In a paper published in the journal Science Robotics, researchers at Stanford University present their latest invention – a soft, tube-like robot that moves by growing.
According to the research team, inspiration came through observing nature – the new robot moves very differently from humans and other bi- and quadri-pedal animals, more closely resembling the locomotion of vines, fungi and nerve cells.
“Essentially, we’re trying to understand the fundamentals of the new approach to getting mobility or movement out of a mechanism,” said Allison Okamura, Professor of Mechanical Engineering and senior author on the paper.
The design of the robot is fairly straightforward – it’s a tube of soft material (in this case – a cheap plastic) folded unto itself, much like an inside-out sock, that grows when the material at the front of the tube everts as a result of being pushed by pressurized air or fluid, and the tube itself becomes right-side-out.
Movements of the robot are guided by an advanced software system that calculates the correct route by reference to the images coming in from a camera at the tip of the device.
This type of design could prove useful in medical applications and even more so during search and rescue missions. “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,” explained lead author on the paper Elliot Hawkes from the University of California, Santa Barbara.
To test the usefulness of the robot, designed mostly for navigating difficult environments with unpredictable features and openings, the research team put a prototype through an impressively wide range of tests.
The robot had to grow through an obstacle course filled with flypaper, sticky glue and nails (once punctured, it successfully continued onwards as the damaged part remained stationary), up an ice wall to deliver a sensor, lift a 100-kilogram crate, squeeze through a door gap that was 10 percent of its diameter, and spiral on itself to form a free-standing structure to send out a radio signal.
The team is now working on scaling-up, developing a version of the robot that could be manufactured automatically, and experimenting with filling the robot with water, which could be delivered to people trapped in tight spaces or to put out fires in closed rooms.