Animal skin has amazing properties. It insulates the animal from the environment, it can sense pressure and temperature, it can stretch significantly allowing motion and in a few animals it can even change colour.
Having this in mind a team of engineers at Cornell University have manage to create an artificial skin showing these properties. It is not intended to replace animal skin but to be used for robots.
They were inspired by octopus skin that in some species shows electroluminescence.
The possibility to provide a robot with soft skin that can light up can turn the surface of the robot into a display (although, so far, with low resolution) providing information to people looking at it. The skin can stretch up to 6 times its "rest" size and this can enable movements and in some cases can even support a small robot to crawl.
To do this the skin can be layered onto a pneumatic substrata that by changing its shape can propel the robot.
Additionally, the skin can ember sensors that measure pressure and stretch tension. This in turns provide the robot with a feedback on the relative position of its parts (arms, legs, tentacles...).
The luminescence is created by sandwiching an elastomer layer of ZnS doped with phosphorous between two hydrogel layers acting as electrodes. The whole creates a rubber fabric that can be stretched and whose resistance and capacitance change as the stretching tension changes. It is a novel kind of smart material.