Ultra-Facile Fabrication of Stretchable and Transparent Capacitive Sensor Employing Photo-Assisted Patterning of Silver Nanowire Networks

Transparent electrodes that can be patterned in a simple manner and remain electrically conductive even under considerable strain are desirable for applications in stretchable and wearable devices. This paper introduces an ultra-facile, fast, and chemical-free method to produce silver nanowire (AgNW) patterns on a stretchable polymer. The AgNWs are deposited on thermoplastic urethane (TPU) and irradiated by intense pulsed light. This results in the fusion of the polymer through the surface of the AgNWs, thereby producing an embedded structure of AgNWs/TPU. A photomask is used to limit the areas affected by the radiation. After liquid washing, the AgNWs in areas that are not irradiated are mechanically separated by peeling. This simple procedure enables stretchable and transparent conducting patterns to be fabricated. The fusion procedure ensures that the patterned AgNWs are robustly adhered to the TPU even when stretched by large strains higher than 33%. Stretch-and-release testing reveals that the resistance of the electrodes reversibly varied, implying that it has good stretchability. The simple fabrication of a reliable stretchable capacitive sensor is demonstrated by employing this facile approach, in that the sensitivity does not deteriorate after severe stretching.