A Miniaturized Wireless Neural Implant with Body-Coupled Data Transmission and Power Delivery for Freely Behaving Animals

Miniaturized neural implants for monitoring neurological disorders have been investigated as a promising alternative to the neural interface for patients. However, such implants rely on physical tethers to external hardware for data and power transmission, which not only causes tissue damage and infection, but also hinders stable in vivo recordings in freely behaving animals. To enable non-tethered implants, a key feature for the robust and high-fidelity neural interface, neural implants using various wireless technologies have been reported (Fig. 20.5.1, top-left) [1]-[3]. However, the use of an inductive link [1] imposes a stringent requirement on the alignment between coils, as well as a limited transfer range. Optical [2] and ultrasound [3] telemetry suffer from attenuation from skull absorption, which requires surgically placed sub-cranial repeater or has only been demonstrated at low data rates (tens of kb/s). Hence, they are limited to the short operation range and the susceptibility to orientation, and in most cases still need a headstage that restricts freedom of action.