Physicists have constructed a pipette that dispenses a billionth of a trillionth of a liter, a droplet that's a thousand times as small as volumes previously achieved. The behavior of these zeptoliter-size drops challenges an accepted theory describing how drops crystallize as they cool, the researchers say.
To build the pipette, Eli A. Sutter and Peter W. Sutter of the Brookhaven National Laboratory in Upton, N.Y., started with a germanium nanowire. It supports an initially solid reservoir of a gold-germanium alloy. A carbon shell encapsulates the assembly, which is about 2 micrometers long.