LCE (liquid crystal elastomer) fibers can achieve large and reversible deformation under stimulation, which has attracted widespread attention in the field of materials. Current LCE fiber production methods include 3D/4D printing that uses layer-by-layer deposition principles. While wet spinning overcomes these limitations by achieving in situ active alignment of mesogens during curing, enabling reliable kilometer-scale continuous fiber fabrication. By varying the polymerization times of LCE oligomers in spinning solutions, we achieved different polymerization degrees, resulting in distinct viscosities. We use wet spinning to prepare LCE fibers with spinning solutions of different viscosities (200, 220, 240, 260, 280, 300, and 320 mPa·s). The strength of LCE fibers prepared at a viscosity of 280 mPa·s reaches up to 170 MPa, and the tensile property reaches 520%, which is higher than those in previous representative works. Temperature response tests showed 35% reversible shrinkage within 2 s at 80 °C. In addition, by blending LCE fibers with traditional cotton yarn fabrics, we prepared smart fabrics that retain the comfort of traditional fabrics and are temperature-responsive. Under active contraction of the LCE fibers, the fabric can show a 32% reversible shrinkage. The LCE continuous fibers prepared by this method can be widely used in the textile industry, providing new insights into the field of smart textiles.
Liquid crystal elastomers (LCEs) are among the key smart materials driving soft robotics and LCE fibers have garnered significant attention for their rapid response characteristics. A convenient and fast method for programming orientations of liquid crystal molecules is a focal issue in LCE applications. Inspired by the Kirigami technique, here, we propose a novel method for fabricating LCE fibers based on customizable cutting paths and secondary photo-cross-linking. While most existing LCE actuators exhibit contraction ratios of around 30 to 40%, our conical spiral actuator, fabricated from LCE-carbon nanotube (CNT) fiber using the proposed method, demonstrates a significantly higher contraction ratio, reaching up to 80%. The contraction ratio can be controlled by adjusting the cutting path parameters and we elucidate the mechanism linking liquid crystal orientation to the distribution of contraction ratio. Additionally, the conical spiral deformation of the actuator can be manipulated with light radiation, enabling versatile functionalities such as catching, twisting, and gripping. We hope that the novel LCE fiber fabrication method presented provides new insights for programming and preparing LCE fibers, offering a valuable reference for the application of smart soft materials.
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）