Researchers have developed a unique, multifunctional smart material that can change shape from heat or light and and also heal its scratches.Smart materials that can react to external stimuli, like light or heat, have been an interesting novelty and look almost magical as they mysteriously fold and unfold themselves.They have a variety of potential applications, such as for actuators, drug delivery systems and self-assembling devices. For instance, smart materials could change shape to unfold a solar panel on a space satellite without need of a battery-powered mechanical device.But smart materials haven't come into widespread use because they are difficult to make and often can only perform one function at a time.The Washington State University research team developed a material that allows multiple functions at once with the potential to add more.
A paper describing the material was published in Applied Materials & Interfaces, a journal of the American Chemical society.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 behaviour.They added groups of atoms that react to polarised 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 one of the lead researchers Michael Kessler, Professor at Washington State University.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 on the material can be fixed by applying ultraviolet light.The material's movements can be pre-programmed and its properties tailored, the researchers said.