Advertisement

Microfluidics and Nanofluidics

, Volume 3, Issue 4, pp 403–416 | Cite as

Integrated electrochemical velocimetry for microfluidic devices

  • Erik Kjeang
  • Bettina Roesch
  • Jonathan McKechnie
  • David A. Harrington
  • Ned Djilali
  • David Sinton
Research Paper

Abstract

We present a new electrochemical velocimetry approach with direct electrical output that is capable of complete device-level integration. The steady reduction rate of a reversible redox species at an embedded microband working electrode is monitored amperometrically. Only one working electrode of arbitrary width is required; all three electrodes, including counter and reference electrodes, are integrated on-chip for complete miniaturization of the sensor. Experimental results are complemented by a theoretical framework including a full 3D electrochemical model as well as empirical mass transfer correlations and scaling laws. When the sensor is operated in the convective/diffusive transport controlled mode, the output signal becomes a predictable function of velocity in two distinct regimes: (i) in the low velocity regime, the signal is directly proportional to flow rate, and (ii) in the high velocity regime, the signal scales as the cube root of the mean velocity. The proposed velocimetry technique is applicable to all practicable pressure-driven laminar flows in microchannels with known cross-sectional geometry.

Keywords

Microfluidics Velocimetry Flow sensor Redox electrochemistry 

Notes

Acknowledgments

The funding for this research provided by a Natural Sciences and Engineering Research Council of Canada (NSERC) strategic grant is highly appreciated.

References

  1. Amatore C, Belotti M, Chen Y, Roy E, Sella C, Thouin L (2004) Using electrochemical coupling between parallel microbands for in situ monitoring of flow rates in microfluidic channels. J Electroanal Chem 573:333–343CrossRefGoogle Scholar
  2. Auroux PA, Iossifidis D, Reyes DR, Manz A (2002) Micro total analysis systems. 2. Analytical standard operations and applications. Anal Chem 74:2637–2652CrossRefGoogle Scholar
  3. Ayliffe HE, Rabbitt RD (2003) An electric impedance based microelectromechanical system flow sensor for ionic solutions. Meas Sci Technol 14:1321–1327CrossRefGoogle Scholar
  4. Baldwin RP (2000) Recent advances in electrochemical detection in capillary electrophoresis. Electrophoresis 21:4017–4028CrossRefGoogle Scholar
  5. Bard AJ, Parsons R, Jordan J (eds) (1985) Standard potentials in aqueous solution. Marcel Dekker, New YorkGoogle Scholar
  6. Booth J, Compton RG, Cooper JA, Dryfe RAW, Fisher AC, Davies CL, Walters MK (1995) Hydrodynamic voltammetry with channel electrodes: microdisc electrodes. J Phys Chem 99:10942–10947CrossRefGoogle Scholar
  7. Coleman JT, McKechnie J, Sinton D (2006) High-efficiency electrokinetic micromixing through symmetric sequential injection and expansion. Lab Chip 6(8):1033–1039CrossRefGoogle Scholar
  8. Duffy DC, McDonald JC, Schueller OJA, Whitesides GM (1998) Rapid prototyping of microfluidic systems in poly(dimethylsiloxane). Anal Chem 70(23):4974–4984CrossRefGoogle Scholar
  9. Erickson D (2005) Towards numerical prototyping of labs-on-chip: modeling for integrated microfluidic devices. Microfluid Nanofluid 1:301–318CrossRefGoogle Scholar
  10. Erickson D, Sinton D, Li D (2003) Joule heating and heat transfer in poly(dimethylsiloxane) microfluidic systems. Lab Chip 3(3):141–149CrossRefGoogle Scholar
  11. Fu R, Li D (2006) Flow velocity measurement in microchannels using temperature-dependent fluorescent dye. Microfluid Nanofluid (in press). DOI:10.1007/s10404–006–0102-yGoogle Scholar
  12. Graetz L (1885) Über die Wärmeleitungsfähigkeit von Flüssigkeiten. Ann Physik 25:337–357CrossRefGoogle Scholar
  13. Incropera FP, De Witt DP (1990) Fundamentals of heat and mass transfer, 3rd edn. Wiley, New YorkGoogle Scholar
  14. Kakac S, Shah RK, Aung W (1987) Handbook of single-phase convective heat transfer. Wiley, New YorkGoogle Scholar
  15. Marken F, Eklund JC, Compton RG (1995) Voltammetry in the presence of ultrasound" can ultrasound modify heterogeneous electron transfer kinetics? J Electroanal Chem 395:335–339CrossRefGoogle Scholar
  16. Meinhart CD, Wereley ST, Santiago JG (1999) PIV measurements of a microchannel flow. Exp Fluids 27:414–419CrossRefGoogle Scholar
  17. Muzikar M, Fawcett WR (2004) Use of ac admittance voltammetry to study very fast electron-transfer reactions. The Ru(NH3)63+/2+ system in water. Anal Chem 76:3607–3611CrossRefGoogle Scholar
  18. Newman J, Thomas-Alyea KE (2004) Electrochemical systems, 3rd Edn. Wiley, HobokenGoogle Scholar
  19. Nusselt W (1923) Der Warmeubergang in den Verbrennungskraftmaschinen. VDI Z 67:206–210Google Scholar
  20. Nyholm L (2005) Electrochemical techniques for lab-on-a-chip applications. Analyst 130:599–605CrossRefGoogle Scholar
  21. Paeschke M, Dietrich F, Uhlig A, Hintsche R (1996) Voltammetric multichannel measurements using silicon fabricated microelectrode arrays. Electroanalysis 8(10):891–898CrossRefGoogle Scholar
  22. Probstein RF (2003) Physicochemical hydrodynamics—an introduction, 2nd edn. Wiley, HobokenGoogle Scholar
  23. Qiu H, Yin XB, Yan J, Zhao X, Yang X, Wang E (2005) Simultaneous electrochemical and electrochemiluminescence detection for microchip and conventional capillary electrophoresis. Electrophoresis 26:687–693CrossRefGoogle Scholar
  24. Ranz WE (1958) Electrolytic methods for measuring water velocities. AIChE J 4(3):338–342CrossRefGoogle Scholar
  25. Reyes DR, Iossifidis D, Auroux PA, Manz A (2002) Micro total analysis systems. 1. Introduction, theory, and technology. Anal Chem 74:2623–2636CrossRefGoogle Scholar
  26. Santiago JG, Wereley ST, Meinhart CD, Beebe DJ, Adrian RJ (1998) A particle image velocimetry system for microfluidics. Exp Fluids 25:316–319CrossRefGoogle Scholar
  27. Sinton D (2004) Microscale flow visualization. Microfluid Nanofluid 1:2–21CrossRefGoogle Scholar
  28. Squires TM, Quake SR (2005) Microfluidics: fluid physics at the nanoliter scale. Rev Mod Phys 77:977–1026CrossRefGoogle Scholar
  29. Wu J, Sansen W (2002) Electrochemical time of flight flow sensor. Sens Actuators A 97–98:68–74CrossRefGoogle Scholar
  30. Wu J, Ye J (2005) Micro flow sensor based on two closely spaced amperometric sensors. Lab Chip 5:1344–1347CrossRefGoogle Scholar
  31. Yang C, Kümmel M, Søeberg H (1991) Dynamic model for a thermal transit-time flow sensor. Chem Eng Sci 46(3):735–740CrossRefGoogle Scholar
  32. Zosel J, Guth U, Thies A, Reents B (2003) Flow measurements in micro holes with electrochemical and optical methods. Electrochim Acta 48:3299–3305CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • Erik Kjeang
    • 1
  • Bettina Roesch
    • 2
  • Jonathan McKechnie
    • 1
  • David A. Harrington
    • 2
  • Ned Djilali
    • 1
  • David Sinton
    • 1
  1. 1.Department of Mechanical Engineering, Institute for Integrated Energy Systems (IESVic)University of VictoriaVictoriaCanada
  2. 2.Department of Chemistry, Institute for Integrated Energy Systems (IESVic)University of VictoriaVictoriaCanada

Personalised recommendations