Ellen Phiddian
Cosmos science journalist
Saudi Arabian researchers have made a tiny “soft robot” that can perform complex tasks such as picking up a cotton ball – when triggered with the right vapours.
The actuator, described in a paper in Chem, can pick up and drop a cotton ball depending on the vapour it’s exposed to.
“It can bend and stretch depending on molecular interactions, which is very sophisticated at this size range,” says senior author Professor Niveen Khashab, a chemist at King Abdullah University of Science and Technology.
“We hope our findings will be used to develop advanced soft robotic systems capable of precise and adaptable movements in various environments,” she adds.
The actuator is made from a polymer that forms tiny “cages”: spaces in the material which the researchers filled with urea.
The urea, the researchers say, is useful because it can form multiple different hydrogen bonds with its surrounds, allowing the material to shift and change shape.
They built a claw using three strips of the material, slightly bigger than a human finger.
When exposed to acetone vapour, the claw could grip a cotton ball. Then, when exposed to ethanol, it released the ball.
The robotic arms can respond to different vapours. Credit: Chem/Liu and Fang et al.
They say that the material can be programmed in this way to handle more complex tasks: something it’s been difficult to get soft robot components to do.
“The most remarkable finding was the unique actuation behavior where the soft actuator performed a complex motion involving ‘curvature, stretching, and reverting,’ which had not been reported previously,” says Khashab.
The researchers are now investigating how they can improve the material’s performance and introduce electricity. They’re ultimately hoping to be able to use it in wearable electronics.
