Field evolution of self-assembled lattice structures of ferrofluid microdroplets on magnetic disc arrays

Abstract

In this paper, we study the effect of magnetic disc arrays on the self-assembly of ferrofluid droplets. By inducing magnetic hydrodynamic instability, we are able to realize the fission of a large ferrofluid droplet into a highly uniform droplet lattice structure under the influence of the magnetic disc array. We have also found that the lattice structure of the droplets alters under different external magnetic fields. When the quantity of the split droplets is a multiple of the magnetic disc number, the droplets can form a specific lattice structure depending on the multiple. Under normal conditions (without magnetic disc arrays), the droplet lattice structure is typically hexagonal; using magnetic disc arrays we are able to dictate the splitting of droplets into a lattice structure other than a hexagonal one.