Elastocapillary Snapping: Capillarity Induces Snap-Through Instabilities in Small Elastic Beams

Aurélie Fargette (1, 2) , Sébastien Neukirch (2) , Arnaud Antkowiak (2)

1 ENS-PSL - École normale supérieure - Paris
2 DALEMBERT - Institut Jean Le Rond d'Alembert

We report on the capillary-induced snapping of elastic beams. We show that a millimeter-sized water drop gently deposited on a thin buckled polymer strip may trigger an elastocapillary snap-through instability. We investigate experimentally and theoretically the statics and dynamics of this phenomenon and we further demonstrate that snapping can act against gravity, or be induced by soap bubbles on centimeter-sized thin metal strips. We argue that this phenomenon is suitable to miniaturization and design a condensation-induced spin-off version of the experiment involving an hydrophilic strip placed in a steam flow.

Mots clés: Buckling; Snapping; Elastocapillarity; Drops; Bubbles; Surface tension

Domaines: Matière Molle [cond-mat.soft]; Mécanique des fluides [physics.class-ph]; Mécanique des fluides [physics.class-ph]

Aurélie Fargette, Sébastien Neukirch, Arnaud Antkowiak. Elastocapillary Snapping: Capillarity Induces Snap-Through Instabilities in Small Elastic Beams. Physical Review Letters, 2014, 112, pp.137802. ⟨10.1103/PhysRevLett.112.137802⟩. ⟨hal-00842065v2⟩