Lateral force modulation atomic force microscope for selective imaging of friction forces

An approach to imaging friction force distribution on the nanometer scale is presented, where a sample is laterally vibrated and both the amplitude and the phase of resultant torsion vibration of the cantilever are employed for imaging. It has an advantage over the conventional friction force microscope (FFM) in that the contrast due to local gradient can be significantly reduced. The topographic contrast was almost completely suppressed on a gold evaporated film sample. A method for characterizing friction, the friction force curve (FFC), is proposed where the friction force amplitude and phase are recorded simultaneously with the normal force, as a function of the tip-sample distance. The usefulness of the FFC was verified in characterizing slip and deformation in the tip-sample interaction.