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Accueil du site > Séminaires > Archives séminaires > Séminaires 2018 > Séminaire MSC. 5 mars 2018. Gwennou Coupier (Liphy, Grenoble) : "Buckling instability and swimming of elastic spherical shells.".

Séminaire MSC. 5 mars 2018. Gwennou Coupier (Liphy, Grenoble) : "Buckling instability and swimming of elastic spherical shells."

Sauf mention contraire, les séminaires et les soutenances se déroulent à 11h30 en salle 454A du bâtiment Condorcet.

Gwennou Coupier Chargé de recherche CNRS au Laboratoire Interdisciplinaire de Physique (LIPhy) CNRS UMR 5588 - Université Joseph Fourier, Grenoble

Buckling instability and swimming of elastic spherical shells.

Abstract : Under pressure, a hollow elastic sphere becomes unstable and collapses. It reinflates back when the pressure is decreased. The shape hysteresis associated to this deformation cycle makes this simple object a good candidate for becoming a microswimmer, that is, a swimmer able to move at low Reynolds number.

We explore this possibility through a macroscopic experiment in fluids of varying viscosities so as to explore different flow regimes [1]. We show that not only the shape sequence hysteresis leads to swimming but the asymetry in the deformation velocity makes the fast buckling phase an efficient mechanism for propulsion that implies inertial effects and subtle coupling between shape post-buckling oscillations and fluid flow patterns. Our modeling shows that such an inertial regime could even be reached at microscopic scale.

[1] A. Djellouli, P. Marmottant, H. Djeridi, C. Quilliet and G. Coupier, Phys. Rev. Lett. 119, 224501 (2017).

Contact : Équipe séminaires / Seminar team - Published on / Publié le 28 novembre 2017

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