Thermotropic monodomain liquid crystal elastomers (mLCEs) exhibit reversible contractile actuation properties along the collimated direction of mesogens when stimulated by external temperature, similar to those of biological skeletal muscle, and have great potential applications in flexible actuators and artificial muscles. However, the existence of flexible chain segments causes mLCEs to elongate under a small load, making calibration under different loads necessary when they are used as an actuator. In this study, a physical crosslinking point between flexible segments is provided through the introduction of designed long-chain molecules (LHS) containing amide bonds on the main chain of LCEs. The 5% LHS-mLCEs with enhanced anti-strain robustness achieved essentially constant original length over a range of loads (0–0.25 MPa) and maintained a reversible contraction ratio of 39.4%, comparable to biological skeletal muscle. Furthermore, a nonreconfigurable topological structure of a metal electrothermal layer with lossless compression properties was designed and prepared on the surface of mLCEs. The film actuators exhibit higher frequency oscillatory actuation (0.1 Hz 9.2%; 0.2 Hz 6.3%; 0.5 Hz 2%) relative to previously reported actuators, benefitting from the optimized heat dissipation structure of LCEs/Ag/air. This study provides valuable references and ideas for applying thermotropic mLCEs in practice.
Monodomain liquid crystal elastomers (m-LCEs) exhibit large reversible deformations when subjected to light and heat stimuli. Herein, we developed a new method for the large-scale continuous preparation of m-LCE fibers. These m-LCE fibers exhibit a reversible contraction ratio of 55.6%, breaking strength of 162 MPa (withstanding a load of 1 million times its weight), and maximum output power density of 1250 J/kg, surpassing those of previously reported m-LCEs. These excellent mechanical properties are mainly attributed to the formation of a homogeneous molecular network. Furthermore, the fabrication of m-LCEs with permanent plasticity using m-LCEs with impermanent instability without external intervention was realized by the synergistic effects of the self-restraint of mesogens and the prolonged relaxation process of LCEs. The designed LCE fibers, which are similar to biological muscle fibers and can be easily integrated, exhibit broad application prospects in artificial muscles, soft robots, and micromechanical systems.
危险品化学品经营许可证（带存储）