Scientists at the University of Michigan have developed a type of material that can change its appearance when subjected to light. The material is host to crystals that react to different wavelengths of light, moving into new shapes and patterns on the fly, without the need for an underlying template. The material could be used to make highly mutable displays and signs in the future.
The crystals are suspended in a solution above a semiconducting sheet. The sheet is made of transparent indium tin oxide, a material often used in screens and displays, while the crystals themselves are chemically similar to those found in latex paint. Light shone on the material creates a positive or negative charge, inducing the crystals into specified shapes.
To demonstrate its capabilities, the researchers at the university used light to project an M onto the material. The crystals are shown to coalesce into shape quickly, copying it, before floating back to their neutral positions. Michael Solomon, who worked on the technology at the university, told Popular Science the new material's reconfigurability was its strength. He was also asked if the material could be eventually used to reflect its surroundings, opening up the possibility of active camouflage. "Though we haven't done that," he said, "I think it's possible."