What is Atomic Force Microscopy?
The atomic force microscope (AFM) is one of the family of scanning probe microscopes, and is widely used in biological applications. The AFM uses a flexible cantilever as a type of spring to measure the force between the tip and the sample. The basic idea of an AFM is that the local attractive or repulsive force between the tip and the sample is converted into a bending, or deflection, of the cantilever. The cantilever is attached to some form of rigid substrate that can be held fixed, and depending whether the interaction at the tip is attractive or repulsive, the cantilever will deflect towards or away from the surface. This cantilever deflection must be detected in some way and converted into an electrical signal to produce the images. The detection system that has become the standard method for AFM uses a laser beam that is reflected from the back of the cantilever onto a detector. The optical lever principle is used, which means that a small change in the bending angle of the cant
