Lane formation in restricted geometries

• Applicants: Professor Dr. Artur Philipp Nikolaus Erbe; Professor Dr. Paul Leiderer; Professor Dr. Peter Nielaba
• Subject Area: Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics ; Experimental Condensed Matter Physics ; Theoretical Condensed Matter Physics
• Term: from 2016 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 299102402

• Final Report Year: 2024

Final Report Abstract

Lane formation is a ubiquitous phenomenon found, for example, in the movement of pedestrians in a busy area or ants following food trails. Common to all those systems is the fact that bodies are moving in opposite directions, and that the mutual interactions between these bodies lead to the fact that it is more favorable to follow the body moving in front rather than going against the stream of counterflowing bodies. The main question arising in this context, is whether the transition from a disordered mixture of particles to an ordered laning state is a stable phase transition or rather a transient phenomenon in a system out of equilibrium. Therefore model systems which allow studying lane formation under various conditions are used to identify the nature of this transition. In this project we concentrate on systems of colloidal particles, which are confined in narrow channels on a substrate plane. The particles thus form a quasi 2-dimensional ensemble, which can be set into motion by a driving force. In order to facilitate motion in counterflow, we investigated experimentally and theoretically mixtures of particles which react differently on the driving forces. Since real counterflow is experimentally difficult to realise, we investigated whether particles moving in the same direction at different speeds show lane formation as well. We could establish the transition to lane formation for particle mixtures containing 2 and 3 different particle species in simulations. In addition, we found a novel effect which is peculiar to particle mixtures in motion: in mixtures of small and large particles moving in the same direction close to a channel wall, the small particles are pushed towards the wall, as opposed to depletion effects in non-moving systems, which lead to the opposite effect. This effect could be reproduced in experimental realisations of particle mixtures sliding down a narrow channel on a tilted sample surface. At very long simulation times, preliminary results suggest that the structure formation in the long time limit is approached by minimisation of interface numbers between the regions of different particle velocities, favouring segregation. In this long time limit, however, other physical phenomena may affect the experimentally observable features of the systems. We thus could establish in this project that lane formation effects are stable phenomena in particle mixtures which move at different speeds in the same direction, at least for experimentally accessible times. This observation adds a novel dimension to the existing knowledge on lane formation.

Publications

• Comparative Studies of Light-Responsive Swimmers: Janus Nanorods versus Spherical Particles. Langmuir, 36(42), 12504-12512.
  Eichler-Volf, Anna; Huang, Tao; Vazquez, Luna Fernando; Alsaadawi, Yara; Stierle, Simon; Cuniberti, Gianaurelio; Steinhart, Martin; Baraban, Larysa & Erbe, Artur
  
• Control over self-assembled Janus clusters by the strength of magnetic field in H2O2. The European Physical Journal E, 44(2).
  Alsaadawi, Yara; Eichler-Volf, Anna; Heigl, Michael; Zahn, Peter; Albrecht, Manfred & Erbe, Artur
  
• Sensitivity of PS/CoPd Janus particles to an external magnetic field. RSC Advances, 11(28), 17051-17057.
  Eichler-Volf, Anna; Alsaadawi, Yara; Luna, Fernando Vazquez; Khan, Qaiser Ali; Stierle, Simon; Xu, Chi; Heigl, Michael; Fekri, Zahra; Zhou, Shengqiang; Zahn, Peter; Albrecht, Manfred; Steinhart, Martin & Erbe, Artur
  
• Lane and band formation of oppositely driven colloidal particles in two-dimensional ring geometries. Physical Review E, 106(2).
  Vater, Tobias; Isele, Marc; Siems, Ullrich & Nielaba, Peter
  
• Transport in Nanowires and Colloidal Systems and Crystal Growth, NIC Symposium 2022, M. Mü ller, Ch. Peter, A. Trautmann (Editors), Publication Series of the John von Neumann Institute for Computing (NIC), NIC Series Volume 51, pp.315, ISBN 978-3-95806-646-5
  K. Beck, B. Gast, K. Hofmann, J. Holder, M. Isele, A. Lüders, F. Müller, M. Ring, R. Schmid, P. Stengele, E. Zander & P. Nielaba
  
• Lane formation of colloidal particles driven in parallel by gravity. Physical Review E, 108(3).
  Isele, Marc; Hofmann, Kay; Erbe, Artur; Leiderer, Paul & Nielaba, Peter
  
• Lane formation in gravitationally driven colloid mixtures consisting of up to three different particle sizes. Physical Review E, 109(6).
  Hofmann, Kay; Isele, Marc; Erbe, Artur; Leiderer, Paul & Nielaba, Peter