Artificial muscles could let us build soft, stretchy robots

'Softbot-3000 Beginning Squidge Subroutine'

Artificial muscles could let us build soft stretchy robots

For years, roboticists have been experimenting with building 'soft' robots, whose bodies can deform to accomplish sensitive tasks or move through tight spaces - a bit like an octopus or a starfish.

But there's a problem - they're sloooooow. The pneumatic and hydraulic systems that move their bodies around only respond very slowly, and they're also difficult to store for long periods of time. Putting a more traditional motor inside defeats the point of a soft robot.

Now, however, engineers at Harvard's John A. Paulson School of Engineering and Applied Sciences have developed an artificial muscle out of carbon nanotubes that could make soft robots more practical.

Their system involves a 'dielectric elastomer' - essentially a soft material that deforms when an electric field is placed across it. These have been developed in the past, but the field strength necessary to drive robot movement have been too high.

Holy Grail

Mishu Duduta and a small team, however, have managed to build one that requires a relatively low voltage, is capable of a wide range of movements, and has no rigid components at all. "We think this has the potential to be the holy grail of soft robotics," he said.

The reason this was possible is thanks to the carbon nanotubes. They act as an electrode, and a multi-layered design for the muscle means they can provide significant force.

Duduta's technology, which was described in a paper in Advanced Materials, could be used to build wearable devices, soft grippers, surgical tools, fully soft robots, or soft components for regular robots.

"Actuation is one of the most difficult challenges in robotics," said Robert Wood, one of the co-authors on the paper.

"This breakthrough in electrically-controlled soft actuators brings us much closer to muscle-like performance in an engineered system and opens the door for countless applications in soft robotics."

  • Duncan Geere is TechRadar's science writer. Every day he finds the most interesting science news and explains why you should care. You can read more of his stories here, and you can find him on Twitter under the handle @duncangeere.

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