Researchers create the first untethered soft robot, test it in snow and fire, and run it over with a car

The world’s first free-walking “soft robot” is extremely resilient.

Image: Harvard University

Developers from Harvard University in the US have created the first “soft robot” - a fleshy-looking quadruped that can stand up and walk away from its creators.

That might sound scary, but, trust us, in reality it's even creepier, as you can see in the video below, which shows it crawling around the lab like a headless posessed doll, and surviving being burnt and run over. 

But once you get past the ick-factor, the research represents a huge step forward in robot design.

Soft robots have been developed in the past, but they all had to be tethered in order to move. This new model, however, carries everything it needs to operate, including micro-compressors, control systems and batteries, on its back, as the developers explain in the journal Soft Robotics.

“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,” Michael Tolley, a research associate in materials science and mechanical engineering at Harvard’s awesomely-named Wyss Institute for Bioligically Inspired Engineering, told Peter Reuell, a staff writer for the Harvard Gazette.

“We think the reason people have settled on using metal and rigid materials for robots is because they’re easier to model and control. This work is very inspired by nature, and we wanted to demonstrate that soft materials can also be the basis for robots.”

This soft robot, which looks kind of like Gumby, is also much larger than previous tethered designs - it measures more than half a metre in length and can carry as much as 3.4 kilograms (7.5 pounds) on its rubbery back.

To give the robot so much strength, the developers had to do more than scale up previous models, they had to redesign how it moved.

The Harvard Gazette explains: “Giving the untethered robot the strength needed to carry mechanical components meant air pressures as high as 16 pounds per square inch (psi), 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 they eventually chose is a composite silicone rubber, which is made from stiff rubber filled with hollow glass microsphere to keep the robot’s weight down. The bottom is made from Kevlar fabric to ensure it's tough and lightweight.

This means that the robot was also super robust. The researchers tested it in snow, submerged it in water, walked it through flames and even ran it over with a car. “After each experiment, it emerged unscathed,” Reuell writes for the Harvard Gazette.

The team is now working on making the robots faster and outfitting them with sensors. But they ultimately hope that these soft robots will transform the way robots are used and thought of.

“One of the things that limit our imagination is that factory robots are very large and scary and dangerous to be around,” said Tolley. “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.”