Abstract

The greatest promise of micro electro mechanical systems (MEMS) lies in the ability to produce mechanical motion on a small scale. Such devices typically run on low power and are fast, taking advantage of such micro scale phenomena as strong electrostatic forces and rapid thermal responses. MEMS-based sensors and actuators have been widely deployed and commercialized. MEMS technologies also have potential applications in optics, transportation aerospace, robotics, chemical analysis systems, biotechnologies, medical engineering and microscopy using scanned micro probes. Microactuators are useful tools for microsystems development. They produce displacement and useful forces to move, grasp or fine tune components of the Microsystems. Thermal actuators are simple devices with good mechanical and dynamic performances. Since integration requires that the designs of the entire system be performed on the micro chip, a good understanding of the performance of the micro thermal actuators is required. Modeling of thermal actuator is a complex task that requires multi physics formulation. In this thesis, a multi-physics analytical model that can accurately predict the performance of a typical U-shaped micro electro thermal actuator fabricated by MUMPS technology is developed and validated through FEM analysis. Further, experiments are carried out on a benchmark micro thermal actuator. On the basis of this model, the relations between geometries of the thermal actuators and their thermal and mechanical behaviors are calculated and mapped out by simulating them in different geometric conditions. A parametric study that evaluates the performance of the devices with respect to the design geometries is carried out. The results are useful for thermal actuator designers