Gholizadeh Pasha Ali Hossein, Sadeghi Ali
Renewable Energy Research Center, Damavand Branch, Islamic Azad University, Damavand, Iran.
Microsc Res Tech. 2021 Apr;84(4):771-781. doi: 10.1002/jemt.23635. Epub 2020 Nov 9.
In this article, the vibrations of V-shaped beam as the most usable atomic force microscope (AFM) beam in contact mode has been modeled using finite element method. This work is a fundamental issue for contact resonance AFM. We have considered carbon tetrachloride (CCL ), methanol, acetone, water, and vacuum the immersion ambiences. For modeling of the beam dynamics, both of the Timoshenko and Euler-Bernoulli beam principles have been used. For presenting the best theoretical model all specifications for AFM beam and sample surface has been assumed. The outcomes show that by raising the interaction force between AFM beam and sample surface, the resonant frequency increases. By diluting the liquid surroundings, the resonant frequency and amplitude of frequency response functions (FRF) of vertical movement increase. The amplitude of FRF increases by raising the beam thickness and rectangular part breadth, but reduces by increasing the rectangular and tapered part lengths. The resonant frequency reduces by boosting the rectangular and tapered parts lengths and rectangular part width, but raises by increasing the beam thickness. Theoretical model in attendance and lack of tip-sample interaction force have been evaluated with experimental works for vacuum and water as the immersion ambiances. Results show good agreement.
在本文中,使用有限元方法对作为接触模式下最常用的原子力显微镜(AFM)梁的V形梁振动进行了建模。这项工作是接触共振原子力显微镜的一个基本问题。我们考虑了四氯化碳(CCl)、甲醇、丙酮、水和真空作为浸没环境。为了对梁动力学进行建模,同时使用了铁木辛柯梁原理和欧拉-伯努利梁原理。为了给出最佳理论模型,假定了AFM梁和样品表面的所有规格。结果表明,通过提高AFM梁与样品表面之间的相互作用力,共振频率会增加。通过稀释液体环境,垂直运动的共振频率和频率响应函数(FRF)的幅度会增加。FRF的幅度通过增加梁厚度和矩形部分宽度而增大,但通过增加矩形和锥形部分长度而减小。共振频率通过增大矩形和锥形部分长度以及矩形部分宽度而降低,但通过增加梁厚度而提高。针对真空和水作为浸没环境的情况,用实验工作对存在和不存在针尖-样品相互作用力时的理论模型进行了评估。结果显示出良好的一致性。