[Zurück]

R. Stark, G. Schitter, M. Stark, R. Guckenberger, A. Stemmer:
"State space model of freely vibrating and surface-coupled cantilever dynamics in atomic force microscopy";
Physical Review B, 69 (2004).

The dynamics of the microcantilever in atomic force microscopy ~AFM! is represented by a multipledegrees-
of-freedom state-space model and is discussed within the framework of system theory. The cantilever
dynamics is modeled as a linear time-invariant system with a nonlinear output feedback due to the tip-sample
interaction. This allows one to use the same model to analyze different aspects of atomic force microscopy
such as the dynamics of contact-mode or the dynamics of tapping-mode AFM. The state-space approach to the
dynamic response of the AFM cantilever allows for numerically efficient simulations. We show that not only
the eigenfrequency but also the modal damping of a cantilever interacting with a surface strongly depends on
the contact stiffness. This is important for a quantitative characterization of elastic sample properties. Additionally,
our model shows the presence of higher harmonics in tapping-mode AFM. The excitation of higher
eigenmodes can strongly distort the system response. The results illustrate that higher eigenmodes have to be
considered in the analysis of dynamic AFM.