Nonlinear dynamic analysis of atomic force microscopy under deterministic and random excitation

摘要: Abstract The atomic force microscope (AFM) system has evolved into a useful tool for direct measurements of intermolecular forces with atomic-resolution characterization that can be employed in broad spectrum applications. This paper is devoted to the analysis nonlinear behavior amplitude modulation (AM) and frequency (FM) modes microscopy. For this, microcantilever (which forms basis operation AFM) modeled as single mode approximation interaction between sample cantilever derived from van der Waals potential. Using perturbation methods such averaging, Fourier transform equations motion are analytically solved advantageous results extracted this analysis. proposed techniques AM-AFM, clearly depict existence two stable one unstable (saddle) solutions some exciting parameters under deterministic vibration. basin attraction different dependent on frequency. From range which will result unique periodic response obtained used practical experiments. Furthermore analytical responses determined by detect parameter region where chaotic avoided. On other hand FM-AFM, relation shift investigation behavior. oscillating tip easily explain observed function distance. Also we have investigated AM-AFM random excitation. statistical properties motion. show use mean square value image when excitation signal random.