According to a report by Japan’s Kyodo News Agency on June 21, the team at iCeMS of Kyoto University in Japan published a result in the British scientific journal Nature on the 19th, saying that it has developed a variety of colors that can be artificially rendered without using ink. Technology.

This technology uses the same principle as peacock feathers and tropical fish due to light reflection, which is characterized by the use of ink, environmental protection and no fading.

The formation of microcavities and microfibers of stress hot spots in polymers is generally undesirable and is one of the causes of material failure. This type of stress crack is accelerated by a solvent which is usually weak and does not dissolve the polymer in large amounts, but it penetrates and plasticizes the polymer to promote the cavity and microfiber formation process. Here, we show that the formation of microfibers and cavities in polymer films can be controlled and utilized, using standing wave optics to design the periodic stress field within Film 4. We can then develop a periodic stress field with a weak solvent to form alternating layers of cavities and microfiber-filled polymers, which we call organized stress microfibrillation. These multilayer porous structures exhibit a structural color throughout the visible spectrum, the color of which can be adjusted by varying the temperature and solvent conditions of the film. By further using standard lithographic and masking tools, the organized stress microfibrillation process becomes an ink-free, large-scale color printing process that produces images with resolutions up to 14,000 dots per inch on flexible and transparent forms.

The team noticed that the polymer formed by the combination of many small molecules can reflect a specific color and develop color if the structure changes after being pressed. The team illuminates the polymer with light, artificially changes its structure, and then fixes it with a solvent to display the colors of various visible light such as red, green and blue.

Using this method, the team produced HD ukiyo-e and famous paintings of about 1 square millimeter. The technology is said to be expected to achieve a variety of applications, such as making banknotes have a specific color rendering function that is difficult to imitate to prevent counterfeiting. Team member material science professor Easan Sivaniah said: "This technology is the most advanced palette. It will probably have a huge impact on the industry."