One Beetle's Way of Getting Water from Fog

The long legged Namib beetle from the Namib desert faces towards the wind. Its outer wings are against it. There, drops of water form from the fog, collecting to form bigger drops that can counter the force of adhesion and roll to the beetles mouth. It usually drinks at dawn. The timing is crucial for the beetle's survival, because later during the day the sun evaporates the fog, and all that is left is the intense heat of the desert. Fog is made up of many water droplets that are so small that they are carried by the wind and air. It is very hard to collect this water. They need to be brought together so gravity can bring them down.

Andrew R. Parker, a zoologist at the University of Oxford, and Chris R. Lawrence, an investigator at a defense research firm, discovered that the beetles' wings have bumps that attract water and small valleys that repel it. The bumps collect drops of water until they can get big enough to fall into the small valleys, which repel water, so the drops roll down to the beetles mouth because of the angle of the beetle's body. Parker and Lawrence were able to develop a surface similar to the beetle's wings. They put glass spheres in a small layer of wax. They conducted experiments and found that if these spheres were arranged and ordered, more water was collected. Other materials similar to the glass and the wax could be used later.

This article is an example of hypothesis science. The scientists observed a beetle that collected water, and tried to find ways to imitate the beetle's surface through experimentation. They came up with that the best solution was an ordered array of glass spheres in a small layer of wax, and that other ways were not so efficient.

This is important for humans because Parker and Lawrence hope to someday use this to clear fog in airports and as a new way of obtaining drinking water, especially in very dry places where people have very little.

Author: Adam Summers
Title of Article: Like Water Off a Beetle's Back
Journal: Natural History
Date Published: February 2004
Pages: 1