Light‐Driven Liquid Crystal Elastomer Composites With Enhanced Pyroelectrics for High‐Performance Energy Harvesting and Sensing

ABSTRACT Liquid crystal elastomers (LCEs) exhibit giant, reversible shape transformations under photo‐thermal stimuli, far exceeding the thermal expansion of conventional materials. This exceptional actuation strain is ideally suited to amplify the secondary pyroelectric effect, where electricity generation is driven by thermal stress. Here, we design an [(N,N‐dimethylethylenediammonium)(18‐crown‐6)]BF 4 /liquid crystal elastomer (MCBF/LCE) composite that harnesses the LCE's photo‐thermal actuation to impose dynamic stress on the pyroelectric MCBF crystals. This strain‐mediated mechanism yields a high pyroelectric coefficient of −8.15 nC·cm − 2 ·K − 1 , which is 5.4 times greater than that of polydomain composites. The MCBF/LCE pyroelectric composite delivers an output voltage of −14.6 V along with a current of 48.9 nA that dwarfs previous LCE‐based composites by 17 times. We further demonstrate the practical efficacy of this material by powering three green LEDs and constructing a real‐time CPU temperature sensor. This work leverages the intrinsic advantage of LCE to break the performance limit of flexible pyroelectrics, establishing a robust platform for self‐powered thermal sensing systems.