Robot fish gets new underwater skill

Researchers at Michigan State University say a high-tech robotic fish developed there has been given a new skill and a new name. The robot fish, which previously moved through the water by moving its tail, can now glide through the water practically indefinitely using little to no energy, they said. The robot's ability to glide comes from a newly installed pump that pushes water in and out of the fish to ascend or descend or glide through the water on a desired path, a university release said Thursday. "Swimming requires constant flapping of the tail," said Xiaobo Tan, an MSU professor of electrical and computer engineering, "which means the battery is constantly being discharged and typically wouldn't last more than a few hours." Gliding uses much less power but has the disadvantage of making the robot slower and less maneuverable while gathering valuable data that can aid in the cleaning of lakes and rivers. "This is why we integrated both locomotion modes -- gliding and swimming -- in our robot," Tan said. "Such integration also allows the robot to adapt to different environments, from shallow streams to deep lakes, from calm ponds to rivers, with rapid currents." With the new gliding capability comes a new name: grace, for "Gliding Robot ACE.