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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Adair RK (1991) Constraints on biological effects of weak extremely-low-frequency electromagnetic-fields. Phys Rev A 43(2):1039–1048
Afshar R, Moser Y, Lehnert T, Gijs MAM (2011) Three-dimensional magnetic focusing of superparamagnetic beads for on-chip agglutination assays. Anal Chem 83(3):1022–1029. doi:10.1021/Ac102813x
Bajaj A, Samanta B, Yan HH, Jerry DJ, Rotello VM (2009) Stability, toxicity and differential cellular uptake of protein passivated-Fe3O4 nanoparticles. J Mater Chem 19(35):6328–6331. doi:10.1039/B901616c
Chung TD, Kim HC (2007) Recent advances in miniaturized microfluidic flow cytometry for clinical use. Electrophoresis 28(24):4511–4520. doi:10.1002/Elps.200700620
Gijs MAM, Lacharme F, Lehmann U (2010) Microfluidic applications of magnetic particles for biological analysis and catalysis. Chem Rev 110(3):1518–1563
Gossett DR, Weaver WM, Mach AJ, Hur SC, Tse HTK, Lee W, Amini H, Di Carlo D (2010) Label-free cell separation and sorting in microfluidic systems. Anal Bioanal Chem 397(8):3249–3267
Huh D, Gu W, Kamotani Y, Grotberg JB, Takayama S (2005) Microfluidics for flow cytometric analysis of cells and particles. Physiol Meas 26(3):R73–R98. doi:10.1088/0967-3334/26/3/R02
Kose AR, Fischer B, Mao L, Koser H (2009) Label-free cellular manipulation and sorting via biocompatible ferrofluids. Proc Natl Acad Sci USA 106(51):21478–21483
Krebs MD, Erb RM, Yellen BB, Samanta B, Bajaj A, Rotello VM, Alsberg E (2009) Formation of ordered cellular structures in suspension via label-free negative magnetophoresis. Nano Lett 9(5):1812–1817
Krishnan KM (2010) Biomedical nanomagnetics: a spin through possibilities in imaging, diagnostics, and therapy. IEEE Trans Magn 46(7):2523–2558. doi:10.1109/Tmag.2010.2046907
Kummrow A, Theisen J, Frankowski M, Tuchscheerer A, Yildirim H, Brattke K, Schmidt M, Neukammer J (2009) Microfluidic structures for flow cytometric analysis of hydrodynamically focussed blood cells fabricated by ultraprecision micromachining. Lab Chip 9(7):972–981. doi:10.1039/B808336c
Lee GB, Chang CC, Huang SB, Yang RJ (2006) The hydrodynamic focusing effect inside rectangular microchannels. J Micromech Microeng 16(5):1024–1032. doi:10.1088/0960-1317/16/5/020
Liu CX, Lagae L, Borghs G (2007) Manipulation of magnetic particles on chip by magnetophoretic actuation and dielectrophoretic levitation. Appl Phys Lett 90(18):184109
Liu C, Stakenborg T, Peeters S, Lagae L (2009) Cell manipulation with magnetic particles toward microfluidic cytometry. J Appl Phys 105(10):102011–102014
Mihajlovic G, Aledealat K, Xiong P, Von Molnar S, Field M, Sullivan GJ (2007) Magnetic characterization of a single superparamagnetic bead by phase-sensitive micro-Hall magnetometry. Appl Phys Lett 91(17):172518
Pamme N (2006) Magnetism and microfluidics. Lab Chip 6(1):24–38
Pamme N (2007) Continuous flow separations in microfluidic devices. Lab Chip 7(12):1644–1659
Pankhurst QA, Connolly J, Jones SK, Dobson J (2003) Applications of magnetic nanoparticles in biomedicine. J Phys D 36(13):R167
Pankhurst QA, Thanh NKT, Jones SK, Dobson J (2009) Progress in applications of magnetic nanoparticles in biomedicine. J Phys D 42(22):224001
Petersson F, Nilsson A, Holm C, Jonsson H, Laurell T (2005) Continuous separation of lipid particles from erythrocytes by means of laminar flow and acoustic standing wave forces. Lab Chip 5(1):20–22. doi:10.1039/B405748c
Peyman SA, Iwan EY, Margarson O, Iles A, Pamme N (2009) Diamagnetic repulsion—a versatile tool for label-free particle handling in microfluidic devices. J Chromatogr A 1216(52):9055–9062
Rodriguez-Villarreal AI, Tarn MD, Madden LA, Lutz JB, Greenman J, Samitier J, Pamme N (2011) Flow focussing of particles and cells based on their intrinsic properties using a simple diamagnetic repulsion setup. Lab Chip 11(7):1240–1248. doi:10.1039/C0lc00464b
Rosensweig RE (1966) Fluidmagnetic buoyancy. AIAA J 4:1751–1758
Rosensweig RE (1985) Ferrohydrodynamics. Cambridge University Press, Cambridge
Shevkoplyas SS, Siegel AC, Westervelt RM, Prentiss MG, Whitesides GM (2007) The force acting on a superparamagnetic bead due to an applied magnetic field. Lab Chip 7(10):1294–1302. doi:10.1039/B705045c
Shi JJ, Mao XL, Ahmed D, Colletti A, Huang TJ (2008) Focusing microparticles in a microfluidic channel with standing surface acoustic waves (SSAW). Lab Chip 8(2):221–223. doi:10.1039/B716321e
Staben ME, Zinchenko AZ, Davis RH (2003) Motion of a particle between two parallel plane walls in low-Reynolds-number Poiseuille flow. Phys Fluids 15(6):1711–1733
Tsutsui H, Ho CM (2009) Cell separation by non-inertial force fields in microfluidic systems. Mech Res Commun 36(1):92–103
Wang L, Flanagan LA, Jeon NL, Monuki E, Lee AP (2007) Dielectrophoresis switching with vertical sidewall electrodes for microfluidic flow cytometry. Lab Chip 7(9):1114–1120. doi:10.1039/B705386j
Whitesides GM (2006) The origins and the future of microfluidics. Nature 442(7101):368–373
Xuan XC, Li DQ (2005) Focused electrophoretic motion and selected electrokinetic dispensing of particles and cells in cross-microchannels. Electrophoresis 26(18):3552–3560. doi:10.1002/Elps.200500298
Xuan XC, Zhu JJ, Church C (2010) Particle focusing in microfluidic devices. Microfluid Nanofluid 9(1):1–16. doi:10.1007/S10404-010-0602-7
Yellen BB, Hovorka O, Friedman G (2005) Arranging matter by magnetic nanoparticle assemblers. Proc Natl Acad Sci USA 102(25):8860–8864
Zhao YQ, Fujimoto BS, Jeffries GDM, Schiro PG, Chiu DT (2007) Optical gradient flow focusing. Optics Express 15(10):6167–6176
Zhu JJ, Xuan XC (2009) Dielectrophoretic focusing of particles in a microchannel constriction using DC-biased AC electric fields. Electrophoresis 30(15):2668–2675. doi:10.1002/Elps.200900017
Zhu TT, Marrero F, Mao LD (2010) Continuous separation of non-magnetic particles inside ferrofluids. Microfluid Nanofluid 9(4–5):1003–1009
Zhu T, Lichlyter D, Haidekker M, Mao L (2011) Analytical model of microfluidic transport of non-magnetic particles in ferrofluids under the influence of a permanent magnet. Microfluidics Nanofluidics 1–13. doi:10.1007/s10404-010-0754-5
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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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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