Elastohydrodynamic wake in a thin elastic film floating on water

Waves can be formed at the surface of water by a moving disturbance. These waves are known as gravity-capillary waves and have been extensively studied both experimentally and theoretically. In this study, the surface of water is covered with a thin elastic film (hundreds of micrometers in thickness). A large tank filled with water is rotated at constant speed and a stationary air jet perturbs the surface of the covering film, thereby producing an elastohydrodynamic wake. The waves are characterized as a function of the speed using a high-resolution cross-correlation method. In particular, we experimentally probe the dispersion relation and compare to the theoretical expression. We find excellent agreement, revealing that gravity, tension and bending all contribute in our system. This study might have implications in geology, ice floes, as well as energy harvesting at the surface of the ocean.