Miniature Piezomotors

Piezoelectric actuators and motors promise to deliver useful work at power densities and order of magnitude greater than that of their electromagnetic counterparts. The circuit concept developed is for a resonant, regenerative switching piezomotor driveamplifier that would efficiently transfer electrical energy that could be coupled into mechanical work through a piezoelectric actuator. The motor/amplifier system would operate at both electrical and mechanical resonances for the system. The amplifier'sefficiency is estimated to be greater than 80% when driving a 1uF piezoelectric load with a 500 Vpk-pk signal. The available output power should be greater than 10 watts continuously from DC to 2.0 kHz. Once operational, future amplifier refinements canfocus on improved analog computation methodologies, mitigation of alignment and calibration difficulties, while trying to reduce sensitivity to actuator capacitance and improvements to output waveshape fidelity and power delivery. Currently, a prototypeamplifier with +50% power efficiency is undergoing design integration and testing.