Self-propulsion in a low-Reynolds-number fluid confined by two walls of a microchannel

The problem of hydrodynamic interactions with confining walls is examined for a model of a microswimmer composed of three connected beads. Two parallel walls of a narrow microfluidic channel confine the fluid flow. We show that different trajectories for this linear swimmer emerge because of long-range hydrodynamic interactions with the walls of the channel. The possibility of space-spanning trajectories for this swimmer can potentially introduce it as a candidate for constructing a mixing device for working at the laminar flow conditions in microfluidic channels.