Origami derived self-assembly stents fabricated via 4D printing

Researches on self-assembly stents are expanding owing to the development of manufacturing technology and advanced materials. Many design strategies have been developed to obtain stents with large shrinkage ratios that facilitate minimally invasive implantation. The design of self-assembly stents that use the origami concept to achieve large shrinkage ratios is expected to introduce new opportunities in the treatment of tracheal diseases or vascular stenosis. Depending on the shape and angle of the unit cells, stents with different shrinkage ratios can be obtained by adjusting the geometric parameters and arranging them periodically. Further, the helical angle is introduced, and the effect on the shrinkage ratios of stents is investigated. Moreover, the lightweight design is presumed to increase structural flexibility and further improve the shrinkage ratio. Self-assembly stents with different unit cells are prepared via 4D printing, and the widespread application is illustrated by comparing experimental and theoretical studies. Furthermore, potential biomedical applications of self-assembly stents with large shrinkage ratios and deployable functions are suggested with demonstrative examples.