Single crystal ultrasonic motor for cryogenic actuations

A novel single crystal piezomotor is presented for large stroke, high precision, cryogenic actuation with the capability of position set-hold at power-off. Single crystal linear motors with/without screw are prototyped and characterized at both room and cryogenic temperatures. Stroke of >10 mm, step resolution /spl sim/20 nm, response time /spl sim/2 ms, and driving voltage of 60 V/sub p-p/ were obtained with the prototypes. The linear motor without screw operated successfully in a liquid nitrogen environment (77 K).