Preparation of autonomously self-healing electrode based on double network supramolecular elastomer

Endowing materials with self-healing ability is an effective way to enhance the reliability, durability and functionality of flexible electronic devices. Recently, self-healing materials have made great progress in improving self-healing efficiency. However, there're still problems to solve, such as harsh self-healing conditions and great mechanical loss, and the broken conductive network that cannot follow the dynamic reconstruction of the self-healing polymer. Here we report a onepot method of using the boric acid to modify hydroxyl terminated polydimethylsiloxane to prepare polyborosiloxanes (PBS) with supramolecular network matrix, and at the same time we introduce the silicone (PDMS) covalent network in supramolecular network matrix to form double network structure. The PBS network with dative bond, hydrogen bond, topological entanglement can provide self-healing and selfadhesion capability, while the chemically cross-linked PDMS network acts as a skeleton in the matrix and renders elasticity and mechanical robustness. Mechanical and electrical characterization methods are applied to investigate the selfhealing behavior of PBS composite. More importantly, when a nanowire conductive network is surrounded by the polymer matrix, the broken conductive network can follow the dynamic reconstruction of the self-healing polymer and autonomously heal to recover not only its high conductivity (100%) but also its mechanical properties (88%). This one-pot method for preparation of autonomous self-healable and stretchable electrode will provide new ideas for flexible pressure sensor design, and promote its application in various areas, such as electronic skin, health monitoring and human-machine interaction.