Polymer film changes texture and color on demand

Yellow or green, matte or glossy, the appearance of a material depends on its color but also its texture. Octopuses and cuttlefish use these properties for camouflage, altering their skin texture and color to instantly blend into their surroundings. Researchers have now created a polymer film that copies this feat for potential use in advanced displays and robotics (Nature 2026, DOI: 10.1038/s41586-025-09948-2). The films are flat and monochrome when exposed to alcohol, but in water they reveal colorful patterns and bumpy textures. Researchers have been mimicking the vibrant hues found in animals and plants due to structural color, which arises from the interaction of light waves with tiny nanostructures. To better mimic cephalopod skin, some scientists are now creating soft materials that change texture.Materials engineers Siddharth Doshi and Mark L. Brongersma of Stanford University and their colleagues came up with a seemingly simple way to independently control texture and color. They use an electron beam of varying doses to write a high-resolution pattern in a film of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), a widely used conductive polymer that swells in water. In spots exposed to higher doses of radiation, the polymer undergoes more cross-linking, limiting how much it swells, and vice versa. “That lets us make complex topographies or textures,” Doshi says. “When you apply alcohol, it becomes totally flat, and you can switch between these two states using microfluidic devices.”To control color, the team sandwiched the polymer between two gold films. Light bounces off these films and interferes in ways