Development of Latching Type Large Vertical-Travel Microactuator Available to Purchase

This paper describes design, fabrication and preliminary characterization of a proof-of-concept vertical-travel microactuator, providing linear motion and high precision positioning in space. The microactuator is capable of providing latching function when it is un-powered to maintain its position. The microactuator consists of two opposing comb drive actuator dies, a slider and bulk PZT actuators sandwiched between the dies. The slider is inserted between clutches. Comb drives are connected to the clutches to engage/disengage clutching. Sequential activation of the comb drives (in-plane motion) and the PZT actuator (out-of-plane motion) provides cumulative linear travel of the slider. The novelty of the slider insertion approach include (1) post-fabrication engagement of comb teeth enabling thick wafer DRIE process for comb drive actuators and (2) stressed tethers enabling zero-power latching. A test device was fabricated and assembled. By applying 100V∼300V DC to the electrostatic comb drive, lateral actuation of clutches was observed. Vertical actuation by PZT was also confirmed using WYKO RST plus interferometer.