A master of disguise, the octopus can change the colour and texture of its skin to blend in with its environment. Inspired by this sea creature, researchers from the University of Pennsylvania and Cornell University developed a silicone skin for robots that can change texture for 3D camouflage.

The synthetic cephalopod skin can transform from a 2D surface into a 3D one with bumps and pits. The researchers took inspiration from the 3D bumps, called papillae, that octopuses can inflate using muscle units. They can change appearance as fast as one fifth of a second. In soft robots, air pockets have already been used as papillae. These pockets are inflated at different times in different spots to generate locomotion.

In the new research, the scientists embedded small fibre-mesh spheres into the silicone, so they could control and shape the texture of the inflated surface, just as an octopus can retexture its skin. In their proof-of-concept prototype, the silicon bubbles were divided with concentric circles of fibre-mesh frames. With this, the researchers can control the shape of the silicone as it inflates. They managed to mimic rounded stones in a river, as well as a succulent plant (Graptoveria amethorum) with leaves arranged in a spiral pattern.

The skin could be used for soft robots, to blend in with their environment, for instance to prevent them to be detected by animals in order to study them in their natural habitat, or for military applications.

For a video about the project, click here.

Photos: University of Pennsylvania / Cornell University / Jean Beaufort