A Fully Self‐Healing and Highly Stretchable Liquid‐Free Ionic Conductive Elastomer for Soft Ionotronics

Soft ionic conductors hold great potential for soft ionotronics, such as ionic skin, human–machine interface and soft luminescent device. However, most hydrogel and ionogel‐based soft ionic conductors suffer from freezing, evaporation and liquid leakage problems, which limit their use in complex environments. Herein, a class of liquid‐free ionic conductive elastomers (ICEs) is reported as an alternative soft ionic conductor in soft ionotronics. These liquid‐free ICEs offer a combination of desirable properties, including extraordinary stretchability (up to 1913%), toughness (up to 1.08 MJ cm−3), Young's modulus (up to 0.67 MPa), rapid fully self‐healing capability at room temperature, and good conductivity (up to 1.01 × 10−5 S cm−1). The application of these ICEs is demonstrated by creating a wearable sensor that can detect and discriminate minimal deformations and human body movements, such as finger or elbow joint flexion, walking, running, etc. In addition, self‐healing soft ionotronic devices are demonstrated to confront mechanical breakdown, such as an ionic skin and an alternating‐current electroluminescent device that can reuse from damage. It is believed that these liquid‐free ICEs hold great promises for applications in wearable devices and soft ionotronics. High‐performance multifunctional liquid‐free ionic conductive elastomers enhanced by three non‐covalent interactions are described, which are applied in various types of flexible ionotronic devices, such as strain sensors, capacitive‐type sensors, and electroluminescent devices.