● Some 900 million people worldwide have no access to safe drinking water. In many areas, it is women and children who trek long distances to find water and then carry it back to their homes. “I think it’s terrible that the poor have to spend hours a day walking just to obtain a basic necessity,” says Shreerang Chhatre, an engineer at the Massachusetts Institute of Technology. To provide relief, Chhatre and his colleagues are exploring the science of fog harvesting, and for inspiration they are looking to the Namib beetle.
Consider: Each morning, a fog drifts through Africa’s Namib desert. The Namib beetle takes advantage of this brief opportunity and faces the wind at just the right angle.a Bumps on the wing covers are composed of a hydrophilic substance that attracts moisture. The moisture builds up, forming ever larger droplets. Gravity then takes over, and aided by water-repellent troughs between the bumps, the droplets run down the wing covers and into the beetle’s mouth.
Chhatre and his associates want to use a similar principle to harvest drinking water for humans. Of course, humans need more water to survive than does the Namib beetle. And financing such an endeavor is a daunting challenge. For now, fog harvesting for humans remains “a work in progress,” Chhatre says.
What do you think? Did the hydrophilic wing cover of the Namib beetle come about by evolution? Or was it designed?
a Other species of beetles have been observed collecting water in a similar fashion.
[Picture on page 22]
Water droplets form and run into the beetle’s mouth
[Picture Credit Line on page 22]
Photo: Chris Mattison Photography/photographersdirect.com