Regimes of motion of magnetocapillary swimmers

The dynamics of a triangular magnetocapillary swimmer is studied using the lattice Boltzmann method. Performing extensive numerical simulations taking into account the coupled dynamics of the fluid-fluid interface and of magnetic particles floating on it and driven by external magnetic fields we identify several regimes of the swimmer motion. In the regime of high frequencies the swimmer's maximum velocity is centered around the particle's inverse coasting time. Modifying the ratio of surface tension and magnetic forces allows to study the swimmer propagation in the regime of significantly lower frequencies mainly defined by the strength of the magnetocapillary potential. Finally, introducing a constant magnetic contribution in each of the particles in addition to their magnetic moment induced by external fields leads to another regime characterised by strong in-plane swimmer reorientations that resemble experimental observations.