Reprogrammable Thermochromic Fiber Actuators for Spatial Temperature Indication Devices

Abstract Cholesteric liquid crystal elastomer fibers (CLCE fibers) that exhibit both thermochromic and thermomechanical responses are ideal candidates for constructing fast and intuitive high‐temperature warning devices. However, their synthesis remains challenging due to the compromise between color and strain using the reported methods. In this study, CLCE fibers with coordinated color change and actuation upon temperature variation are synthesized based on a reprogrammable thermoresponsive network by introducing dynamic covalent bonds. The structural color visibility of CLCE fibers is enhanced through physical doping with Sudan Black B dye. Using these CLCE fibers, three temperature‐responsive structures, namely, the pyramid structure, the tug‐of‐war structure, and the thermal pointer structure, are designed and fabricated to achieve visual warnings and spatial high‐temperature indications. Experimental results show that under thermal stimulation, the CLCE fibers exhibit distinct color changes and mechanical deformation simultaneously, which further drive structural transformation of the devices, enabling rapid and robust high‐temperature warning functionality. This study offers a novel material platform and structural design approach for intelligent temperature warning and thermal safety monitoring.