Description
Brain computer interface (BCI) is an emerging technology that is revolutionizing brain mapping and brain signal recording for a wide variety of applications varying from fundamental understanding to neuronal disease treatment. Development of BCIs has led to many advantageous designs of invasively implemented neural prosthetics. A widely used standard is micro platinum electrode arrays insulated on a flexible polymer. Recent advancement in micro-fabrication processes has steered the discipline towards a different electrode material, glassy carbon. Like platinum, glassy carbon has been proven to be conductive and biocompatible. One of the ultimate goals of neural prosthetics is to successfully achieve long term implantation. Under such condition, the electrode must be able to withstand electrical stimulation of over 1 billion pulses over a course of 5 years. Unfortunately, platinum’s susceptibility to corrosion in a biological environment has made the continued use of this material for long term application undesirable. As an alternative, investigation of glassy carbon has shown that it is a highly electrochemically stable material and can withstand, by many orders of magnitude, more cyclic electrical pulses than platinum. It is theorized that the surface topography of a neural electrode influences its rate of degradation. Sputtered platinum has been shown to have an uneven and rough surface, whereas glassy carbon is smoother and more homogeneous. In this study, the surface characteristics of the different electrodes will be analyzed and compared to the material’s electrochemical responses and corrosion rates.
