Dynamics of Ferrofluid Droplet Impact on Slippery Liquid-Infused Porous Surfaces

In
this study, the impact of ferrofluid droplets on slippery
liquid-infused
porous surfaces (SLIPS) is explored. A model is proposed to take account
of the reduction in the initial volume of the ferrofluid droplet caused
by the nonuniform external magnetic field. Five modes are identified
based on the distinctive postimpact characteristics, and the corresponding
phase diagram is summarized. In the low Weber number range (We ≤ 50), the low energy dissipation caused by the
low friction characteristics of the SLIPS, combined with the suppression
effect of magnetic field on the lateral expansion of the droplet,
accumulates the kinetic energy in the vertical direction. Consequently,
the bounce height of the ferrofluid droplet on the SLIPS increases
with We, which is contrary to that for the superhydrophobic
surfaces. The results offer deeper insights into the magnetic controlled
droplet rebound and the impact dynamics across diverse surface types.