| Description |
Neural electrodes are interfaces through which biological signals are transmitted to external systems and vice-versa. They are a fundamental component for the development of neural prostheses, restoring lost motor or sensory functions of the body. This work investigates a substantially novel approach to improve the charge transfer properties of neural microelectrodes by engineering the substrate material of silicon-based microelectrode arrays. Neural microelectrodes need to fulfill a multitude of requirements such as safe charge transfer, corrosion resistance, and biocompatibility. To this day, several materials and surface modification techniques were investigated and reported to improve the electrochemical properties of neural microelectrodes. This work demonstrates that by engineering the surface of the electrodes' substrate material, electrochemical properties such as charge injection capacity and corrosion resistance are improved regardless of the coating material. By roughening the silicon substrate material and subsequently conformally coating the electrode surface with platinum, the charge injection capacity was increased by a factor of 1.8, whereas the impedance at 1 kHz decreased by a factor of 0.32 compared to unmodified electrodes. Furthermore, the roughened electrodes exhibited less variability across the electrode array. This work demonstrates and validates a method to improve electrochemical properties and robustness of neural microelectrodes by engineering the silicon substrate material. |
