Researchers have 3D-printed hydrogel composites that swell and morph into flower shapes when immersed in water.

Credit: Nature Mater.

Lakshminarayanan Mahadevan and Jennifer Lewis at Harvard University in Cambridge, Massachusetts, and their colleagues used an ink made of cellulose fibrils embedded in a hydrogel matrix, which mimics plant-cell walls and swells in water. By controlling the alignment of the fibrils in the ink during printing, the team produced flat materials that bend and twist when placed in water, producing structures that mimic flowers (pictured).

The approach could be used to create designer, shape-changing structures for biomedical applications or smart textiles, the authors say.

Nature Mater. http://dx.doi.org/10.1038/nmat4544 (2016)