Artificial 'skin' changes colour on demand
12 Mar 2015
Engineers at the University of California at Berkeley (UCB) have developed a chameleon-like material which can be made to adapt its colour by applying a minute amount of force.
According to the UCB research team, the material offers “intriguing possibilities” for an entirely new class of display technologies and colour-shifting camouflage.
The researchers also claim the material could be used within sensors that have the ability to detect otherwise imperceptible defects in buildings, bridges, and aircraft.
“I think it’s extremely cool
UCB researcher Connie J. Chang-Hasnain
“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 UCB team.
“I think it’s extremely cool,” Chang-Hasnain said.
In order to select the range of colours the material would reflect, depending on how it was flexed and bent, the researchers precisely etched tiny features - smaller than a wavelength of light - onto a silicon film one thousand times thinner than a human hair.
“If you have a surface with very precise structures, spaced so they can interact with a specific wavelength of light, you can change its properties and how it interacts with light by changing its dimensions,” said Chang-Hasnain.
To demonstrate the ability of its colour changing material, the UCB team created a one-centimetre square layer of colour-shifting silicon.
Future developments would be needed to create a material large enough for commercial applications, the researchers said.
“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.”
A full account of the research has been published in the journal Optica.
