Activity-induced droplet propulsion and multifractality

To address the collective motion of swimming organisms encapsulated in a droplet, an active-hydrodynamic framework is constructed for assemblies contractile swimmers inside binary-fluid droplet. At low activity, this yields self-propelling droplet whose center mass (CM) displays rectilinear motion. With increasing CM L\'evy-walk-type super-diffusive motion, and interface exhibits multifractal fluctuations.