Repairable, Recyclable and High-Performance Flexible Strain Sensors

Abstract

Flexible wearable devices, especially strain sensors, have attracted extensive attention in recent years due to their promising applications in health monitoring and human-machine interaction. However, most reported flexible strain sensors could not be repaired/healed or recycled, which is vital for their long-term use and a sustainable society. Furthermore, their existing fabrication process often requires expensive raw materials and complex techniques. Here, we develop high-performance flexible strain sensors with both repairable and recyclable capacity, by simply hot-pressing highly electroconductive carbonized silk fabric (CSF) into the surface of exchangeable polyurethane (xPU). The obtained CSF-xPU strain sensors show a large workable strain range (> 80%), fast response (< 60 ms), high sensitivity, and excellent durability. Moreover, the sensors could also be efficiently repaired/healed and recycled based on the dynamic carbamate bonds in the xPU. Due to the abundant source of silk fabric and large-scale production of polyurethane, as well as the simple hot-pressing process to composite the CSF and the xPU, this CSF-xPU strain sensor is low-cost. Therefore, the repairable/healable and recyclable strain sensors here show great potential as high-performance and sustainable wearable devices for practical applications.

Keywords

carbonized silk fabrics / healable / polyurethane / recyclable / strain sensors

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2025 The Author(s). SusMat published by Sichuan University and John Wiley & Sons Australia, Ltd.