A bio-inspired robotic fish can swim among its living counterparts and observe them at close range without startling them.
Most underwater robots have rigid exteriors and are powered by either propellers or jets — features that often scare off real fish. A team led by Robert Katzschmann at the Massachusetts Institute of Technology in Cambridge built a robotic fish that propels itself with a soft, flexible silicone-based tail that moves in a lifelike way. An operator communicates with the device, which has a fisheye camera, using a remote control that sends acoustic signals. In field tests, a diver was able to steer the robotic fish across coral reefs from as far away as 5 metres and at depths of up to 18 metres.
The robot could swim within a metre of fish without scaring them off, making it a potentially useful aid for researchers studying the interactions of marine life.