Chemical polymerization of conducting polymer poly(3,4-ethylenedioxythiophene) onto neural microelectrodes

Abstract

Poly(3,4-ethylenedioxythiophene) (PEDOT) is an organic material with good electrochemical activity and electrical conductivity, and it is usually electrochemically deposited on the neural probes to improve their interface properties. However, the workload for electrode modification using an electropolymerization method becomes greater with the increase in the number of electrode channels. Moreover, the integration of electrodes and amplification circuits makes electropolymerization difficult to implement. In this study, a chemical polymerization method was proposed to produce conducting polymer PEDOT on the electrode sites. Compared with electropolymerization, it does not require each electrode site to be connected to a power source. It is competitive in batch preparation and is particularly suitable for neural microelectrodes prepared by a micro-electromechanical systems (MEMS) process. The charge storage capacity, impedance, mechanical stability, and electrochemical stability of conducting polymer PEDOT prepared by the proposed method are evaluated. The results indicate that the method is feasible for batch modification of the microelectrodes, and it is also suitable in cases where energization is inconvenient. • A chemical polymerization method for conducting polymer poly(3,4-ethylenedioxythiophene) modified neural probes is firstly reported. • The proposed modified method is high-efficiency for neural probes with a large amount of electrodes. • The proposed modified method can be conducted on wafer-level, which is compatible with the micro-electromechanical system process. • The electrodes modified with the chemical polymerization method show good electrochemical characteristics.