AFM探针针尖与试件表面接触力计算方法研究

摘要

原子力显微镜是利用接近试样表面的探针针尖上的作用力而工作的。针尖与试件表面纳米接触力的变化对表面检测有重要的影响。在分析原子力显微镜工作原理和纳米接触力计算模型基础上，根据Hamaker假设，利用连续介质方法，建立了针尖同试样表面在接近过程中的纳米接触力计算模型；根据Hertzian接触理论，建立了针尖同试样表面在接触压入过程中的接触力的计算模型。通过叠加计算，获得了耦合接近过程和接触压入过程中的接触力计算方法。根据计算模型，利用Matlab编程计算获得了针尖与试样表面纳米接触作用力的变化规律。为提高原子力显微镜的表面检测精度和进行误差分析提供基础。%Atomic force microscope ( AFM) works by the force between the probe tip and specimen surface. The nano contact force between the probe tip and specimen surface has an important influence on the detection surface. The theoretical contact force model of the AFM tip was established based on the analysis of the working principle of the AFM and Nano contact force calculation model, Hamaker assumptions, and continuum method. A theoretical model of the contact force during the AFM tip was pressed into the surface of sample was established according to Hertzian contact theory. By superposition calculation, the contact force calculation methods of coupling to process and contact pressure in process were obtained. The variation of the force between the probe tip and specimen surface was found by calculation model and programming calculation of Matlab. This study provides the basis for improving the accuracy of an atomic force microscope surface inspection and error analysis.