Abstract
This paper reports the experimental results on kinematics and deformation of ferrofluid droplets driven by planar coils. Ferrofluid droplets act as liquid magnets, which can be controlled and manipulated by an external magnetic field. In our experiments, the magnetic field was generated by two pairs of planar coils, which were fabricated on a double-sided printed circuit board. The first pair of coils constrains the ferrofluid droplet to a one-dimensional motion. The second pair generates the magnetic gradient needed for the droplet motion. The direction of the motion can be controlled by changing the sign of the gradient or of the driving current. Kinematic characteristics of the droplet such as the velocity–position diagram and the aspect ratio of the droplet are investigated. The analysis and discussion are based on the different parameters such as the droplet size, the viscosity of the surrounding medium, and the driving current. This simple actuation concept would allow the implementation of lab-on-a-chip platforms based on ferrofluid droplets.
Similar content being viewed by others
References
Atencia G, Beebe DJ (2005) Controlled microfluidic interfaces. Nature 437:648–655
Darhuber AA, Troian SM (2005) Principles of microfluidic actuation by modulation of surface stresses. Ann Rev Fluid Mech 37:425–455
Darhuber AA, Davis JM, Troian SM (2003) Thermocapillary actuation of liquid flow on chemically patterned surfaces. Phys Fluids 15:1295–1304
Gijs MAM (2004) Magnetic bead handling on-chip: new opportunities for analytical applications. Microfluid Nanofluid 1:22–40
Guo ZG, Zhou F, Hao JC, Liang YM, Liu WM, Huck WTS (2006) Stick and slide ferrofluidic droplets on superhydrophobic surfaces. Appl Phys Lett 89:081911
Jiao Z, Nguyen NT, Huang X, Ang YZ (2006) Reciprocating thermocapillary plug motion in an externally heated capillary. Microfluid Nanofluid. doi:10.1007/s10404-006-0098-310.1007/s10404-006-0098-3
Lehmann U, Hadjidj S, Parashar VK, Vandvyver C, Rida A, Gijs MAM (2006) Two-dimensional magnetic manipulation of microdroplets on a chip as a platform for bioanalytical application. Sensors Actuators B 117:457–463
Mohan SS, Hershenson MM, Boyd SP, Lee TH (1999) Simple accurate expressions for planar spiral inductances. IEEE J Solid State Circuits 34:1419–1424
Nguyen NT, Wereley ST (2006) Fundamentals and Applications of Microfluidics, 2nd edn. Artech House, London
Nguyen NT, Ng KM, Huang X (2006) Manipulation of ferro fluid droplets using planar coils. Appl Phys Lett 89:052509
Pollack MG, Fair RB, Shenderov AD (2000) Electrowetting-based actuation of liquid droplets for microfluidic applications. Appl Phys Lett 77:1725
Rida X, Fernandez V, Gijs MAM (2003) Long-range transport of magnetic microbeads using simple planar coils placed in a uniform magnetostatic field. Appl Phys Lett 83:2396–2398
Velev OD, Prevo BG, Bhatt KH (2003) On-chip manipulation of free droplets. Nature 426:515–516
White FM (1991) Viscous fluid flow, 2nd edn. McGraw-Hill, New York
Acknowledgments
N. T. Nguyen would like to thank the Agency of Science, Technology and Research, Singapore (A*Star, SERC grant No. 0521010108 ‘Droplet-based micro/nanofluidics’), for its financial support. A. Beyzavi thanks the Nanyang Technological University for a research scholarship. The authors thank Mr. Jiao Zhenjun for his help with the droplet tracking program.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Nguyen, NT., Beyzavi, A., Ng, K.M. et al. Kinematics and deformation of ferrofluid droplets under magnetic actuation. Microfluid Nanofluid 3, 571–579 (2007). https://doi.org/10.1007/s10404-007-0150-y
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10404-007-0150-y