Jason Palmer at the BBC:
The team, which included French and Spanish collaborators, used a variant of a technique called atomic force microscopy, or AFM.
AFM uses a tiny metal tip passed over a surface, whose even tinier deflections are measured as the tip is scanned to and fro over a sample.
The IBM team's innovation to create the first single molecule picture, of a molecule called pentacene, was to use the tip to pick up a single, small molecule made up of a carbon and an oxygen atom.
This carbon monoxide molecule effectively acts as a record needle, probing with unprecedented accuracy the very surfaces of atoms.
It is difficult to overstate what precision measurements these are.
The experiments must be isolated from any kind of vibration coming from within the laboratory or even its surroundings.
They are carried out at a scale so small that room temperature induces wigglings of the AFM's constituent molecules that would blur the images, so the apparatus is kept at a cool -268C.