Page 62 - Biomimetics: Technology Imitates Nature

Biomimetics: Technology Imitates Nature

100-Million-Year-Old Technology Under the Sea

When a submarine fills its ballast tanks with water, the ship becomes
heavier than water and sinks toward the bottom. If water in the tanks is
emptied out by means of compressed air, then the submarine surfaces.
The nautilus employs the same technique. In its body there is a 19-cm
(7.48 in) spiral organ rather like a snail’s shell, inside which are 38 inter-
connected “diving” chambers. To empty out the water; it also needs com-
pressed air—but where does the nautilus find the air it needs?
By biochemical means, the nautilus produces a special gas in its body
and transfers this gas to the chambers, expelling water from them to reg-
ulate its buoyancy. This allows the nautilus to dive or surface when hunt-
ing or chased by predators.
A submarine can only
venture safely to a depth of
about 400 meters (1,310 feet),
whereas the nautilus can eas-
ily descend to a depth of 450
meters (1,500 feet). 49

In order to dive or
surface, submarines
employ special com-
partments that serve
the same purpose as
those in the nautilus.
When these compartments (tanks) are
filled with air, the submarine floats. When
the air is replaced with water, it sinks. The
number of tanks that are filled with water
determines the underwater depth at
which the submarine runs.

Nautilus

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