Beauty may be only skin deep, but for humanoid robots a fleshy covering is about more than mere aesthetics, it could be essential to making them socially acceptable. A touch-sensitive coating could prevent such machines from accidentally injuring anybody within their reach
In May, a team at the Italian Institute of Technology (IIT) in Genoa will dispatch to labs across Europe the first pieces of touch-sensing skin designed for their nascent humanoid robot, the iCub. The skin IIT and its partners have developed contains flexible pressure sensors that aim to put robots in touch with the world.
"Skin has been one of the big missing technologies for humanoid robots," says roboticist Giorgio Metta at IIT. One goal of making robots in a humanoid form is to let them interact closely with people. But that will only be possible if a robot is fully aware of what its powerful motorised limbs are in contact with.
Roboticists are trying a great variety of ways to make a sensing skin. Early examples, such as the CB2 robot, built at Osaka University in Japan, placed a few hundred sensors in silicone skin. But now "many, many sensing methods are emerging", says Richard Walker of Shadow Robot, London. Until a lot of robots are using them, it is going to be hard to say which are best suited for particular applications.
What's more, there are many criteria the skin has to meet, says Metta: it must be resilient, able to cover a large surface area and be able to detect even light touches anywhere on that surface. "Many of these factors conflict with each other," he says.
The iCub is a humanoid robot the size of a child of three-and-a-half years old. Funded by the European Commission, it was designed to investigate cognition and how awareness of our limbs, muscles, tendons and tactile environment fuels the development of intelligence. The iCub's technical specifications are open-source and some 15 labs across Europe have already "cloned" their own, so IIT's skin design could find plenty of robots to enwrap.