In an elegant bit of nanoscale engineering, chemists at the University of California at Los Angeles have designed and built what must be the world's tiniest elevator, a molecular platform on three legs that can be raised or lowered on command.
The device, created by J.Fraser Stoddart, a professor of organic chemistry, and colleagues, is about two and a half nanometers high, and the platform moves less than a nanometer up and down. A nanometer is one-billionth of a meter, or about a 25-millionth of an inch.
Although the elevator is more complex and organized than other so-called molecular machines, Stoddart said the work, which is described in the current issue of the journal Science, was only an 'extremely incremental' step toward developing useful molecular-scale devices that might, for example, function as drug-delivery systems. The elevator or something like it, he said, might someday serve as a valve, opening and closing a tiny cavity to allow a few drug molecules to reach a cell.