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Spontaneous shape transitions of active matter
Par Anne Bernheim-Groswasser (Ben Gurion University)
Le 4 Octobre 2019 à 11h00 - Salle de séminaires du LJP, tour 32-33, 5ème étage, Jussieu


Shape transitions in developing organisms can be driven by active stresses, notably, active contractility generated by myosin motors. The mechanisms generating tissue folding are typically studied in epithelia. There, the interaction between cells is also coupled to an elastic substrate, presenting a major difficulty for studying contraction induced folding. Here we study the contraction and buckling of active, initially homogeneous, thin elastic actomyosin networks isolated from bounding surfaces. The network behaves as a poroelastic material, where a flow of fluid is generated during contraction. Contraction starts at the system boundaries, proceeds into the bulk, and eventually leads to spontaneous buckling of the sheet at the periphery. The buckling instability resulted from system self-organization and from the spontaneous emergence of density gradients driven by the active contractility. Our system offers a well-controlled way to study mechanically induced, spontaneous shape transitions in active matter [1].

[1] Ideses Y. et al., Nat. Comm, 9, 2461 (2018).