A leader they can believe in

A remarkable robot fish guides fish schools away from danger to safety

Growing up in Rome, Maurizio Porfiri often frequented zoos and aquariums, where he observed the collective behaviour of everything from ants to birds. “To me,” he says, “the fascinating part was animal personality.”

And as a science-fiction fan-he enjoyed the work of Philip K. Dick, who wrote Do Androids Dream of Electric Sheep?-Porfiri, who went on to study mechanical engineering, imag­ined a world where robots interact with nature. If the robot fish he’s built is any indication, his childhood fantasy may be edging closer to fruition: beyond merely swimming alongside its live counterparts, Porfiri’s cyberfish becomes their leader.

At first glance, the fishbot doesn’t seem much like a fish at all. Coated in a monochromatic polymer-red or blue or black-the 10-cm-long, battery-powered, remote-controlled machine looks more like a compressed rubber ball than marine life. The same, however, cannot be said of its behaviour: propelled by the electrical stimulation of the battery, the ionic polymers of its skin swell and shrink, and its tail beats back and forth, enabling the robot to glide silently through the water. Its movements, which were designed through extensive mathematical modelling, are fish-like enough to fool a school of golden shiners, despite the fact that it’s a lot bigger than them. “At first, they are engaged by the robot and start exploring it,” says Porfiri, an assistant professor at the Polytechnic Institute of New York University. “As the robot starts moving, they feel comfortable being in its vicinity, and they follow it.”

Continue reading