4D printing of shape memory polymers: Research status and application prospects

Shape memory polymers (SMPs) are a kind of smart material that can present active shape-changing behavior under external stimulus. Shape-changing structures based on SMPs have shown great potential to be applied in the areas ranging from aerospace to biomedicine. However, the design flexibility of such smart structures is restricted by conventional processing technique. 4D printing as the additive manufacturing technique for smart materials provides the new opportunities for the further development of SMPs. In this paper, we first reviewed the research progress about 4D printing of SMPs. Then, the investigation about the application of SMPs-based 4D structures was summarized. At last, we discussed the existing problems and further development of 4D printing of SMPs.