Factors influencing the biocompatibility of insertable silicon microshafts in cerebral cortex

Issues that determine the biocompatibility of insertable microelectrode arrays were investigated. Results from a limited number of tests indicated that there was minimal tissue response along the sides of the shafts when shafts were well sharpened, had sufficiently small tip angles, and were clean. Tissue was usually more reactive at the tips of the shafts. It was concluded that silicon microshafts of appropriate shaft and tip design were biocompatible along the sides of the shaft, but that relatively severe reactions could be anticipated at the tips.