ERJ staff report (PR)
Cambridge, Massachusetts - Developers from Harvard’s School for Engineering and Applied Sciences and the Wyss Institute for Biologically Inspired Engineering claim to have produced the first ever untethered soft robot — a quadruped that can stand up and walk away from its designers.
The invention marks a scale-up earlier soft-robot designs, enabling a single robot to carry on its back all the equipment it needs to operate — micro-compressors, control systems, and batteries. It features the use of silicone rubber instead of metal and other conventionally used rigid materials.
“Earlier versions of soft robots were all tethered, which works fine in some applications, but what we wanted to do was challenge people’s concept of what a robot has to look like,” said Michael Tolley, a research associate in materials science and mechanical engineering at the Wyss Institute.
The system designed by Tolley and colleagues measures more than a half-meter in length and capable of carrying as much as 3.5kg on its back.
Giving the untethered robot the strength needed to carry mechanical components meant air pressures as high as 16 pounds per square inch, more than double the seven psi used by many earlier robot designs. To deal with the increased pressure, the robot had to be made of tougher stuff.
The material the team opted for was a silicone rubber composite made from stiff rubber impregnated with hollow glass microspheres to reduce the robot’s weight. The robot’s bottom was made from Kevlar fabric to ensure it was tough and lightweight.
The result, Tolley said, was a robot that can stand up to a host of extreme conditions. Researchers tested the robot in snow, submerged it in water, walked it through flames, and even ran it over with a car. After each experiment, it emerged unscathed.
Potential future applications for soft robots include in industry, explains Tolley: "Factory robots are very large and scary and dangerous to be around. As a lay person, you can’t just walk into a factory where industrial robots are working.
"But a soft system is inherently less dangerous, so you can start to interact with it more, and I think that opens up many more opportunities.”