Wireless Power Transfer System Design Using Zero-Index Metamaterial for Implantable Medical Devices

This paper presents a novel metamaterial (MTM) integrated, highly efficient approach to designing a wireless power transfer system (WPT), particularly for implantable devices. The proposed implantable WPT system has been constructed by utilizing the radiating principle of the antenna. To design the system, a simple biocompatible circular slot antenna has been constructed on a flexible substrate to use as an implantable receiving (Rx) element. A simple circular patch antenna is designed in air environment to utilize as a transmitting (Tx) element outside the human body for WPT system. Further, the novel zero-index property of the MTM is utilized to enhance the proposed system's power transfer efficiency (PTE). Finally, the prototypes are fabricated, and measurements are performed in a skin-mimicking gel that is equivalent to the human skin tissue. The measured and simulated result confirms the feasibility of the proposed concept by improving the PTE due to the use of MTM.