Source: DVice
Deserts may not have a lot of water in forms that are easy to access (like in rivers or lakes or aquifers), but that doesn't necessarily mean that there isn't a lot of water around somewhere. Many desert-dwelling plants and animals have adapted to extract water from the air itself, relying on fog that reliably shows up in deserts near warm ocean. Fog is absolutely loaded with water, and the trick is to get it to condense out of the air. Humans accomplish this with giant mesh nets that the fog can condense on, with catch basins underneath to collect the runoff. What comes out is cool, clear, and perfectly pure, ready for drinking or irrigation.
Fog harvesting systems are currently in operation in more than a dozen countries worldwide, but MIT has devised a new mesh material that offers more than five times the efficiency of existing harvesters. This new stuff can suck 10% of the water out of coastal fog in windy areas, which translates into over three gallons per cubic meter of mesh, per day. It's easy to scale (just put up more mesh), and the maintenance is essentially zero: collect the water when you need it, and occasionally brush dirt and bugs off of the mesh. It doesn't cost anything to run, and will operate all by itself, more or less forever.
MIT figured out that the effectiveness of fog harvesters depends on three things: the size of the mesh fibers, the size of the spaces in the mesh weave, and the coating on the fibers themselves. By tweaking all of these parameters, the researchers were able to optimize for performance, resulting in "a mesh made of stainless-steel filaments about three or four times the thickness of a human hair, and with a spacing of about twice that between fibers."
Please continue reading at: http://www.dvice.com/2013-9-3/new-fog-harvesting-tech-mit-brings-water-deserts
