Gulf countries like Abu Dhabi may lack freshwater resources, but they also have a lot of humidity. MIT’s new super efficient fog harvesting material could help countries with climates like this capture that moisture for drinking water.
Fog harvesting is modeled after creatures like the Namib Beetle that are well adapted to pulling moisture out of the air – even in extraordinarily dry conditions like the desert.
However, it turns out that the giant nets that are currently used are made of polyolefin mesh that allows water droplets to escape because the pores are simply too large.
A research team from MIT believes they have developed a much finer, tighter material that prevents moisture loss.
“Detailed calculations and laboratory tests indicate that the best performance comes from 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,” according to a recent press release.
“In addition, the mesh is dip-coated, using a solution that decreases a characteristic called contact-angle hysteresis. This allows small droplets to more easily slide down into the collecting gutter as soon as they form, before the wind blows them off the surface and back into the fog stream.”
Once the water has been collected, it can then be funneled and purified as need be for use as drinking water.
Similar fog harvesting systems are being developed in Abu Dhabi and Dubai in order to reduce reliance not only on bottled water – a great scourge in the Middle East – but also on desalination, which is not only expensive given the kind of energy required to filter seawater, but also environmentally destructive.
MIT’s research was published in the journal Langmuir, and a year-long trial is taking place in Chile to determine the best configurations to maximize water yield.
Image of foggy Dubai road, Shutterstock