Atomic Force Microscope Equipment uri icon


  • The operational principle of an atomic force microscope is described by considering a surface of interest being scanned with a sharp tip residing at the free end of a microfabricated cantilever beam. The apex of the tip either gently contacts the surface when imaging is performed in contact mode, or intermittently contacts the surface during tapping mode imaging. The ultrasmall repulsive or attractive forces existing between the tip and the sample cause the cantilever to move up and down in the direction vertical to the surface. This deflection is monitored using an optical deflection setup consisting of a laser beam focused at the free end of the oscillator reflecting into a quad cell photodetector. During this scanning process, bending deflection, oscillation and torsion of the cantilever can be simultaneously measured.