Thermally Stable Liquid Crystal Elastomer Artificial Muscles With Synchronous Super Toughness and High Strength

ABSTRACT Liquid crystal elastomer (LCE) presents a promising artificial muscle candidate yet faces inherent mechano‐thermal limitations. Here, we report a bottom‐up directed assembly strategy to construct topological LCE integrated with TiO 2−x quantum dots (QDs) into tough, high‐strength and thermal stable supramolecular (TiO 2−x ‐LCE) fibers. Covalently bonded TiO 2−x ‐LCE readily forms reversible percolation networks and dynamic hydrogen bonds via molecular conformational transformation. These mechanisms, combined with topological entanglement, endow the fibers with multimodal‐reinforced mechano‐thermal stability. Topological entanglement boosts the entropy elastic response, conferring high toughness and low hysteresis, while the percolation network enhances thermal stability by establishing efficient phonon transmission channels. Furthermore, the reversible reconstruction of the percolation network and dynamic hydrogen bonds expands viscoelastic dissipation pathways, counters modulus attenuation caused by high‐temperature segmental relaxation, and arrests fiber crack propagation. Remarkably, spiral yarn fabricated through fiber twisting exhibits superhigh fracture toughness (121.76 MJ·m −3 ) and tensile strength (120.07 MPa) at 110°C. Its working capacity (7404.8 kJ·m −3 ) reaches 185 times that of human skeletal muscle, surpassing all reported LCE artificial muscles.