A 27μW subcutaneous wireless biosensing platform with optical power and data transfer

We present a batteryless, 27uW barely subcutaneous sensing platform using optical power and data links. We demonstrate an 8.1 mm x 3.2 mm implantable tag powered by an 850nm infrared source through the skin barrier. Measurements using pig skin indicate that optical power transfer through skin achieves a 4.9% efficiency, which is higher than mm scale inductive power links. As a proof-of-concept demo, we sense and transmit temperature to an external body worn reader using a fully optical power and data link. Index Terms — Optical power transfer, optical data transfer, sub-cutaneous implant.