Ultra-tough and high-resilience mechanochromic fibres for real-world stress detection

Abstract

Cholesteric liquid crystal elastomer (CLCE) fibres have gained considerable attention as promising candidates for mechanochromic smart textiles across various domains, ranging from fashion to healthcare. However, intrinsically high hysteresis of CLCE during stress relaxation necessitates a time-lag between successive stimulus detections, thereby constraining the practical use in real-world systems. Here, we develop high-tough and low-hysteresis mechanochromic fibres capable of effectively detecting ultra-fast deformations at practical levels. By utilizing a thermoplastic elastomer (TPE) as a core fibre and CLCE as a sheath, we developed sheath-core composite fibres (named CLCE-SC). The CLCE-SC fibres preserve remarkable optical properties of CLCE sheath while improving mechanical properties, including high strength (100.9 MPa), toughness (27274.53 MJ m-3), and ultra-fast resilience (160 % strain at 128.3 cm s-1 strain speed) due to the TPE core. We demonstrate on-demand mechanochromic fibres with tuneable moduli of core TPE, expanding the fields of smart textile from single fibre to dynamic sensory environment.