In a world where many regions struggle to secure enough water, MIT researchers have developed a new water harvester capable of extracting sufficient fresh water from the air to meet the daily needs of several people.

Water harvesters typically use adsorbent materials to collect water on their surfaces. This new device from MIT maximizes exposure to air with a series of vertical fins spaced 2 mm (0.08 in) apart. These fins are constructed from copper sheets sandwiched in copper foams and coated with a specialized zeolite material, renowned for its water adsorption properties. After an hour, the fins become saturated with water, at which point the copper sheets are heated to release the collected water. Repeating this cycle 24 times a day in air with 30% humidity (considered arid), the harvester can produce up to 1.3 L (0.3 gal) of drinkable water per day per liter of the adsorbent coating. When scaled up, this equates to 5.8 L (1.5 gal) per kilogram (2.2 lb) of material used per day, enough to meet the daily water needs of several people.

This water harvester stands out from others for a few reasons. It collects significantly more water than many existing devices, which often only capture around 100 ml (1.5 oz) of water per kilogram of material. Although a design from Johns Hopkins University boasts an impressive 8.66 L (2.3 gal) per day per kilogram of material, these tests were conducted at 70% humidity. The MIT design, however, can operate continuously day and night, unlike others that collect water overnight and release it in the morning.

One potential drawback is that the system requires energy to release the water, with the base of the device needing to reach 184 °C (363 °F). However, the team suggests that the device can utilize waste energy or heat from other systems, such as buildings or vehicles, to achieve this temperature.

This innovative approach to water harvesting could be a game-changer, particularly in arid regions, by providing a sustainable and efficient way to generate fresh water from the air.

By Impact Lab