The latest issue of Nature features a report on a novel synthetic skin developed by researchers at Stanford University, USA. This groundbreaking material is capable of changing both texture and color simultaneously, holding great promise for applications in camouflage, soft robotics, and advanced display technologies.
In nature, cephalopods such as octopuses and squids can alter their body color and texture within milliseconds by controlling chromatophores and muscle tissues in their skin, enabling them to blend seamlessly into the surrounding environment. This biological camouflage mechanism relies on a sophisticated neural regulation system. However, achieving independent and reversible control over both color and texture in artificial materials has long been a formidable challenge.
Previous studies have separately realized electrochromic materials or shape-morphing materials. Yet, integrating these two functions onto a single flexible surface while enabling independent control still confronts multiple hurdles, including material compatibility, response speed, and durability.
Inspired by the skin-adapting capabilities of octopuses and similar creatures, the research team developed a programmable film that allows dynamic switching between different textures and colors. The material starts in a flat, featureless state and reveals pre-designed patterns and colors upon hydration and swelling.
Researchers “etched” patterns onto the film using electron beam lithography and added an optical layer that generates color effects. These transformations occur rapidly: most color changes take less than 20 seconds, and the material maintains its performance even after hundreds of switching cycles. Moreover, color and texture can be adjusted independently depending on which side of the film comes into contact with liquid.
The research team stated that their success validates the feasibility of the approach. While each current device can only display a single pattern, future iterations are expected to achieve multi-pattern display, electronic control, and large-scale manufacturing.
In a companion News & Views article published in the same issue, researchers from University of Stuttgart, Germany commented: “This dual and independent control of color and texture constitutes one of the most sophisticated camouflage systems found in nature.”