Lotus leaves are famous for their hydrophobic properties. Their ability to repel water lends to a self-cleaning property so that any of the dirt on the leaf roll off along with the water as a result of gravity and the natural bending of the leaf. Its rough surface also allows for the angle of contact to be greater than 90 degrees. This prevents the water from soaking into the leaf and instead forms tiny beads. Given any tiny disturbance, the droplets will roll off, carrying any foreign particles including sand and dirt with it.
This is an example of a lotus leaf's adaptation at work.
Inspired by the lotus leaf's hydrophobic properties, we decided to apply this to roofs so that rain would roll right off instead of soaking in and creating leaks. In order to create a rough surface, our hydrophobic roof tiles would be created with a mold that forms the bumps on the roof. These bumps would act like the rough surface of a lotus leaf and repel rain. This innovation also allows for a self-cleaning property because, given the slant of roofs and the natural force of gravity, the droplets of rain would roll off, taking any of the dirt and grime on the roofs with it.
Our plan for the Hydrophobic Roof.
Of all things, why did you two choose the lotus leaf for your biomimicry project?
To be honest, we came up with this idea while browsing through AskNature.org for inspiration of what to do for this project. After searching adaptations regarding "water," we came across the hydrophobic properties of a lotus leaf. Fascinated by it's ability to repel water, we applied this to rooftops and thought that it would be awesome if our roofs could repel water so that they wouldn't get leaks when there was a lot of rain. Hence, an idea was born!