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


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.


Microfluidics Velocimetry Flow sensor Redox electrochemistry 



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


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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

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