Pumping fluids with periodically beating grafted elastic filaments.

Using Brownian dynamics simulations, we investigate the pumping efficiency of an array of periodically beating semiflexible filaments that are grafted to a surface. Full hydrodynamic interactions among and within filaments and no slip at the surface are considered. Optimal pumping is obtained for a characteristic ratio of applied forward-backward torques and filament persistence length. For independently driven filaments, phase locking between neighboring filaments occurs autonomously via hydrodynamic coupling, giving rise to significantly enhanced pumping efficiency.