BUFFALO, N.Y. -- A thin film that reflects light in intriguing ways could be used to make road signs that shine brightly and change color at night, according to a study that will be published on Aug. 9 in Science Advances.
The technology could help call attention to important traffic information when it's dark, with potential benefits for both drivers and pedestrians, researchers say.
The film consists of polymer microspheres laid down on the sticky side of a transparent tape.
The material's physical structure leads to an interesting phenomenon: When white light shines on the film at night, some observers will see a single, stable color reflected back, while others will see changing colors.
It all depends on the angle of observation and whether the light source is moving.
The research was led by Limin Wu, PhD, at Fudan University in China, whose group developed the material.