Question

With neat diagram explain construction and working of atomic force microscope. 

Answer 1

1. Atomic force microscope is high resolution type of scanning probe of microscope with resolution of 1A.U. Because of these it is one of the foremost tool in the field of nano-science.
2. Atomic force microscope is a modified TEM to overcome which woks as the probe in touch with sample using a microstable cantilever.
3. When the tip is brought in touch with the sample surfaces, force between the tip and the sample lead to the deflection to the cantilever.
4. The force present in the tip is kept constant and the scanning is done. As the scanning continues, the tip will have vertical movement depending upon topography of the sample.
5. The tip has a mirror on the top of it, a laser beam is used to have the record of vertical movements of needle. Interformator is also used for accuracy.
6. The information is later converted to visible one.
7. It overcomes the difficulty of TEM i.e. the problem associated with no-conducting material as AFM does not generate any current.
8. Depending on the situation forces that are measured in AFM include mechanical contact force, vander wall forces, capillary forces, electrostatic and magnetic forces.