STUDY ON ENERGY DISSIPATION IN THE DYNAMIC SYSTEM OF TAPPING MODE ATOMIC FORCE MICROSCOPE

Atomic force microscope is a typical micro-nano resonator and its core component is a micro-cantilever beam probe, which is extremely sensitive to weak force. When it works in different environments, there are various forms and characteristics of energy dissipation mechanisms. These energy dissipations are closely related to the phase image of the system. Among the many dissipation mechanisms, we believe that only the adhesive contact dissipation between the tip of the probe and the sample can truly reflect the nature of the sample, and the other dissipations will reduce the proportion of adhesive contact dissipation in the total dissipation of the system, thus weakening the effective information in the phase image. Therefore, it is important to clarify the quantitative contribution of other dissipations to the quality factor of the system, which helps us to improve the quality of the phase image. In order to study these dissipations, in this paper, we meticulously classify different energy dissipations according to the causes of the dissipation mechanism and systematically summarize the different types of energy dissipations. Then, we study the energy dissipation of micro-cantilever beam probe in different environments and at different positions by theoretical, experimental and simulation methods, and the magnitude contribution of different dissipation to the quality factor of the system is also clarified. Then, for the energy dissipation in different fluid environments, we compare their mechanism of action and their magnitude contribution to the quality factor of the system. Finally, for an atomic force microscope probe operating in an atmospheric environment, we investigate the energy dissipation at different stages of the vibration process from above the sample surface to descending and touching the sample, and the analysis shows that the most significant impact on the system quality factor is caused by the air, including air viscosity damping, squeeze film damping and liquid bridge dissipation.