All-in-one wearable electronics design: Smart electrochromic liquid-crystal-clad fibers without external electrodes

Abstract Smart textiles and wearable sensors based on liquid crystal materials with highly tunable and controllable discoloration are attracting attention due to their promising functionality. However, products previously reported almost relies on the extra transparent conductive electrode to provide a stable electric field and resulting in complexity and inconvenience. Besides, practical applications remain limited by the lack of continuously processed long electrochromic fibers suitable for industrial weaving. This work presents smart electrochromic liquid-crystal-clad (ECLCC) fibers with multi-environmental stability and long-range controllability that are prepared continuously using simple tailormade instruments. By introducing a variety of electrochromic materials (CLCs) and a distinctive device design (coaxial dual-counter-electrode sandwich structure), multiple rapid and uniform color changes can be achieved over a long duration. The monofilament conductive core provides ECLCC fiber with enhanced color effects without viewing angle dependence, as well as good flexibility and stretchability. The fiberized coaxial electrode structure realizes the flexible electrochromic of textiles compared to the previously parallel sandwich structure of the traditional liquid crystal display. Thus, complex textiles can be easily knitted from fibers that respond to different external electro stimuli, showed the potential applications in intelligent clothing that sense and report the healthy condition of the wearer or the situation of the surrounding environment.