Advertisement

Springer Nature is making Coronavirus research free. View research | View latest news | Sign up for updates

Gravity effects on mixing with magnetic micro-convection in microfluidics

Abstract.

Mixing remains an important problem for the development of successful microfluidic and lab-on-a-chip devices, where simple and predictable systems are particularly interesting. One is magnetic micro-convection, an instability happening on the interface of miscible magnetic and non-magnetic fluids in a Hele-Shaw cell under applied field. Previous work proved that the Brinkman model quantitatively explains the experiments. However, a gravity-caused convective motion complicated the tests. Here we first improve the experimental system to exclude the parasitic convection. Afterwards, we experimentally observe the magnetic micro-convection, by finding and quantifying how gravity and laminar flow stabilizes the perturbations that create it. Accordingly, we improve our theoretical model for a zero-flow condition and perform a linear analysis. Two dimensionless quantities --magnetic and gravitational Rayleigh numbers-- are used to compare the experimental observations and theoretical predictions for the critical field of instability and the characteristic size of the emerging pattern. Finally, we discuss the conditions at which gravity plays an important role in microfluidic systems.

Graphical abstract

This is a preview of subscription content, log in to check access.

References

  1. 1

    H.A. Stone, A.D. Stroock, A. Ajdari, Annu. Rev. Fluid Mech. 36, 381 (2004)

  2. 2

    G. Cai, L. Xue, H. Zhang, J. Lin, Micromachines 8, 274 (2017)

  3. 3

    R.-J. Yang, H.-H. Hou, Y.-N. Wang, L.-M. Fu, Sens. Actuators, B 224, 1 (2016)

  4. 4

    X. Chen, L. Zhang, Microchim. Acta 184, 3639 (2017)

  5. 5

    G. Kitenbergs, K. Erglis, R. Perzynski, A. Cebers, J. Magn. & Magn. Mater. 380, 227 (2015)

  6. 6

    M. Maiorov, A. Cebers, Magnetohydrodynamics 19, 376 (1983)

  7. 7

    K. Erglis, A. Tatulcenkov, G. Kitenbergs, O. Petrichenko, F.G. Ergin, B.B. Watz, A. Cebers, J. Fluid Mech. 714, 612 (2013)

  8. 8

    G. Kitenbergs, A. Tatulcenkovs, K. Erglis, O. Petrichenko, R. Perzynski, A. Cebers, J. Fluid Mech. 774, 170 (2015)

  9. 9

    M. Igonin, A. Cebers, Phys. Fluids 15, 1734 (2003)

  10. 10

    C. Derec, P. Boltenhagen, S. Neveu, J.-C. Bacri, Magnetohydrodynamics 44, 135 (2008)

  11. 11

    C.-Y. Wen, C.-Y. Chen, D. Kuan, Phys. Fluids 19, 084101 (2007)

  12. 12

    H. Li, C.-Y. Kao, C.-Y. Wen, J. Fluid Mech. 836, 375 (2018)

  13. 13

    M.-Y. Chen, L.-Q. Chen, H. Li, C.-Y. Wen, Phys. Fluids 29, 024109 (2017)

  14. 14

    G. Kitenbergs, Hydrodynamic instabilities in microfluidic magnetic fluid flows, PhD Thesis, UPMC & Univ. Latvia (2015)

  15. 15

    R. Massart, IEEE Trans. Magn. 17, 1247 (1981)

  16. 16

    A. Cebers, Magnetohydrodynamics 33, 48 (1997)

  17. 17

    A. Cebers, Magnetohydrodynamics 17, 113 (1981)

  18. 18

    D.P. Jackson, R.E. Goldstein, A. Cebers, Phys. Rev. E 50, 298 (1994)

  19. 19

    B.T. Huang, M. Roger, M. Bonetti, T.J. Salez, C. Wiertel-Gasquet, E. Dubois, R. Cabreira Gomes, G. Demouchy, G. Mriguet, V. Peyre, M. Kouyat, C.L. Filomeno, J. Depeyrot, F.A. Tourinho, R. Perzynski, S. Nakamae, J. Chem. Phys. 143, 7 (2015)

Download references

Author information

Correspondence to G. Kitenbergs.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Kitenbergs, G., Tatuļčenkovs, A., Puķina, L. et al. Gravity effects on mixing with magnetic micro-convection in microfluidics. Eur. Phys. J. E 41, 138 (2018). https://doi.org/10.1140/epje/i2018-11749-9

Download citation

Keywords

  • Topical issue: Flowing Matter, Problems and Applications