Wireless Stimulation of Motor Cortex Using an Ultra-Thin Implant Fabricated on Parylene/PDMS

In this paper, we describe the design and in-vivo testing of a wireless, battery-free implant that is fabricated on a
$100 \mu\mathrm{m}$
-thick parylene/PDMS substrate with dimensions of
$15.6 \times{6}.6$
mm
²
. The benchtop test shows that the device can generate monophasic voltage pulses with an amplitude of 20 V at a distance of 25 mm from an RF transmitter, and the frequency and width of these pulses can be externally controlled. The implant's operation was verified in-vivo by generating high-amplitude voltage pulses (8 V) and injecting adequate current (≈ 2 mA) into the motor cortex, leading to a motor response in a rat model. These results demonstrate the implant's ability to eliminate the need for batteries and wires and deliver electrical stimulation.