TRS Technologies, Virginia Tech., and MTech, Inc. propose to develop high torque (>1.5 kg-cm), lightweight (< 250 g), low power (< 2 watts), high precision (<0.2o
), cryogenic stepping motors using single crystal piezoelectric technology. The ultrasonic motors developed on this program will be targeted for use in passive optics positioning systems and interferometers in IR remote sensing and space telescope applications. The above metrics were achieved during the Phase I program using a traveling wave ultrasonic motor with single crystal drive elements. Motor operation was also demonstrated at 77K. In Phase II, motor torque and speed will be increased and size, weight, and power will be further decreased by optimizing the motor design and crystal element configuration. Drive electronics optimized for operation from 300 to 77K will also be developed. Finally, the motor and electronics will be extensively tested at cryogenic conditions and under thermal cycling for reliability and repeatability. At the conclusion of the Phase II program TRS and our partners will have optimized and characterized piezoelectric ultrasonic motors capable of operating over a very broad temperature range (400 to < 77K) with significant performance improvements (torque, speed, precision, and power) over competing technologies with narrower temperature ranges.