OIL lubricates everything from watches to ships, but what will work for the
micromachines of the future? Bharat Bhushan and colleagues at Ohio State
University had a micrometre-sized motor with a propeller that kept jamming. They
tried using an oil-based lubricant—but it gummed up the propeller, making
the problem even worse.
To find out what was going wrong, they used an atomic force microscope to
make the first detailed measurements of friction in such machines. The problem,
Bhushan says, was that the liquid lubricant formed meniscus bridges between the
tiny moving parts and glued them together.
The solution was…
