A flexible material can display patterns much in the same way that cuttlefish, octopuses and squid (pictured) form colourful spots in their skin.
To quickly change their appearance and camouflage themselves, such cephalopods use their muscles to stretch and relax small sacs of pigment under their skin. A team led by Xuanhe Zhao of the Massachusetts Institute of Technology in Cambridge developed an artificial equivalent using silicone rubber and organic compounds called spiropyran mechanophores, which glow when exposed to force. The researchers control the display by applying an electric field to deform the silicone, causing the mechanophores to glow in various repeated patterns including lines, circles and letters.
The display size and resolution could be scaled up for use as a camouflaging coating, the authors say.