Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Configurable thermoacoustic streaming by laser-induced temperature gradients

Martens, Franziska LU ; Qiu, Wei LU orcid ; Jakobsson, Ola LU ; Cierpka, Christian ; Ehn, Andreas LU and Augustsson, Per LU (2025) In Physical Review Applied 23(2).
Abstract
Controlling the streaming flow in acoustically actuated microchannels enables the targeted motion of suspended micro-objects. This can offer novel approaches for rare cell studies or cell sorting in medicine or basic biology. In this work, we utilize the temperature dependence of the acoustic body force, which originates from the interaction of an acoustic field with gradients in compressibility or density. A temperature gradient was optically induced inside an acoustofluidic microchannel by the absorption of light and the resulting streaming flow was measured by particle tracking in three dimensions. Inside a microfluidic channel, two different thermal fields were investigated for a fixed sound field, both in experiments and in... (More)
Controlling the streaming flow in acoustically actuated microchannels enables the targeted motion of suspended micro-objects. This can offer novel approaches for rare cell studies or cell sorting in medicine or basic biology. In this work, we utilize the temperature dependence of the acoustic body force, which originates from the interaction of an acoustic field with gradients in compressibility or density. A temperature gradient was optically induced inside an acoustofluidic microchannel by the absorption of light and the resulting streaming flow was measured by particle tracking in three dimensions. Inside a microfluidic channel, two different thermal fields were investigated for a fixed sound field, both in experiments and in simulations. The results show that shifting the location of the heat source from the center to the side of the channel leads to a transition from four streaming rolls to two rolls in the plane normal to the laser incidence. By modulating the optical absorbance of the medium, the streaming velocity can be tuned such that higher absorption leads to faster thermoacoustic streaming. Further, for higher absorbance, we observe increasing velocity components in the direction of the laser due to asymmetric heat generation along the beam. (Less)
Please use this url to cite or link to this publication:
author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review Applied
volume
23
issue
2
article number
024043
pages
12 pages
publisher
American Physical Society
external identifiers
  • scopus:85218452720
ISSN
2331-7019
DOI
10.1103/PhysRevApplied.23.024043
project
Akustisk gradientfokusering för separation av biopartiklar
High Throughput Microfluidic Cell Nanoparticle Handling by Molecular and Thermal Gradient Acoustic Focusing
Microscale acoustofluidics-enabled single cell mechanotyping and nanoparticle separation
language
English
LU publication?
yes
id
dc480ec9-29ec-4bed-9541-6d3c36cd266a
date added to LUP
2025-02-23 08:08:28
date last changed
2025-11-10 15:11:58
@article{dc480ec9-29ec-4bed-9541-6d3c36cd266a,
  abstract     = {{Controlling the streaming flow in acoustically actuated microchannels enables the targeted motion of suspended micro-objects. This can offer novel approaches for rare cell studies or cell sorting in medicine or basic biology. In this work, we utilize the temperature dependence of the acoustic body force, which originates from the interaction of an acoustic field with gradients in compressibility or density. A temperature gradient was optically induced inside an acoustofluidic microchannel by the absorption of light and the resulting streaming flow was measured by particle tracking in three dimensions. Inside a microfluidic channel, two different thermal fields were investigated for a fixed sound field, both in experiments and in simulations. The results show that shifting the location of the heat source from the center to the side of the channel leads to a transition from four streaming rolls to two rolls in the plane normal to the laser incidence. By modulating the optical absorbance of the medium, the streaming velocity can be tuned such that higher absorption leads to faster thermoacoustic streaming. Further, for higher absorbance, we observe increasing velocity components in the direction of the laser due to asymmetric heat generation along the beam.}},
  author       = {{Martens, Franziska and Qiu, Wei and Jakobsson, Ola and Cierpka, Christian and Ehn, Andreas and Augustsson, Per}},
  issn         = {{2331-7019}},
  language     = {{eng}},
  month        = {{02}},
  number       = {{2}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review Applied}},
  title        = {{Configurable thermoacoustic streaming by laser-induced temperature gradients}},
  url          = {{http://dx.doi.org/10.1103/PhysRevApplied.23.024043}},
  doi          = {{10.1103/PhysRevApplied.23.024043}},
  volume       = {{23}},
  year         = {{2025}},
}