Harvesting Water as Inspired by a Darkling Beetle
Water is a scarce commodity in dry regions so scientists have come up with an ingenious way of collecting water from fog to provide relief to people living in these areas. The idea is borrowed from a beetle that lives in the desert and is able to keep itself alive by trapping water on its body, the Namib or Darkling beetle.
Such a technique of harnessing water would be both environmentally friendly and a revolutionary way of harvesting water particularly in the dry areas where it is scarce.
The Darkling Beetle
The darkling beetle is a small bug that lives in harsh and dry conditions, and the nature of its shell makes it a master water collector. Its hardened shell contains tiny grooves or bumps where water is condensed and channelled to the beetle’s mouth.
The beetle is able to trap water or fog by sticking the back part of its body facing the foggy wind. This behaviour is known as fog-basking. This position is just as important to water collection as the surface is. In addition, the shell is made out of a slick wax that resembles Teflon so water easily flows off its body and into the mouth.
Condensation is process that involves drawing water from the atmosphere. It happens as a result of moist air coming into contact with a cold and dry surface, forming water droplets that flow down the surface once. This is how water collection is done in desert regions where the temperatures drop drastically at night making it easier to collect water via condensation.
After spending a considerable amount of time studying the water collecting mechanism of the Namib Beetle, researchers have imitated this astounding method by creating water collection nets and even bottles.
Water Collection Methods
1. Water Collection Net
The net is hung between two poles in a vertical position. It has a large surface area to maximise the amount of fog it traps. Fog goes through it whilst leaving behind droplets of water which flow down and are collected. This method has been adopted in countries like Chile where they have a lot of fog, and Israel which is a mostly a desert but is now a leading exporter of agricultural products!
2. Liquid Collecting Permeable Structure
A net is however not the only surface that is used to collect water. A research team led by Kyoo-Chul Park of Harvard, for example, created a surface replicating the beetle’s shell. The surface is made up of hundred of grooves that grow wider at the bottom to permit easier runoff. Its slick waxy surface made from a pitcher plant further aids in the runoff. This invention has resulted in increased efficiency in industries that rely on condensation not to mention provision of water to areas that have it in short supply.
3. Dew Bank Bottle
Another fantastic invention is the Dew Bank Bottle that is placed outside at night to collect water. It is made of stainless steel because of its cold property. Since it gets really cold during nights in the desert, the bottle gets colder than the air so water droplets condense on the surface. The droplets immediately collect into the bottle through openings only wide enough for water to penetrate to prevent contamination.
It also has an uneven surface to increase the surface area for water collection. In the morning, water collected can be drank as it’s free from germs. Its inventor claims that it can collect as much as a full glass water, so if each person had their own bottle this would definitely make a difference. It could provide water to the thousands of children living in deserts.
Water harvested from fog is quite clean, lacking microorganisms and bacteria so it’s not only perfect for drinking but also for irrigating plants. Additionally, installation and maintenance of fog-harvesting technology has little to no impact to the environment. No energy is required in this process so toxic gases are not released to the atmosphere. It’s absolutely environmentally friendly.
Water is critical to life. It’s really sad when there are people in the world who are dying due to lack of water yet there such ingenious ways of tapping water! These methods, if implemented, are bound to give water security to millions all across the globe.