Flexible Fibrous Visible Light Sensors Based on Spiropyran for Wearable Devices, Electronic Skins, and Thermal Management Fabrics

Visible light is an important energy source for all living organisms on Earth. Given the importance of visible light, visible light sensors have attracted widespread interest from scientists. With the rapid development of wearable devices, the sensors used in them need to be flexible, stretchable, and lightweight. Herein, an intelligent electrolyte based on spiropyran (SP) that responds to visible light is developed. The reversible change rate in the electrical resistance of an SP/FeCl₃·6H₂O methyl cyanide (MeCN) aqueous solution under visible light irradiation is as high as 19.26%. Additionally, flexible and conductive fibrous visible light sensors with a core-sheath structure are prepared using an SP/FeCl₃·6H₂O MeCN aqueous solution and silicon rubber hollow fibers as the core and outer layers, respectively. These fibrous visible light sensors are then woven into fabrics with multiple functions, such as sensing and locating visible light, reversible photochromism, and thermal management. The fibrous visible light sensors and fabrics prepared in this study have broad development prospects and application potential in the fields of fashion, smart textiles, flexible conductive fibers, flexible fibrous sensors, electronic skins, and wearable devices.