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Water Bottle Fills Itself From the Air 173

mbstone writes "The Namib Desert Beetle generates water from water vapor via its shell, which has alternating hydrophilic and hydrophobic bumps which channel water droplets into its mouth. Scientists at MIT developed a self-filling water bottle using this technology, and have announced a contest for the best design of a countertop water-from-air generator."
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Water Bottle Fills Itself From the Air

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  • by Anonymous Coward

    stuff like this we're gonna need to stave off the water riots coming to a decade near you.

  • by drunkennewfiemidget ( 712572 ) on Friday November 23, 2012 @01:10AM (#42071149) Homepage

    I'm not hydrophobic, I have gay friends!

    • by Anonymous Coward on Friday November 23, 2012 @01:37AM (#42071289)

      I'm not hydrophobic, I have gay friends!

      I'm not hydrophobic, some of my best friends are wet.

      • Re: (Score:2, Funny)

        by Anonymous Coward

        Some of my best friends are wetbacks!

      • by joocemann ( 1273720 ) on Friday November 23, 2012 @02:50AM (#42071555)

        I'm just so thankful that god sent us this invention!

      • And the others are all MUMMIES!
    • by Anonymous Coward

      70% of my friends are water!

  • by zill ( 1690130 ) on Friday November 23, 2012 @01:14AM (#42071173)
    You know what they say, the bottle is half empty for pessimists and 1 year away from being full for an optimist.
    • by Anonymous Coward

      Do the math... That's like 100mL per hour for a water bottle size. That's actually pretty impressive!

      • by zill ( 1690130 ) on Friday November 23, 2012 @02:03AM (#42071387)
        I did. It's roughly 0.7mL per hour for a 710mL coke bottle; takes around 40 days to fill it up.
        • Just in time for the return policies in most places to run out, sounds about right.
        • by sjames ( 1099 ) on Friday November 23, 2012 @03:21AM (#42071653) Homepage Journal

          OTOH, my roof could easily collect more water than I use in a day.

        • by Formalin ( 1945560 ) on Friday November 23, 2012 @05:47AM (#42072171)

          Your math is off. I don't have a 710ml bottle handy, so I did a 12oz can.

          Assuming 6.5cm * 12cm, ignoring the bottom and top surfaces, just the sides of the cylinder, I get 490 cm2, which is .049 m2.

          3l * .049 = 0.147; 147ml/h. The can will be a 40% full in an hour, in 75% RH.

          I assume the performance in drier conditions is much worse, though.

          Although, once the liquid is in the container, it loses surface area? I didnt bother reading to find out whether the inside or outside or both count. math was assuming one side.. If it is the inside surface that does the work, the increasingly covered surface will give reduced efficiency as it approaches full...

          • by Formalin ( 1945560 ) on Friday November 23, 2012 @05:50AM (#42072187)

            shit, 2pi r h, not 2 pi d h.

            so it should be 244cm2, .024m2, producing 73ml/h. Still respectable.

            • by Internetuser1248 ( 1787630 ) on Friday November 23, 2012 @09:08AM (#42073169)
              All of these calculations assume that the air, once the water is absorbed out of it, will flow out of the vessel and be replaced by humid air again at the optimal speed. It also requires power to operate. It may be that the power is used to pump the air which would mean the system has only one of these drawbacks, but the article is light on details so I can't be sure. It is also not a system that can be built at home. On the other hand I read an article by an engineer a few years ago that proposed a system that used piping running below the ground to cool the air and cause condensation, using a wind catcher at one end to push it through. His estimates included air flow and showed that a 10 meter long system could provide drinking water in desert air with a moderate wind for several people. I am unable to find the article again unfortunately.

              My point is that a temperature gradient is far cheaper and available to poor third world desert countries where such a system is required. This technology is neat but not all that practical. Still a combination of the two systems, ie. lining the inside of underground pipes with this substance and letting the wind push air through might have a much higher rate of condensation and could be used for commercial and military operations in the desert.
        • The maths I have says a 710 ml coke bottle should be (we don't have them here, so I'm estimating), about 7cm across and 20cm tall. That would make it's surface area roughly 439 square cm. So you would get 3L * 0.439 = 1.3 litres per hour out of that... It can fill itself in half an hour at 75% humidity. Pretty bloody impressive.

    • by Jorgensen ( 313325 ) on Friday November 23, 2012 @03:36AM (#42071687) Homepage
      50% or 50% empty is a misnomer. Let an engineer look at it, and he'll show you an over-engineered bottle!
      • Re: (Score:2, Informative)

        by Anonymous Coward

        50% or 50% empty is a misnomer. Let an engineer look at it, and he'll show you an over-engineered bottle!

        I am an engineer and I say that it depends on the direction. While filling up the bottle is half full, while drinking it is half empty.

        • by tom17 ( 659054 )

          Not necessarily. You could be drinking it and say it's *still* half full.

          Likewise when filling, you could say it's *still* half empty.

          So still reverses polarity, or something?

    • by laejoh ( 648921 )
      And during that year the physicist [xkcd.com] very slowly ducks!
    • I live in the desert. 75% humidity is unheard of here. I like to think that people are thinking about making water bottles for thirsty people in the desert. Oh, well.
  • by Anonymous Coward

    NBD Nano co-founder Deckard Sorensen wants this green technology available in all walks of life; installing it on people, cars, homes and anything else you can imagine.

    Next stop stillsuits.

    • by Anonymous Coward

      The correct Dune reference is, of course, the windtrap [wikia.com].

  • Star Wars (Score:5, Insightful)

    by Omnifarious ( 11933 ) * <eric-slash@@@omnifarious...org> on Friday November 23, 2012 @01:18AM (#42071199) Homepage Journal

    Now we know what Luke Skywalker was repairing.

  • by Anonymous Coward on Friday November 23, 2012 @01:29AM (#42071253)

    Sounds like vaporware to me.

  • by John Bokma ( 834313 ) on Friday November 23, 2012 @01:31AM (#42071267) Homepage
    FTA: In the near future, it looks as if we’ll have water bottles that can capture drinkable water from the air as well.
  • Now if we can just combine this invention with the water-powered car...
  • Air Water Machine (Score:2, Informative)

    by Ozoner ( 1406169 )

    Wasting my breath I know...

    but machines which extract water from air have been around for a long time.

    Even a humble air-conditioner does this (albeit rather inefficiently)

    Google on "Air Water Machine"

    • by ModernGeek ( 601932 ) on Friday November 23, 2012 @02:10AM (#42071411)
      There is a difference between solving a problem with physics and chemistry with materials technologies, and solving one with electrical and mechanical engineering. It's like dissing the transistor because we have relays...
      • The article mentions that the bottle needs power.
      • Re:Air Water Machine (Score:4, Informative)

        by Ozoner ( 1406169 ) on Friday November 23, 2012 @03:14AM (#42071627)

        The air/water machine extracts water vapour via thermal methods (eg condensation).

        There are of course other ways of collecting water if it is in droplet form (eg mist)

        see http://en.wikipedia.org/wiki/Fog_collection [wikipedia.org] or google on "fog fence"

        This latter method seems to be pretty much what the beetles are doing

        • by Dr_Barnowl ( 709838 ) on Friday November 23, 2012 @06:58AM (#42072507)

          This is much more efficient than the fog net, principally because the arrangement of materials means that your collection surface is fouled with water less - the droplets roll straight off the hydrophobic surface, leaving the hydrophilic surface available to attract another droplet.

          The same physical process is involved regardless of which air/water collection machine you use - it's all applied thermodynamics.

          Like another poster said, it's like the difference between relays and transistors - they both perform the same job (being a switch) but one is a much smarter use of material science and much more efficient.

          • However, as a wee lad I was able to build a relay (a latching one actually) out basic materials. 50 years later and I'll pass on the transisto, if that's OK with you :)
          • Like another poster said, it's like the difference between relays and transistors - they both perform the same job (being a switch) but one is a much smarter use of material science and much more efficient.

            Actually, relays are slower but more efficient than transistors, or triacs or tiristors or any other semiconductor switch. That's because the driven circuit sees no voltage drop - the relay closes a mechanical switch, there is no voltage drop and hence practically no power dissipation. Semiconductors, on the other hand, always have a certain voltage drop, small as it may be, and need to be cooled.

    • Of course, there are also dehumidifiers around. They're being sold where I live big time - especially in summer where you have those 100% humidity weeks (one time we had laundry hanging out for three days, it was 28-30C during the day, but after three days it was still not dry and we took it to the laundry shop to have it tumble dried! That's how bad it can get!). One objection I have is that those things use quite some electricity, or chemicals to attract water and that have to be replaced all the time.


      • This sounds like a solution that does not need any external power input

        That is only true for a moving object, a runner, vehicle, boat, etc. For stationary objects a fan is needed for air flow, the article mentions solar or battery. I suppose a good wind might work too but that limits where and when you can collect water.

        • One could maybe use a chimney, heated by the sun, to draw the air through the system. Though technically that's also an external power input of course, even though it doesn't need moving parts.

      • One other issue, which I think is kind of relevant: You generally wouldn't want to drink water from a dehumidifier. I've heard that some earlier water-from-air attempts stranded on this: they make water all right, but brackish, disgusting water.

        • Water dripping from an airco unit should be safe to drink, that's pure condensation water. Could be as pure as distilled water - depending on how clean the air around it is.

          • by Eroen ( 1563375 )

            It used to be pure condensation water, then it dripped into an AC unit that is neither designed for hygiene or has ever been cleaned. The water is certainly distilled, but on no account safe to drink.

            • by tbird81 ( 946205 )

              About 5 months ago I bought a new dehumidifier. I used it for about a week to get the excess manufacturing chemicals off the coils (or whatever), but, as a nerd, I could not pass up this opportunity to taste a sample. I knew the water should be clean enough after its week of use, and new enough not yet be filled with too much algae and mould - I would not get the chance again.

              It tasted much like tap water, maybe a slightly different smell. I probably only had a couple of glasses worth, drinking direct from

          • It's not like distilled water at all, because it hasn't been at a high temperature. Not many things can live in a tiny water droplet, but some pathogens can.

        • This ought to be easy enough to keep clean.

          Hydrophobic coatings are already in use on self-cleaning glass - because the water rolls right off, water based things (like micro-organisms, algae, etc), and also dry dust, get washed off very quickly. It should be cleaner than a metallic condenser ; you might have to put a particle filter in if you can't tolerate a little dust in your water.

  • Genetically engineer this process straight into the body.

    Or maybe market it. I'm not good at prioritizing steps.
  • The Namid Desert Beatle is a badass, of that there can be no doubt; but it also exists in a highly peculiar environment: practically zero precipitation; but fairly reliable daily fog rolling in, available to be collected. In an environment where the peaks and valleys of ambient humidity are less dramatic, and it either just rains fairly frequently, or is dry all the time, its extremely clever surface structure would be for nothing.

    How much of the world actually encounters regular airborne water but virtuall

    • by drinkypoo ( 153816 ) <martin.espinoza@gmail.com> on Friday November 23, 2012 @03:57AM (#42071775) Homepage Journal

      How much of the world actually encounters regular airborne water but virtually no usable rain?

      It's common for much of the year near coastlines but only in temperate zones, so it can only serve 40% or so of the world's population. Guess we should throw it over, like the electric car :)

      • Wait, you're saying that 40% of the world's population lives in wet coastal areas that don't get rain?

        Can you point to them on a map?

        • Wait, you're saying that 40% of the world's population lives in wet coastal areas that don't get rain?

          I made that number up. And it's not that the areas don't get rain, they don't get rain every day. Sometimes they go months without rain, but they have daily fog. On the west coast of the USA you can look up maps of where the redwood trees used to be to find out the optimal locations, for example. That covers from point sur up into Canada, eh.

          Any place it's foggy more days than it's rainy, it would be useful. Maybe not necessary, but what's bad about a water bottle refilling itself? Are you worried about glo

    • by dbIII ( 701233 )

      How much of the world actually encounters regular airborne water

      Everywhere on earth at ground level, but amounts of humidity vary and the less humid it is the harder it is to extract a given amount.

    • How much of the world actually encounters regular airborne water but virtually no usable rain?

      Most places where the desert meets the sea. Even inland deserts like those found here in Oz commonly have dew forming in the early morning because of the dramatic day/night temperature difference. It's how most of the desert plants and bugs survive, that particular beetle is just an extraordinary example of the technique.

    • by pjt33 ( 739471 )

      Plenty of places don't get as much rain as they could use. In my city it rains a lot but it's quite concentrated in spring and autumn: we can easily go for 4 months over the summer without any rain but with temperatures above 30C and humidity of about 70%. If this technology can condense water cheaply then farmers (and golf course owners) would probably be quite keen on it. Whether the long-term consequences would make people curse them for using it is another question, of course...

    • Quite a bit, actually - we see it a lot here in Santa Barbara. Just this morning it was quite foggy, in fact. But for actual rain? We get about 30cm a year - a "rain event" of 1cm is impressive enough to get a "Severe Weather Alert" going.
  • by quantumphaze ( 1245466 ) on Friday November 23, 2012 @02:07AM (#42071397)

    Water has a specific heat vaporisation of 2260kJ/kg [wikipedia.org]. So can we make a slow working refrigerator without the need for a compressor from this?

    • by solanum ( 80810 )

      The bottle requires an energy input, they are using solar. The submitted article is based on a slightly fuller one: http://www.pri.org/stories/science/technology/scientist-takes-inspiration-from-natural-world-to-create-self-filling-water-bottle-12154.html [pri.org]

      • The power is for forced airflow, not for the membrane.

        People already make third-world refrigerators using evaporative cooling - a large, porous, ceramic container, with another in the middle, the intermediate space filled with damp sand.

        But this is a condenser, so you're harvesting both water and heat. You want to radiate that heat away, so you can continue to collect water. This is why the beetle is black - to radiate the maximum heat away from it's body in the night, so it's carapace is nice and cool for

        • by radtea ( 464814 )

          This is why the beetle is black - to radiate the maximum heat away from it's body in the night, so it's carapace is nice and cool for it's water collection in the morning.

          The color of the beetle, which is determined by its absorption spectrum in the visible, is irrelevant to its IR emissivity, which is what determines its cooling rate.

          What you're saying is equivalent to "That's why the beetle is blue, so it will emit lots of red light in the dark."

          If the beetle is black for thermal reasons it may be because there is an advantage to warming up as quickly as possible in the morning. This is a big deal for flying insects (I don't know if the beetle flies) as they need to warm

        • by solanum ( 80810 )

          Yes, but the airflow is required for it to work. Evaporative fridges have been used for a very very long time, but require energy input in the form of wind. The bottle is inverted in comparison to the evaporative fridge, thus it requires a fan or it would only accumulate a very very small amount of water...

    • To cool, you have to vaporise water. Not condense it: this system should generate heat.

      Using water to cool is done a lot already, in big scale with cooling towers you see at power plants, and on smaller scale for air conditioning systems. The disadvantage is of course that you can not cool to low temperatures, as water doesn't evaporate any more. So it works best for cooling down higher temperatures, like those in a power plant.

      • I suppose I should have wrote more details. You are right about condensing heating up. The refrigerator I'm thinking of would be a system with an evaporative cooler on one end, and this material on the other. A low power heat pump fuelled only by fans.

        (Speaking of heating up, can you make a mug out of it to keep my coffee hot?)

        • Neither will work because for a fridge you're too close to the melting point of water (it's not just because they don't use water as cooling liquid in fridges), and for your coffee mug you're too close to the boiling point (and way above ambient temperatures) to make any condensation happen.

  • by Radak ( 126696 ) on Friday November 23, 2012 @04:11AM (#42071821) Journal

    Make one that does whisky and I'm sold.

  • Self-milking cows can't be far away.

  • The BeetleJuice Law Firm on behalf of AngryBeetle Inc. today launched a patent infringement suit against MIT. Their statement reads: It might be very well that MIT has developed something clever, but this is clearly an infringement of AngryBeetle Inc.'s patented water production method. The fact that you can help millions of people is irrelevant - we want our cash now!.... AngryBeetle Inc. and BeetleJuice Law Partners - have not been available for any further comments. Thanks to Alex for inspiration ;)
  • If the performance numbers are really this good and you can run it off a reasonably sized solar cell, seems this would be great for hiking. Its no fun having to carry a large quantity of water, even relatively wet climates like the eastern US sometimes good water sources are farther apart than you'd like. That was my experience when I did the AT anyway.

    I generally found I needed to carry 3 liters of water to not be thirsty between convenient opportunities to acquire more on hotter days. These were usua

  • These funny green thingies poking out of the ground seem to accumulate moisture from thin air every morning.

    More evidence of visitation by technologically superior extraterrestrials?

  • Spoilers

    Just throw the bottle at Orat as he is chasing you. He will swallow it and explode from all the water generated is situ.

  • Pfft, I heard about this first on Cougar Town.

  • What I really need is a droid that understands the binary language of moisture vaporators.

Always leave room to add an explanation if it doesn't work out.