Researchers in China have devised thin films, inspired by the adaptive iridophores, or nanophotonic structures, of the chameleon’s skin, that respond mechanically and chromatically when exposed to certain vapors (Matter, doi: 10.1016/j.matt.2019.05.012). The researchers believe that the resulting “structural-color actuators” they’ve demonstrated, which can move and change color when confronted with changes in the chemical environment, could find use in “sensing, communication and disguise” for soft robotics.
Actuators for soft robotics have been an active area of research in recent years—with progress, for example, in polymer-based soft actuators that can enable shape shifting and movement. A variety of systems have attempted to add color to the mix, by incorporating integrated microfluidics to pump dyes into the actuators to allow for color changes and camouflage. But some of these systems have been vulnerable to photobleaching and have had slow response times, making them a less-than-ideal fit for truly adaptive coloration.