An electrostatically-actuated MEMS switch for power applications

Abstract

This paper presents the design, analysis, fabrication, and testing of an electrostatically-actuated MEMS power switch. The device can be switched electrostatically (20 V), pneumatically (1200 Pa), or through combined actuation. Prototype switches carry currents in excess of 400 mA in either current direction with a contact resistance as low as 14 m/spl Omega/. Their off-state resistance is higher than the 30 M/spl Omega/ limit of the test equipment. Breakdown voltages of 300 V have been achieved across their small air gaps. Their nominal switching time is 20 ms. Extended lifetime testing has not been carried out but our tests to date show that the prototype switches operate more than 4000 cycles without significant degradation in their contact resistance. Finally, a protective switching scheme is proposed to minimize contact wear due to arcing during switch opening and closing.