原子力显微镜探针振动的简化模型分析

SIMPLIFIED VIBRATION MODELS FOR AFM PROBE

为对原子力显微镜(atomic force microscope,AFM)的微悬臂梁进行定性动力学特性分析,建立AFM微悬臂梁的简化模型,探讨AFM探针的受迫振动.通过理论计算得出AFM探针简化模型的运动方程,并得到振动波形,证明了AFM实际应用中的对称问题和"频漂"问题,并发现AFM简化模型的间歇式碰撞现象.用负弹簧模拟探针针尖与样品之间的长程引力,并通过理论计算探讨长程引力对AFM测量的影响.

The simplified models of the AFM(atomic force microscope)probe are proposed for a qualitative analysis of dynamic characteristics of the AFM.The forced vibration of the probe is analyzed on the basis of the simplified models.The motion equations are derived based on the models and the wave modes of the AFM probe are obtained by a theoretical calculation.The symmetry problem and the frequency drift are confirmed in the calculation,as consistent with the AFM tests.Meanwhile,an intermittent collision phenomenon is found in the simplified models.The effect of the long-range attractive force on the AFM probe is simulated through a negative spring model.