A water bottle that continually refills itself sounds less like a real world object and more like a convenient device in a video game. It’s appropriate then that an attempt to create such a thing is inspired by a bug.
The bug in question is the Namib Desert beetle, which lives in said region in southern Africa. The area of the desert where it lives gets just half an inch of rain a year. To harvest enough water to survive, the beetle uses its wings to catch fog droplets whenever there’s a damp breeze: the droplets are so small, they are carried in the wind rather than falling to earth.
The beetle wings are made up of a combination of hydrophilic (water attracting) bumps and hydrophobic (water repelling) troughs. That helps keep the droplets together long enough to build into tiny “puddles” that eventually become big enough to roll down the back to a part of the beetle’s body that effectively acts like a water bottle from which it can drink.
The technique has already been studied at the Massachusetts Institute of Technology and four graduates from the Boston area have now formed a company called NDB Nano. They are working on ways to mimic the hydrophilic/hydrophobic pattern on the surface of a water bottle.
Where the beetle is able to flap its wings, a bottle would need an electric fan. NDB Nano staff believe the power requirements for this are low enough that a small solar-charged battery would be sufficient.
Co-founder Miguel Galvez told the BBC that the company has already developed a proof of concept and is working on a functioning prototype. At the moment he believes this prototype could collect between 500 milliliters and 3 liters an hour depending on where it is used.
The company believes the technology could have a host of uses including allowing military staff to maneuver without having to choose between carrying large amounts of water or hunting down fresh sources; marathon and ultra-distance runners being able to rehydrate without needing to wait for scheduled water stations; automated watering systems in greenhouses; and improved dehumidifiers.
In theory the technology could also help residents of arid regions. However, the charity WaterAid says it wouldn’t be a complete solution as, while it could produce adequate amounts of drinking water, it likely wouldn’t be enough to support agriculture.
(Image credit: Hans Hillewaert via Creative Commons license)