Droplet impact on an elastic beam; a leaf-raindrop system

We investigate a leaf-drop system exhibiting a unique system of coupled elasticity and drop dynamics by studying water droplet impact on an elastic cantilever beam with a wettable and non-wettable surface. We found that wettable beams experience much higher torque and bending energy than non-wettable beams. This is because a drop sticks to a wettable beam and rolls off of a non-wettable beam. Simple analytical models can explain the difference in bending energy and torque of wettable and non-wettable beams, which is verified with experimental observations.