Friction force microscope

A friction force microscope is an atomic force microscope with a four quadrant photodetector, which allows measuring the frictional force acting on the probing tip sliding on a surface from the torsion of the cantilever beam where the tip is attached. When the tip is modified to bear chemical functionality, chemical force (e.g. hydrophilic - hydrophobic interaction]] operates between the tip and sample. Such mode of operation is called chemical force microscopy (CFM).