Abstract

This thesis presents the results of an on-going research on fundamental issues related to comb drive and the feasibility of the microengine driven by the comb drives. Mechanical analysis and electrical properties are addressed and modeled. In order to suppress rotational motion due to the asymmetry, "balanced comb drive" with torque balance is proposed. Attention is mostly focused on the stability at high frequency in the cases where a cantilever is attached to the comb drive, either for transferring motion to coupling structure or for optical switching. Different measurement approaches in frequency domain are discussed. Theoretical formulas are derived and analyzed. In this work, both balanced and unbalanced comb drives, with or without rack and pinion engagement are fabricated using MUMPs technology. Post-processing, including HF release, application of lubricant and bonding is carried out afterwards. Experiments in probe station and SEM, and frequency domain measurements at atmosphere are carried out. Balanced comb drives exhibit superior stability both in SEM observation and spectrum analysis