Bio – Mimicry of Lotus Leaf

In the case of water-repellent leaves, the particles were removed completely by water droplets that rolled off the surfaces independent of their chemical nature or size. The leaves of N. nucifera afford an impressive demonstration of this effect, which is, therefore, called the ``Lotus-Effect''. The lotus leaf self-cleaning ability is due to the roughness of its surface at micro and nano level. The microrelief of plant surfaces, mainly caused by epicuticular wax crystalloids forming bumps, serves different purposes and often causes effective water repellency. Interdependence between surface roughness, reduced particle adhesion and water repellency is the keystone in the self-cleaning mechanism of the lotus leaf. In the case of water-repellent rough surfaces, air is enclosed between the epicuticular wax crystalloids, forming a composite surface. In this situation, spreading does not occur, the water forms a spherical droplet, and the contact angle θ of the droplet depends almost entirely on the surface tension of the water. Due to high contact angle (> 90) water droplets sit on the bumps cushioned by air under it. The area of contact between the water and the surface is reduced by these bumps. It also causes the dirt particles to preferentially stick to the water droplets and be rolled out. Scanning Electron Microscope (SEM) studies of leaf surfaces have revealed an incredibl