by Aja Hannah
What if humans could pull water out of the air using just a hollowed-out mound of dirt?
An assistant professor at the University of Akron has a theory that termites in Namibia and India are already doing this — and that the mounds could be scaled up for human consumption.
Hunter King’s journey with termites began in 2014 and 2015, when he studied termite mounds on the plains of Namibia and southern India as a postdoc at Harvard. They were attempting to measure the air flow within the termite mound, which almost acted like a set of lungs for the whole organism.
During their study, during the hottest parts of the day, water would drip out of a tube that was attached to an instrument inside the termite mounds. Strange. Hunter filed this curiosity away in his mind.
When Hunter was setting up his lab at the University of Akron, where he now works in the department of Polymer Science in the Goodyear Polymer Center, he and his researchers learned about a new material that can pull water from the air.
“There’s a material that is extremely sorbent, meaning it takes in a lot of moisture in the vapor phase from the humidity in the air. The material is put in a box. At night, it [the box] stores up a lot of moisture in the material. In the day, the sun burns off the moisture quickly and you have a high concentration of moisture in the air. The water then condenses on another plate,” Hunter says.
This new material, developed by MIT, is expensive to make and easy to break. It also contains chemicals that can be toxic.
While trying to think of a simpler way to get water from the air, it occurred to Hunter that there was a biological system that might already be applying the same idea: The one created by termites.
“I had thought I was done with termites,” he chuckled.
Hunter is a physicist by choice. He came to Akron from Harvard because there was an open position in the Biomimicry Research and Innovation Center. But ever the accidental biologist, Hunter couldn’t deny that there were strange, unknown mechanics waiting to be solved in the simple structure of the termite mounds. “The mound is made out of a material that is extremely sorbent and the system already uses thermal cycling,” he says.
From all appearances, the termites seem to harvest moisture using an entirely passive process. The only active steps in the process is the initial construction of the structure. The water pulls itself without human intervention. The materials to build the mound are natural and can be found locally. Compared to other water capture methods, a scaled-up mound would be clean, free of toxic materials and not easily damaged by the elements.
Currently, researchers at the UA Goodyear Polymer Center are working on securing funding and creating the tools they will need for research in the field. They will test their theory by following the moisture levels inside and outside the mounds.
In 2014 and 2015, Hunter and his team at Harvard had to build many of their own tools for this research. In the extreme temperatures and remote area of Namibia, the scientists could not risk the instruments breaking, misreading levels, or being damaged by the termites without being able to fix the instruments and calibrate them by themselves. So the researchers made or modified their own CO2 device and anemometer to fit the termite mounds and withstand brief attacks.
Now, some of the instruments they are building are sensors to measure the water uptake and soil moisture. The aim of the sensors is to measure the change in water uptake between day and night.
Once Hunter can get funding, the crew will return to Africa and India to start gathering data. Then they will analyze the data and write up the research to be peer-reviewed and published in a journal.
Science is methodical, however, so results are not expected to be out for a few years.
Aja Hannah is a writer, traveler, and mama. She believes in the Oxford comma, cheap flights, and a daily dose of chocolate.
Photos used with permission from Hunter King.