Caterpillar robot uses squishy, 3-D printed legs to inch and crawl
A robot caterpillar can use squishy legs to sense the world.
Roboticist Takuya Umedachi and colleagues designed the robot after studying real-life caterpillars. These insects can “bend, wrinkle, buckle, twist, droop, and creep” their way through the environment, and they do it “without massively complex brains,” the researchers write December 7 in Royal Society Open Science.
To mimic a caterpillar, Umedachi’s team built a version that included motors, pulleys and wire. It’s 23 centimeters long — about the length of a tissue box — with four contracting segments, and those squishy legs. Sensors detect when the legs bend. That’s a cue for the robot to crawl, one segment contracting after another in a wave.
But when Umedachi covered the middle two legs with tape, they no longer had enough purchase to push off the ground — they didn’t bend. “It’s slippery, like walking on ice,” says Umedachi, of the University of Tokyo. That’s enough info for the robot to change its gait — without using a lot of “brain” power. When those middle legs stay straight, the robot switches to a new caterpillar-like movement: like an inchworm, back leg scooching to front, and then front leg stretching forward.
Subscribe to Science News
Get great science journalism, from the most trusted source, delivered to your doorstep.
A pliable body lets robots sense and interact with the environment, Umedachi says. And it could give machines yet another way to become more aware of themselves — and their surroundings.
SOFT WALKER When this caterpillar robot’s soft legs press against the floor, they bend — a signal to crawl (top). Tape covering the middle legs (green) makes them slip, not bend, so the bot inches along instead (bottom). T. Umedachi et al./Royal Society Open Science 2016