4D Printing of 3D Carbon-Medium Reinforced Thermosetting Shape Memory Polymer Composites with Superior Load-Bearing and Fast-Response Shape Reconfiguration

4D printing of continuous fiber-reinforced shape memory polymer (SMP) composites is a promising technology that has emerged in recent years. Nonetheless, combining superior load-bearing capacity with fast-response shape reconstruction in intelligently-driven structures is still a challenge due to the inferior thermal conductivity and mechanical properties of the composites along the transverse and thickness directions of the continuous fibers. In this study, a multi-scale 4D printing strategy for 3D carbon medium-reinforced thermosetting SMP (Ts-SMP) is proposed. This 3D reinforcement structure is realized by graphene synergized with continuous carbon fibers (GR-CCF) to provide multidirectional thermal conductivity and load-bearing paths for the composites. The reinforcement mechanism of GR-CCF for Ts-SMP is systematically investigated. The GR-CCF reinforced Ts-SMP composites exhibited superior performance, with a bending strength of 676.99 MPa, shape fixation ratio, and shape recovery ratio of 98.62% and 99.07%, respectively, and the local shape response reconfiguration within 6 s under near-infrared light excitation. This study provides a reference for the integrated fabrication of high-performance Ts-SMP composites for complex structures. The composites offer prospective applications in space deployable antenna locking hoops, flexible solar sail support ribs, and optically driven robot actuators. In this study, a multi-scale 4D printing strategy for graphene-continuous carbon fiber synergistically reinforced thermosetting shape memory polymer composites is proposed. This material demonstrates multifunctional integration, such as superior load bearing, and fast response shape reconfiguration. Their possible applications in locking loops and energy locking of spatially scalable structures are explored. image