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arXiv · 1905.12706

Response of active Brownian particles to boundary driving

Caleb G. Wagner·Michael F. Hagan·Aparna Baskaran
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Abstract

We computationally study the behavior of underdamped active Brownian particles in a sheared channel geometry. Due to their underdamped dynamics, the particles carry momentum a characteristic distance away from the boundary before it is dissipated into the substrate. We correlate this distance with the persistence of particle trajectories, determined jointly by their friction and self-propulsion. Within this characteristic length, we observe new and counterintuitive phenomena stemming from the interplay of activity, interparticle interactions, and the boundary driving. Depending on values of friction and self-propulsion, interparticle interactions can either aid or hinder momentum transport. More dramatically, in certain cases we observe a flow reversal near the wall, which we correlate with an induced polarization of the particle self-propulsion directions. We rationalize these results in terms of a simple kinetic picture of particle trajectories.

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Caleb G. Wagner, Michael F. Hagan, Aparna Baskaran. 2019-05-29. Response of active Brownian particles to boundary driving. https://doi.org/10.1103/physreve.100.042610

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