Design of Efficient Wireless Power Transfer System Using Metamaterial for Bio-Implantable Devices

In this paper, the design and analysis of an efficient wireless power transfer (WPT) system to power the bio-implantable medical devices is presented. Herein, the radiating principle of the antenna is utilized to design the proposed system. A CPW fed ring slot antenna is considered as receiving (Rx) element, whereas a simple patch antenna is used as transmitting (Tx) element to construct the WPT link. The system is designed to operate at the industrial, scientific, and medical (ISM) band of 2.45 GHz. The alumina coating is used around the implant ring slot to eliminate the direct contact with skin tissue and make the Rx antenna bio-compatible. Also, a metamaterial slab with zero-index property is placed above the skin layer in the proposed design to improve the power transfer efficiency of the system. Furthermore, the misalignments between the Tx and Rx elements is studied to show the practical applicability of the proposed design. Finally, the specific absorption rate (SAR) analysis is performed to indicate the effect of the WPT system on the human skin tissue model.