This is scientific American's 60 second science. I'm Christopher Intalyata. Got a minute?

Water laced with heavy metals, like the drinking water in Flint, Michigan, can be stripped of contaminants using chemicals,

filters, membranes, even electric current. But now researchers say they've created what

could be a cheaper, more effective solution, a fleet of microscopic self-propelled aquatic robots, each one the size of just

ten lined up bacteria, so tiny that a billion will fit in a syringe.

Each tube-shaped microbot is a sandwich of three materials,

a graphine outer layer which binds to heavy metals, a middle layer of nickel,

which gives the bot's magnetic polarity, so they can be pulled through wastewater with

magnets, and a platinum inside for propulsion. Just add a bit of peroxide to the

wastewater and it'll react with the platinum to form water and oxygen bubbles,

which propel the tubes along. In an hour a swarm of

200,000 bots scavenged 80% of the lead from 3 millilaters of tainted water and the

researchers estimate that it costs only about 5 cents a liter to do so.

The findings are in the journal Nanol Letters.

The researchers envision the bots as a portable solution for small companies. They'd treat their water on site instead of carting it to a treatment plant.

And after the robots do the rounds, the heavy metals can be stripped away,

meaning companies can reuse the heavy metals and ultimately keep them out of our waterways.

Thanks for the minute.

For Scientific Americans 60 Second Science, I'm Christopher and Dahlia.