The transistor itself is composed of a single phosphorous-31 isotope, which has been precisely placed on a base of silicon using a Scanning Tunneling Microscope in an ultra-high vacuum chamber.

FORBES: Scientists Create A One-Atom Transistor

Nanometer-size materials occur all around us in nature, but it was only 20 years ago, thanks to IBM's introduction of the scanning tunneling microscope, that scientists began to observe and manipulate materials at the atomic level.

FORBES: The science of small