A PDMS DIFFUSION PUMP FOR ON-CHIP FLUID HANDLING IN MICROFLUIDIC DEVICES

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A PDMS DIFFUSION PUMP FOR ON-CHIP FLUID HANDLING
IN MICROFLUIDIC DEVICES
Mark A. Eddings and Bruce K. Gale
Department of Bioengineering, University of Utah,
Salt Lake City, UT
Department of Mechanical Engineering, University
of Utah, Salt Lake City, UT
MicroTAS 2006, pp. 44-46
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Outline

• Introduction
• Fabrication
• Results and Discussion
• Conclusion
• References

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• Introduction
• Fabrication
• Results and Discussion
• Conclusion
• References

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PDMS-Based Micropump
Membrane pump
generate flow Rapid off-chip valving Deflecting
thin PDMS membranes
Marc A. Unger, 2000
Power-free pump
generate flow Gas permeability Additional
preparation time one-time use applications
K. Hosokawa, 2004
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Diffusion-Based Membrane Pump
Diffusion-based membrane pumping method
Theoretical equation
Applied pressure
Flow rate
p2 feed pressure P1 permeate pressure P
permeability coefficient A diffusion area T
absolute temperature P atm atmospheric
pressure t thickness of the membrane
Applied vacuum
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• Introduction
• Fabrication
• Results and Discussion
• Conclusion
• References

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Fabrication
cast
master mold
1.Lithography
2.Xurography(razor and writing)
65C 45min
SU-8 Silicon wafer
vinyl PMMA wafer
bonding
Daniel A. 2005
65C overnight
D. Duffy, 1998
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Microfluidic Device
fluid channel layer
diffusion membrane
vacuum source layer
Green pressure/vacuum inlet Red fluid wells
Measuring flow rates
Demonstrating dead-end chamber filling
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• Introduction
• Fabrication
• Results and Discussion
• Conclusion
• References

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Flow Rate Characterization
device
equation
Variables
p2 feed pressure
A diffusion area
t thickness of the membrane
with a CCD camera
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Comparing Theoretical Data With Experimental Data

• Low aspect ratios and high aspect ratios.
• Diffusion area was changed by membrane elongation
  and contact to the channel ceiling.

low
high
FEA results for membrane deflection in
microchannels of aspect ratios 2 and 10
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Fluid Handling

• Fluid was easily manipulated through turns in
  cross intersections and filling dead-end channels
  and chambers.

1
device
3
5
2
4
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Three different fluids, red, green and blue,
filling dead-end chambers.
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Conclusion

• The gas permeation pump provides a novel and
  convenient method for manipulating fluids within
  microfluidic devices.
• Rapid dead-end channel filling and flow rates in
  the 200 nlmin-1 range have been demonstrated.
• No need high frequency valve operation and
  significantly higher total chip areas.
• Pumping and valving can be performed using one
  control line for pressure and one for the vacuum.

one control line
three control lines
Marc A. Unger, 2000
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References

• Mark A Eddings and Bruce K Gale, A PDMS-based
  gas permeation pump for on-chip fluid handling in
  microfluidic devices, J. Micromech. Microeng. 16
  (2006) 23962402.
• Marc A. Unger, Hou-Pu Chou, Todd Thorsen, Axel
  Scherer, Stephen R. Quake, Monolithic
  Microfabricated Valves and Pumps by Multilayer
  Soft Lithography, SCIENCE VOL 288 7 APRIL 2000,
  113-116.
• D. Duffy, J. McDonald, O. Schueller, G.
  Whitesides, Rapid Prototyping of Microfluidic
  Systems in Polydimethylsiloxane, Anal. Chem. 70,
  pp. 4974-4984.
• K. Hosokawa, K. Sato, N. Ichikawa, M. Maeda,
  Power-free PDMS microfluidic devices for gold
  nanoparticle-based DNA analysis, Lab chip 2004,
  Vol. 4, pp.181185.
• Daniel A. Bartholomeusz, Ronald W. Boutté, and
  Joseph D. Andrade, Xurography Rapid Prototyping
  of Microstructures Using a Cutting Plotter, 2005
  J. Microelectromech. Syst. 14 136474.