Desert beetle catches fog on its back. (Biology).The nubbly back of a beetle in Africa's Namib Desert Namib Desert Desert region, extending 1,200 mi (1,900 km) from Namibe, Angola, along the entire coast of Namibia to the Olifants River in South Africa. It is an almost rainless area, 50–80 mi (80–130 km) wide over most of its length, traversed by rail lines has inspired a device for harvesting water from fog. When a patch of dense fog rolls over the desert, the beetle, a species of the genus Stenocara, upends its body into a handstand. Fog droplets collect on its back and dribble into its mouth. Now, Andrew R. Parker of the University of Oxford in England and Chris R. Lawrence of the technology company QinetiQ in Farnborough, England, have figured out how the fog catchers on the insects' backs work. Manufacturers could readily mimic the texture in what could serve as fog-harvesting sheets, say the researchers in the Nov. 1 NATURE. The thumbnail-size beetle lives in a windy desert where rain is scarce but heavy fog is common. Bumps visible to the naked eye cover the insect's back. Electron microscopy electron microscopy Technique that allows examination of samples too small to be seen with a light microscope. Electron beams have much smaller wavelengths than visible light and hence higher resolving power. revealed a wax- coated carpet of tiny nodules Nodules A small mass of tissue in the form of a protuberance or a knot that is solid and can be detected by touch. Mentioned in: Leprosy covering the sides of the bumps and the valleys between them. As fog wafts by, tiny water droplets gather on the top of a bump, merging into a drop big enough for the wind to nudge nudge 1 tr.v. nudged, nudg·ing, nudg·es 1. To push against gently, especially in order to gain attention or give a signal. 2. off the bump's summit. The water slips down the waxy waxy (wak´se) 1. composed of or covered by wax. 2. resembling wax, especially denoting some combination of pliability, paleness, and smoothness and luster. slope and rolls through water-repellant valleys until it reaches the beetle's mouthparts. The researchers mimicked the natural fog catcher by setting tiny glass beads into a wax surface. It collected more water than either plain glass or a flat wax coating. Parker says that technologies based on this concept might someday help reduce fog at airports and collect water for irrigation irrigation, in agriculture, artificial watering of the land. Although used chiefly in regions with annual rainfall of less than 20 in. (51 cm), it is also used in wetter areas to grow certain crops, e.g., rice. and drinking in those arid regions where fog is common. --S.M. |
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