Fabrication process of flexible cuff electrode based on polyimide substrate

Abstract

This paper presents the fabrication process of flexible cuff electrode for implantable neural prostheses based on Bio-micro-electro-mechanical-system (BioMEMS) technique. The cuff electrode is showed the characteristic of the self-wrap around peripheral nerves. This characteristic has advantage of size-adaptation for the changed peripheral nerve diameters and nerve damage for chronic recording of electroneurogram (ENG) signals is minimized compared to the other implantable neural electrodes. The substrate material of flexible cuff electrode is demanded to good biocompatibility and high insulation. The polyimide (PI) was used as substrate material due to its flexibility and biocompatibility. The titanium (Ti) / platinum (Pt) was deposited on the PI substrates by RF sputtering as conductive materials. The diameter of rat sciatic nerve is about 1~1.5 mm. In other to enhance the contact area between electrode and rat sciatic nerve, a cuff electrode was curled with a diameter of 1mm.