An ocean sponge living in the deep sea grows thin glass
fibers capable of transmitting light better than industrial
fiber optic cables that are now used for telecommunication.
The natural glass fibers are also more flexible than
manufactured fiber optic cable that cracks if bent too
far.
"You can actually tie a knot in these natural biological
fibers and they will not break -- it's really quite amazing,"
said Joanna Aizenberg, who led the research at Bell
Laboratories.
The glassy sponge, nicknamed the "Venus flower basket," grows
the flexible fibers at cold temperatures, using natural
materials, a process materials scientists hope to duplicate
in order to avoid the problems created by current fiber optic
manufacturing methods that require high temperatures and
produce relatively brittle cable.
The sponge also is able to add traces of sodium to the fibers
which increase their ability to conduct light, something that
cannot be done to glass fibers at the high temperatures
needed for commercial manufacturing, Aizenberg said.
"One of the challenges of technology is doping the glass
structure with additives that improve optical properties,"
she said. "If we understand exactly how we can deposit sodium
in glass fibers at low temperatures as nature does, we can
control all the properties."
The sponge grows in deep water in the tropics. It is about a
foot and a half tall with an intricate silica mesh skeleton
that also serves as a home for shrimp. The glass fibers form
a crown at its base that appear to help anchor the sponge to
the ocean floor. The fibers are about 2 to 7 inches long and
each is about the thickness of a human hair.
The study, which appeared in the journal Nature,
details one of the latest discoveries in the emerging
field of biomimetics -- the effort to understand how
biological systems are engineered and apply the principles to
technology.
"We can draw it on paper and think about engineering it but
we're in the Stone Age compared to nature," said one
scientist.
Discoveries in recent years include an enzyme that improves
laundry detergent, taken from bacteria that breaks down fats
in cold water; a glowing protein from jellyfish that allows
surgeons to illuminate cancerous tissue while they operate to
remove it; and another enzyme that improves DNA testing,
drawn from bacteria that live near hydrothermal vents at the
ocean bottom.
The sponge study follows an earlier discovery by Aizenberg
that a starfish called the brittlestar is coated with tiny
lenses that act as a collective "eye," offering engineers a
model for creating sensors and guidance systems. Both
discoveries show how valuable life in the ocean can be to
society and how much of the ocean remains to be explored.
