Scientists created a material that can change color like a chameleon's skin on demand.
The color change can be prompted with nothing more than a tiny bit of force, and could lead to breakthroughs in areas such as display technology, camouflage, and sensors that can pinpoint structural damage, the Optical Society reported.
"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.
The material was created by etching features smaller than a wavelength of light onto a silicon film that was thinner than a human hair, allowing the researchers to create different colors through reflection depending on how the film was bent. The rows of etchings create "bars" of light that reflect very specific wavelengths of light. Scientists can "tune" the spaces between the bars, allowing them to precisely control the colors they reflect, and the colors can be subtly changed by bending the material.
"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," Chang-Hasnain said.
The researchers demonstrated a one-centimeter square layer of color-shifting silicon, and hope to create larger pieces of this type of material in the future.
"The next step is to make this larger-scale and there are facilities already that could do so," Chang-Hasnain said. "At that point, we hope to be able to find applications in entertainment, security, and monitoring."
The material could also be used to create a new class of display technologies, and even create camouflaged vehicles that change their exterior to match their environment. Another potential application for the material could be to create sensors that change color to indicate structural fatigue in buildings, bridges, and even airplanes.
"This is the first time anyone has achieved such a broad range of color on a one-layer, thin and flexible surface," concluded Change-Hasnain. "I think it's extremely cool."
