motion dynamics of ferrofluid droplets in a microchannel with hydrophobic surfaces under a non-uniform magnetic field

Ferrofluids have various applications in microfluidics, such as drug delivery, oil separation from water, and cancer treatment. in this paper, the effect of the non-uniform magnetic field created by a current-carrying wire on the manipulation of ferrofluid droplets in a nanomagnetic fluid is examined using the level-set and finite element methods. a non-uniform magnetic field causes coagulation, mixing of droplets, and emulsion. significant changes in the diameter of ferrofluid droplets are observed with changes in flow rate, nanoparticle volume fraction, and magnetic field intensity. the results demonstrate that the formation time of the first droplet is reduced and the frequency of droplet generation is enhanced with the flow rate of the continuous phase. reducing the hydrophobicity and increasing the surface tension augments the droplet diameter. adjusting the magnetic field intensity can also enhance the droplet size.