Design and fabrication of multi-microelectrode array for neural prosthesis

A multi-microelectrode system for neuroprostheses was designed and manufactured by using microfabrication technologies. For biocompatibility, we used silicone rubber as the base layer, polyimide as the insulation layer and gold as the conduction material. A model simulating the electric properties of the microelectrode array was developed for system design. The electrode system was planar and consisted of 18 microelectrodes. The contact area of each microelectrode was 600 × 400 μm. The sensing capability of the microelectrode system was tested in animal experiments. We put the system underneath the sciatic nerve of New Zealand rabbit and passively move the ankle joint. The results showed that the system could record changes in neural signals during movements. Analyses of the recorded signals and the joint angle revealed that the recorded neural signals had good correlation with the weighted sum of joint angle and angle velocity. In conclusion, we developed a planar multi-microelectrode system, which could sense neural signals in acute animal experiments.