The Role of Nonlinear Dynamics in Quantitative Atomic Force Microscopy

TL;DR

This paper explores how nonlinear dynamics and intermodulation in Atomic Force Microscopy can enhance the accuracy of tip-surface force measurements, introducing new methods for force reconstruction from spectral data.

Contribution

It presents novel techniques for reconstructing both conservative and dissipative forces from intermodulation spectra in AFM, improving force measurement accuracy.

Findings

Intermodulation spectra can be used to focus nonlinear motion near resonance.

Two methods for force reconstruction from spectral data are demonstrated.

Simulated data confirms the effectiveness of the proposed techniques.

Abstract

Various methods of force measurement with the Atomic Force Microscope (AFM) 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 cantilevers 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.