Development of highly conductive, intrinsically biocompatible, and 3D printable electrode based on PEDOT:PSS for bioelectronics

Abstract

poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is widely studied in bioelectronics because it has intrinsic conductivity and biocompatibility. However, bare PEDOT:PSS has a property of poor electrical conductivity and water stability due to non-conducting and hydrophilic PSS-group, research has been conducted to perform secondary doping by adding organic solvent or ionic liquid to improve stability in wet environment and electrical conductivity. However, because these additives are toxic, a detoxification process is required for more than 24 hours after the electrode is manufactured. In this work, We developed high-conductive, ready-to-use, 3D printable PEDOT:PSS ink. Electrode made with this ink has an electrical conductivity of ~286 S/cm and is easily hydrogelized in wet environment. For the demonstration of this material, we manufactured EMG sensor and ECG sensor that measure human nerve signals and an electric device that stimulates the mouse's sciatic nerve. EMG and ECG sensor showed a high signal-to-noise ratio(16.80dB), and stimulation device succeeded in stimulating the mouse's sciatic nerve with a low voltage of 60 mV.