Jumping dew drops clean up, according to articles in ScienceDaily 29 April 2013 ABC News in Science, 30 April 2013 and PNAS doi: 10.1073/pnas.1210770110. A team of scientists from Duke University (USA) and James Cook University (Australia) has discovered how cicada wings are kept free of dust, pollen and other fine particles that can collect on their wing surfaces and hinder flying. Cicada wings are covered with tiny cone shaped bumps. The outer surface layer of the wings is also “superhydrophobic”, i.e. strongly water repellent. In humid air water droplets will form on the bumps, and around any dust particles but the water repellent surface forces them away from the surface so they form droplets with minimal contact with the surface. As they grow they collide with other droplets, and the force of collisions causes droplets to jump off, taking any particles with them. This process does not depend on gravity making the drops roll off, and is therefore effective at whatever angle the wings are held.
The fact that it does not need rain to provide the water droplets to work is important for insects. Many insects have short life spans and may live through an entire dry season without any rain, but by relying on water condensing from the air, their wings are cleaned every day. The researchers suggest the effect could be put to use in making self cleaning surfaces for windows, roof tiles, kitchens, hospitals and even machine and electronic components.
Natural surfaces with self-cleaning properties have been found before, but these depend on water drops rolling off the surface, taking any particles with them. This process was found on lotus leaves, and is called the “lotus effect” even though it has been found to occur on other natural surfaces. As the jumping dew drop effect was found on cicada wings the research team suggest it should be called the “cicada effect”.
Editorial Comment: The idea that cicadas with flat wings covered with dust somehow, by naturalistic or chance processes, developed the genes for water repellent surface with the bumps needed to take advantage of humid air is absurd. It is much more logical to believe the Creator made cicadas complete with best wings needed to fly efficiently, which includes this brilliant self cleaning surface. Furthermore, this self cleaning surface would work very well in a world without rain such as described in the original very good world God created (Genesis 1 and 2). We are told that it did not rain, but a mist rose up each day to water the ground. It was a pleasantly warm, humid environment – just right for this self-cleaning surface to work most effectively. Although it has been called the “cicada effect” we predict it will also be found on other insect wings, because they also have the same need to keep their wings free of debris. (Ref. Insects, arthropods, weather, water)
Evidence News 8 May 2013