A prototype device for generating water from the air. Image: The University of Texas at Austin.
A prototype device for generating water from the air. Image: The University of Texas at Austin.

For significant portions of the globe faced with water-shortage problems, a beacon of hope may be on the way: the ability to easily turn hot air into drinking water.

For the past few years, researchers at the University of Texas at Austin have investigated the potential of using the moisture present in the air as a source of drinking water for drought-stressed populations. In a paper in the Proceedings of the National Academy of Sciences, they now report a significant breakthrough in their efforts to create drinkable water out of thin air: a molecularly engineered hydrogel that can create clean water using just the energy from sunlight.

With this hydrogel, the researchers were able to pull water out of the atmosphere and make it drinkable using solar energy, at temperatures as low as 104°F (40°C), aligning with summer weather in Texas and other parts of the world. That means people in places with excess heat and minimal access to clean water could someday simply place a device outside, and it would make water for them, with no additional effort necessary.

“With our new hydrogel, we’re not just pulling water out of thin air. We’re doing it extremely fast and without consuming too much energy,” said Guihua Yu, a materials science and engineering professor in the Cockrell School of Engineering’s Walker Department of Mechanical Engineering and Texas Materials Institute. “What’s really fascinating about our hydrogel is how it releases water. Think about a hot Texas summer – we could just use our temperatures’ natural ups and downs, no need to crank up any heaters.”

The device can produce between 3.5kg and 7kg of water per kilogram of gel materials, depending on humidity conditions.

A significant feature of the hydrogel is that it can be transformed into microparticles called ‘microgels’, which unlock the speed and efficiency improvements that bring this device much closer to reality.

“By transforming the hydrogel into micro-sized particles, we can make the water capture and release ultrafast,” said Weixin Guan, a graduate student in Yu’s lab and one of the leaders of the research. “This offers a new, highly efficient type of sorbent that can significantly enhance the water production by multiple daily cycling.”

The researchers are now pursuing additional improvements to the technology, with an eye toward turning it into a commercial product. One focus area is optimizing the engineering of the microgels to further improve their efficiency.

Scaling up is an important next step. The researchers aim to translate their work into tangible and scalable solutions that can be used worldwide as a low-cost, portable method for creating clean drinking water. This could be life-changing for countries such as Ethiopia, where almost 60% of the population lacks basic access to clean water.

“We developed this device with the ultimate goal to be available to people around the world who need quick and consistent access to clean, drinkable water, particularly in those arid areas,” said Yaxuan Zhao, a graduate student in Yu’s lab.”

The team is working on other versions of the device made from organic materials, which would reduce costs for mass production. This transition to more commercially viable designs comes with its own challenges in scaling production and maintaining durability over the product’s lifespan. Research is also focused on making the devices portable for various application scenarios.

This story is adapted from material from the University of Texas at Austin, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.