Design and fabrication of a large vertical travel silicon inchworm microactuator for the advanced segmented silicon space telescope

Future concepts for ultra-large lightweight space telescopes include the telescopes with segmented silicon mirrors. This paper describes a proof-of-concept inchworm actuator designed to provide nanometer resolution, high stiffness, large output force, long travel range, and compactness for ultraprecision positioning applications in space. A vertically actuating inchworm microactuator is proposed to achieve large actuation travel by incorporating compliant beam structures within a silicon wafer. An inchworm actuator unit consists of a piezoelectric stack actuator, a driver, a pair of holders, a slider, and a pair of polymer beams connected to a centrally clamped flexure beam. Deep reactive ion etch experiments have been performed for constructing the actuator.