Plant Derived Bio-based Liquid Crystal Elastomer with On-demand Mechanochromic Response

The development of sustainable, high-performance elastomer is an emerging field, driven by the growing demand for eco-friendly materials with multifunctional capabilities that can meet complex performance requirements. Cellulose, as the most abundant and renewable bioresource in nature, pose significant challenges for its use in the design and fabrication of stretchable elastomer. The intrinsic characteristic of cellulose, namely, the intermolecular hydrogen bonding between neighboring linear chain of D-glucose units, hinder processability and limit its mechanical flexibility. In this study, we developed a chiral nematic liquid crystal elastomer mainly composed of plant derived hydroxypropyl cellulose (HPC), in which the mechanical and optical properties were precisely tuned by modulating the intermolecular forces within the HPC complexes through salting-induced Hofmeister effect. The obtained composite exhibits vivid structural color arising from the right-handed chiral nematic architecture, while its elasticity is controlled by the cellulose-water interactions through hydrogen bonds. The HPC-based liquid crystal elastomer shows remarkable mechanochromic behavior with the structural color shifting in response to applied force. This dynamic color changes enable real-time monitoring of mechanical stress, with practical applications in rehabilitation training. Besides, owing to the biocompatible and biodegradable nature of HPC, the resulting liquid crystal elastomer can be fully degraded within 30 days in natural environments. The current work introduces an innovative strategy for the design of sustainable, high-performance devices based on cellulose-derived elastomers, highlighting the potential for eco-friendly and multifunctional applications.