Milligram-scale high-voltage power electronics for piezoelectric microrobots

Piezoelectric actuators can achieve high efficiency and power density in very small geometries, which shows promise for microrobotic applications, such as flapping-wing robotic insects. From the perspective of power electronics, such actuators present two challenges: high operating voltages, ranging from tens to thousands of volts, and a low electromechanical coupling factor, which necessitates the recovery of unused electrical energy. This paper explores the power electronics design problem by establishing the drive requirements of piezoelectric actuators, presenting circuit topologies and control methods suitable for driving different types of piezoelectric actuators in microrobotic applications, and demonstrating experimental realizations of sub-100 mg power electronics circuits.