Light-Driven Transport of a Liquid Marble with and against Surface Flows

Nikita Kavokine (1) , Manos Anyfantakis (1) , Mathieu Morel (1) , Sergii Rudiuk (1) , Thomas Bickel (2) , Damien Baigl (1)

1 PASTEUR - Processus d'Activation Sélective par Transfert d'Energie Uni-électronique ou Radiatif (UMR 8640)
2 LOMA - Laboratoire Ondes et Matière d'Aquitaine

Liquid marbles, that is, liquid drops coated by a hydrophobic powder, do not wet any solid or liquid substrate, making their transport and manipulation both highly desirable and challenging. Herein, we describe the light driven transport of floating liquid marbles and emphasize a surprising motion behavior. Liquid marbles are deposited on a water solution containing photosensitive surfactants. Irradiation of the solution generates photoreversible Marangoni flows that transport the liquid marbles toward UV light and away from blue light when the thickness of the liquid substrate is large enough (Marangoni regime). Below a critical thickness, the liquid marbles move in the opposite direction to that of the surface flow at a speed increasing with decreasing liquid thickness (anti Marangoni). We demonstrate that the anti Marangoni motion is driven by the free surface deformation, which propels the non-wetting marble against the surface flow. We call this behavior "slide effect".

Mots clés: Interfaces; Liquid marbles; Marangoni flows; photoactuation; Surface tension

Domaines: Dynamique des Fluides [physics.flu-dyn]

Nikita Kavokine, Manos Anyfantakis, Mathieu Morel, Sergii Rudiuk, Thomas Bickel, et al.. Light-Driven Transport of a Liquid Marble with and against Surface Flows. Angewandte Chemie International Edition, 2016, 55 (37), pp.11183 - 11187. ⟨10.1002/anie.201603639⟩. ⟨hal-01392406⟩