Silver ‘fish’ cleans as it swims

A student has invented a solar-powered device that sanitizes water by releasing silver ions as it swims.

The “fish” — aptly named by its inventor Ben Griffin, an undergraduate at Brunel University in West London — uses solar cells to recharge batteries that power the fish’s internal propeller and flexible tail fin. As the fish swims, the current also passes over electrodes that spew minute amounts of copper and silver ions into the water. Silver is a powerful biocide and copper ions help prevent algae formation.

Because it relies on solar energy, the 9-inch fish, which is not yet on the market, is perfect for places where no electrical supply exists such as in water tanks or in swimming pools.

The fish’s rechargeable batteries last about 2 hours; then it stops and is replenished by the sun. The fish floats with its dorsal fin just above the water, allowing the solar cells to soak up the sun’s rays.

— The preceding is an excerpt from Silver News, a publication of the Washington, D.C.-based Silver Institute.