Cellular inductive powering system for weakly-linked resonant rodent implants

This paper presents a cellular inductive powering system for neural interface devices to facilitate chronic physiological studies. The system delivers 21-225 mW of power to a 4cm×4cm planar receiver with 21.5% efficiency. It is shown that the implemented multi-coil power transmission technique creates 5 times less non-ionizing radiation at 10cm distance than a single-coil design, for equal amounts of delivered power. The design also implements a low-cost technique which tracks the location of the animal using an impedance measurement circuit which is also used to tune the individual coils.