In 1989, a group of scientists led by Don Eigler astounded the world by using just a few atoms---thirty-five in all---to spell out I-B-M.  This simple demonstration of moving atoms would become an icon for nanotechnology.  The real challenge of moving individual atoms is that everyday objects are so big compared to an atom.  How would you move a single atom…with your fingers, or even tiny tweezers?

Moving around atoms is tough because they are really small.  Less than a nanometer in size.  That means that about a half-million atoms can fit across the width of a hair. 

But that’s not the hard part.  The hard part is that there are a lot of atoms…everywhere.  Even in deep space where it is a vacuum with no air, there are a lot of atoms floating around.  So the first thing that you need to do is to make a really good vacuum and try to remove all of the atoms.  To do that you need really powerful pumps that can suck all of the air (and the atoms) out of the space that you use to move around atoms.

Eigler also needed to have a special kind of atom that could be moved with his microscope needle, so he chose an element called xenon. Xenon is a gas at room temperature but when you cool it down it turns solid.

So how did Eigler move an atom?  With a very special instrument called a scanning probe microscope.  It is not like a regular microscope but ‘sees’ using a tiny needle as a probe.  This special needle is used to ‘feel’ the contours of the surface and if you are careful you can ‘see’ atoms.  Even more exciting is that a scanning probe microscope can also be used to move atoms one at a time.

Not only are atoms small but they are constantly moving.  To keep the atoms from moving around they needed to keep things cold.  How cold?  Almost absolute zero, five degrees Kelvin, that is minus 450 degrees Fahrenheit.  It is so cold that most atoms hardly move at all.

It took them almost a whole day to move those 35 atoms and what happened when they got done?  They took a picture and went home after a long day at work moving a few atoms.

Image Source: The Harrow Group |  Erik Viktor