Journal Article 3 tunable stiffness 4D printing 1 7782-42-5 1 9000-70-8 1 Gelatin 1 Graphite 1 plus ... Hydrogels 1 Oxides 1 Research Support, N.I.H., Extramural 1 Research Support, Non-U.S. Gov't 1 Review 1 active mechanical metamaterials 1 actuators 1 bioinspired 1 electroprogrammable stiffness 1 graphene 1 microgels 1 multilayer constructs 1 programmable materials 1 robotics 1 stiffness control 1 stimuli‐responsive materials 1 ternary programming 1 tissue engineering 1 tunable modulus 1 moins ...