Dresden 2020 – scientific programme

The DPG Spring Meeting in Dresden had to be cancelled! Read more ...

Parts | Days | Selection | Search | Updates | Downloads | Help

DY: Fachverband Dynamik und Statistische Physik

DY 22: Active Matter II (joint session BP/CPP/DY)

DY 22.9: Talk

Tuesday, March 17, 2020, 12:15–12:30, HÜL 386

Active particle scattering in structured and random environments — •Theresa Jakuszeit¹, Samuel Bell², and Ottavio A. Croze¹ — ¹Cavendish Laboratory, JJ Thomson Avenue, CB3 0HE, Cambridge, United Kingdom — ²Laboratoire Physico Chimie Curie, Institut Curie,PSL Research University, CNRS UMR168, 75005 Paris, France

Active propulsion as performed by bacteria and Janus particles, in combination with hydrodynamic interaction at boundaries, can lead to the breaking of time reversibility. One typical example of this is the accumulation of bacteria on a flat wall. However, in microfluidic devices with pillars of sufficiently small radius, self-propelled particles can slide along the surface of a pillar without becoming trapped over long times. Using simulations and theory, we study the impact of different modes of obstacle interaction on the diffusive transport of active particles in a lattice of such obstacles. We find that sliding along obstacles can result in large diffusivities even at high obstacle density, unlike particles that undergo classical specular reflection, as in the Lorentz gas. We introduce a microscopically derived run-and-tumble model, which describes the macroscopic transport for different scattering rules very well, and test it in microfluidic channels for E.coli. Finally, we discuss the role of tumbling in structured and random environments.