Synchronized Circular Motion of Optically Confined Marangoni Microswimmers

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Détails bibliographiques
Auteurs principaux:	Borno, Sabera M., Khisa, Robin, Zarin, Israt H., Mahmud, Md Hasan, Brubaker, Nicholas D., Hayward, Ryan C., Tanjeem, Nabila
Format:	Preprint
Publié:	2025
Sujets:	Soft Condensed Matter
Accès en ligne:	Acceder al recurso
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author	Borno, Sabera M. Khisa, Robin Zarin, Israt H. Mahmud, Md Hasan Brubaker, Nicholas D. Hayward, Ryan C. Tanjeem, Nabila
author_facet	Borno, Sabera M. Khisa, Robin Zarin, Israt H. Mahmud, Md Hasan Brubaker, Nicholas D. Hayward, Ryan C. Tanjeem, Nabila
contents	Understanding the collective actuation of microscopic structures driven by external fields can lead to the development of next-generation autonomous machines. With this goal in mind, we investigated light-induced collective motion of thermocapillary microswimmers at the air-water interface. We found that Marangoni forces, which lead to long-ranged repulsive interparticle interactions, can cause microswimmers to synchronize their circular motion in a collective chase mode that resembles predator-prey behavior often observed in nature. We examined different degrees of confinement in small systems containing 2-6 particles of different individual swimming velocities and shapes. Thanks to the strong repulsive interactions between particles, a sustained chasing mode was observed for particle packing fractions above a critical value of 0.25. At lower packing fractions, swimmers transition between chasing, bouncing, and intermittent pausing, likely due to time-varying activity levels. Additionally, we report that a new synchronized mode can be introduced by incorporating chirality in particle shapes, where the microswimmers collectively reverse the direction of their circular motion periodically. Our results point to a simple but powerful mechanism of obtaining collective synchronization in synthetic confined systems where particles are designed with different shapes and activity levels.
format	Preprint
id	arxiv_https___arxiv_org_abs_2507_20517
institution	arXiv
publishDate	2025
record_format	arxiv
spellingShingle	Synchronized Circular Motion of Optically Confined Marangoni Microswimmers Borno, Sabera M. Khisa, Robin Zarin, Israt H. Mahmud, Md Hasan Brubaker, Nicholas D. Hayward, Ryan C. Tanjeem, Nabila Soft Condensed Matter Understanding the collective actuation of microscopic structures driven by external fields can lead to the development of next-generation autonomous machines. With this goal in mind, we investigated light-induced collective motion of thermocapillary microswimmers at the air-water interface. We found that Marangoni forces, which lead to long-ranged repulsive interparticle interactions, can cause microswimmers to synchronize their circular motion in a collective chase mode that resembles predator-prey behavior often observed in nature. We examined different degrees of confinement in small systems containing 2-6 particles of different individual swimming velocities and shapes. Thanks to the strong repulsive interactions between particles, a sustained chasing mode was observed for particle packing fractions above a critical value of 0.25. At lower packing fractions, swimmers transition between chasing, bouncing, and intermittent pausing, likely due to time-varying activity levels. Additionally, we report that a new synchronized mode can be introduced by incorporating chirality in particle shapes, where the microswimmers collectively reverse the direction of their circular motion periodically. Our results point to a simple but powerful mechanism of obtaining collective synchronization in synthetic confined systems where particles are designed with different shapes and activity levels.
title	Synchronized Circular Motion of Optically Confined Marangoni Microswimmers
topic	Soft Condensed Matter
url	https://arxiv.org/abs/2507.20517

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