Self-Assembled Magnetic Surface Microswimmers

Professor Igor Aronson

Argonne National Laboratory

Self-propulsion of living microorganisms is a fascinating phenomenon attracting enormous attention in the scientific community. A new type of self-assembled micro-swimmers, "magnetic snakes", is an excellent tool to model locomotion in a simple table-top experiment. The snakes self-assemble from a dispersion of magnetic microparticles suspended on the liquid-air interface and subjected to an alternating magnetic field. The snakes often exhibit “life-like behavior”. Formation and dynamics of these swimmers is captured in the framework of theoretical model coupling paradigm equation for the amplitude of surface waves, conservation law for the density of particles, and the Navier-Stokes equation for hydrodynamic flows. The results of continuum modeling are supported by hybrid molecular dynamics simulations of magnetic particles floating on a surface of fluid.