Progress in 4D printing of stimulus-responsive composites and its applications

The stimulus-response composite is a kind of intelligent material, which usually possesses the characteristics of self-perception, autonomous response, shape memory, adaptive and self-healing. The stimulus-response materials used in 4D printing were reviewed in this paper, and the application research progress of 4D printed shape memory composite hydrogels and shape memory polymers (SMPs) and their composites was focused. Finally, the application status of 4D printing in the biomedical and aerospace fields was summarized, and the development trend and application prospect of 4D printing were prospected. 4D printing is an emerging manufacturing technology. Although various printing methods, printable smart materials and driving methods have been developed, 4D printing still faces many challenges in practical engineering applications. Novel printing technologies, smart materials, structural design and modeling software need to be developed to facilitate the practical application of 4D printing in the fields of soft robotics, biomedicine, aerospace and intelligent electronic equipment.