Regeneration microelectrode arrays for direct interface to nerves

The development and testing of a microelectrode array for implantation in the path of a regenerating nerve are underway. A silicon substrate perforated by an array of holes (via holes) is implanted between the deliberately severed ends of a nerve. Axons regenerate through the via holes and thus become spatially fixed with respect to microelectrodes located on the surface of the silicon. Processes were developed for the fabrication of thin-film iridium microelectrodes, micromachined via holes, and silicon nitride passivation layers. All fabrication methods were designed to be compatible with standard CMOS/BiCMOS processes to allow for on-chip signal processing circuits in future designs. The author provides an overview of these fabrication methods, the in vivo testing of passive neural interfaces, and a prototype active circuit version.<>