Supramolecular shape memory hydrogels: a new bridge between stimuli-responsive polymers and supramolecular chemistry

Supramolecular shape memory hydrogels (SSMHs) refer to shape memory polymers, in which temporary shapes are stabilized by reversible crosslinks such as supramolecular interactions and dynamic covalent bonds. Following a brief introduction of the conventional shape memory polymers (SMPs), this tutorial review is focused to summarize the recent advancement in various reversible crosslinks employed to construct SSMHs (supramolecular interactions and dynamic covalent bonds) and different shape memory behaviors (dual and triple shape memory effects). In addition, current challenges and future perspectives in this field are also discussed to suggest a new developing direction.