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AN INTRODUCTION TO MICROFLUIDICS : Lecture n°4

AN INTRODUCTION TO MICROFLUIDICS : Lecture n°4. Patrick TABELING, patrick.tabeling@espci.fr ESPCI, MMN, 75231 Paris 0140795153. Outline of Lecture 1. 1 - History and prospectives of microfluidics 2 - Microsystems and macroscopic approach.

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AN INTRODUCTION TO MICROFLUIDICS : Lecture n°4

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  1. AN INTRODUCTION TO MICROFLUIDICS : Lecture n°4 Patrick TABELING, patrick.tabeling@espci.fr ESPCI, MMN, 75231 Paris 0140795153

  2. Outline of Lecture 1 1 - History and prospectives of microfluidics 2 - Microsystems and macroscopic approach. 3 - The spectacular changes of the balances of forces as we go to the small world. Outline of Lecture 2 - The fluid mechanics of microfluidics - Digital microfluidics

  3. Outline of Lecture 3 1 - Basic notions on diffusive processes 2 - Micromixing 3 - Microreactors. Outline of Lecture 4 1 - Electroosmosis, electrophoresis 2 - Miniaturisation of separation systems 3 - An example of a lab on a chip

  4. Electrophoresis : Charged particles migrate Electroosmose : Fluid is driven by charged layers close to the walls Diélectrophoresis : Particles move under the effect a gradient of Electric field.

  5. Using electric fields in miniaturized systems is easy because E~V/l

  6. A FEW THINGS TO KNOW ABOUTELECTROKINETICS 1 - Electrophoresis Coulomb law In a fluid, the flow equations are

  7. Double electric layer z re

  8. CHARACTERISTICS OF THE DEBYE HUCKEL LAYER Electrical Potential Thickness Debye-Huckel length

  9. ELECTROOSMOSIS 3) Electroosmosis = Flow of an electrolyte produced by the presence of an electric field driving the charged layer close to the walls z E x Core Debye layers

  10. Vitesse de Smoluchowsky

  11. STREAMING POTENTIAL The inverse effect of electroosmosis E U A flow generates an electric field

  12. Principle of chromatography

  13. Microfluidics and separation techniques The first separation experiment was done by Tswett (1902) This led to the discovery of chlorophylle. Column filled with particles Spinach leaves Disolved in toluen

  14. Statistical model for chromatography Trapping times

  15. 5 fundamental types of chromatography

  16. A typical equipment for HPLC

  17. Electrophoretic separation For an isolated particle of charge q, mass m, Coulomb force reads : In a fluid, the charged particle move according to the law : Viscous friction Therefore Seperation is feasible, because ions with different ratio q/R will migrate at different speeds

  18. Separation techniques using electric fields - FSCE : Electrophoresis in a free medium - CEC : Capillary Electro Chromatography (a gel is used) - MEKC : Micellar ElectroKinetic chromatography E E

  19. Un example of an electrochromatogram

  20. How much the bands spread ? U U Taylor Aris estimate d=√Defft Deff≈Pe2D≈U2b2/D

  21. SOME IMPORTANT QUANTITIES USEFUL FOR THECHARACTERIZATION OF THE PERFORMANCESOF THE SEPARATION TECHNIQUE

  22. The number of theoretical plates (From M.C.Hennion (2004))

  23. Retention time in the column One infers Number of theoretical plates

  24. OTHER QUANTITIES OF INTEREST (From M.C.Hennion (2004))

  25. IS MINIATURIZATION ADVANTAGEOUS ? 1) NON ELECTRICAL SEPARATION TECHNIQUES - Small samples - Intégration possible - Parallelism possible But no improvement of the analytical performances tR~l/U~l0

  26. (From M.C.Hennion (2004))

  27. Le premier lab on a chip était une colonne chromatographique à gaz (Terry, 1975)

  28. 2)Electrical separation techniques Number of theoretical plates Maximum electrical field that can be applied Therefore Thereby N~ l0

  29. The number of plates remains the same, while the retention time becomes : tR~ L/V ~l2 Conclusion : it is tremendously advantageous • Same performances, must smaller times • (800 ms, Jacobson et al)

  30. Miniaturization in this case thus leads to : - Small volumes - Intégration and parallélization possible - Conservation of the efficiency of the column - Considerable gain of time

  31. (From M.C.Hennion (2004))

  32. (From M.C.Hennion (2004))

  33. (From M.C.Hennion (2004))

  34. A microfluidic system for DNA separation From Agilent- Caliper Allow to characterize DNA Fragments with excellent Resolution, and in a small time

  35. Miniaturization of electrophoretic separation systems Caliper

  36. Miniaturization of electrophoretic separation systems 200mm Experiment done by E. Brunet (MMN)

  37. (From Kitamuri (2004))

  38. SOME DEVELOPMENTS OF MICROFLUIDIC SYSTEMS DEDICATEDTO SEPARATION

  39. A novel method, based on microfluidics Big particles Move fast Small particles move slower

  40. Institut Curie ESPCI

  41. SAMPLE ANALYSIS IS AN IMPORTANT TOPICS IN MICROFLUIDICS.ALL SORTS OF SYSTEMS HAVE BEEN MICROFABRICATED

  42. KITAMURI

  43. KITAMURI

  44. LAB ON A CHIP DEDICATED TO PROTEOMICS ESPCI Chip demonstrated with a Sample of FITC, Lysosyme, BSA

  45. THIS WAS THE LAST TRANSPARENCY THANK YOU FOR YOUR KIND ATTENTION

  46. The end

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