Chemical Synthesis of Polypyrrole Nanotubes for Neural Microelectrodes

A low impedance electrode/tissue interface is critically important for neural microelectrodes recording to maintain signal quality. In this study, polypyrrole (PPy) nanotubes used to decrease the interface impedance. PPy nanotubes were chemically synthesized inside the alumina template. SEM analysis showed 70 nm inside diameter of nanotubes. Electrochemical impedance spectroscopy (EIS) tests were performed for impedance measurement of PPy nanotubes coated microelectrode surface. The results showed that the impedance of the microelectrodes with PPy nanotubes coatings was four order of magnitude lower than the electrodes without coating in the neural frequency. EIS results also showed significant decrease in impedance of PPy nanotubes rather than PPy thin films.