Chameleons, nautilus and other octopi have fascinated engineers with their ability to change color and instantly mimic the complex patterns of their surroundings. While research into biochemical processes that cause these dramatic changes is progressing, engineers looking to create a man-made reproduction of the phenomena recently made a big breakthrough. In a paper published in the journal Optica, researchers debuted a material that changes colors when you apply force.

In nature, changing the chemical composition of cells activates bio-camouflages. Once the composition is changed, the cells interact with light in a different way to reveal a change in color.

Rather than re-engineering nature’s formula, researchers have tweaked this idea and altered the surface of their material so that it changes color as it’s moved. Though the idea of “structural color” isn’t new (it’s been used in astronomy to analyze the composition of stars and planets for a long time) the process has been impractical until now because the color changes they produced lacked resolution.

To improve the resolution of their color changing material, researchers built a material with rows of ridges etched into a thin layer of silicon. With these rows in place the light reflecting from their material had less space to spread spectrally, increasing the sharpness of the graphic produced on the material. After a bit of fine-tuning to get the spacing between their surface rows just right, the researchers realized they had created a color changing material with massive potential.

“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 researcher working on the project.

In the future, researchers predict that this material could be used to open up a new class of display technologies, or even active camouflage that reacts to its environment.  Researchers are also confident that their new material could be used in more critical applications, like monitoring the fatigue of a building, bridge or aircraft wing. Applications of that nature could be enormously useful to counties, countries and corporations, making this new material almost indispensable.

But before any of these applications can become a reality, they will need the ability to mass-manufacture the material. Fortunately, there may already be facilities and methods for making that jump.  “The next step is to make this larger-scale and there are facilities already that could do so,” said Chang-Hasnain.

With the recipe and method for production in place, it might not be too long before we see artificial, color changing materials out and about in the real world.

Source: OSA

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