Environmentally adaptive and durable hydrogels toward multi-sensory application

Ionic conductive hydrogels are emerging materials applied in flexible electronics due to their integrated conductivity and mechanical flexibility. However, daunting challenges still remain in developing ionic hydrogels with desirable conductivity and mechanical properties in harsh environments. Herein, a series of environmentally adaptive multifunctional hydrogels were synthesized by the in situ polymerization of polyzwitterions in the presence of inorganic nanoclays and LiCl. Their intrinsic and synergetic features rendered the hydrogels excellent environmental adaptivity. They not only displayed superior stretchability (up to 2167%) and considerable conductivity (17.1 mS cm−1) at atmospheric conditions, but also maintained robust electromechanical properties under extreme environments (-60–95 °C, or under vacuum). Moreover, their strong adhesion strength (up to 0.28 MPa on glass), autonomous self-healing capacity (up to 90% recovery efficiency), outstanding injectability and 3D printability enabled them as promising candidates for all-temperature wearable devices. The assembled hydrogel sensors exhibited exceptional multi-sensory capabilities, including strain (1–500%), pressure (0.5–50 kPa), temperature (-20–95 °C), and proximity (0–160 mm). They also functioned reliably at bending tests from −40 to 80 °C, and showed outstanding durability over 10 000 uninterrupted cycles (upon 50% strain and 20 kPa pressure, respectively). The overall merits of the hydrogels provide new insights towards next-generation flexible electronics for healthcare monitoring, human–machine interfaces, and biomedical prostheses.