Active Matter: Flow, Topology, and Control


The spontaneous emergence of collective flows is a generic property of active fluids and often leads to chaotic flow patterns characterized by swirls, jets, and topological disclinations in their orientation field [1]. I will first discuss two examples of these collective features helping us understand biological processes: (i) to explain the tortoise & hare story in bacterial competition: how motility of Pseudomonas aeruginosa bacteria leads to a slower invasion of bacteria colonies, which are individually faster [2], and (ii) how self-propelled defects lead to finding an unanticipated mechanism for cell death [3,4].
I will then discuss various strategies to tame, otherwise chaotic, active flows, showing how hydrodynamic screening of active flows can act as a robust way of controlling and guiding active particles into dynamically ordered coherent structures [5]. I will also explain how combining hydrodynamics with topological constraints can lead to further control of exotic morphologies of active shells [6].
[1] A. Amiri, R. Mueller, and A. Doostmohammadi, J. Phys. A. (2021).
[2] O. J. Meacock et al., Nat. Phys. (2021).
[3] T. N. Saw et al., Nature. (2017).
[4] R. Mueller, J. M. Yeomans, and A. Doostmohammadi, Phys. Rev. Lett. (2019).
[5] A. Doostmohammadi et al., Nat. Comm. (2018).
[6] L. Metselaar, J. M. Yeomans, and A. Doostmohammadi, Phys. Rev. Lett. (2019).

Fig. 1. In-silico design of active self-organizing morphologies.


个人简历:Amin Doostmohammadi obtained my BSc at University of Tehran, followed by Masters and PhD at University of Notre Dame in Mechanical Engineering. After that he moved to Theoretical Physics at Oxford, first as a postdoc and then as an independent research fellow of the Royal Commission. Since 2020 he started Active & Intelligent Matter Group at Niels Bohr Institute, University of Copenhagen, and have received several awards including villum young investigator award, Novo Nordisk NERD award, and ERC Starting Grant from European Union. He has also received the “major advances in biology” prize from French Academy of Science, Emerging Talent Award from IoP, and in 2021 received the young scientist medal and prize in biophysics from the International Union of Pure & Applied Physics (IUPAP).