A thick tendril snakes its way across a desk. It turns sharply, heading up to wrap its single, tube-like appendage around a valve that moves slowly under its pressure. Though it looks like the work of a sentient vine, it’s actually a robot: a soft, plant-inspired creation that “grows” as a form of movement.
Plants adapt to their surroundings in clever ways. They sprout around, or sometimes through, physical obstacles like brick and wood; they rise in the direction of light sources to better soak up nutrients. And so, inspired by nature, a group of scientists has come up with a “soft robot” that mimics plant-like movements. According to a paper, published by the journal Science Robotics, one of these robots can “extend from its tip to thousands of times its original body length at a speed comparable to animal and robotic locomotion.” Scientists have already built robots that look like hellmonster dogs, but there’s something unnerving about this particular version of tentacle-like creeping.
Joey Davis Greer, one of the paper’s authors, tells The Verge that growth is an under-explored navigation method in robotics. He says mimicking plant movement serves two purposes: “First, its length can increase on the order of 1,000 percent, similar to a plant. Second, and maybe more importantly, is that if you were to watch a time-lapse of a growing root, its body does not slide with respect to its environment as it grows.” This means it can move with ease around environments ranging from search and rescue areas, to the human body.
Armed with a camera and onboard sensors, the robot can steer through its surroundings free of human control at a speed of up to 22 miles per hour. It moves through pressure — as the robot is pressurized, its tip extrudes new material, so the robot essentially grows. This is called tip eversion. “The tip of the growing robot behaves like half of a water wiggle toy and the other half of the robot is fixed at its base,” Greer says.
“if there is a way it can extend, it probably will.”
It also has the not-terrifying-at-all ability to fit through narrow spaces, as well as lift or push objects or form a fire hose or radio antennae. Greer says the robot uses the pressure inside its body to lift objects as it grows. The pressure inside the robot itself may be low, but because it comes in contact with a large amount of surface area, it can lift a large amount. A robot with an interior pressure of three pounds per square inch, for example, would be able to lift 300 pounds if the weight were resting on a 100-square-inch crate.
When it comes to how well the robot can squeeze into the aforementioned tight spaces, Greer says it’s a little shocking. “One thing we found with this growing robot, is that it is surprisingly difficult to stop it from lengthening when it is pressurized — if there is a way it can extend, it probably will,” he says.
Greer says there’s still much more to explore with this type of robot, including tweaking its scale and materials, or how it turns. It could help in situations that require navigate cluttered areas, from disaster zones to the human body. The paper’s authors claim it could even guide a medical catheter. Our thoughts are with the brave soul who volunteers first for this procedure.