[Research Progress of Four-dimensional Hydrogels in Implantable Medical Devices]

Four-dimensional (4D) printing is an emerging technology that combines science and engineering techniques. The term, "4D printing" was coined in 2013 and since then it has attracted a lot of interests due to its unique ability to have structural or functional transformations over time in response to external stimuli. The most important element of 4D printing is the responsive material. The recent progress research of hydrogels and related new technologies for 4D printing was summarized in the field of implanted medical devices at home and abroad in this paper. Then, it was pointed out the problems of responsive materials for 4D printing. Finally, it was prospected that the development of 4D printing technology in the field of implantable medical devices.