The role of nonlinear dynamics in quantitative atomic force microscopy.
Various methods of force measurement with the atomic force microscope are compared for their ability to accurately determine the tip-surface force from analysis of the nonlinear cantilever motion. It is explained how intermodulation, or the frequency mixing of multiple drive tones by the nonlinear tip-surface force, can be used to concentrate the nonlinear motion in a narrow band of frequency near the cantilever's fundamental resonance, where accuracy and sensitivity of force measurement are greatest. Two different methods for reconstructing tip-surface forces from intermodulation spectra are explained. The reconstruction of both conservative and dissipative tip-surface interactions from intermodulation spectra are demonstrated on simulated data.
Nanostructure Physics, Royal Institute of Technology-KTH, Roslagstullsbacken 21, Stockholm, Sweden.
Daniel
D
Platz
Daniel
D
Forchheimer
Erik A
EA
Tholén
David B
DB
Haviland