Cargando…

Coalescence Dynamics of Acoustically Levitated Droplets

The contactless coalescence of a droplet is of paramount importance for physical and industrial applications. This paper describes a coalescence method to be used mid-air via acoustic levitation using an ultrasonic phased array system. Acoustic levitation using ultrasonic phased arrays provides prom...

Descripción completa

Detalles Bibliográficos
Autores principales: Hasegawa, Koji, Watanabe, Ayumu, Kaneko, Akiko, Abe, Yutaka
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7231308/
https://www.ncbi.nlm.nih.gov/pubmed/32224992
http://dx.doi.org/10.3390/mi11040343
_version_ 1783535161378340864
author Hasegawa, Koji
Watanabe, Ayumu
Kaneko, Akiko
Abe, Yutaka
author_facet Hasegawa, Koji
Watanabe, Ayumu
Kaneko, Akiko
Abe, Yutaka
author_sort Hasegawa, Koji
collection PubMed
description The contactless coalescence of a droplet is of paramount importance for physical and industrial applications. This paper describes a coalescence method to be used mid-air via acoustic levitation using an ultrasonic phased array system. Acoustic levitation using ultrasonic phased arrays provides promising lab-on-a-drop applications, such as transportation, coalescence, mixing, separation, evaporation, and extraction in a continuous operation. The mechanism of droplet coalescence in mid-air may be better understood by experimentally and numerically exploring the droplet dynamics immediately before the coalescence. In this study, water droplets were experimentally levitated, transported, and coalesced by controlled acoustic fields. We observed that the edges of droplets deformed and attracted each other immediately before the coalescence. Through image processing, the radii of curvature of the droplets were quantified and the pressure difference between the inside and outside a droplet was simulated to obtain the pressure and velocity information on the droplet’s surface. The results revealed that the sound pressure acting on the droplet clearly decreased before the impact of the droplets. This pressure on the droplets was quantitatively analyzed from the experimental data. Our experimental and numerical results provide deeper physical insights into contactless droplet manipulation for futuristic lab-on-a-drop applications.
format Online
Article
Text
id pubmed-7231308
institution National Center for Biotechnology Information
language English
publishDate 2020
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-72313082020-05-22 Coalescence Dynamics of Acoustically Levitated Droplets Hasegawa, Koji Watanabe, Ayumu Kaneko, Akiko Abe, Yutaka Micromachines (Basel) Article The contactless coalescence of a droplet is of paramount importance for physical and industrial applications. This paper describes a coalescence method to be used mid-air via acoustic levitation using an ultrasonic phased array system. Acoustic levitation using ultrasonic phased arrays provides promising lab-on-a-drop applications, such as transportation, coalescence, mixing, separation, evaporation, and extraction in a continuous operation. The mechanism of droplet coalescence in mid-air may be better understood by experimentally and numerically exploring the droplet dynamics immediately before the coalescence. In this study, water droplets were experimentally levitated, transported, and coalesced by controlled acoustic fields. We observed that the edges of droplets deformed and attracted each other immediately before the coalescence. Through image processing, the radii of curvature of the droplets were quantified and the pressure difference between the inside and outside a droplet was simulated to obtain the pressure and velocity information on the droplet’s surface. The results revealed that the sound pressure acting on the droplet clearly decreased before the impact of the droplets. This pressure on the droplets was quantitatively analyzed from the experimental data. Our experimental and numerical results provide deeper physical insights into contactless droplet manipulation for futuristic lab-on-a-drop applications. MDPI 2020-03-26 /pmc/articles/PMC7231308/ /pubmed/32224992 http://dx.doi.org/10.3390/mi11040343 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Hasegawa, Koji
Watanabe, Ayumu
Kaneko, Akiko
Abe, Yutaka
Coalescence Dynamics of Acoustically Levitated Droplets
title Coalescence Dynamics of Acoustically Levitated Droplets
title_full Coalescence Dynamics of Acoustically Levitated Droplets
title_fullStr Coalescence Dynamics of Acoustically Levitated Droplets
title_full_unstemmed Coalescence Dynamics of Acoustically Levitated Droplets
title_short Coalescence Dynamics of Acoustically Levitated Droplets
title_sort coalescence dynamics of acoustically levitated droplets
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7231308/
https://www.ncbi.nlm.nih.gov/pubmed/32224992
http://dx.doi.org/10.3390/mi11040343
work_keys_str_mv AT hasegawakoji coalescencedynamicsofacousticallylevitateddroplets
AT watanabeayumu coalescencedynamicsofacousticallylevitateddroplets
AT kanekoakiko coalescencedynamicsofacousticallylevitateddroplets
AT abeyutaka coalescencedynamicsofacousticallylevitateddroplets