Evaporation-induced alterations in oscillation and flow characteristics of a sessile droplet on a rose-mimetic surface

Kabi, P and Razdan, V and Roy, D and Bansal, L and Sahoo, S and Mukherjee, R and Chaudhuri, S and Basu, S (2021) Evaporation-induced alterations in oscillation and flow characteristics of a sessile droplet on a rose-mimetic surface. In: Soft Matter, 17 (6). pp. 1487-1496.

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Abstract

Strategic control of evaporation dynamics can help control oscillation modes and internal flow field in an oscillating sessile droplet. This article presents the study of an oscillating droplet on a bio-inspired �sticky� surface to better understand the nexus between the modes of evaporation and oscillation. Oscillation in droplets can be characterized by the number of nodes forming on the surface and is referred to as the mode of oscillation. An evaporating sessile droplet under constant periodic perturbation naturally self-tunes between different oscillation modes depending on its geometry. The droplet geometry evolves according to the mode of evaporation controlled by substrate topography. We use a bio-inspired, rose patterned, �sticky� hydrophobic substrate to perpetually pin the contact line of the droplet in order to hence achieve a single mode of evaporation for most of the droplet's lifetime. This allows the prediction of experimentally observed oscillation mode transitions at different excitation frequencies. We present simple scaling arguments to predict the velocity of the internal flow induced by the oscillation. The findings are beneficial to applications which seek to tailor energy and mass transfer rates across liquid droplets by using bio-inspired surfaces. © The Royal Society of Chemistry 2021.

Item Type:	Journal Article
Publication:	Soft Matter
Publisher:	Royal Society of Chemistry
Additional Information:	The copyrights to this article belongs to Royal Society of Chemistry.
Keywords:	Biomimetics; Drops; Evaporation; Mass transfer; Topography, Energy and mass transfer; Excitation frequency; Flow charac-teristics; Hydrophobic substrate; Internal flow field; Periodic perturbation; Strategic control; Substrate topography, Oscillating flow
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	22 Dec 2021 10:26
Last Modified:	22 Dec 2021 10:26
URI:	http://eprints.iisc.ac.in/id/eprint/68190

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