A neural recording microimplants with wireless data and energy transfer link

We have developed a wireless neural recording microimplant for a minimally invasive brain-machine interface. The proposed device utilizes a novel dual-band midfleld antenna to establish an efficient power and data link between an antenna and a coil receiver. It also uses a bipolar junction transistor to convert neural signals into third-order backscattering signals with high detection sensitivity levels. The overall performance of this system is evaluated with a head phantom which closely simulates an in-vivo recording condition. Our antenna achieves high transmission efficiency at 2.5/5 GHz when a miniaturized coil is placed at a target separation distance of about 20mm. This powering scheme allows the neural recording sensor to have a small footprint of a comparable passive neural implant. Thus, we have demonstrated an RFID-like system based on midfield wireless energy/data transfer to extract neural signals from the brain while minimizing potential trauma and physiological interference from the implant.