The method was inspired by the way plants change shape over time in response to environmental stimuli. The orchid-shaped structure is printed with a hydrogel composite ink containing aligned cellulose fibrils, which enable anisotropic swelling. A proprietary mathematical model developed by the team is claimed to precisely predicts how the fibrils will swell in water.
After printing, the 4D orchid is immersed in water to activate its shape transformation.
Donald Ingber, Wyss Institute founding director, said: “This 4D printing advance enables the design of almost any arbitrary, transformable shape from a range of available materials with different properties and potential applications, establishing a platform for printing self-assembling, dynamic microscale structures that could be applied to a range of industrial and medical applications."
