0000000000644179
AUTHOR
Jean-claude Bacri
Shape transitions of giant liposomes induced by an anisotropic spontaneous curvature
International audience; We explore how a magnetic field breaks the symmetry of an initially spherical giant liposome filled with a magnetic colloid. The condition of rotational symmetry along the field axis leads either to a prolate or to an oblate ellipsoid. We demonstrate that an electrostatic interaction between the nanoparticles and the membrane triggers the shape transition. PACS numbers: 75.
Magnetic forces in 2D foams
The asymptotic expression for the ponderomotive force in the magnetic liquid film is derived and a role of the disjoining pressure in 2D magnetic foam formation is considered. New equation for the force balance at the vertex of 2D magnetic foam is proposed and modified Plateau rule for the films is obtained. The theoretical relation for the angle between films fits the experimental data for small magnetic Bond numbers very well.
Twisting and buckling: A new undulation mechanism for artificial swimmers
Among the various locomotion strategies of the animal kingdom, the undulation locomotion is of particular interest for biomimetic applications. In this paper, we present an artificial swimmer set into motion by a new and non-trivial undulation mechanism, based on the twisting and buckling of its body. The swimmer consists of a long cylinder of ferrogel which is polarized transversely and in opposite directions at each extremity. When it is placed on a water film and submitted to a transverse oscillating magnetic field, the worm-like swimmer undulates and swims. Whereas symmetry breaking is due to the field gradient, the undulations of the worm result from a torsional buckling instability as…