New robots crawl like sea turtles
Researchers have designed a new type of robot modeled on sea turtles known as FlipperBot. This is the first robot to use flippers against pliable surfaces and has moved the work toward amphibious robots forward.
Flippered robots inspired by sea-turtle hatchlings could shed light on how the ancestors of terrestrial animals first evolved to crawl on land, researchers say.Skip to next paragraph
Subscribe Today to the Monitor
Such research could also lead to amphibious robots that can tackle both land and sea, investigators added.
Scientists are designing robots that can go where humans cannot or should not go, and often rely on inspiration from nature to do so. For instance, snakelike robots could, in principle, slither into crevices to help find disaster victims.
RECOMMENDED: Are you scientifically literate? Take our quiz
Challenging environments for robots to cross include sand, gravel, soil, mud and other unstable granular surfaces that can deform around legs in complex ways. To learn new ways to navigate such ground, Daniel Goldman, a physicist at the Georgia Institute of Technology in Atlanta, and his colleagues investigated sea-turtle hatchlings.
"These little turtles are remarkably effective at moving over solid ground, with limbs designed for moving in fluid," Goldman told TechNewsDaily.
The researchers analyzed 25 baby loggerhead sea turtles from nests on Jekyll Island, one of Georgia's coastal islands, at night. They investigated how the turtles crawled on tracks of beach sand housed in a truck parked near the beach, video-recording them as they moved in the darkness toward a light that simulated the moon. [See also: 10 Animal-Inspired Robots]
Goldman and his colleagues Nicole Mazouchova and Paul Umbanhowar were surprised to learn the hatchlings moved about as quickly on soft sand as they did on hard sand.
"The turtles insert their flippers just deep enough into soft sand so that the material does not yield behind the flipper as they move," Goldman said. "That means the sand doesn't flow around the flippers, and they don't slip — so they can propel themselves."
The key to performing well, regardless of the conditions of the sand, seemed to lie in how the turtles controlled their wrists.
"On hard ground, their wrists locked in place, and they pivoted about a fixed arm," Goldman said. "On soft sand, they put their flippers into the sand, and the wrist would bend as they moved forward. We decided to investigate this using a robot model."
These findings led to the development of FlipperBot, the first robot to employ flippers against malleable surfaces. The small droid is about 7.5 inches (19 centimeters) long, weighs 2 lbs. (970 grams), and has two motor-driven flippers with flexible wrists similar to sea turtle wrists