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  • Deserts are not particularly welcoming environments,

  • and yet at least hundred million people live in desert regions around the world, according to the UN.

  • They have to make due with less than 25 cm of rainfall each year,

  • and for many, even that miniscule water supply is under threat as climate change is making dry areas even drier.

  • So scientists at UC Berkeley have been experimenting with materials that can pull drinking water out of thin air.

  • The compound they've devised is one of a family of materials called Metal-Organic-Frameworks, or MOFs.

  • MOFs are, well it's pretty much right in the name, frameworks of metal atoms

  • connected to each other with organic linkers.

  • This structure makes them porous like a sponge,

  • giving them incredible surface areas; a single gram of a MOF can have

  • the surface area of a football field.

  • And depending on the metal and organic molecules they're made of,

  • they can be tailored to capture different things in their pores.

  • MOFs have potential uses capturing CO2 and turning it into the fuel methanol,

  • or neutralizing nerve agents like sarin gas.

  • The function the Berkeley scientists tuned their MOF for was extracting water vapor that's present in the air.

  • The first one they made in 2014, called MOF-801, was zirconium based.

  • When tested in a water harvester it worked entirely passively,

  • absorbing and condensing water overnight and giving it up again when the sun warmed it up.

  • So the concept worked, and used a lot less energy than the other way of extracting water from low humidity air,

  • which involves cooling the air below freezing.

  • But Zirconium is expensive, so the scientists set to developing MOF-303

  • based on the much cheaper element aluminum.

  • Not only is the new MOF cheaper, it also performs much better.

  • It can hold 30% more water and fill up and empty in just 20 minutes in the right conditions.

  • And because the MOF was designed to leave no traces of organic or inorganic material in the water,

  • it's completely pure and drinkable right away.

  • Using the same passive technique in a harvester left overnight in the Arizona desert,

  • one kilogram of MOF-303 harvested 0.2 liters of water.

  • Now I know what you're thinking. That doesn't sound like a lot of water. And you're right.

  • But the good news is the aluminum based MOF's ability to fill and empty in minutes can be exploited.

  • The scientists changed up their design.

  • Instead of passively relying on a day night cycle, their latest harvester relies on solar powered fans

  • and heaters to run dozens of cycles a day.

  • Ideally it can make more than 1.3 liters of water per kilogram of MOF each day,

  • and the researchers hope to get that number as high as 8 or 10 liters per kilogram.

  • The lead researcher behind this has started a private company called Water Harvesting.

  • The plan is to launch a microwaved sized device that can supply 2 adults with enough drinking water

  • for their daily hydration and cooking needs.

  • Eventually they envision a harvester big enough to supply a small village.

  • If the devices are affordable, safe, and reliable enough,

  • these metal-organic frameworks have the potential to turn even the driest deserts into oases.

  • Clean drinking water has always been a challenge for humanity, and sometimes we make mistakes.

  • Like when we decided lead pipes were a good idea.

  • Thankfully, researchers are developing ways to render the poisonous pipes harmless.

  • Amanda has more here.

  • If you liked this video let us know in the comments, and don't forget to subscribe.

  • Thanks for watching and I'll see you next time on Seeker.

Deserts are not particularly welcoming environments,

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