Formation of Particle Clusters from Rotating Particle Chains

D. Kappe[1], A. Hütten[1]
[1]Universität Bielefeld, Bielefeld, Germany
Published in 2014

Wittbracht et al. proposed a technique to assemble monolayers of magnetic beads utilizing rotating magnetic fields. The magnetic beads align their magnetization with any applied magnetic field. As long as this field is homogeneous, the particles will only interact with each other. As their magnetic moments are all facing the same direction, they will attract each other if they come close. This leads to the formation of 1D particle chains. These chains will follow the rotation of the applied magnetic field for low frequencies. The particle chains deform into an s-shape as soon as the drag of the fluid gets stronger and finally fragment into smaller and more stable chain fragments. The highly ordered monolayers form at higher frequencies.