Quantitative Force Measurements In Liquid Using Frequency Modulation Atomic Force Microscopy
Quantitative Force Measurements In Liquid Using Frequency Modulation Atomic Force Microscopy
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DOI：
10.1063/1.1803932
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发表时间：
2004-10
影响因子：
4
通讯作者：
T. Uchihashi;M. Higgins;S. Yasuda;S. Jarvis;S. Akita;Y. Nakayama;J. Sader
中科院分区：
文献类型：
--
作者：
T. Uchihashi;M. Higgins;S. Yasuda;S. Jarvis;S. Akita;Y. Nakayama;J. Sader
用原子力显微镜（AFM）测量近程力通常需要采用动态技术来保持灵敏度和稳定性。虽然调频原子力显微镜（FM-AFM）广泛用于真空中的高分辨率成像和定量力测量，但在液体中使用FM-AFM进行定量力测量已被证明是难以实现的。在这里，我们证明了在真空中导出的操作形式也可以用于液体，只要进行一定的修改。为了便于与先前使用表面力仪器进行的测量进行比较，我们选择了一种已知的模型系统（八甲基环四硅氧烷），当限制在两个表面之间时，它会表现出短程结构有序。所获得的力测量结果与先前报道的结果非常吻合。因此，本研究确立了FM-AFM作为定量测量液体中力的有力工具。
The measurement of short-range forces with the atomic force microscope (AFM) typically requires implementation of dynamic techniques to maintain sensitivity and stability. While frequency modulation atomic force microscopy (FM-AFM) is used widely for high-resolution imaging and quantitative force measurements in vacuum, quantitative force measurements using FM-AFM in liquids have proven elusive. Here we demonstrate that the formalism derived for operation in vacuum can also be used in liquids, provided certain modifications are implemented. To facilitate comparison with previous measurements taken using surface forces apparatus, we choose a model system (octamethylcyclotetrasiloxane) that is known to exhibit short-ranged structural ordering when confined between two surfaces. Force measurements obtained are found to be in excellent agreement with previously reported results. This study therefore establishes FM-AFM as a powerful tool for the quantitative measurement of forces in liquid.