A mm-sized implantable device with ultrasonic energy transfer and RF data uplink for high-power applications

Abstract

A first proof-of-concept mm-sized implant based on ultrasonic power transfer and RF uplink data transmission is presented. The prototype consists of a 1 mm x 1 mm piezoelectric receiver, a 1 mm x 2 mm chip designed in 65 nm CMOS and a 2.5 mm x 2.5 mm off-chip antenna, and operates through 3 cm of chicken meat which emulates human tissue. The implant supports a DC load power of 100 μW allowing for high-power applications. It also transmits consecutive UWB pulse sequences activated by the ultrasonic downlink data path, demonstrating sufficient power for an Mary PPM transmitter in uplink. Index Terms — Implantable biomedical devices, ultrasonic power delivery, mm-sized implants, AC-DC power converters, radio transmitters.