Patent ID: 8601609

Claim:
A friction force microscope, comprising: a cantilever including a probe at a free end portion thereof; an X-Y drive mechanism for moving the probe on a sample surface opposed to the probe in an X-Y plane parallel to the sample surface; a Z drive mechanism for moving the probe in a Z direction perpendicular to the sample surface; displacement detection means for detecting displacement information of the cantilever in a bending direction and displacement information of the cantilever in a torsional direction; and a controller configured to calculate a probe height h from a center of cantilever torsion to the tip of the probe and a torsional spring constant K t based on bending sensitivity determined from the displacement information of the cantilever in the bending direction and torsional sensitivity determined from the displacement information of the cantilever in the torsional direction, and calculate a friction force between the sample and the probe based on the calculated probe height h and torsional spring constant K t .