Work from IISER Mohali Published in Nature Communications

The study of passive particles within active fluids, like bacterial swarms and the cellular cytoskeleton, offers valuable insights into these complex systems. This approach, known as microrheology, can reveal properties like the dynamics of intracellular vesicles and granules through the cytosol, or the far from equilibrium dynamics of dense bacterial swarms. While recent experiments have shown some success in manipulating rigid inclusions within active fluids, the behavioud of deformable boundaries remains unexplored. To answer this fundamental question, we suspend a passive droplet as a model for a soft particle, in an active turbulent fluid. The droplet fluctuates in shape and shows periods of moving and stopping. At low interfacial tension, the droplet breaks and mixed with the outer active bath. We establish that the droplet motion is influenced by the interplay of spatial correlations of the flow and droplet size.
https://www.nature.com/articles/s41467-024-47727-1