A recipe for a soft robotic skin that is sensitive to touch and deformation, and has the ability to change colour like an octopus, has been developed by engineers in the US.
Soft-skinned robots that can sense their environment and interact safely with humans are a major engineering goal.
But the technology is currently limited by a lack of suitable electronics that can stretch continuously over the body of the robot, as well as acting as a sensor or a display.
Now, a team at Cornell University led by researcher Rob Shepherd have found a way to nail all three problems at once with the development of a rubber-based skin that can both "feel" and also change colour.
The technology is presented in the current edition of the journal Science. It's multilayered and resembles a rubber sandwich.
The "bread" consists of a supporting flexible layer. Enclosed within, from the bottom up, are a pneumatic strip that can change the shape of each piece of skin, a layer of rubber containing a conductive liquid, an insulating layer and then another conductive rubber layer.
Applying a small voltage to the two conducting layers of rubber turns them into a capacitor. Deforming the skin - either by touching it, or making it move, changes the capacitance in a detectable and measurable way providing feedback about the level of force being applied.
The team also realised that if they embedded tiny light-emitting particles into the insulating rubber layer, they could also make the skin glow when the power is applied.
And varying the composition of the light-producing chemicals means that a range of colours can be emitted.
"So we now have a soft robotic skin that can display information - or even make a robot blush - as well as 'feel' a surface by registering how much it's being deformed," says Shepherd.
So far the team have made an 64-pixel piece of their skin that measures about 5 centimetres by 5 centimetres, is 5 millimetes thick and can stretch elastically in any dimension by almost 500%.
"We're now working to scale this up so we could cover an entire robot with it," explains Shepherd.
"And we have a project with NASA to investigate how this could be used to make exploratory rovers that can probe bodies of water and light their way as they go along."
That's amazing! Modern technology has developed very rapidly!