Experimental Characterization of Acoustic Streaming in Gradients of Density and Compressibility

Wei Qiu, Jonas Tobias Karlsen, Henrik Bruus, Per Augustsson

Research output: Contribution to journalJournal articleResearchpeer-review

342 Downloads (Pure)

Abstract

Suppression of boundary-driven Rayleigh streaming has recently been demonstrated for fluids of spatial inhomogeneity in density and compressibility owing to the competition between the boundary-layer-induced streaming stress and the inhomogeneity-induced acoustic body force. To understand the implications of this for acoustofluidic particle handling in the submicrometer regime, we here characterize acoustic streaming by general defocusing particle tracking inside a half-wavelength acoustic resonator filled with two miscible aqueous solutions of different density and speed of sound by adjusting the mass fraction of solute molecules. We follow the temporal evolution of the system as the solute molecules become homogenized by diffusion and advection. The acoustic streaming is suppressed in the bulk of the microchannel for 70-200 s, depending on the choice of inhomogeneous solutions. From confocal measurements of the concentration field of fluorescently labeled Ficoll solute molecules, we conclude that the temporal evolution of the acoustic streaming depends on the diffusivity and the initial distribution of these molecules. Suppression and deformation of the streaming rolls are observed for inhomogeneities in the solute mass fraction down to 0.1%.
Original languageEnglish
Article number024018
JournalPhysical Review Applied
Volume11
Issue number2
Number of pages11
ISSN2331-7019
DOIs
Publication statusPublished - 2019

Cite this

@article{4fac5c1a4e0a4037ab6bd00e7aee902a,
title = "Experimental Characterization of Acoustic Streaming in Gradients of Density and Compressibility",
abstract = "Suppression of boundary-driven Rayleigh streaming has recently been demonstrated for fluids of spatial inhomogeneity in density and compressibility owing to the competition between the boundary-layer-induced streaming stress and the inhomogeneity-induced acoustic body force. To understand the implications of this for acoustofluidic particle handling in the submicrometer regime, we here characterize acoustic streaming by general defocusing particle tracking inside a half-wavelength acoustic resonator filled with two miscible aqueous solutions of different density and speed of sound by adjusting the mass fraction of solute molecules. We follow the temporal evolution of the system as the solute molecules become homogenized by diffusion and advection. The acoustic streaming is suppressed in the bulk of the microchannel for 70-200 s, depending on the choice of inhomogeneous solutions. From confocal measurements of the concentration field of fluorescently labeled Ficoll solute molecules, we conclude that the temporal evolution of the acoustic streaming depends on the diffusivity and the initial distribution of these molecules. Suppression and deformation of the streaming rolls are observed for inhomogeneities in the solute mass fraction down to 0.1{\%}.",
author = "Wei Qiu and Karlsen, {Jonas Tobias} and Henrik Bruus and Per Augustsson",
year = "2019",
doi = "10.1103/PhysRevApplied.11.024018",
language = "English",
volume = "11",
journal = "Physical Review Applied",
issn = "2331-7019",
publisher = "American Physical Society",
number = "2",

}

Experimental Characterization of Acoustic Streaming in Gradients of Density and Compressibility. / Qiu, Wei; Karlsen, Jonas Tobias; Bruus, Henrik; Augustsson, Per.

In: Physical Review Applied, Vol. 11, No. 2, 024018, 2019.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Experimental Characterization of Acoustic Streaming in Gradients of Density and Compressibility

AU - Qiu, Wei

AU - Karlsen, Jonas Tobias

AU - Bruus, Henrik

AU - Augustsson, Per

PY - 2019

Y1 - 2019

N2 - Suppression of boundary-driven Rayleigh streaming has recently been demonstrated for fluids of spatial inhomogeneity in density and compressibility owing to the competition between the boundary-layer-induced streaming stress and the inhomogeneity-induced acoustic body force. To understand the implications of this for acoustofluidic particle handling in the submicrometer regime, we here characterize acoustic streaming by general defocusing particle tracking inside a half-wavelength acoustic resonator filled with two miscible aqueous solutions of different density and speed of sound by adjusting the mass fraction of solute molecules. We follow the temporal evolution of the system as the solute molecules become homogenized by diffusion and advection. The acoustic streaming is suppressed in the bulk of the microchannel for 70-200 s, depending on the choice of inhomogeneous solutions. From confocal measurements of the concentration field of fluorescently labeled Ficoll solute molecules, we conclude that the temporal evolution of the acoustic streaming depends on the diffusivity and the initial distribution of these molecules. Suppression and deformation of the streaming rolls are observed for inhomogeneities in the solute mass fraction down to 0.1%.

AB - Suppression of boundary-driven Rayleigh streaming has recently been demonstrated for fluids of spatial inhomogeneity in density and compressibility owing to the competition between the boundary-layer-induced streaming stress and the inhomogeneity-induced acoustic body force. To understand the implications of this for acoustofluidic particle handling in the submicrometer regime, we here characterize acoustic streaming by general defocusing particle tracking inside a half-wavelength acoustic resonator filled with two miscible aqueous solutions of different density and speed of sound by adjusting the mass fraction of solute molecules. We follow the temporal evolution of the system as the solute molecules become homogenized by diffusion and advection. The acoustic streaming is suppressed in the bulk of the microchannel for 70-200 s, depending on the choice of inhomogeneous solutions. From confocal measurements of the concentration field of fluorescently labeled Ficoll solute molecules, we conclude that the temporal evolution of the acoustic streaming depends on the diffusivity and the initial distribution of these molecules. Suppression and deformation of the streaming rolls are observed for inhomogeneities in the solute mass fraction down to 0.1%.

U2 - 10.1103/PhysRevApplied.11.024018

DO - 10.1103/PhysRevApplied.11.024018

M3 - Journal article

VL - 11

JO - Physical Review Applied

JF - Physical Review Applied

SN - 2331-7019

IS - 2

M1 - 024018

ER -