Abstract

The goal of this research is mainly to study the feasibility of using thermal expansion buckle up effect of a microbridge structure to develop a vertical motion, large-force, large-displacement electrical thermal actuator device for micro systems application. Initial results on a prototype system are described in this thesis. The focus of this investigation is to understand the physical properties and performance of an out-of plane deflection microactuator, to develop a preliminary device, and to test the performance of the device including displacement and frequency response. Five sets of devices with different structural design were fabricated and tested. The functions of devices were characterized both in vacuum and in air ambient. SEM was used to conduct accurate measurement. A device with total length of 500om, and beams with width of 20 om, demonstrated 15.6 om vertical displacement in vacuum ambient when 3.5 mA input current (4.1 V voltage) applied. The observed operational frequency of the devices was less than 103 Hz. A successful application of stiction avoid structure is also documented in this report. It is demonstrated that a 792om * 20om double clamped single layer polysillicon beam was successfully fabricated and released without suffering stick down problem. The physical properties of these micro actuators are modeled. The temperature distribution throughout the structure, the values and the point of maximum temperature are calculated and reported in this thesis. The devices were fabricated using MUMPS technology supported by CMC, following by a post-processing technique.