Influence of force-based crosstalk on the 'wedge method' in lateral force microscopy
The lateral force mode of an atomic force microscope is a contact-based measurement where the cantilever moves laterally in order to contribute to the lateral component of the tip–surface interaction. An accurate quantitative measure is difficult to achieve and is subject to the calibration of a model of the machine such that the output signal is related to the contact forces. Currently available models and calibration methods do not consider the existence of crosstalk. The influence of the latter on the measurement is not clearly identified and raises the question of the result's accuracy. In this paper a definition of the crosstalk is given and the diversity of the crosstalk briefly presented. A first-order, two-dimensional model of the system that includes the force-based crosstalk is presented. The model is used to simulate a calibration method known as the 'wedge method'. A parametric study is carried out to evaluate the calibration errors that can be made by the 'wedge method'. Results show that force-based crosstalk can have a noticeable influence on the calibration as well as on the estimated friction coefficient.