Noncontact friction force microscopy based on quartz tuning fork sensors

Noncontact friction force microscopy (NC-FFM) measures the damping of the resonant oscillation of an atomic force microscope (AFM) tip that vibrates parallel to the sample surface at a controlled distance. By exploiting the two fundamental orthogonal vibration modes of a quartz tuning fork, such technique can be realized by all-piezoelectric sensing by simultaneously employing an AFM noncontact mode for distance control. The low noncontact-mode vibration amplitude used increases the effective interaction time for shear measurement. Application to polymeric samples shows that the dissipation contrast of NC-FFM is higher than that of the corresponding noncontact-mode phase imaging. (c) 2006 American Institute of Physics.