Spider silk inspires water harvesting technology

Image: Marc Clinton Labiano

Spider silk is the inspiration for a new technique to address water scarcity in areas with limited access to drinking water.

The artificial microfibre threads, developed by researchers at Beihang University in China, are based on the fine silk produced by spiders. Covered with spiral-shaped bumps that can attract large droplets of water, they mimic the way spider silk naturally collects dew.

The spiral helix creates a larger surface area for a water droplet to attach to and forms more robust bonds with it, which means each bump can carry 2,000 times more water than the volume of the bump itself. The innovative technology could provide a more energy-efficient method for harvesting water from fog, compared to traditional condensation techniques.

To make the bumps, a plastic microfibre is coated with a layer of hydrophilic titanium dioxide, creating bulges in the fibre. The researchers then used a high temperature to crack the bumps into a spiral or helix shape.

Why do we need to find new ways of harvesting water?

In order to meet the water needs of the future, we need to find new and innovative ways to harvest water. Atmospheric water harvesting (AWH) is a promising technology that could help to address the water crisis.

AWH is the process of extracting water vapour from the air and converting it into liquid water. Many different AWH technologies are available, but they all work on the same basic principle. Air is passed through a condenser, which cools it below its dew point. This causes the water vapour in the air to condense and form liquid water. The liquid water is then collected and stored.

Water capture techniques have a number of advantages over extracting water from traditional sources. It is a renewable resource, unaffected by droughts or floods, does not pollute the environment, and can also be used in remote areas that do not have access to traditional water sources.

AWH also has some challenges. It requires energy to cool the air, and the efficiency of AWH technologies varies depending on the climate. AWH is not a perfect solution for all water problems and is most effective when used with a combination of different technologies.

However, the design of these artificial microfibre threads opens up possibilities for large-scale water collection, offering a promising solution for water scarcity challenges.