Self-Healable Soft Ionotronic Skin for Gesture Recognition

We report a self-healable soft body-integrated ionotronic skin (i-skin) for gesture recognition. The device is made of naturally extracted silk fibroin proteins in the format of hydrogel and functionalized by adding calcium ions and glycerin for high stretchability and conductivity. The silk-Ca
²⁺
-glycerin network has high stretchability (up to 600%) and low Young's modulus (0.2-0.3MPa) for conformable contact to the skin. Importantly, the silk i-skin shows excellent self-healing capability and stays functional under a wide range of temperatures from −25°C to 80°C. As a proof-of-concept, we have used the device as a strain sensor which shows characteristic responses to various complex hand motions for gesture recognition. Additionally, we have demonstrated the use of these devices for real-time monitoring sporting motions of finger joints. Our work provides insight for wearable devices under harsh environments.