Polymer hydrogel microelectrodes for neural communication

A conducting polymer hydrogel electrode was electrochemically deposited in micromachined via holes and the charge delivery capacity (CDC) was studied. Polymer hydrogel microelectrodes, with a geometric area of 1000 mum(2), and a capacitance of up to 850 nF were fabricated. The impedance of a 1,000 mum(2) polymer hydrogel electrode deposited with 8 muC was measured as low as 8.5 kOmega. We studied neural cell growth on structures to be used as neural interfaces. Directed cell growth was achieved by imposing a topographical structure on the substrate. Due to the interesting mechanical and chemical adaptability of the polymer hydrogel material and its large charge delivery capacity and low impedance we think that it is an interesting material for neural communication.