Large Stroke Electrostatic Comb-Drive Actuators Based on a Novel Flexure Mechanism

Abstract

This paper presents in-plane electrostatic comb-drive actuators with stroke as large as 245 µm that is achieved by employing a novel Clamped Paired Double Parallelogram (C-DP-DP) flexure mechanism. For a given flexure beam length, comb gap, and actuation voltage, this is currently the largest comb-drive actuator stroke reported in the literature. The C-DP-DP flexure mechanism design offers high bearing direction stiffness while maintaining low motion direction stiffness over a large range of motion direction displacement. The high stiffness ratio between the bearing and motion directions mitigates the on-set of sideways snap-in instability, thereby offering significantly greater actuation stroke compared to existing designs.