Analysis and optimization of MEMS electrostatic microactuator

This paper presents the results of analysis and optimizing a MEMS electrostatic microactuator. Although, variable kinds of MEMS microactuators have built but the most commonly used ones are electrostatic micromotors. In this paper, a practical design for a variable capacitance electrostatic micromotor has been analyzed using a two-dimensional numerical finite element method. Optimization the micromotor means maximizing its driving torque or minimizing the torque ripple. The procedure presented here for optimizing the micromotor consists of two stages: optimization the excitation sequence and optimization the geometric structure. Several excitation sequences have been studied for maximizing the driving torque, and finally the optimal excitation sequence has been found for supplying the micromotor. Geometric structure is optimized to minimize the torque ripple. The Geometric structure optimization procedure is based on the successive sampling of geometric parameters. This paper demonstrates the optimal values for some geometric parameters witch is of great advantage during design stage of the micromotor. These parameters include stator tooth width, rotor tooth width and slot radius.