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Focusing microparticles in a microfluidic channel with ferrofluids

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Abstract

We report a novel on-chip microparticles focusing technique using stable magnetic nanoparticles suspension (i.e., ferrofluids). The principle of focusing is based on magnetic buoyancy forces exerted on non-magnetic particles within ferrofluids under non-uniform magnetic field. The design, modeling, fabrication, and characterization of the focusing scheme are presented. Focusing of 4.8, 5.8, and 7.3 μm microparticles at various flow rates are demonstrated in a microfluidic channel. Our scheme is simple, low-cost, and label-free compared to other existing techniques.

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Acknowledgments

This research was financially supported by the Office of the Vice President for Research at the University of Georgia, and by the Centers for Disease Control and Prevention.

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Correspondence to Leidong Mao.

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Zhu, T., Cheng, R. & Mao, L. Focusing microparticles in a microfluidic channel with ferrofluids. Microfluid Nanofluid 11, 695–701 (2011). https://doi.org/10.1007/s10404-011-0835-0

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  • DOI: https://doi.org/10.1007/s10404-011-0835-0

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