Atomic Force Microscope (AFM) is a technique which belongs to the Scanning Probe Microscopy (SPM) family. It visualizes and generates images by ‘feeling’ the surface of the sample. The main operation modes of AFM depend on the force range due to the tip-sample separation distance. The AFM operates basically in three modes i.e. contact mode, intermittent contact or tapping mode and non-contact mode. In contact mode of operation of AFM the cantilever is in contact with the sample surface. The interaction between the cantilever and the sample surface is in the repulsive regime. In non-contact mode the tip does not come in contact with the surface of the sample and the tip – sample distance is generally of the order of few tens of nanometers and the tip experiences long range attractive forces. Therefore, tip and sample can be preserved. Tapping mode (i.e., intermittent contact mode) shares similar principle with non-contact mode. AFMs have been widely used in various applications of diverse fields ranging from surface sciences, biology, chemistry and so on.

The target of this session is to understand the interaction between the tip and the specimen surface while mapping sample surface.