Acoustic control of suspended particles in micro fluidic chips

Research output: Contribution to journalArticle

Standard

Acoustic control of suspended particles in micro fluidic chips. / Lenshof, Andreas; Petersson, Filip; Bjursten, Henrik; Laurell, Thomas.

In: Lab on a Chip, Vol. 4, No. 2, 2004, p. 131-135.

Research output: Contribution to journalArticle

Harvard

APA

CBE

MLA

Vancouver

Author

RIS

TY - JOUR

T1 - Acoustic control of suspended particles in micro fluidic chips

AU - Lenshof, Andreas

AU - Petersson, Filip

AU - Bjursten, Henrik

AU - Laurell, Thomas

PY - 2004

Y1 - 2004

N2 - 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.

AB - 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.

U2 - 10.1039/b313493h

DO - 10.1039/b313493h

M3 - Article

VL - 4

SP - 131

EP - 135

JO - Lab on a Chip - Miniaturisation for Chemistry and Biology

T2 - Lab on a Chip - Miniaturisation for Chemistry and Biology

JF - Lab on a Chip - Miniaturisation for Chemistry and Biology

SN - 1473-0189

IS - 2

ER -