Microfluidics and Nanofluidics

, Volume 5, Issue 5, pp 631–638 | Cite as

Formation of ionic depletion/enrichment zones in a hybrid micro-/nano-channel

  • Kuan-Da Huang
  • Ruey-Jen YangEmail author
Research Paper


This study fabricates a cross-form microchip in which the two side channels are attached to the main channel via a nanochannel bridge. Ionic depletion and enrichment zones are established on the anodic and cathodic sides of the nanochannel. Results show that the low conductivity within the depletion zone induces a rapid electroosmotic flow, which in turn prompts the generation of vortex flow structures within the depletion zone. Both the lengthening of the depletion bulk charge layer and decrease in length of the diffusion layer as the applied voltage is increased are also demonstrated in this study.


Concentration polarization Electroosmosis Nanofluidics Microfluidics 



The authors gratefully acknowledge the financial support provided to this study by the National Science Council of Taiwan under Grant no. NSC-96-2628-E-006-162-MY3.

Supplementary material

ESM1 (MPG 6940 kb)

ESM2 (MPG 5970 kb)

ESM3 (MPG 7273 kb)


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Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  1. 1.Department of Engineering ScienceNational Cheng Kung UniversityTainanTaiwan

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