Electrogelation of PEDOT:PSS and its Copolymers for Bioelectronics

Abstract

There is a strong interest in the developing scalable deposition techniques for conducting polymer coatings for applications in bioelectronics. Here, we e explore the potential of electrogelation to develop coatings from poly(3,4-ethylenedioxythiophene) polystyrene sulphonate (PEDOT:PSS) and its copolymer with polystyrene sulphonate-co-styrene methenamine (PEDOT:PSS-co-PSMA). The coatings were used to lower the impedance of screen-printed silver electrodes, leading to a decrease in the voltage needed to achieve cutaneous stimulation of small fibres and an increase in the signal-to-noise ratio in cutaneous biopotential recordings. Additionally, PEDOT:PSS-co-PSMA was integrated as the gate electrode in an organic electrochemical transistor, showing improved performance compared to non-modified and PEDOT:PSS-coated gold electrodes i.e., threshold voltage decreased from 0.7 V for pristine gold to 0.5 V for PEDOT:PSS-co-PSMA gate electrode. The results show that electrogelation offers a scalable and cost-effective solution for the deposition of conducting polymers, including non-solution-processable conducting polymers, as performance-enhancing coatings for bioelectronic applications.