Page 114 - Biomimetics: Technology Imitates Nature

Biomimetics: Technology Imitates Nature

Stenocara: A Fully-Fledged Water Capturing Unit

In the desert, where few living things are to be found, some species
possess the most astonishing designs. One of these is the tenebrinoid bee-
tle Stenocara, which lives in the Namib Desert, in Southern Africa. A report
in the November 1, 2001, edition of Nature describes how this beetle col-
lects the water so vital to its survival.
Stenocara’s water capture system basically depends on a special fea-
ture of its back, whose surface is covered with tiny bumps. The surface of
the regions between these bumps is wax-coated, though the peaks of the
bumps are wax-free. This allows the beetle to collect in a more productive
manner.
Stenocara extracts from the air the water vapor that occurs only rarely
in its desert environment. What is remarkable is how it separates out the
water from the desert air, where tiny water droplets evaporate very quick-
ly due to heat and wind. Such droplets, weighing almost nothing, are
borne along parallel to the ground by the wind. The beetle, behaving as if
it knew this, tilts its body for-
wards into the wind. Thanks to
its unique design, droplets
form on the wings and roll
down the beetle's surface to its
mouthparts. 77
The article about Stenocara

included the following com-
ment: “The mechanism by which
water is extracted from the air and
formed into large droplets has so
far not been explained, despite its

biomimetic potential.” 78

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