Discovering dynamic laws from observations: the case of self-propelled, interacting colloids

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Ruiz-Garcia, Miguel, G., C. Miguel Barriuso, Alexander, Lachlan C., Aarts, Dirk G. A. L., Ghiringhelli, Luca, Valeriani, Chantal
Format: Preprint
Publié: 2022
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866916650389864448
author Ruiz-Garcia, Miguel
G., C. Miguel Barriuso
Alexander, Lachlan C.
Aarts, Dirk G. A. L.
Ghiringhelli, Luca
Valeriani, Chantal
author_facet Ruiz-Garcia, Miguel
G., C. Miguel Barriuso
Alexander, Lachlan C.
Aarts, Dirk G. A. L.
Ghiringhelli, Luca
Valeriani, Chantal
contents Active matter spans a wide range of time and length scales, from groups of cells and synthetic self-propelled particles to schools of fish, flocks of birds, or even human crowds. The theoretical framework describing these systems has shown tremendous success at finding universal phenomenology. However, further progress is often burdened by the difficulty of determining the forces that control the dynamics of the individual elements within each system. Accessing this local information is key to understanding the physics dominating the system and to create the models that can explain the observed collective phenomena. In this work, we present a machine-learning model, a graph neural network, that uses the collective movement of the system to learn the active and two-body forces controlling the individual dynamics of the particles. We verify our approach using numerical simulations of active brownian particles, considering different interaction potentials and levels of activity. Finally, we apply our model to experiments of electrophoretic Janus particles, extracting the active and two-body forces that control the dynamics of the colloids. Due to this, we can uncover the physics dominating the behavior of the system. We extract an active force that depends on the electric field and also area fraction. We also discover a dependence of the two-body interaction with the electric field that leads us to propose that the dominant force between these colloids is a screened electrostatic interaction with a constant length scale. We expect that this methodology can open a new avenue for the study and modeling of experimental systems of active particles.
format Preprint
id arxiv_https___arxiv_org_abs_2203_14846
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Discovering dynamic laws from observations: the case of self-propelled, interacting colloids
Ruiz-Garcia, Miguel
G., C. Miguel Barriuso
Alexander, Lachlan C.
Aarts, Dirk G. A. L.
Ghiringhelli, Luca
Valeriani, Chantal
Soft Condensed Matter
Disordered Systems and Neural Networks
Active matter spans a wide range of time and length scales, from groups of cells and synthetic self-propelled particles to schools of fish, flocks of birds, or even human crowds. The theoretical framework describing these systems has shown tremendous success at finding universal phenomenology. However, further progress is often burdened by the difficulty of determining the forces that control the dynamics of the individual elements within each system. Accessing this local information is key to understanding the physics dominating the system and to create the models that can explain the observed collective phenomena. In this work, we present a machine-learning model, a graph neural network, that uses the collective movement of the system to learn the active and two-body forces controlling the individual dynamics of the particles. We verify our approach using numerical simulations of active brownian particles, considering different interaction potentials and levels of activity. Finally, we apply our model to experiments of electrophoretic Janus particles, extracting the active and two-body forces that control the dynamics of the colloids. Due to this, we can uncover the physics dominating the behavior of the system. We extract an active force that depends on the electric field and also area fraction. We also discover a dependence of the two-body interaction with the electric field that leads us to propose that the dominant force between these colloids is a screened electrostatic interaction with a constant length scale. We expect that this methodology can open a new avenue for the study and modeling of experimental systems of active particles.
title Discovering dynamic laws from observations: the case of self-propelled, interacting colloids
topic Soft Condensed Matter
Disordered Systems and Neural Networks
url https://arxiv.org/abs/2203.14846