A mixed team of scientists and engineers developed a thin, flexible 4-layer material that autonomously camouflages itself to the surroundings, constantly evaluating the optical surroundings and automatically adapting to them - much like a chameleon or an octopus does.
It's the first system of its kind; it takes it just 1-2 seconds mimic the characteristics of the surroundings, just like the chameleon. But the inspiration didn't come from the ever popular chameleon - instead, researchers studied cephalopods such as the mimic octopus. Cephalopods typically have much faster response times, from 250-750 milliseconds.
The prototype is, of course, a simplification of the animals' skin. It looks like a pixelated frame, with no central processor controlling the changes. With octopuses, the eyes play a crucial role in the camouflage process, but the skin has its own photoreceptors similar to those found in the retina. This material works the same way - it has optical sensors that monitor the surroundings and then order individual parts to adapt. Think of it as a pixel screen - each pixel changes its color, mimicking the surroundings. But this is just the top layer.
The next layer is a matrix of shiny silver surfaces that create a bright white background made from silver. Silver was chosen for a number of reasons, including its thermal conductiveness, high reflectivity and chemical stability. Below that, the next layer heats the "pixels" through the silver layer, and at the bottom, there is a layer that contains an array of light detectors. Everything is placed ontop a flexible plastic support. It's a complicated design, but then again, it's a complicated objective.
The main reason why this was develop is, of course, military, but there are also potential applications in industry and recreation.
Journal Reference: Cunjiang Yu et al, Adaptive optoelectronic camouflage systems with designs inspired by cephalopod skins. 12998–13003, doi: 10.1073/pnas.1410494111