4D printing of multi-stimuli responsive rigid smart composite materials with self-healing ability

Smart materials combined with favourable mechanical strength, high self-healing efficiency, and multi-stimuli responsive ability show promising applications in diverse fields, such as biotechnology and minimally invasive devices. However, the mutually exclusive conflicts among these properties make it challenging to balance them simultaneously. In this study, we proposed a multi-stimuli responsive rigid smart material based on modularization scheme for the first time, which can respond to temperature and magnetic stimulation, are designed and successfully prepared by 4D printing of shape memory epoxy resin, Fe3O4@GO, and self-healing microcapsules. The resultant smart materials show excellent tensile strength (17.2 MPa), high self-healing efficiency (91.2%) at room temperature, and rapid magnetic-stimuli responsive (15 s). It is worth noting that the recovery rate of fractured samples can be still up to 82.0% after three times fracture repairs, suggesting their strong self-healing ability at room temperature. More importantly, the obtained materials can be further exploited for a wide variety of applications, such as smart space deformable structures, temperature sensors, and grippers, exhibiting enormous potential for the development of next-generation smart structural components.