IIT Guwahati researchers develop 'novel material' to harvest water from humid air

Researchers at IIT Guwahati on Tuesday claimed to have developed a method to tap non-traditional source of water: humid air.

A team of researchers said they developed a "novel material" that can efficiently harvest water from humid air, something which can reduce drinking water woes in the country.

The team led by Uttam Manna, an associate professor of Chemistry and Centre for Nanontechnology, IIT Guwahati said they used the concept of chemically patterned Slippery Liquid-Infused Porous Surface (SLIPS) for the first time, to effectively harvest water from moist air.

Such water-harvesting techniques use the concept of hydrophobicity or water-repelling nature of some materials, Manna said in a statement on Tuesday.

The researchers produced a patterned hydrophilic SLIP by spraying a sponge-like porous polymeric material on top of a simple A4 printer paper. Further, chemically modulated hydrophilic spots were associated on the coating prior to lubricating with two distinct types of oils – natural olive oil and synthetic krytox. This surface could harvest water from foggy/water vapour laden air without the need for any cooling arrangement, it said.

Led by Manna, the team comprising research scholars Kousik Maji, Avijit Das and Manideepa Dhar has published their work in journal of Royal Society of Chemistry.

"With increasing water scarcity throughout the world, there have been attempts to collect and conserve water through non-traditional means. Scientists have turned to nature to design ways of water harvesting. For example, in regions of the world with naturally scanty rainfall, plants and insects have devised ingenious strategies to pull and collect water right out of the air. Mimicking this, scientists worldwide are trying to build technologies that can pull out water from thin air, both literally and figuratively," Manna said.

Given that more than 50% of India’s population has no access to safe drinking water and about 200,000 people die every year due to lack of access to safe water, the "inexpensive method" for harvesting water from water vapour or fog droplets in air can potentially alleviate the water scarcity issues in the country, said the statement.

Apart from water harvesting, SLIPS could be used for other purposes, such as easily cleanable household appliances, in underwater hulls of ships and submarines to prevent bio-fouling and anti-icing windows for aircraft.