Scientists in the US have designed a robot that crawls like a sea turtle and could lead to future multi-terrain robots to help with turtle conservation by providing an understanding of the locomotion of sea turtles on uneven beach surfaces.
Researchers at Northwestern University and Georgia Institute of Technology designed the 19 cm-long robot dubbed ‘Flipperbot’. Their aim was to use the robot to test how seals, sea turtles and mudskippers use their fins and flippers to move towards water on uneven surfaces, such as sand. Their paper was published yesterday in the Institute of Physics journal Bioinspiration & Biomimetics.
The robot, which weighs 790g, is not propelled by legs or wheels but instead crawls using two flipper-like front limbs, spanning 40cm. Each limb is driven by small motors and has a lightweight flipper at its end.
The robot has been tested on a bed of poppy seeds and recorded using a high-speed digital camera. The goal of the study was to use a robot to delve deeper into the mechanics of flipper-based movement on land.
Prof Daniel Goldman from Georgia Institute of Technology said Flipperbot allowed the scientists to explore aspects of a sea turtle’s gait and structure that were challenging, if not impossible, to investigate in field experiments using actual animals.
"One of the main findings of our research was that when the robot was fitted with a free wrist, it was able to move more effectively over the ground as it allowed the flipper to remain locked in place within a solid region of sand and thus disturbed less material during the forward thrust," said Goldman.
The researchers found that a fixed wrist hindered the robot’s movements as it interacted with the ground that had already been disturbed by its previous steps.
To back up the results, Nicole Mazouchova, also from Georgia Tech, carried out a six-week field study of hatchling loggerhead sea turtles. She said these sea turtles experienced similar failures.
Mazouchova believes that further robot testing could help in turtle conservation biology.
"The natural beach habitat of hatchling sea turtles is endangered by human activity. Robot modelling can provide us with a tool to test environmental characteristics of the beach and implement efforts for conservation," she said.