PMMH Laboratory
@pmmh-lab.bsky.social
Research unit on #physics and #mechanics of heterogeneous media
CNRS, ESPCI Paris-PSL, Sorbonne Université, Université Paris Cité
France
Home: www.pmmh.espci.fr
🦣: mathstodon.xyz/@PMMH_lab
CNRS, ESPCI Paris-PSL, Sorbonne Université, Université Paris Cité
France
Home: www.pmmh.espci.fr
🦣: mathstodon.xyz/@PMMH_lab
[5] Yang Y, Turci F, Kague E, Hammond CL, Russo J and Royall CP, “Dominating Lengthscales of Zebrafish Collective Behaviour” PLOS Comp. Biol. 18 e1009394 (2020).
November 24, 2025 at 6:55 PM
[5] Yang Y, Turci F, Kague E, Hammond CL, Russo J and Royall CP, “Dominating Lengthscales of Zebrafish Collective Behaviour” PLOS Comp. Biol. 18 e1009394 (2020).
[3] Chao, Skipper, Royall, Henkes, Liverpool: Traveling strings of active dipolar colloids, Phys. Rev. Lett. 134 018302 (2025).
[4] Sakaï, Skipper, Moore, Russo, Royall: Active Dipolar Colloids in Three Dimensions : Non–Equilibrium Structure and Re-entrant Dynamics”, Soft Matter, 21 5204 (2025).
[4] Sakaï, Skipper, Moore, Russo, Royall: Active Dipolar Colloids in Three Dimensions : Non–Equilibrium Structure and Re-entrant Dynamics”, Soft Matter, 21 5204 (2025).
November 24, 2025 at 6:55 PM
[3] Chao, Skipper, Royall, Henkes, Liverpool: Traveling strings of active dipolar colloids, Phys. Rev. Lett. 134 018302 (2025).
[4] Sakaï, Skipper, Moore, Russo, Royall: Active Dipolar Colloids in Three Dimensions : Non–Equilibrium Structure and Re-entrant Dynamics”, Soft Matter, 21 5204 (2025).
[4] Sakaï, Skipper, Moore, Russo, Royall: Active Dipolar Colloids in Three Dimensions : Non–Equilibrium Structure and Re-entrant Dynamics”, Soft Matter, 21 5204 (2025).
[1] Royall, Charbonneau, Dijkstra, Russo, Smallenburg, Speck, Valeriani: Colloidal Hard Spheres: Triumphs, Challenges and Mysteries, Rev. Mod. Phys. (2024)
[2] Zampetaki, Yang, Loewen, Royall: Dynamical Order and Many-Body Correlations in Zebrafish show that Three is a Crowd, Nature Commun (2024)
[2] Zampetaki, Yang, Loewen, Royall: Dynamical Order and Many-Body Correlations in Zebrafish show that Three is a Crowd, Nature Commun (2024)
November 24, 2025 at 6:55 PM
[1] Royall, Charbonneau, Dijkstra, Russo, Smallenburg, Speck, Valeriani: Colloidal Hard Spheres: Triumphs, Challenges and Mysteries, Rev. Mod. Phys. (2024)
[2] Zampetaki, Yang, Loewen, Royall: Dynamical Order and Many-Body Correlations in Zebrafish show that Three is a Crowd, Nature Commun (2024)
[2] Zampetaki, Yang, Loewen, Royall: Dynamical Order and Many-Body Correlations in Zebrafish show that Three is a Crowd, Nature Commun (2024)
The mutant fish are described by the same Vicsek model, but occupy a different state space. Finally, we show that that the system size dependence of zebrafish shows little change once the system has three fish when interpreted through suitable order parameters, so for fish, “three is a crowd” [4].
November 24, 2025 at 6:55 PM
The mutant fish are described by the same Vicsek model, but occupy a different state space. Finally, we show that that the system size dependence of zebrafish shows little change once the system has three fish when interpreted through suitable order parameters, so for fish, “three is a crowd” [4].
We use similar methods to analyse the collective behaviour of zebrafish. We show that trajectories of the fish can be mapped onto a modified Vicsek model with surprising accuracy [2]. Colloidal systems can be tuned and we show that the zebrafish can also be tuned through genetic modification.
November 24, 2025 at 6:55 PM
We use similar methods to analyse the collective behaviour of zebrafish. We show that trajectories of the fish can be mapped onto a modified Vicsek model with surprising accuracy [2]. Colloidal systems can be tuned and we show that the zebrafish can also be tuned through genetic modification.
and acquires a dipolar interaction parallel to the field, and exhibits new phenomena such as travelling strings [3], a wildly fluctuating labyrinth and phonon-like behaviour, all of which are forbidden in the passive analogue [4].
November 24, 2025 at 6:55 PM
and acquires a dipolar interaction parallel to the field, and exhibits new phenomena such as travelling strings [3], a wildly fluctuating labyrinth and phonon-like behaviour, all of which are forbidden in the passive analogue [4].
Until now, experiments with active colloids have been limited to (quasi) 2D systems, but we may expect that moving to 3D will bring new phenomena. Here we introduce a 3D active colloidal system of Janus particles in an AC electric field, which is active in the plane perpendicular to the field
November 24, 2025 at 6:55 PM
Until now, experiments with active colloids have been limited to (quasi) 2D systems, but we may expect that moving to 3D will bring new phenomena. Here we introduce a 3D active colloidal system of Janus particles in an AC electric field, which is active in the plane perpendicular to the field
Modelling them is very different: understanding (active) colloids builds on a century of development of effective interactions between particles based on accurate physical models [1]. In contrast, for zebrafish one seeks a model reproducing their collective behaviour, without emphasis on why [2].
November 24, 2025 at 6:55 PM
Modelling them is very different: understanding (active) colloids builds on a century of development of effective interactions between particles based on accurate physical models [1]. In contrast, for zebrafish one seeks a model reproducing their collective behaviour, without emphasis on why [2].
Understanding collective behaviour in active systems is greatly enhanced by model systems which can be studied in the laboratory. We consider two very different examples: active colloids in 3D and zebrafish. We approach each with the same philosophy of studying trajectories with simple models.
November 24, 2025 at 6:55 PM
Understanding collective behaviour in active systems is greatly enhanced by model systems which can be studied in the laboratory. We consider two very different examples: active colloids in 3D and zebrafish. We approach each with the same philosophy of studying trajectories with simple models.
#### Come to PMMH laboratory: www.pmmh.espci.fr/Contact-357
#### Next Seminars
Décembre 5th : Francesca Borghi (U. Milan)
Décembre 12th : to be announced
December 19th : Lara Kohler (Max Planck, Dresden)
Full list at www.pmmh.espci.fr/Seminaires.
#### Next Seminars
Décembre 5th : Francesca Borghi (U. Milan)
Décembre 12th : to be announced
December 19th : Lara Kohler (Max Planck, Dresden)
Full list at www.pmmh.espci.fr/Seminaires.
Physique et Mécanique des Milieux Hétérogènes
UMR 7636 : Come to PMMH
Physique et Mécanique des Milieux Hétérogènes
www.pmmh.espci.fr
November 24, 2025 at 6:55 PM
#### Come to PMMH laboratory: www.pmmh.espci.fr/Contact-357
#### Next Seminars
Décembre 5th : Francesca Borghi (U. Milan)
Décembre 12th : to be announced
December 19th : Lara Kohler (Max Planck, Dresden)
Full list at www.pmmh.espci.fr/Seminaires.
#### Next Seminars
Décembre 5th : Francesca Borghi (U. Milan)
Décembre 12th : to be announced
December 19th : Lara Kohler (Max Planck, Dresden)
Full list at www.pmmh.espci.fr/Seminaires.
Both examples highlight intricate hydrodynamic couplings in active systems and their potential consequences for the accumulation of microbial communities and the onset of biofilm formation.
November 4, 2025 at 2:32 PM
Both examples highlight intricate hydrodynamic couplings in active systems and their potential consequences for the accumulation of microbial communities and the onset of biofilm formation.
Although in the absence of flow, agents accumulate at boundaries, shear also generates extended trapping phases of microswimmers in areas of the flow backbone, leading to prominent power-law tails in the exit-time distributions.
November 4, 2025 at 2:32 PM
Although in the absence of flow, agents accumulate at boundaries, shear also generates extended trapping phases of microswimmers in areas of the flow backbone, leading to prominent power-law tails in the exit-time distributions.
behaviors that are fundamentally different to swimming near rigid walls. In the second part, I will discuss the impact of flows on active transport through a disordered, porous channel.
November 4, 2025 at 2:32 PM
behaviors that are fundamentally different to swimming near rigid walls. In the second part, I will discuss the impact of flows on active transport through a disordered, porous channel.
In this talk, I will first discuss the hydrodynamic interactions of microswimmers with a nearby deformable boundary, like a biological membrane. Using a far-field description for the flows and a perturbation theory for small deformations, we find that elastohydrodynamic couplings can generate
November 4, 2025 at 2:32 PM
In this talk, I will first discuss the hydrodynamic interactions of microswimmers with a nearby deformable boundary, like a biological membrane. Using a far-field description for the flows and a perturbation theory for small deformations, we find that elastohydrodynamic couplings can generate
Swimming microorganisms represent fascinating exemplars of non-equilibrium systems and display a range of unusual physical phenomena. These active agents often operate in complex environments, characterized by confining boundaries and flows, that can strongly modify their swimming dynamics.
November 4, 2025 at 2:32 PM
Swimming microorganisms represent fascinating exemplars of non-equilibrium systems and display a range of unusual physical phenomena. These active agents often operate in complex environments, characterized by confining boundaries and flows, that can strongly modify their swimming dynamics.
#### Come to PMMH laboratory: www.pmmh.espci.fr/Contact-357
#### Coming Seminars
Nov 14: Romain Mari (LiPhy, Grenoble)
Nov 21: Christiana Mavroyiakoumou (Oxford, UK)
Nov 28: Paddy Royall (Gulliver)
Dec 5: Francesca Borghi (U. Milan)
Full list at www.pmmh.espci.fr/Seminaires.
#### Coming Seminars
Nov 14: Romain Mari (LiPhy, Grenoble)
Nov 21: Christiana Mavroyiakoumou (Oxford, UK)
Nov 28: Paddy Royall (Gulliver)
Dec 5: Francesca Borghi (U. Milan)
Full list at www.pmmh.espci.fr/Seminaires.
Physique et Mécanique des Milieux Hétérogènes
UMR 7636 : Come to PMMH
Physique et Mécanique des Milieux Hétérogènes
www.pmmh.espci.fr
November 4, 2025 at 2:32 PM
#### Come to PMMH laboratory: www.pmmh.espci.fr/Contact-357
#### Coming Seminars
Nov 14: Romain Mari (LiPhy, Grenoble)
Nov 21: Christiana Mavroyiakoumou (Oxford, UK)
Nov 28: Paddy Royall (Gulliver)
Dec 5: Francesca Borghi (U. Milan)
Full list at www.pmmh.espci.fr/Seminaires.
#### Coming Seminars
Nov 14: Romain Mari (LiPhy, Grenoble)
Nov 21: Christiana Mavroyiakoumou (Oxford, UK)
Nov 28: Paddy Royall (Gulliver)
Dec 5: Francesca Borghi (U. Milan)
Full list at www.pmmh.espci.fr/Seminaires.
Reposted by PMMH Laboratory
José BICO, formé à l'ESPCI et diplômé #Ingénieur en 1996 (#ESPCIAlum 111e promotion), professeur @espciparispsl.bsky.social et chercheur @pmmh-lab.bsky.social, a été élu Fellow de l'American Physical Society @apsphysics.bsky.social :
www.aps.org/funding-reco...
c/ @olivetree33.bsky.social
[3/3]
www.aps.org/funding-reco...
c/ @olivetree33.bsky.social
[3/3]
Division of Statistical and Nonlinear Physics Fellowship
The American Physical Society is a nonprofit membership organization working to advance physics by fostering a vibrant, inclusive, and global community dedicated to science and society.
www.aps.org
October 24, 2025 at 10:38 AM
José BICO, formé à l'ESPCI et diplômé #Ingénieur en 1996 (#ESPCIAlum 111e promotion), professeur @espciparispsl.bsky.social et chercheur @pmmh-lab.bsky.social, a été élu Fellow de l'American Physical Society @apsphysics.bsky.social :
www.aps.org/funding-reco...
c/ @olivetree33.bsky.social
[3/3]
www.aps.org/funding-reco...
c/ @olivetree33.bsky.social
[3/3]
"For outstanding contributions to elasto-capillary phenomena, elastic instabilities, and shape-morphing materials that combine creative experiments and elegant modeling."
https://www.aps.org/funding-recognition/aps-fellowship/dsnp-fellowship
https://www.aps.org/funding-recognition/aps-fellowship/dsnp-fellowship
October 10, 2025 at 8:20 AM
"For outstanding contributions to elasto-capillary phenomena, elastic instabilities, and shape-morphing materials that combine creative experiments and elegant modeling."
https://www.aps.org/funding-recognition/aps-fellowship/dsnp-fellowship
https://www.aps.org/funding-recognition/aps-fellowship/dsnp-fellowship
We will show how this invariant may be used to quickly derive useful information on the equilibrium shapes of elastica in self-contact or in interaction with obstacles, sliding sleeves, force fields, and droplets.
October 8, 2025 at 9:41 PM
We will show how this invariant may be used to quickly derive useful information on the equilibrium shapes of elastica in self-contact or in interaction with obstacles, sliding sleeves, force fields, and droplets.
This static-dynamic analogy allows us to write a quantity that is invariant along the elastic rod at equilibrium. For a pendulum, mechanical energy constant in time whereas, for a planar elastica, the sum of its curvature energy and its axial force will be uniform along the structure.
October 8, 2025 at 9:41 PM
This static-dynamic analogy allows us to write a quantity that is invariant along the elastic rod at equilibrium. For a pendulum, mechanical energy constant in time whereas, for a planar elastica, the sum of its curvature energy and its axial force will be uniform along the structure.
The static-dynamic analogy discovered by G. Kirchhoff shows that the statics of the planar elastica are equivalent to the dynamics of the pendulum. In this analogy, time and angular velocity are, for example, equivalent to arc length and curvatures.
October 8, 2025 at 9:41 PM
The static-dynamic analogy discovered by G. Kirchhoff shows that the statics of the planar elastica are equivalent to the dynamics of the pendulum. In this analogy, time and angular velocity are, for example, equivalent to arc length and curvatures.