原子力显微镜处于轻敲模式工作于大气环境时，由于悬臂和被测试样间的距离很小，悬臂的振动会产生相应的压膜阻尼，影响悬臂的动态特性。基于欧拉-伯努利梁方程对悬臂梁进行建模，结合雷诺方程建立悬臂阻尼作用的分析模型，研究悬臂压膜阻尼效应的主要影响因素，分析不同谐振模态下压膜阻尼效应对悬臂阻尼系数、动态原子力显微镜的测量特性的影响，并基于多模态原子力显微镜进行了实验和测试。理论及实验结果表明，空气压膜阻尼对于基础谐振模态原子力显微镜的测量特性有一定的影响，在悬臂试样20~2 μm逼近过程中，悬臂品质因数明显降低，两种悬臂振幅分别减少了7.8%和20.6%，悬臂宽度增大则受到的压膜阻尼影响也增加；相同实验条件下，二阶谐振模态下的悬臂品质因数和振幅均没有明显变化。在基础谐振模态下压膜阻尼效应会引起微悬臂品质因数的降低，从而导致原子力显微镜测量分辨率的减小和测量速度的降低；多模态原子力显微镜的高阶谐振模态可显著降低空气压膜阻尼效应对悬臂品质因数及测量特性的影响。

When tapping mode atomic force microscopy （AFM） is operated in air， the distance between the cantilever and the sample is so small that cantilever oscillation induces squeeze film air damping in the gap. This study aims to model and analyze the effects of squeeze film damping by using the Euler-Bernoulli and Reynolds equations. Theoretical analysis shows that squeeze film damping can decrease the damping coefficient depending on the distance between the cantilever and the sample and the cantilever width. Then， resonant amplitude and quality factor （Q） of the cantilever in multi-mode AFM are tested. Experimental results show that the Q of the fundamental resonant cantilever decreases obviously. The amplitudes of two cantilevers with widths of 20-2 μm decrease by 7.8% and 20.6%. Squeeze film damping can affect the cantilever with a large width to a greater extent than the cantilever with a small width. This phenomenon can also influence AFM dynamic characteristics； in particular， it can decrease flexural sensitivity and scanning speed. However， this phenomenon can only slightly affect the Q and amplitude of the cantilever. The impact of squeeze film damping of the cantilever is significantly reduced when AFM is operated in a higher-order resonant mode.