Formation and Dynamics of Droplets in a Magnetic Fluid in Microchannels in an Inhomogeneous Magnetic Field of a Ring Magnet

A study was made of the dynamics of nonmagnetic droplets in magnetic fluids in microchannels with the flow-focusing configuration under the action of an inhomogeneous magnetic field of a ring magnet. Two types of multiphase systems were investigated: nonmagnetic emulsions “oil in water,” “water in oil,” and “water in oil in water,” as well as magnetic oil-in-water emulsions in which the magnetic fluid was used as the continuous phase. Characterization was made of the dependences of the sizes of the generated nonmagnetic inclusions on the flow rate of the continuous magnetic phase and on the displacement of the magnetic field source relative to the dispersed phase supply connector horizontally along the channel axis are obtained.