Self-Repairable Carbon\nFiber-Reinforced Epoxy Vitrimer\nActuator with Multistimulus Responses and Programmable Morphing

Smart shape-changing structures in aerospace applications\nare vulnerable\nto damage in harsh environments. Balancing high mechanical performance\nwith self-repair capabilities poses a challenge due to inherent trade-offs\nbetween strength and flexibility. To address this challenge, an asymmetric\nbilayer-structured actuator was fabricated using commercially available\ncontinuous carbon fiber tows (CFs) as the passive layer and a dynamic\ncross-linked epoxy vitrimer as the active layer. The construction\nof the vitrimer-CF actuator involves a simple and scalable hot-pressing\nprocess, resulting in a tensile strength of 234 MPa and an interfacial\nbonding strength of 405 N·m<sup>–1</sup>. This actuator\nexhibits remarkable deformation capability (210°/7 s) and an\nefficient self-repair ability under various stimuli, including thermal\n(60–160 °C), light (0.4–1.0 W·cm<sup>–2</sup>), electric (2–4 V), and solvent (acetone). By adjustment\nof the orientation angle of CFs, complex left-handed and right-handed\ncurling structures can be achieved. Leveraging the insights from photothermal/electrothermal\nactuation mechanisms, a quadruped crawling robot is developed capable\nof crawling 4 cm with a single light illumination. The actuator can\nlift objects 45 times its weight when subjected to light stimuli.\nAdditionally, a flap actuator is constructed to achieve an angle change\nof 63° within 10 s under an electric stimulus, enabling remote\ncontrol over the aircraft flight angle. These results demonstrate\nthe potential of the vitrimer-CF actuator for advanced applications\nin intelligent aerospace structures.