A team of researchers from the University of California, Berkeley, and the Massachusetts Institute of Technology has developed a new device that uses solar energy to harvest water out of thin air, a recent study published in Science reports.
The team built the machine with a special material known as metal-organic framework (MOF). This substance combines different metals — such as magnesium or aluminum — with organic molecules to form a hard, porous structure able to store both liquids and gases.
To create the device, researchers developed a zirconium-based material that binds water vapor. This allows the device to absorb condensed water during the night and then use a series of porous crystals to evaporate it again during the day. As sunlight heats up the MOF, it drives the water down towards a condenser where it forms into liquid water and drips into a collector.
Early testing showed the device can harvest 2.8 liters of water per kilogram of MOF each day. In addition, it required no additional energy input, Tech Times reports.
Early forms of the device were first developed over 20 years ago. However, the technology has been adapted over 20,000 times with no success. The new machine may change that trend by finally creating a working model that can reliably harvest water in a brand new way.
“This work offers a new way to harvest water from air that does not require high relative humidity conditions and is much more energy efficient than other existing technologies,” said study co-author Evelyn Wang, a mechanical engineer at the Massachusetts Institute of Technology, in a statement.
Researchers have high hopes for the machine. Not only do they believe it could lead to new off-grid water supplies and bring water to people all over the world, they think it could one-day power entire households as well. This is because the device is able to work in both wet and dry climates. Testing showed that it could collect 12 ounces of water — the basic water requirement for survival in the desert — in about one hour.
“It’s not just that we made a passive device that sits there collecting water; we have now laid both the experimental and theoretical foundations so that we can screen other MOFs, thousands of which could be made, to find even better materials,” said study co-author Omar Yaghi, a faculty scientist at Lawrence Berkeley National Laboratory. “There is a lot of potential for scaling up the amount of water that is being harvested. It is just a matter of further engineering now.”