Hybrid hydrogel sheets that undergo pre-programmed shape transformationsElectronic supplementary information (ESI) available: The synthesis recipe and experimental details, simulation process, and shape transformation of this hybrid hydrogel response to temperature and ion concentration. See DOI: 10.1039/c4sm01299b

This communication describes a novel strategy to achieve programmable shape transformation of hybrid hydrogel sheets by modulating both the in-plane and out-of-plane mismatches in mechanical properties. Both our experimental and computational results demonstrate that the shape transformation of hybrid hydrogel sheets shows rich features ( e.g. , rolling direction, axis, chirality, etc. ) and versatile tunability ( e.g. , via various external stimuli, material properties, pattern geometry, etc. ). This work can provide guidance for designing soft materials that are able to undergo more precise and complex shape transformation. This communication describes a novel strategy to achieve programmable shape transformation of hybrid hydrogel sheets by modulating both the in-plane and out-of-plane mismatches in mechanical properties.