Dual frequency modulation with two cantilevers in series: a possible means to rapidly acquire tip-sample interaction force curves with dynamic AFM

摘要

One common application of atomic force microscopy (AFM) is the acquisition of tip-sample interaction force curves. However, this can be a slow process when the user is interested in studying non-uniform samples, because existing contact- and dynamic-mode methods require that the measurement be performed at one fixed surface point at a time. This paper proposes an AFM method based on dual frequency modulation using two cantilevers in series, which could be used to measure the tip-sample interaction force curves and topography of the entire sample with a single surface scan, in a time that is comparable to the time needed to collect a topographic image with current AFM imaging modes. Numerical simulation results are provided along with recommended parameters to characterize tip-sample interactions resembling those of conventional silicon tips and carbon nanotube tips tapping on silicon surfaces.