Over the past few decades, soft robotics have made significant advancements in flexibility, allowing them to mimic the movement of biological muscles through the use of actuators. As with a human hand, this physical flexibility allows them to adapt and perform a range of tasks.
However, this dexterity tends to come at the cost of strength, since softer and more flexible materials are often used. In the new design, air or water pressure gives the actuators added strength that otherwise couldn’t be achieved through the materials themselves.
“Artificial muscle-like actuators are one of the most important grand challenges in all of engineering,” Rob Wood, a professor of engineering at Harvard and one of the authors of a paper published this week in the journal PNAS, said in a statement. “Now that we have created actuators with properties similar to natural muscle, we can imagine building almost any robot for almost any task.”
If the soft robots’ strength sounds extraordinary, that’s because it is. In fact, it was a shock even to its creators.
“We were very surprised by how strong the actuators […] were. We expected they’d have a higher maximum functional weight than ordinary soft robots, but we didn’t expect a thousand-fold increase. It’s like giving these robots superpowers,” said Daniela Rus, a professor of engineering and computer science at MIT and one of the authors of the paper.
Inspired by origami, the robots’ design allows them to fold into programmable patterns to save space. Twist them in a certain way and they’ll fold together neatly. Useful as that may be for keeping things packed and orderly, it does create a drawback in that they’re not as easily controlled as conventional robots, since their movements depend on their skeleton, which cannot be adjusted.
Still, the researchers don’t consider this to be all that limiting. By physically designing the robots to move in certain ways, the algorithms required to control them can be simplified. And since the robots are made up of such simple materials, the researchers say one of the actuators can be built in ten minutes for less than a dollar.
Moving forward Rus and her team want to develop even more complex structures, including an artificial elephant trunk that can move and grip just like the real thing.