Superpowered origami muscles in soft robots can be built for less than $1

28 Nov 2017

Snake-like robotic arm with a flower-like gripper driven by a single vacuum source. Image: Shuguang Li

In an effort to build stronger and more flexible robots, a team of researchers turned to origami to build some truly powerful machines.

Robotics has come on in leaps and bounds in just a few short years – in some cases, quite literally – but especially in the field of soft robotics, where researchers are building everything from lifesaving sleeves for hearts to powerful exosuits.

Now, researchers from the Wyss Institute at Harvard University and MIT’s Computer Science and Artificial Intelligence Laboratory have achieved a substantial breakthrough that uses artificial muscles inspired by origami to give soft robots enormous strength.

In a paper published to Proceedings of the National Academy of Sciences, the team revealed artificial muscle actuators with the ability to carry up to 1,000 times their own weight using only air or water pressure.

Each artificial muscle consists of an inner ‘skeleton’ that can be made from various materials, such as a metal coil or a sheet of plastic folded into a certain pattern, surrounded by air or fluid and sealed inside a plastic or textile bag that serves as the robot’s ‘skin’.

When a vacuum is applied to the inside of the bag, it moves the muscle by causing the skin to collapse onto the skeleton, creating tension and movement in the muscle.

This action also allows the muscles to contract down to 10pc of their original size. When moving, they can generate about six times more force per unit area than human skeletons can.

With a weight of just 2.6g, a muscle can lift 3kg. It is incredibly easy to produce, taking just 10 minutes, at a cost of less than $1.

Most importantly, no other power source is needed to get the muscle moving as it is entirely powered by the shape and composition of the skeleton.

Soft robot tyre

A demonstration of the strength of the artificial muscle. Image: Shuguang Li

“We were very surprised by how strong the [muscles] were,” said Daniela Rus, a senior author on the paper.

“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.”

The only problem with these muscles is that they aren’t controllable because their movement is entirely dependent on the origami shapes within them. However, as design algorithms improve, our ability to create more and more intricate shapes will allow for greater control.

“The possibilities really are limitless,” Rus added. “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.”

Colm Gorey was a senior journalist with Silicon Republic