Lotus effect

About: Lotus effect is a research topic. Over the lifetime, 1754 publications have been published within this topic receiving 56419 citations.

Purity of the sacred lotus, or escape from contamination in biological surfaces

Abstract: The microrelief of plant surfaces, mainly caused by epicuticular wax crystalloids, serves different purposes and often causes effective water repellency. Furthermore, the adhesion of contaminating particles is reduced. Based on experimental data carried out on microscopically smooth (Fagus sylvatica L., Gnetum gnemon L., Heliconia densiflora Verlot, Magnolia grandiflora L.) and rough water-repellent plants (Brassica oleracea L., Colocasia esculenta (L.) Schott., Mutisia decurrens Cav., Nelumbo nucifera Gaertn.), it is shown here for the first time that the interdependence between surface roughness, reduced particle adhesion and water repellency is the keystone in the self-cleaning mechanism of many biological surfaces. The plants were artificially contaminated with various particles and subsequently subjected to artificial rinsing by sprinkler or fog generator. 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” and which may be of great biological and technological importance.

Petal Effect: A Superhydrophobic State with High Adhesive Force

Abstract: Hierarchical micropapillae and nanofolds are known to exist on the petals' surfaces of red roses. These micro- and nanostructures provide a sufficient roughness for superhydrophobicity and yet at the same time a high adhesive force with water. A water droplet on the surface of the petal appears spherical in shape, which cannot roll off even when the petal is turned upside down. We define this phenomenon as the “petal effect” as compared with the popular “lotus effect”. Artificial fabrication of biomimic polymer films, with well-defined nanoembossed structures obtained by duplicating the petal's surface, indicates that the superhydrophobic surface and the adhesive petal are in Cassie impregnating wetting state.

A Lotus‐Leaf‐like Superhydrophobic Surface: A Porous Microsphere/Nanofiber Composite Film Prepared by Electrohydrodynamics

Abstract: [*] Prof. Dr. L. Jiang, Dr. Y. Zhao, Prof. Dr. J. Zhai Center of Molecular Sciences Institute of Chemistry, Chinese Academy of Sciences Beijing 100080 (P. R. China) Dr. Y. Zhao Graduate School of the Chinese Academy of Sciences (P. R. China) Prof. Dr. L. Jiang National Center for Nanoscience and Nanotechnology Beijing 100080 (P. R. China) Fax: (+86)10-8262-7566 E-mail: jianglei@iccas.ac.cn [**] The authors thank the State Key Project for Fundamental Research (G1999064504) and the Special Research Foundation of the National Nature Science Foundation of China (29992530) for continuing financial support. The Chinese Academy of Sciences is gratefully acknowledged. Communications

Slip on Superhydrophobic Surfaces

Abstract: This review discusses the use of the combination of surface roughness and hydrophobicity for engineering large slip at the fluid-solid interface. These superhydrophobic surfaces were initially inspired by the unique water-repellent properties of the lotus leaf and can be employed to produce drag reduction in both laminar and turbulent flows, enhance mixing in laminar flows, and amplify diffusion-osmotic flows. We review the current state of experiments, simulations, and theory of flow past superhydrophobic surfaces. In addition, the designs and limitations of these surfaces are discussed, with an eye toward implementing these surfaces in a wide range of applications.