The electron beam scans across the graphene sample line by line, revealing the locations of the carbon atoms that make up the lattice, as well as the brighter silicon impurities (see Background). In addition to imaging, the researchers can also control the electron beam with a mouse, directing the irradiation at individual atoms, very much as is shown in the simulator below. By placing the beam on an atom next to an impurity, the silicon atoms can be moved.
Patience is required for the game: it takes a few seconds until it can be seen whether the electron beam has actually moved an atom. If you need instructions, please see the video at the bottom of the page. Not every pattern can be realized in this way. Which pattern will you create?