Design of high-efficiency miniaturized ultrasonic receivers for powering medical implants with reconfigurable power levels

Miniaturized ultrasonic receivers are designed for high efficiency ultrasonic powering of implants. Several piezoelectric materials are investigated for their practicality in designing millimeter-sized ultrasonic receivers. Piezoelectric receivers were built from these materials and measurements were performed in order to characterize their impedance and efficiency. We show operation of the piezoelectric receivers in an inductive frequency band, near resonance, allowing for impedance matching to typical implant loads. Finally, adaptive matching and frequency tuning techniques are demonstrated showing high power matching efficiencies across variable implants loads.