7.32 Engineering the neural interface

Implanted neuroprosthetics and neuroelectrode systems have been under investigation for a number of decades and have been proven to be safe and efficacious as treatments for several neurological disorders as well as for biosensor systems. Neuroelectrode technologies are typically fabricated from metallic conductors, such as platinum, gold iridium, and their oxides, materials that while chemically inert and excellent electrical conductors are often not intrinsically cytocompatible and do not promote integration with neural tissues. The performance of the electrode-tissue interface ultimately rests on the optimization of the material substrate, to enable effective stimulation/recording and chronic functionality. Physicochemical modification of implantable electrode systems is recognized as a viable strategy to enhance tissue/electrode integration and electrode performance in situ. Critically, new avenues in neuroprosthetic fabrication have come on-line from a recent focus on novel biomaterials strategies to develop innovative biocompatible materials that mimic neural tissue characteristics, cause minimal inflammation and neuronal cell loss, and are chronically stable in vivo. This chapter will focus on current developments and ongoing challenges in neuroprosthetic design, with an emphasis on biomaterials approaches to engineering the neural interface.