Collective behavior of active particle

by Dr Jérémy Vachier (NORDITA)

Tuesday 20 Oct 2020, 15:00 → 17:00 Europe/Stockholm

Join Zoom Meeting
https://stockholmuniversity.zoom.us/j/622224375

Meeting ID: 622 224 375

 

Active matter is everywhere, from macroscopic to microscopic scales, we find systems such as human crowd or flock of birds as well as bacterial colonies. These systems composed of particles are able to convert their surrounding energy into motion, and naturally exist out of thermodynamic equilibrium. At the microscopic scale, a specific class of active particles is particularly interesting: called microswimmers, these are biological or artificial micro-sized particles able to move in a fluid, such as bacteria or chemically driven Janus particles. In nature, these microswimmers rarely swim alone and can exhibit intriguing collective behavior at interfaces such as cluster formation, as well as swarming, swirling, raft and biofilm formation. The fundamental mechanisms of the emergence of collective behavior for living and inanimate active systems is not yet understood, especially because these systems are far from equilibrium, where our experimental and theoretical understanding is limited.

This talk aims to elucidate the impact of the activity on the emergence of collective behavior in an active system, at a microscopic level, by using a stochastic approach, over two works, from active sedimenting particles to early biofilm formation in the case of the bacteria Pseudomonas aeruginosa.

 

References:

- Vachier, J., & Mazza, M. G. (2019). Dynamics of sedimenting active Brownian particles. The European Physical Journal E, 42(1), 11.

- Lee, C. K., Vachier, J., de Anda, J., Zhao, K., Baker, A. E., Bennett, R. R., ... & Hogan, D. A. (2020). Social Cooperativity of Bacteria during Reversible Surface Attachment in Young Biofilms: a Quantitative Comparison of Pseudomonas aeruginosa PA14 and PAO1. Mbio, 11(1).