Robust Self‐Healing Polyurethane‐Based Solid‐State Ion‐Conductive Elastomers with Exceptional Strength and Ionic Conductivity for Multifunctional Strain Sensors and Triboelectric Nanogenerators

Abstract Flexible ionic conductors hold potential for wearable sensors and energy harvesting. However, most gel‐based conductors suffer from solvent evaporation and liquid leakage, limiting practical applications. Although solid‐state ionic conductors mitigate these issues, achieving strong mechanics, high conductivity, self‐healing, and stability remains challenging. Here, by integrating supramolecular engineering and dynamic covalent adaptive networks, a self‐healing polyurethane‐based solid‐state ion‐conductive elastomer (DACPU/100Li) with outstanding overall properties is successfully synthesized. DACPU/100Li exhibits ultrahigh ionic conductivity (1.23 × 10⁻³ S cm⁻¹) and high tensile strength (7.62 MPa), along with an elongation at break of 1200%. Additionally, it exhibits excellent tear resistance and a fracture energy of 45.6 kJ m⁻², along with 96% self‐healing efficiency (after self‐healing at 120 °C for 24 h), good recyclability, and stability under extreme conditions. The DACPU/100Li‐based sensor has high sensitivity (5.89) and a wide strain range (0.1–1000%). Integrated with machine learning, it enables precise gesture recognition and human–machine interaction. Furthermore, the triboelectric nanogenerator based on DACPU/100Li achieves a high power density of 3.87 W m⁻². It harvests energy from body motion to power small devices and aids object recognition via machine learning. It is believed that these solid‐state ion‐conductive elastomers provide new opportunities for wearable electronics, energy harvesting, and ionotronics.