Oct 17, 2020 - Science

Researchers build machine to extract drinkable water from air

MIT's prototype water harvesting device.

MIT's prototype water harvesting device. Photo: Alina LaPotin

Researchers developed a workable, solar-powered device that can extract drinkable water directly from the air, even in desert regions.

Why it matters: If the technology can be made commercially viable, it could help alleviate water scarcity in some of the world's driest regions.

What's happening: Researchers at MIT and several other institutions published a paper earlier this week describing how they were able to significantly boost the output of a prototype water-harvesting device.

  • The original design harnessed temperature differences within the device to draw in moisture from the air at night and release it the next day. But its utility was limited because it required specialized and expensive materials called metal organic frameworks.
  • The new design adds a second stage and makes use of a more common material called zeolite, doubling its capacity to generate water.

Details: While other harvesting technologies that can draw water from fog or dew exist, they generally require humidity levels of at least 50%, if not much higher.

  • The new design, by contrast, can work with humidity levels as low as 20%, good enough to operate on an average day in a desert city like Phoenix.

The catch: Even the improved system can still only produce 0.8 liters of water per square meter per day, while humans need at least 2.5 liters per day to survive.

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