Heat can bend a thin polymer film into different shapes inspired by origami.

Previous self-folding materials could either bend themselves into a shape and return to their original form, or permanently change shape. Tao Xie at Zhejiang University in Hangzhou, China, and his colleagues created a material that could do both. At a relatively low temperature of around 80 °C, the polymer's molecular chains shift but chemical bonds in the network remain intact, which causes the material to temporarily fold into a predefined shape. At a higher temperature of around 130 °C, the bonds break and reform, inducing a permanent change in the material's molecular structure.

The same polymer could fold into multiple different shapes, which might eventually be useful in devices that are deployed in the body or in space.

Sci. Adv. 2, e1501297 (2016)