Supramolecular Conductive Hydrogels With Homogeneous Ionic and Electronic Transport.

Abstract

Mechanically resilient hydrogels with ion-electron mixed transport properties effectively bridge biology with electronics. An ideal bioelectronic interface can be realized through introducing electronically conductive polymers into supramolecular hydrogels. However, inhomogeneous morphologies of conducting polymers, such as poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), have limited mechanical properties and ion-electron interactions. Here, supramolecular conductive hydrogels that possess homogeneous ionic and electronic transport are achieved. The materials demonstrate high toughness (620 kJ m^-3), stretchability (>1000%), softness (10.5 kPa), and conductivity (5.8 S cm^-1), which surpasses commonly used inhomogeneous PEDOT:PSS-based hydrogels. The homogeneous network leads to higher charge injection capacitance and lower skin impedance compared to commercial electrodes or commonly used inhomogeneous PEDOT:PSS conducting networks. This significant advance arises from the homogeneous incorporation of the hydrophilic self-doped conducting polymer S-PEDOT, which has polymerized within a supramolecular polymer network template mediated by high-binding affinity host-guest crosslinks. Furthermore, the compatibility of S-PEDOT with hydrophilic secondary networks enables the realization of fully dryable and reswellable electronic devices, facilitating reusability and improving their ease of handling. It is anticipated that achieving such material architectures will offer a promising new direction in future synthesis and implementation of conductive hydrogels in the field of bioelectronics.