Japanese researchers invented structural coloring to reveal color without dye

Have you ever thought about how the beautiful colors on the butterfly wings are produced? Where does the metallic luster on the beetle come from?

The secret is that light is reflected by tiny gaps in the surface of their bodies to produce color. This is called "structural coloring."

Following the footsteps of nature, researchers at Kyoto University have developed a way to produce full-color, fade-resistant images without the use of ink.

To produce this effect, Wosa Sivagna, a professor of materials science at the University's Institute of Cellular Materials Science, and his colleagues made tiny cavities on the plastic film used in the bottles and placed them in In an acid solution.

The interruption of light caused by an inadvertently flat surface causes the structure to be colored, which is very similar to the phenomenon in nature.

The team said the study could lead to the development of low-cost printing technology because pigments are not needed and the materials and reagents involved are cheaper than traditional methods that rely on pigments.

Researcher Ito Masahiro, a researcher at the University's Institute of Integrated Cell Materials Science, pointed out that it can be applied to banknote anti-counterfeiting technology.

The details of the research project were published online in the June 20 issue of the British science journal Nature.

Researchers have shown that this method produces color throughout the visible spectrum and that the shape and size of the image can be adjusted.