Researchers at Stanford University have developed a soft growing robot that could be used to support rescue operations or in medical devices.

Inspired by the natural growth of things like vines or fungi, that stretch over a distance by growing, the team developed prototypes and put them through different tests.

“Essentially, we’re trying to understand the fundamentals of this new approach to getting mobility or movement out of a mechanism,” said Allison Okamura, professor of mechanical engineering and senior author of the paper – published in a Science Robotics.

Using a cheap plastic – folded inside itself – the device is controlled using pumped pressurised air, or fluid, pumped into the stationary end. The tip is able to move without the body moving – giving it a number of useful applications.

“The body lengthens as the material extends from the end but the rest of the body doesn’t move,” explained Elliot Hawkes, a visiting assistant professor from the University of California, Santa Barbara and lead author of the paper. “The body can be stuck to the environment or jammed between rocks, but that doesn’t stop the robot because the tip can continue to progress as new material is added to the end.”

The team tested the prototypes in a variety of situations, including through an obstacle course, where it successfully delivered a sensor which would be capable of detecting carbon dioxide produced by people trapped in rubble.

“The applications we’re focusing on are those where the robot moves through a difficult environment, where the features are unpredictable and there are unknown spaces,” added Laura Blumenschein, a graduate student in the Okamura lab and co-author of the paper. “If you can put a robot in these environments and it’s unaffected by the obstacles while it’s moving, you don’t need to worry about it getting damaged or stuck as it explores.”

Research on this is ongoing and the team plans to scale it at different sizes and try other variations to maximise the potential of the technology.