Swimmers in thin films: from swarming to hydrodynamic instabilities.

  title={Swimmers in thin films: from swarming to hydrodynamic instabilities.},
  author={Marco Leoni and Tanniemola B. Liverpool},
  journal={Physical review letters},
  volume={105 23},
We investigate theoretically the collective dynamics of a suspension of low Reynolds number swimmers that are confined to two dimensions by a thin fluid film. Our model swimmer is characterized by internal degrees of freedom which locally exert active stresses on the fluid. We find that hydrodynamic interactions mediated by the film can give rise to spontaneous continuous symmetry breaking (swarming), to states with either polar or nematic homogeneous order. For dipolar swimmers, the stroke… 

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