Glassy sponge has better fibre optics than man-made

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from http://www.examiner.ie/breaking/2003/08/21/story110506.html

Scientists say they have identified an ocean sponge capable of transmitting light better than industrial fibre optic cables used for telecommunication.

The natural glass fibers also are much more flexible than manufactured fibre optic cable that can crack 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 fibres at cold temperatures using natural materials, a process materials scientists hope to duplicate in order to avoid the problems created by current fibre 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 fibres at the high temperatures needed for commercial manufacturing, Aizenberg said.

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 two to seven inches (five to 18 centimeters) long and each is about the thickness of a human hair.

The study, which appears 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. Biomimetics has driven a form of "bioprospecting" in the ocean, said Randy Kochevar, a marine biologist at the Monterey Aquarium in California.

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.