Electrical Interface Parameters of PEDOT:PSS: Effect of Electrodeposition Charge Evaluated Under Body Conditions for Neural Electrode Applications

This study explores the influence of deposition charge during fabrication of poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS) on its electrical interface parameters. For this purpose, PEDOT:PSS was fabricated under state-of-the-art conditions desirable for neural bioelectrodes on commercial platinum electrodes with the electrodeposition time limited by different charges (1, 3, 6, 9 mC). Further, the electrodes were characterized regarding their electrical interface such as interfacial impedance, potential window, double-layer capacitance, charge storage capacity, and current injection limit under simulated body conditions. The work showed whether and to what extent the change of deposition charge affected the electrical interface parameters of PEDOT:PSS-based platinum electrodes. The electrodes polymerized with 9 mC exhibited a significant increase in specific capacitance, indicating enhanced charge storage capacity. Additionally, this sample demonstrated lower resistance in phosphate-buffered saline, suggesting improved conductivity.