Development of a Low Power Consuming Micro Actuator using Micromachining Technology

Abstract

Comb actuator is a one of the widely used micro actuator in the field of micro electro-mechanical systems (MEMS). Most of the comb actuators which have been presented previously have rectangular shaped fingers which produce a constant force during actuation. In this paper, we propose a novel micro actuators which have sawtooth shaped fingers for the purpose of reducing driving power(voltage). The dimensions of the sawtooth were derived from finite element analysis (FEA) of simplified finger models with sawtooth type fingers of various dimension and were compared to the rectangular finger model that showed that the sawtooth type fingers have 7~9 times stronger driving force. Finally, comb drive actuators with sawtooth type and rectangular fingers were fabricated and although the gap was bigger, the comb actuator with sawtooth type fingers showed about 1.7 times greater electrostatic force than the one with rectangular fingers at equal driving voltages. In conclusion, using the proposed sawtooth type fingers in a comb actuator makes it possible to increase its driving force.