Material that changes color like chameleons

The nature is the best creator and teacher it has teaches us many things the latest what scientists are able to get the idea from nature and implement it is that a new material skin has been prepared for the first time that changes its color on various occasion just the similar way a chameleon does.

This is the first time anybody has made a flexible chameleon-like skin that can change color simply by flexing it," said Connie J. Chang-Hasnain, a member of the Berkeley team and co-author on a paper published today in Optica, The Optical Society's (OSA) new high-impact journal.

Everything around us is visible to us by the fact it reflects a certain wavelength of the light falling on it and absorbing all other in it, and it is true that we cannot know the true color of any object because till date it is not possible to know what color wavelength has been absorbed by the object. But despite this we can see any color that falls in the visible range spectrum ranging from high wavelength of red to low wavelength violet.

It is possible to make a specific color reflect from the object in two ways one of which includes changing the chemical composition of the object and the other which is used by the scientists is that to make the surface in such a way that it reflects a certain wavelength of light. The authors of the Optica paper applied a similar principle, though with a radically different design, to achieve the color control they were looking for. In place of slits cut into a film they instead etched rows of ridges onto a single, thin layer of silicon. Rather than spreading the light into a complete rainbow, however, these ridges -- or bars -- reflect a very specific wavelength of light. By "tuning" the spaces between the bars, it's possible to select the specific color to be reflected. Unlike the slits in a diffraction grating, however, the silicon bars were extremely efficient and readily reflected the frequency of light they were tuned to.

"The next step is to make this larger-scale and there are facilities already that could do so," said Chang-Hasnain. "At that point, we hope to be able to find applications in entertainment, security, and monitoring." Even high levels of camouflage may be achieved with this or the materials that changes color with the change in stresses in them, in future gadgets or any other unknown features.