A Novel Mat-Based System for Position-Varying Wireless Power Transfer to Biomedical Implants

Abstract

Wireless power transfer via magnetically resonant coupling is a new technology to deliver power over a relatively long distance. Here, we present a mat-based design to wirelessly power moving targets based on this technology. Our design is specifically applied to transcutaneously power medical implants within free-moving laboratory animals. Our system comprises a driver coil array, a hexagonally packed transmitter mat, a receiver coil, and a load coil, and generates a nearly flat magnetic distribution over a defined area to produce an approximately constant power output independent of the location of the receiver coil. This paper also describes a novel power receiver coil design of the same shape as the exterior of the implant, allowing for maximum magnetic coupling, eliminating the space restrictions due to the coil within the implant, and matching the resonant frequencies of the implant and the transmitter coil. Our new transmitter and receiver designs significantly reduce the size of a biomedical implant and may provide a lifetime power supply to implanted circuits without the need for an internal battery. Our designs are also useful in various other applications involving moving targets, such as part of a robot or a vehicle.