Development of a Microfabricated Flat Interface Nerve Electrode Based on Liquid Crystal Polymer and Polynorbornene Multilayered Structures

This paper reports on the development of a mechanically-flexible microfabricated flat interface nerve electrode using liquid crystal polymer (LCP) and polynorbornene (PNB) as the structural materials. The device consists of two electrode arrays each fabricated on a LCP base with thin film Pt electrodes and a photolithographically patterned PNB capping layer. The two arrays are inserted into a silicone housing designed to create a flat interface between the electrodes and the nerve bundle. Electrical tests showed that the resistance of the thin film Pt electrode interconnect traces are unaffected by flexing around a 1.5 mm radius. Electrical testing in PBS shows that the resistance of the traces is about 1 kOmega. A 10 day leakage current test in PBS indicates that the PNB absorbs moisture but still maintains its insulating behavior. These and other tests indicate that the LCP/PNB multilayer may be a viable material system for microfabricated electrodes.