Design and modelling of a comb-drive-based microengine for mechanism drive applications

摘要

The design and modelling of a comb-drive-based microengine is presented. The motivation for developing such a device came from our own need to drive specific micromechanisms. Difficulty in connecting an external load to an existing micromotor and insufficient torque led us to a design which uses the comb drive concept of Tang, Nguyen, and Howe, to convert linear oscillatory motion into rotational motion. The microengine provides output in the form of a continuously rotating output gear that is capable of delivering torque to a micromechanism. The microengine can be operated at varying speeds and its motion can be reversed. Modelling of the system indicates that dynamic effects are important and that the device behaves in ways similar to that of ''high speed'' machinery. Processing considerations address the elimination of natural interferences that arise when conformally deposited polysilicon films form the links, joints, and gears. The resultant device is completely batch fabricated without the need for manual assembly steps.