Now, a shape-changing 'smart' material that heals itself

A team of researchers has come up with a new multifunctional 'smart' material that can morph its shape when exposed to heat and light and can also disassemble itself.

The Washington State University researchers, who have filed a provisional patent on the work, were able to combine several smart abilities, including shape memory behavior, light-activated movement and self-healing behavior, into one material.

The team worked with a class of long-chain molecules, called liquid crystalline networks (LCNs), which provide order in one direction and give material unique properties. The researchers took advantage of the way the material changes in response to heat to induce a unique three-way shape shifting behavior. They added groups of atoms that react to polarized light and used dynamic chemical bonds to improve the material's reprocessing abilities.

"We knew these different technologies worked independently and tried to combine them in a way that would be compatible,'' said lead author Michael Kessler.

The resulting material reacts to light, can remember its shape as it folds and unfolds and can heal itself when damaged. For instance, a razor blade scratch in the material can be fixed by applying ultraviolet light. The material's movements can be preprogrammed and its properties tailored.

The study is published in ACS Applied Materials and Interfaces.