Active control of ferrofluid droplet breakup dynamics in a microfluidic T-junction

International audience; This work aims at investigating the breakup dynamics of the ferrofluid droplet under magnetic fields in a microfluidic T-junction. The whole breakup processes of the ferrofluid droplets under uniform magnetic field and non-uniform magnetic field were exhaustively considered. The influence of both the flow rates and magnetic flux density on the formation and breakup were extensively studied. It was found that the type of breakup process can be changed and the breakup frequency of ferrofluid droplets can be actively modulated by applying a uniform magnetic field. While under non-uniform magnetic field, the asymmetric breakup of ferrofluid droplets can be realized. Both the magnetic field intensity and hydrodynamic force affect the asymmetry of the breakup process. The non-uniform magnetic field can exert attraction on ferrofluid droplets in a dissymmetrical way to avoid breakup.