Directional Anchoring Doping Networks for Robust Polymeric Bioelectronics

Abstract

The development of conductive polymers that simultaneously achieve high electrical conductivity and tissue-like stretchability represents a persistent challenge in bioelectronics. Here, we demonstrate an "anchoring-buffering" molecular design strategy that overcomes this limitation through rationally designed in situ polymerizable hydroxyalkyl acrylate (HAX) dopants in poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT: PSS). Our dopant architecture features rigid acrylate groups that are inferred to maintain conjugation pathways by preferentially interacting with less conjugated PEDOT regions, and hydroxyl-terminated alkyl spacers that form a dynamic hydrogen-bond network for strain dissipation. By systematically varying alkyl chain lengths (HA0 to HA4), we optimize electrostatic screening to improve doping efficiency and pi-stacking order, achieving a composite film with exceptional performance (850 S/cm conductivity and 88% elongation) that surpasses existing stretchable conductive polymers. When integrated into conformal biointerfaces, the electrode maintains stable electrophysiological signal acquisition (EMG/ECG/EEG) with 99.5% gesture recognition accuracy after 24 h of continuous wear, establishing a general molecular design framework to decouple conductivity and stretchability for next-generation wearable and implantable electronics.