Wearable and Implantable Magnetic Resonant Wireless Power Transfer (optimal design of in-body resonator by capacitance and air gap)

In this study, we suggested optimal design of in-body resonator by capacitance and air gap. We proposed magnetic resonance wireless power transfer (MR-WPT) system consisted of three resonators and was therefore called a three resonator MR-WPT system. The proposed power transfer occurs between a wearable transmitter in the air and an implantable receiver in the fabricated muscle-mimicking liquid. According to the analysis of measurement results, the muscle-mimicking leads blocking on the H-field of MR-WPT system. This phenomenon has an affect the decreasing transfer efficiency that could be explained by the change in resonant frequency of the receiver resonator due to the impact of the dielectric constant and the conductivity of the MML liquid. To solve this problem, we suggested utilizing either an optimal capacitor or an air pocket to prevent the MML liquid from having this effect. These solutions improved the transfer efficiency of the MR-WPT system.