Marangoni Convection-Driven Laser Fountains and Waves on Free Surfaces of Liquids
Authors:
Feng Lin,
Aamir Nasir Quraishy,
Tian Tong,
Runjia Li,
Guang Yang,
Mohammadjavad Mohebinia,
Yi Qiu,
Talari Visha,
Junyi Zhao,
Wei Zhang,
Hong Zhong,
Hang Zhang,
Chaofu Zhou,
Xin Tong,
Peng Yu,
Jonathan Hu,
Suchuan Dong,
Dong Liu,
Zhiming Wang,
John R. Schaibley,
Jiming Bao
Abstract:
It is well accepted that an outward Marangoni convection from a low surface tension region will make the surface depressed. Here, we report that this established perception is only valid for thin liquid films. Using surface laser heating, we show that in deep liquids a laser beam actually pulls up the fluid above the free surface generating fountains with different shapes. Whereas with decreasing…
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It is well accepted that an outward Marangoni convection from a low surface tension region will make the surface depressed. Here, we report that this established perception is only valid for thin liquid films. Using surface laser heating, we show that in deep liquids a laser beam actually pulls up the fluid above the free surface generating fountains with different shapes. Whereas with decreasing liquid depth a transition from fountain to indentation with fountain in-indentation is observed. Further, high-speed imaging reveals a transient surface process before steady elevation is formed, and this dynamic deformation is subsequently utilized to resonantly excite giant surface waves by a modulated laser beam. Computational fluid dynamics models reveal the underlying flow patterns and quantify the depth-dependent and time-resolved surface deformations. Our discoveries and techniques have upended the century-old perception and opened up a new regime of interdisciplinary research and applications of Marangoni-induced interface phenomena and optocapillary fluidic surfaces-the control of fluids with light.
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Submitted 24 March, 2021;
originally announced March 2021.