Electrodeposition of Gold and Polypyrrole Thin Films for Neural Microelectrodes

Abstract

A low impedance electrode/tissue interface is critically important for neural microelectrodes recording to maintain signal quality. In this study, gold/polypyrrol thin films used to decrease the interface impedance. Gold thin film was electrodeposited by cyclic voltammetry in the potential range of-0.3 to 1 volt on the stainless steel surface of microelectrodes with 127 micrometer in radius. Then polypyrrole was electrodeposited on the gold layer. Electrochemical impedance spectroscopy tests were performed for impedance measurement of microelectrode surface. The effect of morphology and thickness on the impedance of thin film was studied. The results showed that the impedance of the microelectrodes with gold/polypyrrol coatings was 38.2% lower than the electrodes without coating in the neural frequency.