Enhanced laser-induced PEDOT-based hydrogels for highly conductive bioelectronics

Abstract Conductive hydrogels, particularly poly(3,4-ethylenedioxythiophene) (PEDOT)-based hydrogels present mechanical properties like biological tissues and superior biocompatibility. Laser treatment affords a promising approach for the development of well-patterned PEDOT bioelectrodes. However, the weak photothermal conversion of pristine PEDOT-based solution results in very limited phase separation and thus low conductivity. Here, we report an enhanced laser-induced PEDOT (ELIP)-based hydrogel via a metastable liquid-liquid contact (MLLC) strategy. Such MLLC pretreatment renders the extension of PEDOT chains with increase of conjugation length, which highly improves light absorbance and photothermal conversion capability, achieving a conductivity of up to 955 S/cm and ∼3 μm-precision patterning. The laser treatment with intensive and instantaneous thermal effect also elevates the proposed ELIP's interfacial adhesion and electrochemical stability in physiological environments. Serving as the stimulator and signal recording for bioelectronic devices, the patterned ELIP showcases potentials in nerve conduction blocks for pain treatments.