VelociRoACH: A tiny robotic cockroach with a need for speed
The common cockroach may make your skin crawl, but it turns out the household pest is the perfect model for miniature legged robots. That's why Duncan Haldane and his colleagues at the University of California, Berkeley, have been studying the six-legged pests to improve their millirobots. Their latest creation, the VelociRoACH, is made primarily out of cardboard and measures just 10 cm long, yet it can run 2.7 meters per second, making it the fastest robot of its size, capable of covering 26 times its body length in a single second.
The VelociRoACH is actually faster than a real roach (which can achieve 1.5 m/s) and second only to Boston Dynamics' Cheetah, which holds the current record of 3.2 m/s, when it comes to legged robots. Key to its speed are VelociRoACH's six springy C-shaped legs, which spin around rapidly, striking the ground up to 15 times per second to propel it forward.
To maintain stability, it is equipped with a thin strip of plastic that provides aerodynamic damping at high speeds, and legs programmed so that three of its feet contact the ground simultaneously (which is called an alternating tripod gait). When it comes to overcoming obstacles, it copies a real roach by simply slamming head first into whatever is in its way, causing it to rear up on its back set of legs.
That's not all they've learned from cockroaches – another robot called DASH is able to mimic how roaches and geckos hide themselves by swinging under surfaces. And Nick Kohut, another member of UC Berkeley's Biomimetic Millisystems Lab, is working on a version with a tail called the TAYLRoACH. The tail has a weight on the end, which causes the robot's body to pivot when swung around. This allows the robot to make a 90 degree turn in less than a quarter of a second without slowing down.
The VelociRoACH weighs just 30 grams, but it can carry up to 120 grams, so it's possible that it could be outfitted with sensors or other equipment in the future. Unfortunately, it's just as susceptible to a stomping as a real insect, so Haldane plans to make it a more robust body in the future – perhaps similar to this printed insect robot from MIT.
You can watch some impressive footage of the VelociRoACH running in the following video.