  In the present work we report on the behavior of ferrofluid microdrops in an
immiscible nonmagnetic carrier fluid and vice versa subjected to the action of
magnetic fields. Our experiments evidence previously unexplored instability and
flow patterns. We investigated the instabilities initiated by constant magnetic
field and by combined action of constant and rotating magnetic fields. The
observed instabilities lead to the formation of various microdrop
configurations such as star-like and comb-like shapes, bending deformation,
ridges and crests, spiral arms and rings, etc. The reviled peculiarities of the
microscopic drops behavior can be of interest in applications to the
ferrofluid-based microfluidics.
