But where are the tiny Refs?

Microscopic robots playing soccer.

Exploding from the other end of the field, a silver robot glinted under the light of the cameras and burst toward the lone defender standing between it and the goal.

That's when the "Whirling Dervish," as its creators call it, lived up to its name, spinning furiously in a show of razzle-dazzle. But suddenly, the robot stopped dead in its tracks, hopelessly mired as if it were stuck on superglue.

A metal arm appeared to rescue the wayward robot, but it was no crane — it was an acupuncture needle. And the field it plucked the robot from was hardly the size of a grain of rice.

What do you expect when the robot is six times smaller than an amoeba and weighs no more than a few hundred nanograms?