Soft robots will go where first responders can’t
Say “robot” and I picture C-3PO, the gold-plated diplomatic robot in Star Wars. Say “robot” and Michael Tolley is more likely to talk about octopi.
“We have a sense of these rigid, metal robots,” said Tolley, postdoctoral associate with the Harvard Microrobotics Laboratory. “But if you look to nature you realize that natural organisms use materials with a broad spectrum of properties and elasticity. Look at the octopus, which is able to squeeze itself through tiny holes that are a small fraction of its normal body size.”
Tolley and colleagues at Harvard's School for Engineering and Applied Sciences and the Wyss Institute for Biologically Inspired Engineering have produced the first soft robot that doesn’t need to be tethered to an operator.
The four-footed robot – developed under grants from DARPA, the Department of Energy and the Wyss Institute – can carry on its back all the equipment it needs, including air compressors, control circuits and batteries. While the prototype has not yet been fitted out with sensors, the nearly two-foot-long device can carry as much as 7.5 pounds on its back.
The device, which is as yet unnamed, is made primarily of stiff silicone rubber, impregnated with hollow glass microspheres. The microspheres provide strength while keeping the weight of the device to a minimum. The bottom of the device is made of Kevlar.
Apart from it softness, one of the most unusual features of the device is that it moves by means of air pumped into channels in the silicone.
“The challenge was that we needed higher working pressures to be able to be two feet long and to carry 7.5 pounds, which is the weight of all the components plus an extra payload,” Tolley said. The micro-compressors carried on the device generate 16 pounds per square inch of pressure.
Thanks to its flexibility, the robot can withstand conditions that could debilitate other robots. In tests, for example, it survived being run over by a car. It also works well in snow, in flames and submerged in water.
These qualities, Tolley said, make soft robots good candidates for such chores as search and rescue. “They can tolerate a range of conditions that many traditional systems might not be able to tolerate,” he said.
Tolley and his colleagues are also working at giving soft robots the ability to jump.
“I just presented another soft robot that uses combustion to make a jump,” Tolley said. While this work is in its early states, he said, his team used small explosions of butane to cause the robot to jump approximately two feet.
“We’re looking at developing a system that can do search and rescue in a disaster area,” Tolley said. “Soft robots can crawl and squirm through a lot of things, but if there’s some new area where you have to jump to get access, that’s the kind of thing we’re working on.” While the first prototype can jump two feet, Tolley says he hopes to achieve jumps on the order of six feet.
Posted by Patrick Marshall on Sep 23, 2014 at 12:47 PM