Highly Robust and Self-Powered Electronic Skin Based on Tough Conductive Self-Healing Elastomer

Abstract

Self-powered electronic skin (E-skin) can be endowed with high robustness by employing self-healing materials. However, most self-powered E-skin employs two heterogeneous materials with high modulus mismatch at the interface and poor fully self-healing ability, which reduces the robustness of the whole device. Here, a conductive polyurethane elastomer (PUE) with excellent mechanical toughness and self-healing ability is prepared. Based on the self-healing insulated/conductive PUE homogeneous structure and triboelectric-electrostatic induction effect, a highly robust and self-powered E-skin (HRSE-skin) is developed. The HRSE-skin possesses stable mechanosensation capability during the 50% stretching deformation due to a low modulus mismatch in the homogeneous structure. In addition, the stretchability and mechanosensation capability of the HRSE-skin can be restored after the fracture owing to the fully self-healing ability of the homogeneous structure. Therefore, the HRSE-skin has high robustness of the whole device including stable service behaviors and excellent restorability. The developed HRSE-skin demonstrates high robustness in the detection of the force and bending angle of the prosthetic joint. This work solves the low robustness of self-powered E-skin by the preparation of conductive self-healing PUE and the construction of the homogeneous structure, which is important for the practical applications of self-powered E-skin in prosthetic limbs and advanced robotics.