Bacterial scattering in microfluidic crystal flows reveals giant active Taylor–Aris dispersion

• DOI: 10.1073/pnas.1819613116
• Publication Date: 2019-05-17T00:25:49Z
• Authors: Amin Dehkharghani; Nicolas Waisbord; Jörn Dunkel; Jeffrey S. Guasto
• Keywords: Active matter; Taylor dispersion

The natural habitats of planktonic and swimming microorganisms, from algae in the oceans to bacteria living soil or intestines, are characterized by highly heterogeneous fluid flows. complex interplay flow-field topology, self-propulsion, porous microstructure is essential a wide range biophysical ecological processes, including marine oxygen production, remineralization organic matter, biofilm formation. Although much progress has been made understanding microbial hydrodynamics surface interactions over last decade, dispersion active suspensions flow environments still poses unsolved fundamental questions that preclude predictive models for transport spreading under realistic conditions. Here, we combine experiments simulations identify key physical mechanisms scaling laws governing dispersal idealized media By tracing scattering dynamics microfluidic crystal lattices, show hydrodynamic gradients hinder transverse bacterial dispersion, thereby enhancing stream-wise [Formula: see text]-fold beyond canonical Taylor-Aris passive Brownian particles. Our analysis further reveals cell reorientation Lagrangian structure induce filamentous density patterns depend upon incident angle disorder medium, striking analogy classical light-scattering experiments.