Dynamical Origami

A drop falling on a thin elastic sheet is rapidly trapped after impact by self-folding of the sheet around the drop. This trapping process, due to capillary forces, occurs on the fast timescale of hydrophobic rebound. The resulting packed drop presents a complex three-dimensional shape, characteristic of the interplay between elasticity and capillarity (Py \textit{et al.}, \textit{Phys. Rev. Lett.} \textbf{98}, 2007). We study experimentally the encapsulation dynamics with high-speed video camera. A shape selection exhibited by the system is evidenced. The role played by the different parameters of impact (drop radius, impact velocity...) in the final shape of this ``dynamical origami'' is eventually discussed.