An Atomic Force Microscope (AFM) provides 3 dimensional topographic information about a sample by probing its surface structure with a very sharp tip. The tip is scanned laterally across the surface, and the vertical movements of the tip are recorded and used to construct a quantitative 3 dimensional topographic map. The lateral resolution of the image can be as small as the tip radius (typically 5-15 nm), and the vertical resolution can be on the order of angstroms.