A Growing Soft Robot to the Rescue

Stanford's newest soft rescue robot moves like no other machine. (Image courtesy of Stanford.)

Being pinned beneath the rubble of a collapsed building or trapped in some other disaster scenario is a terrifying prospect. But, on the bright side, your chances of being found and rescued by first responders are increasing, thanks in part to odd ‘bots that are being developed across the world. In fact, another new search and rescue bot has just been developed by Stanford engineers, and it has its own set of special qualities.

Stanford’s prototype soft robot, which was described in the latest edition of Science Robotics, is a snake-like pneumatic machine tipped with a video camera. The robot can contort itself to shift around any boundary and climb across any surface. Actually, describing it as “snake-like” might be giving the robot short shrift. Unlike snakes, Stanford’s latest design can grow instantly to expand its reach, making it more like a vine than a snake.

To achieve its expansive growth, the robot begins its life as a flexible plastic tube that’s folded in on itself like a crumpled sock. Once compressed air is introduced into the interior of the machine’s body, it begins to expand. To control the direction of the robot’s movements, compressed air can be directed across a specific interior surface of the crawler, forcing it to bend and curl in response to its surroundings.

But what makes this machine even more compelling is that regardless of how far it needs to crawl through an obstacle field, it never has to untether itself from its origin, it simply unfurls more and more, growing to enormous lengths in the process.

“Essentially, we’re trying to understand the fundamentals of this new approach to getting mobility or movement out of a mechanism,” explained Allison Okamura, professor of mechanical engineering and senior author of the paper. “It’s very, very different from the way that animals or people get around the world.”

And while Stanford’s design is undeniably unique, the machine’s performance in a recent series of tests highlights its true potential.

According to the researchers, the pneumatic bot was able to traverse an obstacle course passing over fly paper, sticky glues, and even a nail without any impediment to its movement. In another test the robot was able to squeeze itself under a 100 kilo crate, inflate itself, and lift the enormous load. I think that alone qualifies it for the heavy duty work of freeing disaster victims from collapsed buildings.

Beyond disaster rescues, the pneumatic snake could also be used in a number of other fields, including medicine where, if miniaturized it could help with surgeries and diagnostics.

In the near future, Stanford’s engineers will begin redesigning their novel robot with more robust materials in the hopes of moving the machine beyond the proof-of-concept phase and into more serious, real-world tests.

For more soft robotics news, check out Controlling Soft Robots with Magnetic Fields.