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  • Letter
  • Open Access

Orientational order in confined systems of self-driven spinners

Rushil Pingali

Erik Luijten*

  • Departments of Materials Science and Engineering, Engineering Sciences and Applied Mathematics, Chemistry, and Physics & Astronomy, Northwestern University, Evanston, Illinois 60208, USA

  • *Contact author: luijten@northwestern.edu
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Phys. Rev. Research 7, L042049 – Published 2 December, 2025

DOI: https://doi.org/10.1103/y7qz-r5l1

Abstract

Hydrodynamic interactions play a critical role in the collective behavior of active matter. Here, we investigate large systems of self-driven spinners confined over a substrate. Direct numerical simulation of three-dimensional hydrodynamics demonstrates that these systems generate unique flows from which spatial and orientational order emerges. We show that a transition in particle orientation accompanies the appearance of crystallinity as the packing fraction is increased. Further exploration reveals a rich, tunable state space, offering insights into the biophysics of natural microswimmers with rotational motion as well as into the design of synthetic spinner systems.

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Phys. Rev. Research 7, L042049– Published 2 December, 2025
  • Received 9 February 2025
  • Revised 19 June 2025
  • Accepted 21 October 2025
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