Active particles in turbulent waters

Bacteria, algae, and many other motile microorganisms navigate turbulent and chaotic flows in search for nutrients. Their swimming speeds, however, are often much weaker than the background flows in their natural habitats. This raises the question: under what conditions does motility offer an advantage? Here, using table-top experiments and numerical simulations, we investigate the swimming dynamics of active particles in the presence of 2D cellular and chaotic flows fields. We probe how the competition between the swimming velocity and flow structures impacts the dispersion, trapping, and escaping dynamics of active particles. Our work sheds light on the role of motility in the survival of microorganisms in turbulent environments.