Liquid contact resonance atomic force microscopy via experimental reconstruction of the hydrodynamic function
Liquid contact resonance atomic force microscopy via experimental reconstruction of the hydrodynamic function
复制标题
通过流体动力学函数的实验重建液体接触共振原子力显微镜
DOI：
10.1063/1.4882755
复制
发表时间：
2014
影响因子：
3.2
通讯作者：
D. Hurley
中科院分区：
文献类型：
--
作者：
R. Tung;J. Killgore;D. Hurley
提出了一种修正液体中接触共振原子力显微镜（AFM）实验中表面耦合惯性力和粘性流体加载力的方法。基于分析流体力学理论，该方法依赖于实验测量的样品表面附近的AFM悬臂梁的自由共振峰。空气和液体中的自由共振频率和品质因数允许重建连续流体动力学函数，其可用于调整液体中的CR数据。利用热激发的自由和接触光谱进行验证实验，以评估我们的方法的准确性。结果表明，该方法恢复空气频率值约6%。流体加载力的知识允许目前的CR分析技术制定用于在空气和真空环境中应用到液体环境。我们的技术大大扩展了CR-AFM的测量环境范围。
We present a method to correct for surface-coupled inertial and viscous fluid loading forces in contact resonance (CR) atomic force microscopy (AFM) experiments performed in liquid. Based on analytical hydrodynamic theory, the method relies on experimental measurements of the AFM cantilever's free resonance peaks near the sample surface. The free resonance frequencies and quality factors in both air and liquid allow reconstruction of a continuous hydrodynamic function that can be used to adjust the CR data in liquid. Validation experiments utilizing thermally excited free and in-contact spectra were performed to assess the accuracy of our approach. Results show that the method recovers the air frequency values within approximately 6%. Knowledge of fluid loading forces allows current CR analysis techniques formulated for use in air and vacuum environments to be applied to liquid environments. Our technique greatly extends the range of measurement environments available to CR-AFM.