Working alongside researchers from MIT’s Computer Science and Artificial Intelligence Laboratory, scientists from Harvard University’s Wyss Institute have developed origami-inspired artificial muscles.
Traditionally, the stronger engineers want a robot to be, the heavier it has to become. This fundamental rule tends to create more problems than it solves in terms of mobility. Now, a new technique is bringing together the familiar concepts of origami and vacuum-packing to build artificial muscles without the downsides.
The team discovered that the simple act of folding materials and pushing them through differing water or air pressures can add an enormous amount of strength to even the softest of robots. It’s estimated that the technique could allow them to lift more than 1,000 times their own weight. The results of the study are due to be published in Proceedings of the National Academy of Sciences (PNAS) later this week.
Giving robots superpowers
In order to give soft robots this artificial strength, each ‘muscle’ consists of an internal skeleton. But instead of having a rigid structure, inner layers are made up of flexible material – such as plastic or metal coil – and folded into a specific pattern.
The joint is then surrounded by air or water and sealed inside a vacuum bag – as close to having a skin as a robot is going to get. When the vacuum is applied, the skin contracts. The strength and motion are derived from the tension created. No further input is needed to direct the movement of the artificial muscle. Instead, the application of strength is determined by the shape and make-up of the skeleton.
“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, Professor of Electrical Engineering and Computer Science at MIT and one of the senior authors of the paper.
Possible applications of artificial muscles
“Artificial muscle-like actuators are one of the most important grand challenges in all of engineering,” said Rob Wood, co-author of the research paper. “Now that we have created actuators with properties similar to natural muscle, we can imagine building almost any robot for almost any task.”
Because of how scalable the simple muscle system is, there are numerous potential applications for the technology. Miniature surgical devices, transformable architecture and deployable structures for exploring space have all been suggested.
“In addition to their muscle-like properties, these soft actuators are highly scalable. We have built them at sizes ranging from a few millimeters up to a meter, and their performance holds up across the board,” Wood said.
“The possibilities really are limitless. But the very next thing I would like to build with these muscles is an elephant robot with a trunk that can manipulate the world in ways that are as flexible and powerful as you see in real elephants,” Rus said.