Highly Stretchable, Adhesive, and Conductive PEDOT Nanocomposite Hydrogels for High‐Performance Flexible Bioelectronics

Conductive hydrogels have emerged as excellent candidates for next-generation bioelectronic devices due to their skin-like properties and biocompatibility. However, their practical application remains limited by poor intrinsic adhesion, insufficient electrical conductivity, and the hydrophobic nature of conventional conductive fillers, which hinder the integration of multiple essential functionalities. Herein, an effective strategy is developed to fabricate conductive and water-soluble multifunctional nanofillers by employing tannic-acid-modified MXene as a template to direct the in situ polymerization of poly(3,4-ethylenedioxythiophene) (PEDOT). The tannic acid-modified MXene not only introduces abundant catechol groups that improve hydrophilicity and dispersibility, but also contributes intrinsic conductivity to the resulting PEDOT composite nanosheets (385 S·m^-1). These nanosheets act as multifunctional fillers, enabling the hydrogel to simultaneously achieve excellent stretchability (>800%), strong tissue adhesion (≈22 kPa), and high conductivity (≈125 S∙m^-1). This integrated performance exceeds that of conventional PEDOT: poly(styrenesulfonate) (PSS) based conductive hydrogels, supporting reliable and high-resolution acquisition of electrophysiological signals in vivo and in vitro. The proposed strategy provides an effective platform for the development of advanced soft bioelectronic materials and expands the application potential of hydrogel-based bioelectronics.