By Peter Weiss
“What are the possibilities of small but movable machines? They may or may not be useful, but they surely would be fun to make.” —Richard P. Feynman, 1959
Like a tiny powerboat streaking across a shallow lake of grease, the tip of a scanning tunneling microscope skids through a film of engine lubricant. The slick coating parts behind the onrushing needle, exposing a vein of underlying platinum until the lubricant flows back in again. In the laboratory of physicist Jacqueline Krim, the needle’s mad dashes test a lubricant for possible use on microscopic machines.