Hu Shuiqing, Raman Arvind
School of Mechanical Engineering, Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA.
Nanotechnology. 2008 Sep 17;19(37):375704. doi: 10.1088/0957-4484/19/37/375704. Epub 2008 Aug 1.
Quantifying the tip-sample interaction forces in amplitude-modulated atomic force microscopy (AM-AFM) has been an elusive yet important goal in nanoscale imaging, manipulation and spectroscopy using the AFM. In this paper we present a general theory for the reconstruction of tip-sample interaction forces using integral equations for AM-AFM and Chebyshev polynomial expansions. This allows us to reconstruct the tip-sample interactions using standard amplitude and phase versus distance curves acquired in AM-AFM regardless of tip oscillation amplitude and in both the net attractive and repulsive regimes of oscillation. Systematic experiments are performed to reconstruct interaction forces on polymer samples to demonstrate the power of the theoretical approach.
在使用原子力显微镜（AFM）进行纳米级成像、操纵和光谱分析时，量化幅度调制原子力显微镜（AM-AFM）中的针尖-样品相互作用力一直是一个难以实现但又很重要的目标。在本文中，我们提出了一种通用理论，用于利用AM-AFM的积分方程和切比雪夫多项式展开来重建针尖-样品相互作用力。这使我们能够使用在AM-AFM中获取的标准幅度和相位与距离曲线来重建针尖-样品相互作用，而不管针尖振荡幅度如何，并且适用于振荡的净吸引和排斥区域。我们进行了系统实验来重建聚合物样品上的相互作用力，以证明该理论方法的有效性。
