Underwater communication

A University of Washington assistant professor of aeronautics and astronautics has built three robot fish that can communicate with one another underwater.

In the future, such ocean-going robots could co-operatively track moving targets underwater, such as groups of whales or spreading plumes of pollution.

The Robofish, as they are known, are roughly the size of a 10-pound salmon, and use fins rather than propellers to move in the water. The fins make them potentially more manoeuverable and are thought to create lower drag than propeller-driven vehicles.

In the design of the Robofish, the researchers faced a major challenge; they needed to develop an on-board system that would allow the fish to transmit information through dense water.

'When you're underwater you run into problems with not being able to send a lot of data,' said Kristi Morgansen, a University of Washington assistant professor of aeronautics and astronautics, and the builder of the robot fish. 'State of the art is 80 bytes per second'.