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Clustering and emergent hyperuniformity by breaking microswimmer shape and actuation symmetries

Anson G. Thambi1 and William E. Uspal1,2,*

  • 1Department of Mechanical Engineering, University of Hawai'i at Mānoa, 2540 Dole Street, Holmes Hall 302, Honolulu, Hawaii 96822, USA
  • 2International Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM2), 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan

  • *Contact author: uspal@hawaii.edu
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Phys. Rev. Fluids 10, 113102 – Published 7 November, 2025

DOI: https://doi.org/10.1103/fdt2-drqj

Abstract

Hydrodynamic interactions driven by particle activity are ubiquitous in active colloidal systems. Although these interactions are strongly influenced by the interfacial actuation mechanism and geometry of the swimming particles, theoretical understanding of how these microscopic design parameters govern collective dynamics remains limited. Here we investigate the collective dynamics of oblate spheroidal microswimmers. Using an approximate kinetic theory and corroborating boundary element method calculations, we demonstrate that breaking symmetries in both particle shape and interfacial actuation enables the emergence of dynamically stable immotile n-particle clusters. At larger scales, the clustering process drives the system into a dynamically arrested absorbing state characterized by disordered class I hyperuniform structures. Our analysis highlights the essential role of cluster-sourced long-range flows in establishing this long-range order. Overall, our findings reveal a promising, purely hydrodynamic mechanism for hierarchical self-organization in active matter systems, introducing a strategy for engineering multifunctional hyperuniform materials.

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Phys. Rev. Fluids 10, 113102– Published 7 November, 2025
  • Received 20 June 2025
  • Accepted 1 October 2025
Article part of CHORUS
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