Inspired by spider webs, scientists harvest water from air

Jul 11, 2023

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Inspired by spider webs and beetles, scientists have conceived of an efficient way to harvest water from thin air by capturing water vapor and turning it into liquid.

This is according to a press release by the University of Waterloo published on Monday.

The researchers now hope their invention will address the world’s freshwater scarcity problem and offer a viable alternative to water collected from rivers, lakes, groundwater, and oceans.

The research was led by University of Waterloo professor Michael Tam and his PhD students Yi Wang and Weinan Zhao. It consists of sponges or membranes with a large surface area that continually capture moisture from their natural environment without the use of heavy machinery or complex processes.

The idea for the invention came from spider webs and beetles.

“A spider’s web is an engineering marvel,” said Tam, a University Research Chair in the field of functional colloids and sustainable nanomaterials. “Water is efficiently captured by the web. The spider doesn’t need to go to the river to drink, as it traps moisture from the air.”

Using a similar process, Namib desert beetles produce “water from thin air by leaning into the wind to capture droplets of water from the fog with their textured body armor. This allows the moisture to accumulate and drip into their mouths.”

To invent their new device, the researchers have put to use a process called biomimetic surface engineering. They have essentially recreated the beetle’s unique surface structure by using a cellulose-stabilized wax emulsion to construct surfaces that attract smaller water droplets while swiftly and efficiently releasing larger ones.

Better yet, the invention uses net zero carbon materials (natural and plant-based materials) to ensure the resulting technology is sustainable. These tools almost magically capture and repel water droplets by harnessing the power of interfacial science and nanotechnology.

Using a minimum amount of energy, the researcher’s invention captures water from the air and efficiently dehumidifies it. Since the solution is inexpensive, energy-efficient, and environmentally friendly, the researchers are now looking into scaling their process.

This is not the first development that sees water produced from thin air.

In April of 22, Interesting Engineering reported on a company called SOURCE Global that produced hydropanels that utilized solar energy to deliver clean drinking water from the air.

The firm’s onboard water reservoir could even be conveniently placed directly into a building's drinking tap and the solution processes the water to ensure improved taste.

"Girls and women spend an average of 200 million hours daily collecting water. That was the main motivation for our company — women shouldn't have to haul water anymore. It inspired Cody Friesen [the founder] to look into finding a way to tap this unlimited resource, which is water vapor in the air, and put it in the hands of people who need it," Thomas Borns, the US Direct Sales Manager at SOURCE Global, told IE in a video interview at the time.

Could it be that the air around contains all we need to survive? These inventions are definitely showing that with a little ingenuity water vapor can go a long way!

The study is published in Nature Water.

Study abstract:

Freshwater scarcity is becoming a global issue due to changing climatic conditions, which has stimulated the development of all-weather water harvesting technologies. Recent advances in regulating surface properties to tailor water capture/release behaviours have attracted increasing attention for water harvesting applications such as fog/dew harvesting, moisture harvesting, and solar evaporation. This Review provides an overview of the design of surfaces and the manipulation of active components to tune the behaviour of water droplets in different water harvesting systems. Taking inspiration from nature, we present a critical survey of the surface wettability, structures, and compositions used by various insects and plants to manage their water demands. We summarize the latest progress in developing desired surface properties and strategies to advance key processes in water harvesting such as droplet nucleation, growth and removal, vapour sorption–desorption, and evaporation. The challenges and opportunities to further develop a sustainable water harvesting system, encompassing both fundamental research and practical implementation, are highlighted.