Washington State University engineers have created a multi-tasking “smart” material that can change shape in response to heat or light and can assemble and disassemble itself. The development is considered a breakthrough because smart materials can only preform one function at a time. A provisional patent has been filed on the work.

Multifunctional “smart” material can fold and unfold, remember and self-heal. Source: Washington State UniversitySo-called “smart” materials can react to external stimuli, such as light or heat, and change shape, open or close and even self-repair a cut or tear. These materials have a variety of commercial, industrial and medical applications. They could be used, for example, to fold or unfold a solar panel on a space satellite without the need for a battery-powered device.

But these materials remain far from widespread use as they are difficult to make, usually perform only one function and their ability to repeat the desired function time after time hasn’t been proven.

What the WSU research team created was a material that performs multiple functions at once, with the potential to add more.

Working with a class of long-chain molecules called liquid crystalline networks, or LCNs, which provide order in one direction and give material unique properties, researchers took advantage of the way the material changes in response to heat to induce a 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.

As shown in this lab video, the resulting material reacts to light, can remember its shape as it folds and unfolds and can heal itself when damaged. For example, 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 WSU work was conducted in collaboration with the Energy Department’s Oak Ridge National Laboratory.