Dynamics of microswimmers at a liquid interface mediated by self-induced Marangoni flow

We study the dynamics of a single and a pair of self-propelled microswimmers bound to move along a surfactant-loaded liquid-air interface. Some bacteria on the seawater surface secrete some chemicals in the form of surfactants, which reduce the surface tension on liquid-air interface and generate Marangoni flow. We study the combined effect of intrinsic self-propulsion velocity, Marangoni flow and the hydrodynamic coupling between the microswimmers on their dynamics. Our results show that self-induced Marangoni flow can stabilize the unstable rotational equilibria generated by two pushers bound to move along a surfactant-loaded liquid-air interface.