Researchers Devise New Printing Technique To Produce High-Resolution Color Images Without Using Ink

An anonymous reader writes: Researchers at the Technical University of Denmark have taken inspiration from creatures like butterflies and peacocks, whose wings and feathers create bright, iridescent colors not through light-absorbing pigments, but by bending and scattering light at the molecular level, creating what's known as structural color. The new printing method the team has developed starts with sheets of plastic covered in thousands of microscopic pillars spaced roughly 200 nanometers apart. To get those tiny plastic pillars to produce color, or at least appear to, they're first covered with a thin layer of germanium -- a shiny, grayish-white metalloid material. An ultra-fine laser blasts the germanium until it melts onto each pillar, strategically changing their shape and thickness (Editor's note: original research paper). This is then followed by a protective coating that helps preserves the shape and structure of all those tiny pillars. When light hits this modified plastic surface, the lightwaves bounce around amongst the various pillars, which end up changing their wavelength as they're reflected, producing different colors. The researchers were able to predict what colors would be produced by those nanoscale pillars, and by creating specific patterns, they were able to generate recognizable, high-contrast images.