Pulling Drinking Water Out of Thin Air

A new material being developed by scientists at Harvard University could achieve the feat of creating harvesting drinking water literally out of the air. Inspired by biology, this synthetic material is unique in that it mimics and fuses water collecting strategies from a number of plant and animal species including the Namib Desert Beetle, the spines of cactus plants and the Pitcher Plant.

At the core of this new material design is the biomimicry of the external bumps of the Namib Desert Beetle. The Harvard team already knew that the hydrophillic (water-attracting) bumps and the hydrophophobic (water-repelling) surroundings of the beetle’s shell helped them collect water content from the air. But through their studies, the team also found that the convex part of the bumps might have the potential to harvest water as well.

With the help of 3d modelling, the team further discovered that the water-trapping characteristics of this desert beetle could be enhanced by mimicking the geometry and slopes of cactus spines, which evolved through nature to direct water droplets down slopes. In addition to this, the team developed a nano-coating that emulates the slippery surface of the Pitcher Plan. This coating aids in greater water droplet formation as well as the direction of droplets downwards.

The resulting fusion of bio inspirations in the surface of this new material was found to make water droplets grow six times faster, increasing along with a rise in temperature. And the fusion of bio inspiration was key to the outcome. Chemical biologist Joanna Aizenberg from Harvard’s Wyss Institute for Biologically Inspired Engineering explains that ‘so far, we tend to mimic one inspirational natural system at a time.’

It is thought that this new design could be of great help in increasing water generation where it is scarce. But furthermore, it could also be used to enhance condensation in industrial machinery.

“Thermal power plants, for example, rely on condensers to quickly convert steam to liquid water,” said one of the team, Philseok Kim. “This design could help speed up that process and even allow for operation at a higher temperature, significantly improving the overall energy efficiency.”

The team is composed of researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences and the Wyss Institute for Biologically Inspired Engineering at Harvard.