Analytical model for monitoring of AFM tip wear through resonance frequency measurements

A sharp tip is essential for high resolution surface characterization images using atomic force microscope (AFM). We propose an analytical model for in-situ monitoring of AFM tip wear by tracking the resonance frequency of the cantilever tip that can be measured in a commercial AFM. The tip is modeled as a mass-loaded cantilever, and an expression for the resonance frequency shift with changing tip height is obtained analytically. The model agrees well with FEM simulations performed in COMSOL FEM and experimental measurements conducted with an Oxford Asylum MFP3D Origin AFM.