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arXiv · 2201.08792

Elucidating the oscillation instability of sessile drops triggered by surface acoustic waves

Nicolas Chastrette·Michael Baudoin·Philippe Brunet·Laurent Royon·Regis Wunenburger
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Abstract

The oscillation instability of sessile drops is ubiquitous in surface acoustic wave (SAW)-powered digital microfluidics. Yet, the physics underlying these phenomena has not been elucidated owing to the interplay between hydrodynamics, acoustics and capillarity. We decipher the instability by combining high-speed imaging with pressure measurements. We rationalize the observed behaviour with a model inspired from optomechanics, which couples an intracavity acoustic mode excited by the SAW to a surface deformation eigenmode through amplitude modulation and delayed radiation pressure feedback.

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Nicolas Chastrette, Michael Baudoin, Philippe Brunet, Laurent Royon, Regis Wunenburger. 2022-01-21. Elucidating the oscillation instability of sessile drops triggered by surface acoustic waves. https://arxiv.org/abs/2201.08792

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