30 July - 5 August 2012 - orsam

In the report Fog Collection by Mimicking Nature, published in the 2010 Journal of Biomimetics,
Biomaterials and Tissue Engineering, Ahmad and other co-writers describe how the beetle travels to
the top of sand dunes laden with early morning fog. The fog water droplets are attracted to the top of
micro bumps on the exoskeleton of the beetle, and the drops then roll down to the waxy troughs,
delivering very small amounts of water at a time.
The micro bumps are hydrophilic, which means they readily absorb water and the troughs are
hydrophobic; that is, they repel water. These troughs are filled with nanopores, micro fluid channels
and nano wax crystallites. Droplets with 15-20 micrometer diameters are attracted by the micro
bumps and roll down the troughs on the beetle‘s back. These rolling drops eventually fall into the
beetle‘s mouth as it pushes its mouth backward to obtain water.
―The design of our fog collector is based on creating a nano-micro hybrid surface structure, which
mimics the skin of the desert beetle,‖ Ahmad explains.
He added that as soon as the fog comes in contact with the stainless steel meshed net, water droplets
start to form and roll down the drainage channel and collect in a water tank down the slope of the
sand dunes. Underground PTFE water storage tanks with hand pumps are recommended to prevent
contamination by dust and sand. The water is then filtered through rubber tire powder, making it
pathogen free and suitable for human consumption.
He said this method, although initially costly, offers a sustainable fog collecting system that can be
adopted for arid and semi-arid regions of Pakistan and similar areas.
―Pakistan Researchers Use Nanotechnology to Make Water From Fog ―, 01/08/2012, online at:
http://www.ooskanews.com/daily-water-briefing/pakistan-researchers-use-nanotechnology-make-water-fog_23660
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