Increasing voltage transients using implanted titanium nitride neural stimulation electrodes

Abstract

The electrochemical properties of porous titanium nitride (TiN) stimulation electrode coatings were investigated in vivo in the chronic setting. Four titanium pins were coated with porous TiN and implanted in the pelvic region of two minipigs. Electrochemical impedance spectroscopy (EIS) was performed daily, while voltage transient measurements (VTM), electrical stimulation and cyclic voltammetry (CV) were performed every other week. Electrical stimulation was applied successfully during the course of the study. Voltage transients and tissue impedance increased, while charge storage decreased during the first 3-4 weeks after implantation. This is most likely related to encapsulation of the electrode.