A sunlight self-healable transparent strain sensor with high sensitivity and durability based on a silver nanowire/polyurethane composite film

In this work, a novel material design is proposed and implemented for developing a high performance resistive-type strain sensor. Accordingly, an electrically conductive composite film of polyurethane/silver nanowires is prepared. Owing to the synergistic effects of the transparent and sunlight self-healable polyurethane matrix, low-density and thin network of welded long silver nanowires, spray-coating, and sandwich structure consisting of two polyurethane layers and a silver nanowire network interlayer, the key factors that control the robustness and responsivity of the conduction paths while contradicting each other, are united, and the long-term cyclic loading induced failure can be self-repaired under sunshine. As a result, the composite successfully integrates high transparency, sensitivity, durability, selfhealability and flexibility together, exhibiting promising application potential.