In studying the interaction between animals and robotic devices, researchers from the Polytechnic Institute of New York University have found that real fish would follow a robotic fish if it saves them energy in swimming.
In a study to be published in a forthcoming issue of the Journal of the Royal Society Interface, Stefano Marras and Maurizio Porfiri were trying to understand what causes a fish to form a school. To help them do that, the authors constructed a biomimetic robot fish and placed it in a water tunnel.
They then placed six Golden shiners (Notemigonus crysoleucas) in the tunnel and observed the behaviour of the fish when they varied the tail beat frequencies of the robot and the flow speeds of the water in the tunnel.
Not surprisingly, the researchers found that the robot fish attracted little attention from the live fish when it was stationary. But once the robotic tail started beating, the live fish tended to spend more time close to it.
At particular combinations of tail-beat frequencies and water speeds, the live fish began to hold station behind the robot, as if swimming in a school.
The authors noted that the fish that did so appeared to position themselves in the wake of the robot, beating their tails with a slower frequency that implied that the followers were enjoying a hydrodynamic advantage from the robot leader.
According to the authors, using such biomimetic robotic devices in the wild may help conserve fish by acting as leaders and driving them away from anthropogenic disturbances.
For more information, see the paper: Marras S and M Porfiri (2012) Fish and robots swimming together: attraction towards the robot demands biomimetic locomotion. Journal of the Royal Society Interface doi:10.1098/​rsif.2012.0084
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