Breakup of thin films of micro-magnetic drops in perpendicular fields

Sliding and Rolling Motion of a Ferro-Liquid Droplet on the Hydrophobic Surface under Magnetic Influence

“…The breakup instabilities of the impacting droplets having the magnetic microcolloids can also be manipulated by the external magnetic fields. The magnetic forces can destabilize the evolution of droplets while forming additional droplets in a circular array . The size of the magnetic particles influences the droplet motion, and the droplet accelerations can be maximized through the proper selection of the magnetic particle size .…”

Magnetowetting dynamics of sessile ferrofluid droplets: a review

“…The critical wavelength also suggests that the larger droplet will always be susceptible to fission, and as a result, numerous daughter droplets are generated following multiple fission. 90,122,137 The aforementioned horizontal fission scenarios mediated by droplet elongation, although they appear visually analogous to the Rosensweig instability of a thin FF film in uniform magnetic field, 97,140–142 are fundamentally different in many aspects. As discussed previously (in Section 2.2), during the classical Rosensweig instability in a homogenous magnetic field, the periodicity of the undulations is defined as .…”

“…On the other hand, the attractive force due to a non-uniform magnetic field gradient, d H /d z , also contributes towards the elongation ( g̃ ) and fission of the droplet, and hence the daughter droplet periodicity has the form . Furthermore, while the peak-formation dynamics during Rosensweig instability are reversible, 97,140–142 the horizontal fission dynamics are irreversible in nature as the daughter droplets remain kinetically trapped in the potential well. 90,122,143 The kinetically trapped state originates from the static repulsion between the produced daughter droplets and also from the substrate non-wetting behavior.…”

Ordered microdroplet formations of thin ferrofluid layer breakups

“…17,18 The ferrodrop is observed breaking up into numerous subscale droplets with the breakup pattern dependent strongly on its initial diameter and field condition. This particularly simple phenomenon of drop rupture can possibly be applied as a noninvasive means for the partition of small drops as well as a tunable mechanism for orderly formation of microdroplets.…”

“…Different patterns of striking rupture instabilities are reported in a condition of dry plate. 17,18 To better understand the mechanisms acting on the ferrofluids as well as the important issues for practical applications, such as the number and volume of the breaking subscale droplets, a more comprehensive study 19 has been presented in which both the top and side views of breaking droplets are recorded and analyzed. Based on the fully three-dimensional observations, the film rupture mechanism is interpreted in terms of general dimensionless parameters.…”