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Cacti and desert beetles can live in arid environments because they’ve adapted to
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suck water out of the air. So, can we do that if we’re in a drought?
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Hi guys, Amy here for DNews. We know the Earth’s climate is warming from a mix of natural changes,
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including solar activity, and man-made causes, namely greenhouse gases and aerosols. This
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is taking a toll on global weather. There is more water vapour in the atmosphere so
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rainfall is increasing in tropical areas, but drier areas are experiencing some of the
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worst droughts in history.
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The thing is, even in deserts, there's humidity in the air. So, to help tackle the world's
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drought problems, a team of scientists from Harvard, with support from the Department
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of Energy, looked to plants and insects that are able to pull water out of the air to survive
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in the desert.
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This biologically-inspired technology described in the journal Nature involves collecting
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water from air by condensing water vapor on surfaces inspired by beetles, cacti and other
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desert-dwelling organisms. They looked at the bumpy surfaces of desert beetles’ shells
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and found that, if the geometry is right, water droplets grow faster on the tops of
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convex bumps than on a raised flat surface of the same height. They looked at the asymmetric
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structure of cactus spines and found they had the best topography to guide the condensation
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off the bumps to be collected. And, the slippery surface of carnivorous pitcher plants inspired
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the researches to guide those formed water droplets down a smooth, non-stick surface.
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The team combined these elements with a material that repels liquid called Slippery Liquid-Infused
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Porous Surfaces technology or SLIPS. The three nature-inspired inventions combined with the
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SLIPS technology make an excellent collector to gather water from the air! When set up,
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any atmospheric moisture pools on the bumps and flows as water droplets down the asymmetrically
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pitted water-repellant surface! But could it make a difference? I asked the
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paper’s lead author Kenneth Park. He roughly calculates that the volume of air the size
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of a house in a desert holds about 16 liters of water. That’s not a lot for people in
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developed countries, but in desert regions it could be life changing access to drinking
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and cooking water. And of course in humid areas, that number rises even more. Basically,
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as long as surface temperature gets below the dew point, there will be condensation
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to harness from the air.
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The challenge now facing the team is controlling the size of the water droplets and the direction
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in which they flow. But with the details worked out, this could be a step towards developing
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a passive system capable of collecting and transporting atmospheric water to a reservoir.
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But remember, while this technology is great, it’s a proof of concept. We still need to
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conserve resources, especially those of us living in areas affected by drought, like
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California, which is experiencing the worst drought in more than a century.
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So with scientists developing these kinds of technologies, just how serious is the global
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drought that we’re looking to thin air as a water source? Julia’s got the information
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on this current crisis in this episode right here.
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Some people are creeped out drinking recycled water… would you feel weird drinking water
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pulled from the air? Let us know in the comments and don’t forget to subscribe so you never
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miss an episode of DNews.