Simulation of higher harmonics generation in tapping-mode atomic force microscopy

In tapping-mode atomic force microscopy, nonlinear tip-sample interactions give rise to higher harmonics of the cantilever vibration. We present an electrical circuit to model the atomic force microscope cantilever with its first three flexural eigenmodes. An electrical circuit simulator is used to simulate the tapping-mode operation. Amplitude and phase responses of the third flexural eigenmode are obtained for different sample properties. It is found that amplitude and phase of higher harmonics depend highly on sample properties. © 2001 American Institute of Physics.