How we can harvest drinking water from thin air

By Mark Waghorn via SWNS

Drinking water could be harvested from thin air using a technique inspired by desert plants and insects.

An almost limitless supply exists in naturally occurring sources such as fog and dew.

Cacti capture moisture by collecting and absorbing water molecules with their spines.

A similar phenomenon occurs in beetles which use tiny grooves or bumps in their hard shells.

They stick their backs to face the wind - channeling it into their mouths. The behavior has been dubbed "fog-basking."

Now scientists have achieved the same feat through smart energy converters called organic crystals.

A quarter of the world's population, nearly two billion people across 17 countries, are facing drought and famine over the next few years.

Project leader Dr. Pance Naumov, of New York University's Abu Dhabi lab, said: "Our team has discovered a new way to move water across a dynamic solid surface, a fundamentally new underlying principle of water collection.

"This can provide an inspiration for emerging technologies that could potentially maximize the efficiency of experimental systems used for the collection of aerial humidity."

He added: "The findings may lead to the creation of naturally occurring sources of water such as dew and fog - used by some desert plants and animals for survival."

The U.S. group achieved spontaneous condensing from vapor to liquid form by moving water slowly over the crystals.

This was found to be caused by changes in the width of small channels that appear over time and guided it across the surface.

The study in Nature Chemistry was inspired by plants, said Dr. Naumov.

He explained: "The motion of water on solid surfaces is one of the most fundamental phenomena found in nature.

"Through millennia-long evolutionary processes, surfaces of natural organisms have been optimized for efficient transport of water for a variety of life-supporting functions.

"Plants have been seen to do this by moving water against gravity."

Organic crystals are a new class of materials that serve as energy converters for emerging technologies.

By 2025 severe global water shortages and hunger will affect 1.8 billion people due to the loss of fertile farming lands.

Alternative harvesting techniques could alleviate the foreseeable socioeconomic impacts.

The study described the process in which tiny particles of dust and metal were carried on the surface of crystals of hexachlorobenzene - a compound used as a fungicide.

They have a rigid topography with defined parallel channels. The motion was found to be caused by condensed aerial water.

It migrates through the channels due to changes in their cross-section and width.

Autonomous water flow has previously been achieved using surface chemical modifications or on the surface of natural systems - such as some plants and insects.

The latest work sheds fresh light on the water collection mechanisms of biological structures. It also presents a fundamentally different water transportation method.

It is feared climate change will make dry regions drier and wet areas wetter - exacerbating the crisis.