Atomic force microscope (AFM)

An instrument which allows the topography of a surface to be determined at the atomic level. It is equipped with an extremely small and sharp tip (some nanometres) placed on a flexible cantilever. This tip is both attracted and repelled by the atoms on the surface. These repulsion/attraction forces cause the tip to move, making the cantilever drift. These deviations are recorded and then transformed into topography. An ‘image’ of the surface is thus obtained, atom by atom.