Fabrication and characterization of stimulus nerve cuff electrode with highly roughened surface for chronic implant

Nerve cuff electrodes for peripheral nerve prostheses are required chronically implanted electrodes which simultaneously stimulate and record nerve activity. It is inevitable challenge to investigate electrode material with low interfacial impedance and enhanced charge transfer capacity. In this study, stimulus nerve cuff electrodes on polyimide with Pt, conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT), black Pt, and IrO_x were fabricated and characterized. The electrochemical properties were investigated using cyclic voltammetry, electrochemical impedance spectroscopy, and voltage transient measurements. From th experimental results, stimulus nerve cuff electrodes with black Pt showed the highest charge delivery capacity (80 times higher than Pt), charge injection capacity (6 times higher than Pt), and lowest interfacial impedance (3.8 times lower than Pt).