Photo-adaptable shape memory hydrogels based on orthogonal supramolecular interactions

A novel shape memory hydrogel with photo-adaptable permanent shape has been developed on the basis of alginate–Ca²⁺ coordination and the host–guest interaction between α-cyclodextrin and azobenzene. The reversible nature of alginate–Ca²⁺ confers the hydrogel with functions such as shape memory and shape recovery, and the light-responsive transition of azobenzene could be applied to generate a new permanent shape by tuning the host–guest complexation via UV light.