In Situ Formation of Ion‐Clusters on Liquid Metals Surface for Simultaneously Improving Adhesive Toughness and Conductivity Toward Epidermal Electrodes

Abstract Developing epidermal electrodes that possess mechanic softness, tough adhesion, and high conductivity simultaneously is important but still remains challenging. Here, polyvinylpyrrolidone (PVP) is introduced into poly(α‐thioctic acid) (PTA) to in situ generate ion‐clusters both in PTA network and on liquid metal particles (LMPs) surface, enhancing the mechanical strength and toughness of PTA, as well as its interfacial interaction with LMPs. As a result, a poly(TA‐PVP)‐LMPs (noted as PTPL) epidermal electrode is reported with mechanic softness (Young's modulus of 175.86 kPa), tough adhesion (1604 J m −2 ), high stretchability (>20 000%), rapid self‐healing, and good biocompatibility. And attributed to the peel sintering of LMPs, the PTPL epidermal electrodes further exhibit high electrical conductivity (26.19 mΩ sq −1 ) and low skin impedance, providing high signal‐to‐noise ratios (SNR of 28.07 dB) and accuracy in monitoring multiple human electrophysiological signals. This work provides a new strategy for balancing the tough self‐adhesion, softness, and high conductivity of polymer materials in epidermal electrodes fabrication.