The development of scanning probe microscopes in the
early 1980s brought a breakthrough in imaging, throwing open a
window into the world at the nanoscale. The key idea is to scan an
extremely sharp tip over a substrate and to record at each location
the strength of the interaction between tip and surface. In
scanning force microscopy, this interaction is—as the name
implies—the force between tip and structures on the surface. This
force is typically determined by measuring how the dynamics of a
vibrating tip changes as it scans over objects deposited on a
substrate. A common analogy is tapping a finger across a table and
sensing objects placed on the surface.
