Harvesting water from the air: Finding inspiration from beetles and spiders

Namib beetles.

A novel approach to capturing water vapour from the air attempts to mimic spider’s webs and the bodies of Namib desert beetles.

It involves the development of sponges or membranes with a large surface area that continually capture moisture from their surrounding environment.

“A spider’s web is an engineering marvel,” said University of Waterloo professor Michael Tam, a 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.”

Similarly, Namib desert beetles have no easy access to water but acquire water from thin air by leaning into the wind to capture droplets of water from the fog with their textured body armour. This allows the moisture to accumulate and drip into their mouths.

Tam is working on the project with PhD students Yi Wang and Weinan Zhao.

The group are engaged in biomimetic surface engineering for sustainable water harvesting. One technology is called atmospheric water harvesting. To mimic the beetle’s unique surface structure, the research group is designing a similar surface structure using a cellulose-stabilized wax emulsion to fabricate surfaces that attract tiny water droplets while swiftly releasing larger ones.

The fog-harvesting setup (image credit: University of Waterloo).

The group group is developing technologies that capture and repel water droplets by harnessing the power of interfacial science and nanotechnology. Tam has successfully developed superhydrophobic and waterproof paper. He is also engineering a smart and tunable surface that captures water from the air and dehumidifies it with seemingly minimal energy consumption. The next step is to develop a scalable process to engineer such surfaces.

Solar evaporation systems directly harvest solar energy, absorbing water and generating fresh collectible vapour through evaporation. Unique mushroom structures inspired the smart biomimetic structural designs for solar evaporation.

The proposed freshwater generation systems could be inexpensive, energy-efficient, and environmentally friendly.

In a recent publication in Nature Water, the group discuss several promising new water collection and purification technologies.

More information on the research is available in the video below.