Chameleon-like material promises colour-shifting films for camouflage and displays

This new material is claimed to offer possibilities for an entirely new class of display technologies, colour-shifting camouflage, and sensors that can detect otherwise imperceptible defects in buildings, bridges, and aircraft.

“This is the first time anybody has made a flexible chameleon-like skin that can change colour simply by flexing it,” said Connie J. Chang-Hasnain, a member of the Berkeley team and co-author on a paper published in Optica.

By precisely etching tiny features - smaller than a wavelength of light - onto a silicon film one thousand times thinner than a human hair, the researchers were able to select the range of colours the material would reflect, depending on how it was flexed and bent.

Controlling light with structures rather than traditional optics is not new with diffraction gratings routinely used in astronomy to direct light and spread it into its component colours. Efforts to control colour with this technique, however, have proved impractical due to optical losses.