometer utilizing the optogalvanic effect. The heart of the instrument, as well as this thesis, is a microplasma source. The plasma source is a split-ring resonator, chosen for its simplicity, pressure range and easily accessible plasma, and modified to fit the challenging application, e.g., by the adding of an additional ground plane for improved electromagnetic shielding, and the integration of microscopic plasma probes to extract the pristine optogalvanic signal. Plasma sources of this kind have been manufactured in both printed circuit board and alumina, the latter for its chemical inertness and for compatibility with other devices in a total analysis system. From previous studies, classical optogalvanic spectroscopy (OGS), although being very sensitive, is known to suffer from stability and reproducibility issues. In this thesis several studies were conducted to investigate and improve these shortcomings, and to improve the signal-to-noise ratio. Moreover, extensive work was put into understanding the underlying physics of the technique. The plasma sources developed here, are the first ever miniature devices to be used in OGS, and exhibits several benefits compared to traditional solutions. Furthermore, it has been confirmed that OGS scales well with miniaturization. For example, the signal strength does not decrease as the volume is reduced like in regular absorption spectroscopy. Moreover, the stability and reproducibility are greatly increased, in some cases as much as by two orders of magnitude, compared with recent studies made on a classical OGS setup. The signal-to-noise ratio has also been greatly improved, e.g., by enclosing the sample cell and by biasing the plasma. Another benefit of a miniature sample cell is the miniscule amount of sample it requires, which can be important in many applications where only small amounts of sample are available. To conclude: With this work, an important step toward a miniature, yet highly performing, instrument for detection of extraterrestrial life, has been taken.