Recent advances in power supply strategies for untethered neural implants

Recent advances in neural implantable systems have paved the way for neuroscience and neurosurgery research and clinical practice. Conventional tethered neural implants use physical wires for power supply and signal transmission, which impose many restrictions on the subjects. Untethered, wireless power solution has been one of the widely recognized engineering goals for neural implants. The past decade has witnessed significant technical advancement on how to achieve wireless neural implants and how to solve the wireless power delivery challenge. This paper briefly reviews and discusses the recent advances in wireless neural implantable systems based on existing power supply techniques, including batteries, electromagnetic power transfer, photovoltaic device, ultrasound power transfer, and self-powered energy harvester. Finally, future opportunities and challenges of wireless neural implantable systems are discussed.