For the first time, researchers have made a miniature robot that can jump on water by launching itself into mid-air from the water’s surface — without causing a single splash. The achievement, described in Science today, means that an army of small, robotic creatures might one day help search for flood survivors — or they could end up being used to creep on your enemies, according to the researchers.
"This robotic technology could probably be used for building [a] large number of robots that can float, and jump on water for surveillance missions," the researchers write in a statement to the press. "An example can be found in the movie Minority Report, where many small insect-like robots are deployed in an apartment in search for a fugitive — of course, we do not want the robots to be used by bad people."
Robots that can "jump on water for surveillance missions."
Despite the Tom Cruise reference, the robot, developed by researchers at Seoul National University and Harvard University, isn't actually equipped with surveillance technology. Rather, the study's goal was to explore aquatic mobility in a small-scale robot.
(Carla Schaffer / AAAS)
"We were fascinated by the fact that insects can actually jump on water quite well, something that humans or any engineered system cannot not replicate," the researchers write. By observing how an insect called a water strider pushes off from the water’s surface — and recording the behavior using a high-speed camera — the scientists were able to build robot legs that move in much the same way. They also adapted a catapult mechanism inspired by fleas to help it jump. The result is a thumb-sized robot that can leap 5.5 inches in the air, without ever breaking the water’s surface. And it can jump as high on water as it as can on the ground, the scientists write.
(Seoul National University)
Previous attempts weren't as faithful to the insect they were modeled after
This isn’t the first robot to mimic the water strider’s movements. Researchers at Carnegie Mellon University have already made a small robot that can walk on water. And three years ago, scientists at the University of Waterloo designed a robot that could leap 5.5 inches in the air and 14 inches forward from the water's surface. But previous robots weren’t quite as faithful to the water striders that they were modeled after; the Waterloo robot used wide paddles for its jumps and weighed about a thousand times more than a water strider. Today’s robo-insect is only seven times heavier than a strider and replicates its long, thin legs.
"We were able to reveal the core principle needed to jump on water at the scale of an insect," the researchers write. "This robotic tool can help deepen the understanding of how the insects and animals move."