They look like tiny, floating eyeballs. The black-capped drops bobbing along on oil are US researchers' attempt at ferrying substances around a chip. Many chemists are working out ways to shrink the beakers and Bunsen burners of the lab onto minuscule, automated chips. But friction makes it tough to force liquids and solids through the miniature carved channels in such 'microfluidic' devices. "It's a wacky example of what nanotechnology is about," says Velev.