Innovation: Tech Pioneers

Sometimes you have to quit what you're doing to pursue your ideas. These scientists took the risk--and it paid off

Who??says??there's??no??such??thing??as??a??eureka??moment? Physicist David Grier sure had one. Grier and graduate student Eric Dufresne were trying to build a new kind of "optical trap"--a device that splits a laser beam and uses it to capture particles of a single substance. They knew that multiple traps, used in tandem, could let scientists play traffic cops on a molecular level, separating a substance into component parts--removing bacteria from blood, for example. For a year, Grier and Dufresne had been trying out fancy glass splitters, but nothing had done the trick. As a joke, Grier tried a $5 piece of plastic. "It should not have...