Lee S I, Howell S W, Raman A, Reifenberger R
School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907-1288, USA.
Ultramicroscopy. 2003 Oct-Nov;97(1-4):185-98. doi: 10.1016/S0304-3991(03)00043-3.
Dynamic force microscopy (DFM) utilizes the dynamic response of a resonating probe tip as it approaches and retracts from a sample to measure the topography and material properties of a nanostructure. We present recent results based on nonlinear dynamical systems theory, computational continuation techniques and detailed experiments that yield new perspectives and insights into DFM.A dynamic model including van der Waals and Derjaguin-Müller-Toporov contact forces demonstrates that periodic solutions can be represented as a catastrophe surface with respect to the approach distance and excitation frequency. Turning points on the surface lead to hysteretic amplitude jumps as the tip nears/retracts from the sample. New light is cast upon sudden global changes that occur in the interaction potential at certain gap widths that cause the tip to "stick" to, or tap irregularly the sample. Experiments are performed using a tapping mode tip on a graphite sample to verify the predictions.
动态力显微镜（DFM）利用共振探针尖端在接近和远离样品时的动态响应来测量纳米结构的形貌和材料特性。我们基于非线性动力学系统理论、计算延拓技术和详细实验展示了近期的研究成果，这些研究为DFM带来了新的视角和见解。一个包含范德华力和德亚金-米勒-托波罗夫接触力的动力学模型表明，周期解可以表示为相对于接近距离和激励频率的一个突变面。当尖端接近/远离样品时，曲面上的转折点会导致滞后的振幅跳跃。某些间隙宽度下相互作用势中发生的突然全局变化会使尖端“粘”在样品上或不规则地轻敲样品，我们对这些变化有了新的认识。使用敲击模式的尖端在石墨样品上进行实验以验证这些预测。
