Force calibration in lateral force microscopy: a review of the experimental methods

Lateral force microscopy (LFM) is a variation of atomic/scanning force microscopy (AFM/SFM). It relies on the torsional deformation of the AFM cantilever that results from the lateral forces acting between tip and sample surface. LFM allows imaging of heterogeneities in materials, thin films or monolayers at high spatial resolution. Furthermore, LFM is increasingly used to study the frictional properties of nanostructures and nanoparticulates. An impediment for the quantification of lateral forces in AFM, however, is the lack of reliable and established calibration methods. A widespread acceptance of LFM requires quantification coupled with a solid understanding of the sources of uncertainty. This paper reviews the available experimental calibration methods and identifies particularly promising approaches.