I saved this article from a Radio Electronics magazine in 1990 !!!

Scientists at IBM's Almaden Research Center (San Jose, CA) have managed to position individual atoms on a surface, and have used that technique to build structures one atom at a time. Besides helping scientists to better understand the fundamental behavior of atoms on surfaces—knowledge that is crucial to many industrial processes—the achievement opens the door for a broad range of future applications. Some of the possibilities are building custom molecules, making ultra-small electrical circuits, storing data on an atomic scale at densities more than a million times greater than is now possible, and perhaps even duplicating structures atomfor-atom. The technique might one day be adapted to reduce the size of semiconductor chips by a factor of more than 500.

The process, which demonstrates that atoms can be moved across a surface and accurately positioned where desired, was first used to create the letters "IBM" in xenon atoms. Next, a chain of seven xenon atoms bound together—the first atomic cluster built one atom at a time—was created. Both demonstrations required the atoms to be cooled to —269°C ( —453°F), which is only slightly higher than absolute zero.

Physicists Donald M. Eigler and Erhard K. Schweizer (a visiting scientist at Almaden, on leave from the Fritz-Haber-Institut in Berlin) used a special scanning tunneling microscope (STM) to move the atoms into place and to view their progress. STM's can image individual atoms on a metal or semiconductor surface by scanning the tip of a needle over the surface at a height of only a few atomic diameters. To study how atoms and molecules interact with surfaces, Eigler built an STM that could operate with extraordinary sensitivity and precision. He placed the STM in a high vacuum, cooled it with liquid helium, and isolated it from vibrations.

In a process similar to using the motion of a nearby magnet to move another magnet, a xenon atom can be "dragged" across a surface by placing the STM's needle tip close to the atom and moving the tip parallel to the surface. At the desired position, the tip is lifted, leaving the atom fixed in its new location. The exacting process—atoms are moved at a rate of 16 billionths of an inch per second—requires the STM operator to maintain a delicate balance of several attractive forces between the atoms. It took 22 hours to move the xenon atoms to form the letters "IBM."

Revised 2013 by Larry Gentleman