Self-Cleaning Coatings

self cleaning surfaceWhen rain hits the leaves of the lotus plant, it simply beads up.

When the leaves are tilted, water runs off instantaneously.

While the water is rolling off, it carries away any dirt.

Despite growing in muddy conditions, the leaves and flowers remain clean because their surfaces are composed of micron- and nano-scale structures that – along with a waxy coating – prevent dirt and water from adhering.

The plant’s ability to repel water and dirt results from an unusual combination of a superhydrophobic (water-repelling) surface and a combination of micron-scale hills and valleys and nanometer-scale waxy bumps that create rough surfaces that don’t give water or dirt a chance to adhere.

The self-cleaning action of the lotus plant has intrigued researchers for decades. C.P. Wong at Georgia Tech is studying one of Nature’s best non-stick surfaces to help create more reliable electric transmission systems, photovoltaic arrays, and surfaces able to prevent bacteria from adhering. [story]