Department of Mechanical Engineering, Clemson University, Clemson, South Carolina 29634, USA.
Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Phys Rev Lett. 2019 Nov 1;123(18):188002. doi: 10.1103/PhysRevLett.123.188002.
We report experimental observations of surface oscillations in an ultrasoft agarose gel drop. Ultrasonic levitation is used to excite shape oscillations in the gel drop and we report the natural frequency of the drop as it depends upon a nondimensional elastocapillary number, which we define as the ratio of the elastocapillary length to drop size. Our experiments span a wide range of experimental parameters and we recover the appropriate scaling laws in the elastic and capillary wave limits. The crossover between these two limits is observed and agrees well with a proposed frequency relationship.
我们报告了在超软琼脂糖凝胶滴中的表面振动的实验观察结果。超声悬浮用于激发凝胶滴中的形状振动，我们报告了随着无量纲弹性毛细数（我们定义为弹性毛细长度与滴尺寸的比值）变化的滴的固有频率。我们的实验涵盖了广泛的实验参数，并在弹性波和毛细波极限中恢复了适当的标度定律。观察到这两个极限之间的交叉，并与提出的频率关系很好地吻合。
