Defect dynamics in clusters of self-propelled rods in circular confinement

Zhengjia Wang, Tieyan Si, Junhua Hao, Yu Guan, Feng Qin, Bin Yang, Wenwu Cao

Research output: Contribution to journalArticle

Abstract

Abstract.: Rod-shaped active micro/nano-particles, such as bacterial and bipolar metallic micro/nano-motors, demonstrate novel collective phenomena far from the equilibrium state compared to passive particles. We apply a simulation approach --dissipative particle dynamics (DPD)-- to explore the collectively ordered states of self-propelled rods (SPRs). The SPRs are confined in a finite circular zone and repel each other when two rods touch each other. It is found that for a long enough rods system, the global vortex patterns, dynamic pattern oscillation between hedgehog pattern and vortex pattern, and hedgehog patterns are observed successively with increasing active force Fa. For the vortex pattern, the total interaction energy between the rods U is linear with active force Fa, i.e., U ∼ Fa. While the relation U ∼ Fa 2 is obtained for the hedgehog structure. It is observed that a new hedgehog pattern with one defect core is created by two ejections of polar cluster in opposite directions from the original hedgehog pattern, and then merges into one through the diffusion of the two aggregates, i.e., the creation and annihilation of topological charges. Graphical abstract: [Figure not available: see fulltext.].

Original languageEnglish (US)
Article number150
JournalEuropean Physical Journal E
Volume42
Issue number11
DOIs
StatePublished - Nov 1 2019

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All Science Journal Classification (ASJC) codes

  • Biotechnology
  • Biophysics
  • Chemistry(all)
  • Materials Science(all)
  • Surfaces and Interfaces

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