A self-compliant and adhesive hydrogel interface for chronic electrophysiological monitoring

High-quality electrophysiological monitoring is crucial in healthcare and precision medicine. However, challenges persist in constructing a robust, durable interface between epidermal electrodes and skin’s irregular surface. This work developed a self-compliant, adhesive hydrogel interface for long-term, high-quality electrophysiological monitoring via multiple non-covalent associations of continuous topological entanglements as complementary crosslinks. The prepared hybrid hydrogel interface, copolymer (acrylic amide and acrylic acid)/gelatine/AgNWs/Al 3+ , overcomes a molecular structure trade-off between ultra-softness and high robustness. Thus, the hydrogel achieves not only a low modulus that matches with human skin (30 kPa) and adhesion but also subtle mechanical hysteresis (5.06% energy loss coefficient). Thus, the hydrogel electrode achieves 6 h continuous EEG signal monitoring at high fidelity (28 dB). Moreover, the hydrogel electrode maintains high stability and plug-and-play portability, regardless of motion states (relaxing and exercising) or skin conditions (oiling and sweating). This work provides a generalisable, multimolecular coupling design strategy to advance the design of epidermal hydrogel interfaces and high-quality signal acquisition. • PPGA-Al hydrogel is well-designed via multimolecular coupling design strategy of non-covalent association. • PPGA-Al hydrogel shows skin-matched modulus, high adhesion and hysteresis-free features. • Hydrogel electrode supports long-term and high-quality electrophysiological monitoring.