Gadgets to see Beneath World’s Oceans

Italian researchers are developing gadgets that can drift like plankton, which they believe may help improve their understanding of the world’s oceans.

Experts at the University of Genoa say that their “smart plankton”, which will carry sensors and communicate using flashing lights, will drift through the ocean collecting data.

Davide Brizzolara, a researcher associated with the project, says that using this approach will provide greater coverage than static underwater sensors do, and would be cheaper than using autonomous underwater vehicles.

He and his colleagues hope that smart plankton swarms containing thousands of individuals will help environmental monitoring, underwater archaeological surveys, and mine detection.

Each sensor will collect data such as water temperature or salinity as it moves with the ocean currents, which will then be relayed from plankton to plankton back to a fixed hub on a floating buoy.

Brizzolara’s current design uses flashing LEDs to send messages rather than radio waves, which cannot penetrate more than a metre or so underwater.

His team has found that visible wavelengths of light are scattered less by underwater particles, such as real plankton and sediment than radio waves are.

The researcher says that the best wavelength to use varies depending on the size of the particles, so the plankton will be adaptable.

“If the communication bit rate falls below a certain rate it can switch to another colour, to see if the communication improves,” New Scientist magazine quoted him as saying.

Brizzolara feels that this should allow nodes up to 10 metres apart to communicate at bit rates around 1 gigabit per second – similar to a home broadband connection.

Measuring the delay will also allow an estimate of the distance between nodes and the fixed buoy, he says.

Presently, the researchers are trying to develop a a large proof-of-principle prototype roughly 20 cm in diameter, but they plan to reduce the size to smaller than 2 cm per unit.

The plankton will draw power from small piezoelectric flags that flutter in the surrounding water, and produce voltage as they move.

A paper on smart plankton was presented at Alife Conference in Winchester, UK earlier this month.