Fabrication of electroplated nickel multielectrode microprobes with flexible parylene cable

We have designed, fabricated and characterized nickel-based multielectrode microprobes with flexible parylene cable employing low-cost nickel electroplating and parylene etching techniques, used for chronic recording of neural signals. Electroplated nickel microprobes, which are encapsulated with parylene for biocompatibility, are more mechanically robust than silicon-based ones. The parylene cable facilitates the connection with external circuit and reduces the packaging requirements. Moreover, the bump-shaped electrodes allow a better contact with neural tissues and consequently improve the signal to noise ratio of recording signals. The impedance magnitude of 25μm×25μm electrodes at 1kHz is ~1.0MΩ. In-vitro penetration of the fabricated microprobes into the muscle tissue has been successfully demonstrated.