Electrokinetic transport and separation of droplets in a microchannel

Abstract

This work presents theoretical, numerical and experimental investigations of electrokinetic transport and separation of droplets in a microchannel. A theoretical model is used to predict that, in case of micron-sized droplets transported by electro-osmotic flow, the drag force is dominant as compared to the dielectrophoretic force. Numerical simulations were performed to capture the transient electrokinetic motion of the droplets using a two-dimensional multi-physics model. The numerical model employs Navier–Stokes equations for the fluid flow and Laplace equation for the electric potential in an Arbitrary Lagrangian–Eulerian framework. A microfluidic chip was fabricated using micromilling followed by solvent-assisted bonding. Experiments were performed with oil-in-water droplets produced using a cross-junction structure and applying electric fields using two cylindrical electrodes located at both ends of a straight microchannel. Droplets of different sizes were produced by controlling the relative flow rates of the discrete and continuous phases and separated along the channel due to the competition between the hydrodynamic and electrical forces. The numerical predictions of the particle transport are in quantitative agreement with the experimental results. The work reported here can be useful for separation and probing of individual biological cells for lab-on-chip applications.

This is a preview of subscription content, log in to check access.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11

References

  1. Abkarian M, Faivre M, Stone HA (2006) High-speed microfluidic differential manometer for cellular-scale hydrodynamics. Proc Natl Acad Sci USA 103:538–542

    Article  Google Scholar 

  2. Abkarian M, Faivre M, Horton R, Smistrup K, Best-Popescu CA, Stone HA (2008) Cellular-scale hydrodynamics. Biomed Mater 3:034011

    Article  Google Scholar 

  3. Ai Y, Joo SW, Jiang Y, Xuan X, Qian S (2000) Transient electrophoretic motion of a charged particle through a converging–diverging microchannel: effect of direct current-dielectrophoretic force. Electrophoresis 30:2499–2506

    Article  Google Scholar 

  4. Ai Y, Park S, Zhu J, Xuan X, Beskok A, Qian S (2010) DC electrokinetic particle transport in an l-shaped micro-channel. Langmuir 26(4):2937–2944

    Article  Google Scholar 

  5. Ai Ye, Mauroy B, Sharma A, Qian S (2011) Electrokinetic motion of a deformable particle: dielectrophoretic effect. Electrophoresis 32(17):2282–2291

    Article  Google Scholar 

  6. Barman U, Baruah P, Sen AK, Mishra SC (2013) Performance studies of an interdigitated electrode electro osmotic flow micropump. J Microsyst Technol. Accepted (in press)

  7. Bhardwaj P, Sen AK (2012) Microfluidic system for rapid enumeration and detection of microparticles. J Fluids Eng 134(11):111401–111408

    Article  Google Scholar 

  8. Bhardwaj P, Bagdi P, Sen AK (2011) Microfluidic device based on a microhydrocyclone for particle liquid separation. Lab Chip 11:4012–4021

    Article  Google Scholar 

  9. Bruus H (2008) Theoretical microfluidics. Oxford University Press. ISBN 978-0019-923509-4

  10. Chen YC, Chen GY, Lin YC, Wang GJ (2010) A lab-on-a-chip capillary network for red blood cell hydrodynamics. Microfluid Nanofluid 9:585–591

    Article  Google Scholar 

  11. Davison SM, Sharp KV (2008) Transient simulations of the electrophoretic motion of a cylindrical particle through a 90° corner. Microfluid Nanofluid 4:409–418

    Article  Google Scholar 

  12. Doddi SK, Bagchi P (2009) Three-dimensional computational modeling of multiple deformable cells flowing in microvessels. Phys Rev E 79:046318

    Article  Google Scholar 

  13. Dolnik V, Liu SR, Jovanovich S (2000) Capillary electrophoresis on microchip. Electrophoresis 21:41–54

    Article  Google Scholar 

  14. Dondorp AM, Angus BJ, Chotivanich K, Silamut K, Ruangveerayuth R, Hardeman MR, Kager PA, Vreeken J, White NJ (1999) Red blood cell deformability as a predictor of anemia in severe falciparum malaria. Am J Trop Med Hyg 60:733–737

    Google Scholar 

  15. Eggleton CD, Popel AS (1998) Large deformation of red blood cell ghosts in a simple shear flow. Phys Fluids 10:1834–1845

    Article  Google Scholar 

  16. Ennis J, Anderson JL (1997) Boundary effects on electrophoretic motion of spherical particles for thick double layers and low zeta potential. J Colloid Interf Sci 185:497–514

    Article  Google Scholar 

  17. Gallo-Villanueva RC, Rodriguez-Lopez CE, Diaz-De-La-Garza RI, Reyes-Betanzo C, Lapizco-Encinas BH (2009) DNA manipulation by means of insulator-based dielectrophoresis employing direct current electric fields. Electrophoresis 30:4195–4205

    Article  Google Scholar 

  18. Gao T, Hu HH (2009) Deformation of elastic particles in viscous shear flow. J Comput Phys 228:2132–2151

    Article  MATH  Google Scholar 

  19. Gloria O, Christina S, Matthew BK, Anubhav T, Anuj C (2008) Electrophoretic migration of proteins in semidilute polymer solutions. Electrophoresis 29:1152–1163

    Article  Google Scholar 

  20. Goet G, Baier T, Hardt S, Sen AK (2013) Isotachophoresis with emulsions. Biomicrofluidics 7(4):044103–044116

    Article  Google Scholar 

  21. Graciaa A, Creux P, Dicharry C, Lachaise J (2002) Measurement of the zeta potential of oil drops with the spinning tube Zetameter. J Dispers Sci Technol 23(1–3):301–307

    Article  Google Scholar 

  22. Hase M, Yoshikawa K (2006) Structural transition of acting filament in a cell-sized water droplet with a phospholipid membrane. J Chem Phys 124:104903

    Article  Google Scholar 

  23. Hsu JP, Kuo CC (2006) Electrophoresis of a finite cylinder positioned eccentrically along the axis of a cylindrical pore. J Phys Chem B 110:17607–17615

    Article  Google Scholar 

  24. Hsu JP, Yeh LH, Ku MH (2006) Electrophoresis of a spherical particle along the axis of a cylindrical pore filled with a Carreau fluid. Colloid Polym Sci 284:886–892

    Article  Google Scholar 

  25. Jonassen N (2002) Electrostatics. Springer. ISBN 140-2071-612, 9781402071614

  26. Kang YJ, Li DQ (2009) Electrokinetic motion of particles and cells in microchannels. Microfluid Nanofluid 6:431–460

    Article  Google Scholar 

  27. Kang KH, Kang YJ, Xuan XC, Li DQ (2006) Continuous separation of microparticles by size with direct current-dielectrophoresis. Electrophoresis 27:694–702

    Article  Google Scholar 

  28. Keh HJ, Anderson JL (1985) Boundary effects on electrophoretic motion of colloidal spheres. J Fluid Mech 153:417–439

    Article  MATH  Google Scholar 

  29. Kemprai P, Sen AK (2012) Electro-kinetic assisted mixing in a microchannel with lateral electrodes. Micro Nanosyst 4(4):304–313

    Google Scholar 

  30. Kirby BJ, Hasselbrink EF Jr (2004) Zeta potential of microfluidic substrates: 2. Data for polymers. Electrophoresis 25:203–213

    Article  Google Scholar 

  31. Korin N, Bransky A, Dinnar U (2007) Theoretical model and experimental study of red blood cell (RBC) deformation in microchannels. J Biomech 40:2088–2095

    Article  Google Scholar 

  32. Leopold K, Dieter B, Ernst K (2004) Capillary electrophoresis of biological particles: viruses, bacteria, and eukaryotic cells. Electrophoresis 25:2282–2291

    Article  Google Scholar 

  33. Li D (2004) Electrokinetics in microfluidics. Elsevier Academic, New York

    Google Scholar 

  34. Liang LT, Ai Y, Zhu JJ, Qian S, Xuan XC (2010) Wall-induced lateral migration in particle electrophoresis through a rectangular microchannel. J Colloid Interf Sci 347:142–146

    Article  Google Scholar 

  35. MacMeccan RM, Clausen JR, Neitzel GP, Aidun CK (2009) Simulating 3D deformable particle suspensions using lattice Boltzmann method with discrete external boundary force. J Fluid Mech 618:13–39

    Article  MATH  MathSciNet  Google Scholar 

  36. Martinez-Lopez JI, Moncada-Hernandez H, Baylon-Cardiel JL, Martinez-Chapa SO, Rito-Palomares M, Lapizco-Encinas BH (2009) Characterization of electrokinetic mobility of microparticles in order to improve dielectrophoretic concentration. Anal Bioanal Chem 394:293–302

    Article  Google Scholar 

  37. Pietrini AV, Luisi PL (2004) Cell-free protein synthesis through solubilisate exchange in water/oil emulsion compartments. Chem Bio Chem 5:1055–1062

    Article  Google Scholar 

  38. Risso F, Colle-Paillot F, Zagzoule M (2006) Experimental investigation of a bioartificial capsule flowing in a narrow tube. J Fluid Mech 547:149–173

    Article  MATH  Google Scholar 

  39. Schoch RB, Han JY, Renaud P (2008) Transport phenomena in nanofluidics. Rev Mod Phys 80:839

    Article  Google Scholar 

  40. Secomb TW, Styp-Rekowska B, Pries AR (2007) Two-dimensional simulation of red blood cell deformation and lateral migration in microvessels. Ann Biomed Eng 35:755–765

    Article  Google Scholar 

  41. Sen AK, Darabi J (2007) Droplet ejection performance of a monolithic thermal inkjet print head. J Micromech Microeng 17:1–8

    Article  Google Scholar 

  42. Sen AK, Darabi J, Knapp DR (2011a) Analysis of droplet generation in electrospray using a carbon fiber based microfluidic emitter. J Fluids Engineering 133:0713011–0713018

    Article  Google Scholar 

  43. Sen AK, Darabi J, Knapp DR, Liu J (2006) Modeling and characterization of a carbon fiber emitter for electrospray ionization. J Micromech Microeng 16:620–630

    Article  Google Scholar 

  44. Sen AK, Darabi J, Knapp DR (2007) Modeling and parametric study of a novel multi-spray emitter for ESI-MS applications. Microfluid Nanofluid 3(3):283–298

    Article  Google Scholar 

  45. Sen AK, Darabi J, Knapp DR (2011b) Aerosol formation in electrospray ionization using a microfluidic emitter. IEEE Sens J 11(10):2335–2341

    Article  Google Scholar 

  46. Shizhi Q, Ye A (2012) Electrokinetic particle transport in micro-nanofluidics: direct numerical simulation analysis. Surfactant Science, 19 June 2012 by CRC Press, pp. 197–398

  47. Sugiyama K, Ii S, Takeuchi S, Takagi S, Matsumoto Y (2011) A full Eulerian finite difference approach for solving fluid–structure coupling problems. J Comput Phys 230:596–627

    Article  MATH  MathSciNet  Google Scholar 

  48. Swaminathan TN, Gao T, Hu HH (2010) Deformation of a long elastic particle undergoing electrophoresis. J. Colloid Interf Sci 346:270–276

    Article  Google Scholar 

  49. Tawfik DS, Griffiths AD (1998) Man-made cell-like compartments for molecular evolution. Nat Biotechnol 16:652–656

    Article  Google Scholar 

  50. Thwar PK, Linderman JJ, Burns MA (2007) Electrodeless direct current dielectrophoresis using reconfigurable field-shaping oil barriers. Electrophoresis 28:4572–4581

    Article  Google Scholar 

  51. Tomaiuolo G, Simeone M, Martinelli V, Rotoli B, Guido S (2009) Red blood cell deformation in microconfined flow. Soft Matter 5:3736–3740

    Article  Google Scholar 

  52. Tomaiuolo G, Barra M, Preziosi V, Cassinese A, Rotoli B, Guido S (2011) Microfluidics analysis of red blood cell membrane viscoelasticity, Lab Chip 2011. Lab Chip 11(3):449–454

    Article  Google Scholar 

  53. Unni HN, Keh HJ, Yang C (2007) Analysis of electrokinetic transport of a spherical particle in a microchannel. Electrophoresis 28:658–664

    Article  Google Scholar 

  54. van den Heuvel MGL, Bondesan R, Lagomarsino MC, Dekker C (2008) Single-molecule observation of anomalous electrohydrodynamic orientation of microtubules. Phys Rev Lett 101:118301

    Article  Google Scholar 

  55. Wang XJ, Wang XB, Gascoyne PRC (1997) General expressions for dielectrophoretic force and electrorotational torque derived using the Maxwell stress tensor method. J Electrost 39:277

    Article  Google Scholar 

  56. Xuan XC, Raghibizadeh R, Li D (2006) Wall effects on electrophoretic motion of spherical polystyrene particles in a rectangular poly (dimethylsiloxane) microchannel. J Colloid Interf Sci 296:743–748

    Article  Google Scholar 

  57. Yariv E (2006) Force-free electrophoresis? Phys Fluids 18:031702

    Article  MathSciNet  Google Scholar 

  58. Ye CZ, Li DQ (2004) 3-D transient electrophoretic motion of a spherical particle in a T-shaped rectangular microchannel. J. Colloid Interf Sci 272:480–488

    Article  Google Scholar 

  59. Ye CZ, Xuan XC, Li DQ (2005) Eccentric electrophoretic motion of a sphere in circular cylindrical microchannels. Microfluid Nanofluid 1:234–241

    Article  Google Scholar 

  60. Zhu J, Xuan X (2009) Particle electrophoresis and dielectrophoresis in curved microchannels. J Colloid Interf Sci 340:285–290

    Article  Google Scholar 

Download references

Acknowledgments

The authors would like to thank the Science and Engineering Research Council (SERC), Department of Science and Technology, for providing the financial support for the project.

Author information

Affiliations

Authors

Corresponding author

Correspondence to Ashis Kumar Sen.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Sen, A.K., Sajeesh, P. Electrokinetic transport and separation of droplets in a microchannel. Microfluid Nanofluid 17, 97–106 (2014). https://doi.org/10.1007/s10404-013-1292-8

Download citation

Keywords

  • Zeta Potential
  • Drag Force
  • Droplet Size
  • Electric Field Increase
  • Electrokinetic Transport