Optical Wireless Power Transmission Through Biological Tissue Using Commercial Photovoltaic Cells Under 810 nm LEDs: Feasibility Study

Abstract

Ensuring the provision of sustainable and secure electrical power for ingestible/implantable medical devices (IMDs) is crucial for facilitating the multifaceted capabilities of these IMDs and preventing the need for recurrent battery replacements. Using photovoltaic (PV) energy harvesting in conjunction with an external light source can be advantageous for an optical wireless power transfer (OWPT) system to enable energy self-sufficiency in IMDs. This study investigates the performance of OWPT using commercial monocrystalline silicon PV cells exposed to an 810 nm Near-infrared (NIR) LED light. The ethical concerns are addressed by utilizing porcine samples (ex vivo approach), eliminating the need for live animal experimentation. The experimental setup employs porcine meat samples with several compositions, e.g., pure fat, pure muscle, and different layers of fat-muscle. The primary goal of this initial study is to analyze the open-circuit voltage output (VOC) of the PV against received optical power in the presence of biological tissue. Our study demonstrates that PV cells can generate voltage even when exposed to light passing through porcine samples with a thickness of up to 30 mm. Furthermore, the VOC values of PV cells attained in this study meet the required voltage input level for supplying current IMDs, typically ranging from 2V to 3V. The findings of this study provide valuable insights into OWPT systems in the future, where monocrystalline silicon PV cells can be employed as energy harvester devices to supply various IMDs utilizing NIR light.