Coming soon: robots with jellyfish skin

An electronic skin that takes a lesson from jellyfish and glows when in danger of being damaged is being developed by a team of scientists in China.

The new e-skin design – described in the journal Applied Materials and Interfaces – potentially solves one of the most stubborn – and counterintuitive – problems facing roboticists.

E-skin research is both widespread and robust, with products in demand for multiple uses in fields as varied as factory design and prosthetics. In October this year, for instance, another Chinese team reported the development of electronic skin that approached human fingertips in terms of its sensitivity.

The sector-wide drive to improve precision and receptiveness, however, has meant the other end of the touch scale has been left largely unexplored.

While many types of e-skin can detect and respond to light pressure, heavy blows leave them (metaphorically, at least) numb. Strong impacts above a certain level fail to raise more than week response signals, meaning there is little impetus for the system itself, or its human operator, to take evasive action to avoid damage.

Bin Hu and colleagues from China’s Huazhong University of Science and Technology, however, might have now solved the problem.

The team has designed a flexible e-skin that is sensitive to both slight and heavy pressure. When it feels force above an alarm-set trigger level, it glows.

To create their new skin, the researchers looked for inspiration to a species of deep sea crown jellyfish called Atolla wyvillei. The animal is bioluminescent, and flashes brightly whenever it senses danger.

To recreate the effect in their prototype, Hu and his colleagues took two layers of a type of silicone called polydimethylsiloxane and embedded silver nanowires into each. In between the layers is a third, comprising fluorescent phosphors.

Thanks to the electrical current running through the nanowires in the super-stretchy silicone, the e-skin can detect pressures as light as that created by a breeze. Pressure above a set level, however, activates the phosphors, producing a highly visible warning signal.

In their paper, the researchers suggest that the new skin “may find a wide range of applications in intelligent robots”.

The skin, by the way, is not the only invention inspired by the Atolla jellyfish.

In 2005, marine biologist Edith Widder used the idea of the jellyfish’s bioluminescence to create a substance she dubbed “e-jelly”.

She used it to mimic the real jellyfish in order to lure a giant squid into camera range for a film made by the US Discovery Channel and Japanese broadcaster NHK.