A new material could give a Chameleon a run for its money - it can rapidly change colour to match that of any in the visible spectrum.
The synthetic material can be likened to an opal, a mineral that owes its variety of colours to its layered structure: regions with a high refractive index, in which light travels slowly, are interleaved with regions with a low refractive index. Light waves with a wavelength - or colour - similar to that of the space between layers are scattered in a way that gives opal its iridescent sheen.
The chameleon-like "opal" developed by British and Canadian chemists has a similar layered structure. But their material goes one better than nature. It can rapidly shrink or swell to change the distance between its layered regions, changing the colour of light that it scatters (video).
Source :Newscientist, 23 December 2008.
