Combined normal and torsional mode in frequency-modulation atomic force microscopy for lateral dissipation measurement

We present a new method to measure lateral dissipation in frequency-modulation atomic force microscopy (FM-AFM). Conventional FM-AFM has been used to measure the topography. Additionally the cantilever has been excited in the first torsional mode, leading to a tip motion parallel to the surface. The dissipation of this motion is measured and reveals information that is different from the information provided by the dissipation of the tip motion normal to the surface.