Magnetocapillary Swimmers

Abstract

We present an experiment where three mesoscopic soft ferromagnetic beads are placed onto a liquid surface and submitted to the influence of magnetic fields. A vertical magnetic field creates a repulsion which counterbalances the capillary attraction. We show that the competition with a second, oscillating field, deforms the structure in a non reciprocal way. As a consequence, the structure is able to swim. This experiment is fully described in a fluid dynamics video attached to this submission.