Lotus plants have a peculiar way of staying dirt-free and being highly water repellant. As an aquatic plant in a muddy habitat, this is an obvious advantage, as clean leaves means more photosynthesis. The leaves’ microscopic structure holds the answer to their superhydrophic properties.
Zoomed in on the leaf, we can see wax crystals and folds in the surface protruding from the surface, like tiny pyramids or traffic cones pointing upwards. Droplets of water are thus only supported by the tips, with plenty of air inbetween the tips. The lack of contact surface means the droplets don’t stick very well. It takes only a light breeze to make them dance and roll off the leaf, taking dirt particles with them.
The microscopic structure of lotus leaves has inspired self-cleaning paints, glass, textiles and more.