Défense de thèse

Soutenance de thèse de Ylona Collard


Info

Dates
21 novembre 2022
Location
Petits Amphithéâtres, bât. B7b, amphi. 142
Quartier Agora - allée du 6-Août 17
4000 Liège (Sart Tilman)
See the map
Schedule
15h30

Le lundi 21 novembre 2022, Ylona COLLARD présentera l'examen en vue de l’obtention du grade académique de Docteur en Sciences (Collège de doctorat en Physique) sous la direction de Nicolas VANDEWALLE.

Cette épreuve consistera en la défense publique d’une dissertation intitulée :

« Magnetocapillary self-assemblies. Floating crystals, Metastable states and Locomotion ».

Abstract

Magnetocapillary self-assemblies, forming crystal-like patterns, are created when soft ferromagnetic particles are deposited on a liquid surface and subjected to a magnetic field. They result from the competition of a repulsive magnetic dipolar interaction and an attractive capillary interaction. Under static magnetic fields and for a fixed number of particles, several possible configurations are reported, having different shapes, mesh and symmetries. These structures can be used to increase our knowledge on general physics problems such as the tilt of the contact line, which increases the capillary attraction between floating objects, as well as metastable states and how to switch from one to another. Under the effect of dynamic magnetic fields, these self-assembled structures swim along the interface. Different swimming regimes can be studied, depending on the assemblies chosen and the properties of the applied magnetic field. With their simple design, they allow us to verify and extend our general knowledge of swimmers at the mesoscopic and microscopic scales. Different configurations of particles can be created: from identical particle structures to complex ones mixing different bead sizes; from simple one-dimensional swimmers to bio-inspired complex ones.

 

Le Jury sera composé de :

M. T. BASTIN (Président), Mme et MM. L. DREESEN, P. LAMBERT (ULB), G. LUMAY (Secrétaire), A.S. SMITH (Friedrich Alexander University Erlangen-Nürnberg), N. VANDEWALLE (Promoteur).

 
Photo by Annie Spratt on Unsplash

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