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."
Milsleading title (surprise!) (Score:5, Informative)
Air Water Machine (Score:2, Informative)
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"
Re:3L per square meter per hour @ 75 percent humid (Score:5, Informative)
The bottle requires power ... (Score:4, Informative)
Windtraps could also work using condensation techniques like refrigeration, or a regenerative moisture absorber. Of course, those techniques require power.
So does this device. From the article: "The self-filling bottle can operate using a battery or solar cell to collect and filter the water."
Re:Air Water Machine (Score:4, Informative)
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
Re:How broadly useful? (Score:5, Informative)
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 :)
Re:3L per square meter per hour @ 75 percent humid (Score:2, Informative)
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.
Re:3L per square meter per hour @ 75 percent humid (Score:4, Informative)
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...
Re:3L per square meter per hour @ 75 percent humid (Score:5, Informative)
shit, 2pi r h, not 2 pi d h.
so it should be 244cm2, .024m2, producing 73ml/h. Still respectable.