In the fictional world of George Lucas' "Star Wars," Tatooine is a desert planet where there are moisture farmers using devices called "vaporators" to extract water from desert air. On the real world of planet Earth, researchers have built a device utilizing the same principle.
A team composed of scientists from the Universities of California, Berkley and the Massachusetts Institute of Technology in Cambridge; foresee the device to be most beneficial to arid areas and in areas where water pollution is rampant.
To demonstrate how the device does it, visualize a tall iced glass of any drink, water droplets form on the outside of the glass. This water condensate is what Luke Skywalker may have looked at in their machines on Tatooine, and the scientists' new device works on the same principle, according to IFLScience.
Condensation occurs when warm air is cooled down, which can then be collected. Water vapor is naturally present in air, the warmer it is and with higher humidity, the more water vapor it carries. In desert locales, there is lower water content in the air making the system less efficient. Cooling more air to extract more water would require more energy, which would make it more expensive.
To solve this problem, a passive cooling technology is employed along with a type of material and surface quality critical for water collection. Researchers have shown this can be realized by adding a special coating that attracts water molecules.
However, it can also utilize active cooling technologies similar to that used in refrigerators and airconditioners. Additionally, employing solid-state thermoelectric cooling can also be used, which would involve the principle of the Peltier effect.
However, scientists at the Massachusetts Institute of Technology (MIT) have developed technology that is potentially more efficient. It works even greater by using only the power of the sun by utilizing the unique properties of a new type of material called a metal-organic framework, or MOF, as described in their study published in the journal Science. The system then traps water vapor through a network of metal and organic molecules, which is released by employing heat captured from the sun.
Reports indicate that a kilogram of this material can potentially harvest 2.8 liters of water a day in environments with humidity levels as low as 20 percent without the need of an external power source. This prospect makes it attractive for use in arid or desert regions.
One last obstacle is air pollution. In some parts of the world, it may be necessary to add special filtration systems to make captured water safe for drinking. However, with the rapid advancement in technology, it is almost certain that this obstacle can be solved posthaste.
