Contact dynamics of tapping mode atomic force microscopy

Abstract

a b s t r a c tA comprehensive model on the dynamics of a tilted tapping mode atomic force microscopy (AFM) is presented, which includes the multimodal analysis, mode coupling mechanisms, adhesion, contact and friction forces induced by the tilting angle. A displacement criterion of contact/impact is proposed to eliminate the assumptions of the previous models such as infinite stiffness of sample or zero impact velocity, which makes the model presented here suitable for more general AFM application scenario, especially for the soft sample case. The AFM tip mass, tip-sample damping, contact forces and intermittent contact can all induce the higher modes participation into the system motion. One degree of freedom or one mode study on the AFM contact dynamics of tapping mode is shown to be inaccurate. The Hertz and Derjaguin-Muller-Toporov models are used for the comparison study of the non-adhesive and adhesive contacts. The intermittent contact and the contact forces are the two major sources of the system nonlinearity. The rich dynamic responses of the system and its sensitivity to the initial conditions are demonstrated by presenting various subharmonic and nonperiodic motions.

Comparing the performance of single and multifrequency Kelvin probe force microscopy techniques in air and water

“…Under conditions where the tip starts tapping the surface, the linearity of the amplitude signal in response to V AC and/or V CPD may be disrupted leading to artefacts in the measurements. For multifrequency techniques, this nonlinear motion of the cantilever due to tapping the surface can induce motion of the lever at higher harmonics and distort the frequency response characteristics of the system [104][105][106].…”

Experimental and theoretical studies of frequency response function of dagger‐shaped atomic force microscope cantilever in different immersion environments

“…Zhang et al . (2012) studied about the nonlinear dynamics behaviour of a rectangular AFM cantilever by considering DMT contact theory for modelling the tip–sample interaction force. In their analysis, all related details about the cantilever and sample surface has been considered.…”