In Frank Herbert’s book Dune the inhabitants of a desert planet collect water using giant “windtraps,” now we can do the same on earth. Researchers at MIT have built a prototype, which can be easily scaled up, that can capture a lot of water from even the driest of places. Basically, air is filled with moisture and when it flows through the wind collector it comes in contact with a slightly charged surface that sucks the water right from the air. The amount of power needed is negligible, which means that the device can run using only solar panels.
The researchers built a small prototype water collector that contains a thin layer of MOF powder. The powder absorbs water vapor until it is saturated.
“Once you achieve that maximum amount,” Wang says, “you apply some type of heat to the system to release that water.”
And when the water is released, it collects in the bottom of the prototype.
There are other compounds that can suck water from the air, zeolites for example, but Wang says it takes a significant amount of energy to get these materials to release the water. Not so with a MOF device. “The amount of energy required is very low,” she says.
In the prototype, the heat needed to drive the water out of the MOF comes from ambient sunlight — no external power supply is needed.