Materials Science Program, University of Wisconsin, Madison, Wisconsin 53706-1595, United States.
Langmuir. 2012 Dec 18;28(50):17302-12. doi: 10.1021/la303381z. Epub 2012 Dec 4.
Molecular dynamics simulations have been performed to study frictional slip and its influence on energy dissipation and momentum transfer at atomically smooth solid/water interfaces. By modifying the surface chemistry, we investigate the relationship between slip and the mechanical response of a vibrating solid for both hydrophilic and hydrophobic surfaces. We discover physical phenomena that emerge at high frequencies and that have significant contributions to energy dissipation. A new analytical model is developed to describe the mechanical response of the resonators in this high-frequency regime, which is relevant in such applications as microelectromechanical-system-based biosensors. We find a linear relationship between the slip length and the ratio of the damping rate shift to the resonant frequency shift, which provides a new way to obtain information about the slip length from experiments.
已经进行了分子动力学模拟,以研究摩擦滑移及其对原子光滑固体/水界面上能量耗散和动量传递的影响。通过改变表面化学性质,我们研究了亲水和疏水表面上滑移与振动固体机械响应之间的关系。我们发现了在高频下出现的物理现象,这些现象对能量耗散有很大的贡献。我们开发了一个新的分析模型来描述在这个高频范围内谐振器的机械响应,这在基于微机电系统的生物传感器等应用中是相关的。我们发现滑移长度与阻尼率变化与共振频率变化之比之间存在线性关系,这为从实验中获取滑移长度的信息提供了一种新方法。