On a Bi-directional Driving Electrostatic Actuator

Abstract

We propose a bi-directional driving electrostatic actuator which has multiple parallel plate electrodes. The actuator generates a large force that is twice as much as the force of a conventional uni-directional driving actuator. In this paper, we describe the driving theory and its experimental verification. To verify the driving theory, a micro actuator is fabricated by a reactive ion etching process with an piece of SOI wafer. The experimental results on a voltage-displacement curve and a resonance agree with the theoretical calculation results. We also propose the modified driving method to increase the sensitivity around 0-displacement. According to this study, we can conclude that a bi-directional driving electrostatic actuator is very useful for driving optical switches, magnetic head elements of hard disk drives and so on.