Rational design of robust Cu@Ag core-shell nanowires for wearable electronics applications

Copper nanowires (CuNWs) have shown great potential as transparent electrodes for cost-effective wearable electronics. However, its unsatisfactory electrical conductivity and intrinsic susceptibility to oxidation hinder practical applications. To address these issues, herein, ultra-stable Cu@Ag core–shell NWs have been designed via a facile galvanic replacement method for wearable applications. The thermal stability of the NWs is significantly enhanced after introducing Ag, and superior stability is achieved with a more uniform Ag coating. The structural integrity of the percolation networks is basically maintained after 5 days' annealing treatment at a high temperature (≥150 °C). The devices based on core–shell NWs show reliable heating performance, and can further be used for defrosting and heating water/ice applications. Owing to optimized contact between Ag-coated NWs, the devices exhibit excellent mechanical performance under repetitive bending. Based on above structural design, the resultant strain sensors show high sensitivity, good repeatability and a wide sensing range, which are capable to detect various hand gestures and communicate with Morse code. Furthermore, the fabricated core–shell NWs show robust antibacterial activity, which is essential for wearable healthcare applications, outperforming that of pristine CuNWs. This work provides a promising way for the design of high-performance metal NWs for advanced wearable electronics.