Bilayer curling and winding in a viscous fluid

Abstract

Induced spontaneous curvature is a new mechanism of microcapsules bursting by nucleation and growth of a hole surrounded by a curling rim. Here we study the dynamics of curling on a macroscopic scale induced by the elastic curvature of a bilayer of tracing paper and tape after soaking by water. The ribbon which is fully stretched at time t = 0 is immersed in a viscous oil. We observe the winding from the free end and find two regimes: rolling at constant velocity at short times, and a slowdown at long times. We interpret these two regimes by a balance of the elastic driving force and the friction force on the roll.