A variety of creatures, including chameleons, octopuses and frogs, can change color as a result of changes in the environment. Some insights into the mechanisms behind this on the anatomical, cellular and molecular levels have been obtained. But a lot of work is still required to get a sufficient understanding of this phenomenon and to translate it into useful artificial applications.
As published in the journal Small researchers at the Nagoya University Molecular Design and Technology Department developed a material containing dyes and crystals that can change the colors and patterns displayed depending on the background color used in it and its exposure to visible or ultraviolet light.
The team was inspired to develop this material of bargain achieved in the skin of some frogs, combining different layers of cells with different properties to allow remarkable color changes.
Each component of this new material plays a key role in its color properties. Coloring agents, for example, contribute with their inherent colors to the appearance of the material, which can be customized by mixing them to different sizes. These dyes also include those that change color when exposed to light.
Spherical crystals were also introduced into the system, which, instead of affecting the color through its inherent pigmentation, affects it through microscopic structures that can directly interfere with light. Finally, a black pigment and different background colors were used to change the colors to other components of the system display.
"We examined the influences of the various components in the system, for example by changing the size of the crystal, changing the background from white to black, or exposure to visible or ultraviolet light," said the author, Yukikazu Takeoka. "We found that these changes resulted in different colors appearing across the material, similar to how some organisms can change color in response to various factors in their environment."