Capillary Force Models for Interactions of Several Tip/Substrate in AFM Based on the Energy Method

Abstract

In this paper, an analytical model is derived for computation of the capillary force between AFM tip and sample surface. Several tip geometries are considered with the both symmetric and asymmetric liquid/solid interfaces. To investigate the validity and efficiency of the derived models, we have performed numerical analysis and the effect of various physical parameters including air humidity, the distance between AFM tip and sample surface, AFM tip geometry and contact angles on the meniscus force are investigated. Finally, the derived model for AFM blunt tip is compared with the experimental measurement and the accuracy and precision of the presented approach is summarized. Based on the analytic mathematical models presented in this paper, the analysis of realistic physical situations and the study of chemistry influence of different substrates on the capillary force have been possible.In this paper, an analytical model is derived for computation of the capillary force between AFM tip and sample surface. Several tip geometries are considered with the both symmetric and asymmetric liquid/solid interfaces. To investigate the validity and efficiency of the derived models, we have performed numerical analysis and the effect of various physical parameters including air humidity, the distance between AFM tip and sample surface, AFM tip geometry and contact angles on the meniscus force are investigated. Finally, the derived model for AFM blunt tip is compared with the experimental measurement and the accuracy and precision of the presented approach is summarized. Based on the analytic mathematical models presented in this paper, the analysis of realistic physical situations and the study of chemistry influence of different substrates on the capillary force have been possible.