Abstract
In electrokinetically driven microfluidic applications, reservoirs are indispensable and have finite sizes. During operation processes, as the liquid level in reservoirs keeps changing as time elapses, a backpressure is generated. Thus, the flow in microfluidic channels actually exhibits a combination of the electroosmotic flow and the time-dependent induced backpressure-driven flow. In this paper, a model is presented to describe the effect of the finite reservoir size on electroosmotic flow in a rectangular microchannel. Important parameters that describe the effect of finite reservoir size on flow characteristics are discussed. A new concept termed as “effective pumping period” is introduced to characterize the reservoir size effect. The proposed model identifies the mechanisms of the finite-reservoir size effects and is verified by experiment using the micro-PIV technique. The results reported in this study can be used for facilitating the design of microfluidic devices.
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Acknowledgments
D.G. Yan wishes to acknowledge the PhD scholarship from Nanyang Technological University.
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Yan, D.G., Yang, C. & Huang, X.Y. Effect of finite reservoir size on electroosmotic flow in microchannels. Microfluid Nanofluid 3, 333–340 (2007). https://doi.org/10.1007/s10404-006-0135-2
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DOI: https://doi.org/10.1007/s10404-006-0135-2