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Cluster dynamics in macroscopic photoactive particles

Soft Condensed Matter 2025-09-03 v2 Other Condensed Matter

Abstract

We present an experimental study on the collective behavior of macroscopic self-propelled particles that are externally excited by light. This property allows testing the system response to the excitation intensity in a very versatile manner. We discover that for low excitation intensities, clustering at the boundaries is always present, even when this is prevented by implementing flower-shaped confining walls. For high excitation intensities, however, clusters are dissolved more or less easily depending on their size. Then, a thorough analysis of the cluster dynamics allows us to depict a phase diagram depending on the number of agents in the arena and the excitation intensity. To explain this, we introduce a simple kinetic model where cluster evolution is governed by a balance between adsorption and desorption processes. Interestingly, this simple model is able to reproduce the phase space observed experimentally.

Keywords

Cite

@article{arxiv.2412.14419,
  title  = {Cluster dynamics in macroscopic photoactive particles},
  author = {Sára Lévay and Axel Katona and Hartmut Löwen and Raúl Cruz Hidalgo and Iker Zuriguel},
  journal= {arXiv preprint arXiv:2412.14419},
  year   = {2025}
}
R2 v1 2026-06-28T20:41:28.036Z