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Acoustic control of suspended particles in micro fluidic chips

Lenshof, Andreas LU ; Petersson, Filip LU ; Bjursten, Henrik LU and Laurell, Thomas LU (2004) In Lab on a Chip 4(2). p.131-135
Abstract
A method to separate suspended particles from their medium in a continuous mode at microchip level is described. The method combines an ultrasonic standing wave field with the extreme laminar flow properties obtained in a silicon micro channel. The channel was 750 mum wide and 250 mum deep with vertical side walls defined by anisotropic wet etching. The suspension comprised "Orgasol 5mum" polyamide spheres and distilled water. The channel was perfused by applying an under pressure ( suction) to the outlets. The channel was ultrasonically actuated from the back side of the chip by a piezoceramic plate. When operating the acoustic separator at the fundamental resonance frequency the acoustic forces were not strong enough to focus the... (More)
A method to separate suspended particles from their medium in a continuous mode at microchip level is described. The method combines an ultrasonic standing wave field with the extreme laminar flow properties obtained in a silicon micro channel. The channel was 750 mum wide and 250 mum deep with vertical side walls defined by anisotropic wet etching. The suspension comprised "Orgasol 5mum" polyamide spheres and distilled water. The channel was perfused by applying an under pressure ( suction) to the outlets. The channel was ultrasonically actuated from the back side of the chip by a piezoceramic plate. When operating the acoustic separator at the fundamental resonance frequency the acoustic forces were not strong enough to focus the particles into a well defined single band in the centre of the channel. The frequency was therefore changed to about 2 MHz, the first harmonic with two pressure nodes in the standing wave, and consequently two lines of particles were formed which were collected via the side outlets. Two different microchip separator designs were investigated with exit channels branching off from the separation channel at angles of 90degrees and 45degrees respectively. The 45degrees separator displayed the most optimal fluid dynamic properties and 90% of the particles were gathered in 2/3 of the original fluid volume. (Less)
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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Lab on a Chip
volume
4
issue
2
pages
131 - 135
publisher
Royal Society of Chemistry
external identifiers
  • pmid:15052353
  • wos:000221029900012
  • scopus:1942469916
ISSN
1473-0189
DOI
10.1039/b313493h
language
English
LU publication?
yes
id
f0b632ea-9a0c-42e9-83bb-14b65c759207 (old id 280403)
date added to LUP
2016-04-01 11:53:34
date last changed
2022-04-13 02:52:13
@article{f0b632ea-9a0c-42e9-83bb-14b65c759207,
  abstract     = {{A method to separate suspended particles from their medium in a continuous mode at microchip level is described. The method combines an ultrasonic standing wave field with the extreme laminar flow properties obtained in a silicon micro channel. The channel was 750 mum wide and 250 mum deep with vertical side walls defined by anisotropic wet etching. The suspension comprised "Orgasol 5mum" polyamide spheres and distilled water. The channel was perfused by applying an under pressure ( suction) to the outlets. The channel was ultrasonically actuated from the back side of the chip by a piezoceramic plate. When operating the acoustic separator at the fundamental resonance frequency the acoustic forces were not strong enough to focus the particles into a well defined single band in the centre of the channel. The frequency was therefore changed to about 2 MHz, the first harmonic with two pressure nodes in the standing wave, and consequently two lines of particles were formed which were collected via the side outlets. Two different microchip separator designs were investigated with exit channels branching off from the separation channel at angles of 90degrees and 45degrees respectively. The 45degrees separator displayed the most optimal fluid dynamic properties and 90% of the particles were gathered in 2/3 of the original fluid volume.}},
  author       = {{Lenshof, Andreas and Petersson, Filip and Bjursten, Henrik and Laurell, Thomas}},
  issn         = {{1473-0189}},
  language     = {{eng}},
  number       = {{2}},
  pages        = {{131--135}},
  publisher    = {{Royal Society of Chemistry}},
  series       = {{Lab on a Chip}},
  title        = {{Acoustic control of suspended particles in micro fluidic chips}},
  url          = {{http://dx.doi.org/10.1039/b313493h}},
  doi          = {{10.1039/b313493h}},
  volume       = {{4}},
  year         = {{2004}},
}