Title:	Simple model for self-propulsion of microdroplets in surfactant solution
Authors:	Ray, Swarnak Roy, Arun
Keywords:	interfacial flows low reynolds number flows surface and interfacial phenomena
Issue Date:	8-Sep-2023
Publisher:	American Physical Society
Citation:	Physical Review E, 2023, Vol. 108,p035102
Abstract:	We propose a simple active hydrodynamic model for the self-propulsion of a liquid droplet suspended in micellar solutions. The self-propulsion of the droplet occurs by spontaneous breaking of isotropic symmetry and is studied using both analytical and numerical methods. The emergence of self-propulsion arises from the slow dissolution of the inner fluid into the outer micellar solution as filled micelles. We propose that the surface generation of filled micelles is the dominant reason for the self-propulsion of the droplet. The flow instability is due to the Marangoni stress generated by the nonuniform distribution of the surfactant molecules on the droplet interface. In our model, the driving parameter of the instability is the excess surfactant concentration above the critical micellar concentration, which directly correlates with the experimental observations. We consider various low-order modes of flow instability and show that the first mode becomes unstable through a supercritical bifurcation and is the only mode contributing to the swimming of the droplet. The flow fields around the droplet for these modes and their combined effects are also discussed.
Description:	Restricted Access.
URI:	http://hdl.handle.net/2289/8150
ISSN:	2470-0045 2470-0053 (Online)
Alternative Location:	https://arxiv.org/abs/2307.05196 https://ui.adsabs.harvard.edu/abs/2023PhRvE.108c5102R/abstract https://doi.org/10.1103/PhysRevE.108.035102
Copyright:	2023 American Physical Society
Appears in Collections:	Research Papers (SCM)

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