Wireless power transfer application of piezoelectric resonators using BiFeO₃ epitaxial films

Wireless power transfer (WPT) for implantable medical devices (IMDs) has garnered significant research attention in recent years, primarily driven by the imperative to mitigate the risks associated with surgical battery replacement. This study demonstrates a WPT system that utilizes a magnetically responsive piezoelectric MEMS resonator, actuated by a low-frequency alternating magnetic field generated by a rotating magnet. The receiver unit incorporates epitaxially grown BiFeO 3 (BFO) thin film, chosen for its biocompatibility and energy conversion efficiency, along with a 5 × 1 × 1 mm 3 neodymium magnet. Experimental evaluations demonstrated a maximum output power of 0.41 μW at a transmission distance of 50 mm. This proposed system, combining a rotating magnet transmitter with a BFO thin-film-based resonator, offers notable advantages in terms of safety, compactness, and energy efficiency, positioning it as a highly suitable solution for WPT in IMDs.