An Optical Scanner Based on a Cantilever-Type Zipping Actuator

Abstract

The modeling, design, fabrication and experimental characterization of an optical scanner based on a cantilever-type electrostatic zipping actuator are presented. The electrostatic actuator has been designed to achieve high displacements for large optical scanning angles at lower actuation voltages. The zipping actuators are fabricated using commercial multi-layer polysilicon foundry fabrication processes. The electrostatic force between the cantilever and the electrode on the substrate pulls the cantilever down. Force on the warped cantilever closes the gap from the anchor end and gradually the zipping effect actuates the entire cantilever. In our design, mechanical structures are arranged to avoid electrical short-circuit. With various annealing temperatures during fabrication, the warp angles of the cantilevers are controllable. The cantilever serves as a reflective surface and the high out-of-plane displacement is used to steer a reflected laser beam for imaging and scanning applications. In this article, we present the design considerations in displacement and control of electrostatic zipping actuator fabricated by the PolyMUMPS process. The arrangement for optical scanning utilizing the zipping actuator is also presented.