Some of the most interesting forms of locomotion in the animal kingdom come from creatures without bones. We're talking cephalopods, like octopi, who can use their tentacles to both "walk" like we do and move in a bunch of other ways, often while carrying objects. This has inspired researchers from the Italian Institute of Technology and Kings College London to design a new sort of quadruped robot that walks around on air-powered soft tentacles instead of legs.
This quadruped is called a continuum robot, which means that it's got limbs (or arms or manipulators or what have you) that are curvy and flexible. The amount of curvature in each leg can be adjusted by altering the air pressure inside the three air-filled tubes that act as muscles and bones, and by doing this rapidly and in the right sequence, the robot can wiggle its way across a variety of surfaces at a speed that's somewhere between silly and menacing:
One particularly nice feature about air-filled limbs is that they're inherently compliant, which is a fancy robot term for bendy. They make great shock absorbers, and you can also beat on them with staplers (among other things) and they won't break, mostly because there's nothing in there to break: they're just tubes with air inside. When fully inflated, the limbs are nearly rigid; they're springy when partially inflated, and they're soft when uninflated to the point where the robot can stuff itself into small holes. Or that's the idea.
At this point, the engine (whatever is providing compressed air) isn't mounted inside the robot itself, but it looks like there's plenty of room in there for some solenoids and a gas generator or something like that. The researchers suggest that robots like this might be adaptable to a wide variety of tasks, ranging from planetary exploration to swimming to mine detection. Mine detection is especially appropriate, even with the current incarnation of the robot: with everything offboard, the robot itself doesn't really weigh anything, which is exactly what you want when you're trying not to blow yourself up.
"Locomotion with Continuum Limbs," by Isuru S. Godage, Thrishantha Nanayakkara, and Darwin G. Caldwell with the with the Istituto Italiano di Tecnologia and King’s College, University of London, was presented today at the 2012 IEEE/RSJ International Conference on Intelligent Robots and Systems in Vilamoura, Portugal.
Evan Ackerman is a senior editor at IEEE Spectrum. Since 2007, he has written over 6,000 articles on robotics and technology. He has a degree in Martian geology and is excellent at playing bagpipes.