Atomic Force Microscope

Atomic Force Microscope (AFM) is a powerful tool to manipulate matters at the nanoscale. It is today used for imaging a wide range of surfaces such as glass, composites, ceramics, polymers and biological samples. Atomic Force Microscopy finds increasing application in nanotechnology and biophysics.

The integral part of an AFM is a microscale cantilever containing a sharp tip (probe) at its end. This is utilised for scanning the specimen surface. The cantilever is typically microfabricated from Silicon (Si) or Silicon Nitride (Si3N4). The tip radius of curvature is on the order of 10 nm).

The functioning of the AFM is as follows when the tip is put in close proximity to the sample surface, the forces that act between the sample and the tip results into deflection of the cantilever. The deflection is measured by a multi-segment photodiode through a laser beam that gets reflected on the surface of the cantilever.