Ultra‐stretchable, self‐healable, and reprocessable ionic conductive hydrogels enabled by dual dynamic networks

Abstract The pursuit of stretchable ionic conductive hydrogels for skin‐inspired sensors is highly attractive but challenging due to the difficulty in fabricating an ionic conductive hydrogel with combined characteristics of high stretchability, notch insensitivity, self‐healability, and unique reprocessability. Herein, a dual‐dynamic‐network ionic conductive hydrogel (DICH) with both hydrophobic association network and metal coordination network is one‐pot synthesized. Benefiting from the formation of the highly dynamic double networks, the resultant DICH exhibited large stretchability (>2800%) and excellent fracture toughness (4820 kJ m−3). The DICH also demonstrated autonomous healability, notch insensitivity, and unique remoldability because of the formation of the active reversible interactions including hydrophobic association and metal coordination. Due to the integration of high stretchability and favorable ionic conductivity of the DICH containing substantial amounts of electrolytic ions, stretchable ionic strain sensors could be assembled, displaying high sensitivity (gauge factor of 2.6), fast response time (180 ms), and wide response range (0.5%–600% strain). The ionic sensors could also maintain excellent strain‐sensing abilities even after being cut/self‐healed or reprocessed. Wearable DICH resistive‐type strain sensors could be assembled, demonstrating high performance in detecting and distinguishing both large and subtle motions of a human body.