title: Analysis of dynamic cantilever behavior in tapping mode atomic force microscopy.
abstract: Tapping mode atomic force microscopy (AFM) provides phase images in addition to height and amplitude images. Although the behavior of tapping mode AFM has been investigated using mathematical modeling, comprehensive understanding of the behavior of tapping mode AFM still poses a significant challenge to the AFM community, involving issues such as the correct interpretation of the phase images. In this paper, the cantilever's dynamic behavior in tapping mode AFM is studied through a three dimensional finite element method. The cantilever's dynamic displacement responses are firstly obtained via simulation under different tip-sample separations, and for different tip-sample interaction forces, such as elastic force, adhesion force, viscosity force, and the van der Waals force, which correspond to the cantilever's action upon various different representative computer-generated test samples. Simulated results show that the dynamic cantilever displacement response can be divided into three zones: a free vibration zone, a transition zone, and a contact vibration zone. Phase trajectory, phase shift, transition time, pseudo stable amplitude, and frequency changes are then analyzed from the dynamic displacement responses that are obtained. Finally, experiments are carried out on a real AFM system to support the findings of the simulations.
authors: General Engineering Research Institute, Liverpool John Moores University, Liverpool, L3 3AF, United Kingdom.
authors: Wenqi
authors: W
authors: Deng
authors: General Engineering Research Institute, Liverpool John Moores University, Liverpool, L3 3AF, United Kingdom.
authors: Guang-Ming
authors: GM
authors: Zhang
authors: General Engineering Research Institute, Liverpool John Moores University, Liverpool, L3 3AF, United Kingdom.
authors: Mark F
authors: MF
authors: Murphy
authors: General Engineering Research Institute, Liverpool John Moores University, Liverpool, L3 3AF, United Kingdom.
authors: Francis
authors: F
authors: Lilley
authors: General Engineering Research Institute, Liverpool John Moores University, Liverpool, L3 3AF, United Kingdom.
authors: David M
authors: DM
authors: Harvey
authors: General Engineering Research Institute, Liverpool John Moores University, Liverpool, L3 3AF, United Kingdom.
authors: David R
authors: DR
authors: Burton
keywords: dynamic response; finite element; phase shift; tapping mode AFM