RF powering of micro coils array for wireless spherical particle-based neural probes

This paper presents a RF powering system that can wirelessly transfer power to an array of 10 × 10 1.5 mm-diameter micro coils positioned at 2 cm away from a powering coil. Under 10 W external RF power, the micro coils can receive 5 mW and 0.6 mW at the center and edge of the array, respectively, enabling spherical particle-based neural recording applications. Presence of saline solution between the powering coil and micro coils array causes a power transfer reduction, which can be compensated by improving the quality factor of the micro coils in the array.