Atomic Force Microscopes - Tutorial Page

Using the feedback control in the AFM, it is possible to scan a sample with a fixed cantilever deflection. Because the deflection of the cantilever is directly proportional to the force on the surface, a constant force is applied to the surface during a scan. This scanning mode is often called "contact" mode. However, because the forces of the probe on the surface are often less than a nano-newton, the probe is minimally touching the surface.