Dynamically Bonded MXene‑Composite Hydrogel via Confined‑Space Gelation for Multimodal Sensing, Photothermal Response and Human‑Machine Interaction

ABSTRACT Achieving synergistic optimization of the hydrogel network through proactive molecular‐level design is key to developing flexible electronic materials that combine excellent mechanical, electrical, and multifunctional properties. Regarding this issue, we propose a “thermal activation–annealing synergy” preparation strategy, focusing on revealing the decisive influence of the environment on strengthening intermolecular chain interactions. Compared with an open atmosphere, the confined high‐temperature and high‐pressure environment greatly promotes effective collisions and hydrogen bond formation between polymer chains (the molecular simulation g(r) value increases nearly tenfold), thereby constructing a denser physical network. Consequently, by integrating the rigid network of κ‐carrageenan, the reinforcement from dynamic borate ester bonds, and the conductive/photothermal functions of MXene, the κ‐carrageenan‐poly(vinyl alcohol)‐MXene/borax (KPM‐B) composite hydrogel is successfully prepared. This hydrogel exhibits high strength (compressive stress up to 2.4 MPa), high toughness (up to 567.3 kJ/m ³ ), and outstanding fatigue resistance (3000 cycles). Based on these merits, we successfully apply it to full‐range monitoring from physiological signals (e.g., ECG) to large‐amplitude joint movements, and integrate it into a smart glove to achieve precise human–machine interaction. This work provides a new paradigm for preparing high‐performance multifunctional hydrogels through environmental regulation.