In-vitro Experiment of Magnetoelectric Wireless Power Transfer System on Human Tissue Mimicking Phantom

Magnetoelectric heterostructure based devices are drawing major attention due to their capability to convert the low-intensity magnetic field into electrical energy. In this work, a miniaturized low frequency magnetoelectric wireless power transfer (WPT) system is reported for powering implantable medical devices (IMDs). The proposed device addresses the limitations of the existing WPTs in terms of miniaturization, power generation, and bio-compatibility. The device comprises a piezoelectric (PVDF) layer sandwiched between two layers of magnetostrictive (Metglas (FeSiB)) material. The device is operated at the resonance frequency of 50kHz, which is medically suitable for IMD applications. The biocompatibility is confirmed by the cytotoxicity tests after the device is encapsulated using conformal parylene coating. Experimentally, the device can generate 0.4V output voltage when an alternating magnetic field of 0.4Oe is applied at 50kHz. The maximum power transferred by the device are 6.66µW and 5µW in air and tissue-mimicking phantom medium, respectively. A battery-less power management circuit (PMC) (55×65mm
²
) enabling synchronous electric charge extraction (SECE) is also demonstrated in this work that can suitably regulates input voltage from 0.5V to 10V and generates 2.5V DC voltage while limiting the intrinsic power consumption.