Sensitivity of flexural vibration mode of the rectangular atomic force microscope micro cantilevers in liquid to the surface stiffness variations
Sensitivity of flexural vibration mode of the rectangular atomic force microscope micro cantilevers in liquid to the surface stiffness variations
复制标题
DOI：
10.1016/j.ultramic.2013.07.006
复制
发表时间：
2013-12-01
期刊：
影响因子：
2.2
通讯作者：
Payam, Amir Farokh
中科院分区：
文献类型：
--
作者：
Payam, Amir Farokh
本文分析了浸没在液体中的矩形原子力显微镜（AFM）悬臂梁弯曲振动模态的共振频率和模态灵敏度对表面刚度变化的响应，并推导出了闭合形式的表达式。为此，Euler-Bernoulli梁理论被用来发展的AFM悬臂梁模型在液体中。在此基础上，推导了AFM悬臂梁在液体中的共振频率的表达式，并与实验结果进行了比较。基于此表达式，表面接触刚度的影响，在流体中的矩形AFM悬臂梁的弯曲模式进行了研究，并与AFM悬臂梁在空气中工作的情况进行了比较。结果表明，在低表面刚度下，第一模态是最敏感的模态，激发该模态可获得最佳的图像对比度，但随着样品表面刚度的增加，激发较高模态可获得更好的图像对比度。此外，在空气和液体中的模态灵敏度之间的比较表明，在空气中的共振频率的偏移大于在流体中的偏移，这意味着对于类似的表面刚度，在空气中的图像对比度，比液体更好。(C)2013年爱思唯尔B。版权所有© 2016
In this paper, the resonance frequencies and modal sensitivity of flexural vibration modes of a rectangular atomic force microscope (AFM) cantilever immersed in a liquid to surface stiffness variations have been analyzed and a closed-form expression is derived. For this purpose, the Euler-Bernoulli beam theory is used to develop the AFM cantilever model in liquid. Then, an expression for the resonance frequencies of AFM cantilever in liquid is derived and the results of the derived expression are compared with the experimental measurements. Based on this expression, the effect of the surface contact stiffness on flexural mode of a rectangular AFM cantilever in a fluid is investigated and compared with the case that AFM cantilever operates in the air. The results show that in the low surface stiffness, the first mode is the most sensitive mode and the best image contrast is obtained by excitation this mode, but by increasing the sample surface stiffness the higher modes have better image contrast. In addition, comparison between modal sensitivities in air and liquid shows that the resonance frequency shifts in the air are greater than the shifts in the fluid, which means that for the similar surface stiffness the image contrast in air, is better than liquid. (C) 2013 Elsevier B. V. All rights reserved.