By atomic force microscope, a three-dimensional, digital image of a sample surface can be created. A tip-mounted needle (cantilever) scans the surface of the sample, and measures the deflection by means of a laser beam and a segmented photodiode, generating a three-dimensional image of the surface. The resolution can ideally be few Å, so it is of the order of magnitude of large atoms. This method is also suitable for electrically non-conductive substances and for investigations in liquids.
AFM image of a TiB2 layer