Instead of pushing out heated plastic, the printer head lays down hydrogel, a material that absorbs water, mixed with cellulose fibers harvested from plants. When the resulting structure is immersed in water, it swells — but by carefully controlling the alignment of the fibers in the gel lattice forming the object, the researchers can control how that happens.
"It is wonderful to be able to design and realize, in an engineered structure, some of nature's solutions," said L. Mahadevan, who worked on the Nature Materials paper describing the technique, in a news release.
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