A new electrostatic actuator providing improved stroke length and force

Abstract

The electrostatic actuator considered consists of a silicon membrane bonded to a glass plate by anodic bonding. On the glass plate a circular gold electrode is made and a thin oxide layer is grown on the silicon membrane before bonding. A pressure is applied to the cavity between the membrane and the glass plate causing the membrane to deflect away from the electrode. When a voltage is applied between the gold electrode and the membrane, high electrostatic forces acting along the membrane periphery will pull the membrane into contact with the glass plate. Experimental results are presented demonstrating a stroke length of 18 mu m working against a pressure of 2200 Pa using a voltage of 41 V. The actuator performance has in addition been investigated by means of mathematical analysis and numerical simulations, and a model relating the principal design parameters is presented.