Anna Sato: Ward Melville High School

Anna Sato has devoted more than 18 months of research to water filtration projects. But the focus of her lab work sharpened in March of last year,

when a huge earthquake triggered a tsunami that devastated northeastern Japan and its Fukushima nuclear power plant.

Sato, 17, has relatives in Tokyo -- 170 miles south of the stricken plant -- and she worried about radioactive fallout. So she shifted her research at Stony Brook University to removal of radioactive isotopes from water.

The result: a new class of cellulose membranes that form a unique structure capable of absorbing radioactive materials. Sato expects that the low-cost membranes eventually will have a major impact, not only to remove radioactive contaminants from water but also to address a broader global shortage of clean drinking water.

Two full summers in university labs weren't Sato's only time investment. "I was also constantly thinking about it at home," she said.