CLEO 2022, San Jose, USA

Patch-Type Wireless Power Transfer System Based on Electromagnetic Wave Focusing Meatasurface for Bioimplantable Devices

Semin Jo, Wonwoo Lee, and Hojin Lee

Abstract

  Bioimplantable devices require miniaturization, stability, and long-term operation characteristics for electroencephalogram (EEG) monitoring and stimulation within the human body. Generally, batteries have been widely used in bioimplantable devices due to the stable power supply capability. However, bioimplantable devices using batteries have challenges in bulky size, limited lifetime, and need for replacement that essentially requires surgical method. To overcome aforementioned challenges, wireless power transfer (WPT) have attracted attention as an alternative approach to avoid the surgical procedure. Nevertheless, the stable and sustainable wireless power supply to bioimplantable devices still remains as the challenge due to the low WPT efficiency. Recently, WPT systems using metasurfaces exhibiting exotic electromagnetic (EM) characteristics were introduced in bioimplantable devices to enhance the efficiency and to reduce the geometrical dimension. In this work, we propose a novel patch-type WPT system using EM wave focusing metasurface. In contrast to previous approaches, the proposed metasurface enables to enhance the transmitted power intensity of EM wave by forming a focal point at a specific location into the tissue. Through the in-vitro experiment, the maximum voltage enhancement was confirmed at a desired depth of 10 mm in saline solution that mimics the actual tissue characteristics.