Séminaire

Mardi 4 Mars 2025 à 11h00.

Bioinspired & out-of-equilibrium soft matter systems

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The fascinating out-of-equilibrium self-organization processes found in nature are driven by complex interactions between living units and their environment. These intricate behaviors can be mimicked using synthetic soft matter systems to design new adaptive materials, harnessing the fundamental properties of their biological analogues [1,2]. Here, we explore the out-of-equilibrium behavior of two types of colloidal model systems: Janus active colloids and giant vesicles. By tuning particle motility via AC electric fields, we induce a diverse range of microstructures and dynamic behaviors.

First, I will showcase a new form of collective behavior in Janus colloids, leading to the formation of polar clusters, particularly when Janus particles with two distinct swimming speeds are present. Experimental observations, supported by an ABP model, reveal how interactions between fast and slow particles drive cooperative dynamics and species segregation [3]. Second, I will elaborate on how cell-inspired architectures, particularly lipid vesicles, represent the future of fundamental active systems, where membrane properties play a crucial role in their reconfigurable active motion [4]. These studies illustrate how careful material design of artificial microswimmers enables the creation of unique dynamic patterns and cooperative group dynamics, offering pathways for designing advanced materials with programmable collective and tactic behaviors.

[1] G.Volpe, N. A. M. Araújo, M. Guix, M. Miodownik, N.Martin, L. Alvarez, et.al., Animated Matter Roadmap (arXiv, under review) 2024
[2] Gerhard Gompper et al 2025 J. Phys.: Condens. Matter 37 143501
[3] L. Alvarez*, D. Levis*, E. Sesé, I. Pagonarraba, L. Isa (in preparation)
[4] V. Willems, A. Baron, D. A. Matoz-Fernandez, G. Wolfisberg, E. Dufresne, J. C. Baret, and L. Alvarez (arXiv, under review, 2024).

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