Abstract: Based on Hamaker hypotheses and Lennard-Jones potential, the interaction between an atom and a sphere is obtained to investigate the energy dissipation in tapping-mode atomic force microscopy (AFM). By considering the interaction between a sphere and an atom of a plane as the distributing adhesion force between a sphere and a plane, and combining with the elastic theory, a novel elastic model is established of adhesive contact between a sphere and a plane. With the adhesive model established, the variation of the adhesive force with the AFM tip-sample distance is obtained. Simulation results indicate that the variation of the adhesive force with the distance in the load process is different from that in the unload process, i.e., the adhesive hysteresis is demonstrated, which is the indication of the energy dissipation. So the energy dissipation is shown by the proposed model in the tapping-mode AFM.

Key words: AFM, adhesion model, tapping mode, energy dissipation