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 陳睿鈞

Outline Introduction Fabrication Results and Discussion Conclusion References

Introduction Fabrication Results and Discussion Conclusion References

PDMS-Based Micropump generate flow Rapid off-chip valving Deflecting thin PDMS membranes generate flow Gas permeability Additional preparation time one-time use applications K. Hosokawa, 2004 Marc A. Unger, 2000 Power-free pump Membrane pump

Diffusion-Based Membrane Pump p 2 : feed pressure P 1 : permeate pressure P : permeability coefficient A : diffusion area T : absolute temperature P atm : atmospheric pressure t : thickness of the membrane Flow rate Applied pressure Applied vacuum Diffusion-based membrane pumping method Theoretical equation

Introduction Fabrication Results and Discussion Conclusion References

Fabrication 1.Lithography2.Xurography(razor and writing) SU-8 Silicon wafer vinyl PMMA wafer 65°C 45min 65°C overnight master mold cast bonding D. Duffy, 1998 Daniel A. 2005

Microfluidic Device Measuring flow ratesDemonstrating dead-end chamber filling fluid channel layer diffusion membrane vacuum source layer Green : pressure/vacuum inlet Red : fluid wells

Introduction Fabrication Results and Discussion Conclusion References

Flow Rate Characterization device Variables : p 2 : feed pressure A : diffusion area equation : with a CCD camera t : thickness of the membrane

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. FEA results for membrane deflection in microchannels of aspect ratios 2 and 10 lowhigh

Fluid Handling Fluid was easily manipulated through turns in cross intersections and filling dead-end channels and chambers device Three different fluids, red, green and blue, filling dead-end chambers.

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 nl·min -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 Marc A. Unger, 2000 three control lines

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) 2396–2402. Marc A. Unger, Hou-Pu Chou, Todd Thorsen, Axel Scherer, Stephen R. Quake, “Monolithic Microfabricated Valves and Pumps by Multilayer Soft Lithography”, SCIENCE VOL APRIL 2000, D. Duffy, J. McDonald, O. Schueller, G. Whitesides, “Rapid Prototyping of Microfluidic Systems in Polydimethylsiloxane”, Anal. Chem. 70, pp 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.181–185. Daniel A. Bartholomeusz, Ronald W. Boutté, and Joseph D. Andrade, “Xurography: Rapid Prototyping of Microstructures Using a Cutting Plotter”, 2005 J. Microelectromech. Syst –74.