School of Physics and Astronomy and Nottingham Nanotechnology and Nanoscience Centre, University of Nottingham, Nottingham, United Kingdom.
Langmuir. 2013 Apr 16;29(15):4737-42. doi: 10.1021/la304520c. Epub 2013 Apr 4.
Vibrations of small (microliter) sessile liquid droplets were studied using a simple optical deflection technique. The droplets were made to elongate in one direction by taking advantage of the anisotropic wetting of the liquids on structured diffraction grating surfaces. They were vibrated by applying a puff of nitrogen gas. Motion of the droplets was monitored by scattering laser light from their surfaces. The scattered light was collected using a photodiode, and the resulting time-dependent intensity signals were Fourier-transformed to obtain the vibrational response of the drops. The vibrational spectra of elongated sessile drops were observed to contain two closely spaced peaks. A simple model that considers the frequency of capillary wave fluctuations on the surfaces of the drops was used to show that the vibrational frequencies of these peaks correspond to standing wave states that exist along the major and minor profile lengths of the droplets.
使用简单的光学偏折技术研究了小（微升）液滴的振动。通过利用液体在结构光栅表面的各向异性润湿，使液滴沿一个方向伸长。通过施加氮气吹泡使液滴振动。通过散射液滴表面的激光来监测液滴的运动。使用光电二极管收集散射光，得到的时变强度信号进行傅里叶变换，以获得液滴的振动响应。观察到伸长的固着液滴的振动谱包含两个非常接近的峰值。使用一个简单的模型来考虑液滴表面的毛细波波动频率，表明这些峰值的振动频率对应于沿液滴的主要和次要轮廓长度存在的驻波状态。
