AFM探针-样品作用力模拟及动力学分析
Simulating Interaction Force of Tip-Sample of Atomic Force Microscopy and Analyzing Its Nonlinear Dynamic system

针对原子力显微镜中探针-样品系统间力学特性的复杂性，本文建立了针尖-样品系统的分子动力学模型，采用混合势模拟了它们间的相互作用力并获得了力-距离曲线表达式。基于该表达式，建立了系统动力学方程，分别采用多尺度法和数值仿真研究了不同样品材料对原子力显微镜针尖-样品耦合系统动力学特性的影响。结果表明：不同样品材料对针尖的受力情况影响较大，力-距离曲线波动明显，分析中应区别对待；针尖样品系统中存在丰富的周期运动，且不同的样品材料对原子力显微镜耦合系统的非线性动力学行为有较大的影响。
The mechanical properties of atomic force microscope (AFM) between tip-sample systems were investigated. The model of molecular dynamics between tip-sample systems was established and the hybrid potential was used to simulate the interaction force of the tip-sample system and obtain the expression of force-distance curve. Based on the expression, the dynamic equation of the tip-sample system was established and the influence of different sample materials on the dynamical characteristic in AFM-coupled system was studied with the multi-scale method and numerical simulation respectively. The simulation results indicate that it has a great impact on the tip of load for different materials and that the force-distance curve fluctuates greatly and should be treated differently. Besides, various periodic motions occur in the tip-sample system and different sample materials have a high impact on the nonlinear behavior of the AFM-coupled system