It's said that eating fish is food for the brain. Now it seems fish--specifically, skeletons of marine creatures--could lead to a brighter future for telecommunications networks.
Scientists from Lucent Technologies' Bell Labs have found that chalk-like calcite crystals in the skeletons of marine creatures known as brittlestars have a remarkable dual function: They act as both armor and as optical receptors for an all-seeing compound eye.
The scientists say that studies of this novel multifunctional biomaterial may lead to better-designed optical elements for telecommunications networks.
"This is an excellent example of something we can learn from nature," said Federico Capasso, physical research vice president at Bell Labs, in a statement. "These tiny calcite crystals are nearly perfect optical microlenses, much better than any we can manufacture today."
Brittlestars, also known as serpent stars, are marine invertebrates that usually have five thin long arms emanating from a small, disk-shaped body. They belong to the phylum of echinoderms, which also includes starfish, sea urchins and other related classes of marine organisms.
Analysis of bony structures in the arms of the brittlestar Ophiocoma wendtii show the presence of a regular array of spherical microstructures that look like lenses. Experiments subsequently showed that these microstructures, which are absent in closely-related but light-indifferent species of brittlestars, were indeed sophisticated optical elements that have the optimal design for focusing light.
The lenses focus light about 5 microns below their surface. Nerve bundles running through the skeleton underneath the lenses are thought to pick up the light signal. Acting together, thousands of calcite crystals form a kind of primitive compound eye that covers much of the organism's body, and researchers think this must be useful in detecting and escaping from predators.
The calcite microlenses expertly compensate for birefringence and spherical aberration, or physical effects common in lenses that distort light. Now, scientists want to mimic nature's success and design microlenses based on the brittlestar model. Such biomimetic lenses may prove useful as components of optical networks, and in chip design, where they could potentially improve optical lithography techniques.
"Biomimetics builds on nature's expertise," said John Rogers, director of nanotechnology research at Bell Labs. "In this case, a relatively simple organism has a solution to a very complex problem in optics and materials design."
"I have always been fascinated with nature's ability to perfect materials," said Joanna Aizenberg, the Bell Labs scientist who led the international research team of materials scientists, physicists, chemists and biologists. "The more you study biological organisms the more you realize how much there is to be learned from them."
The discovery was made by an international multidisciplinary team of researchers, comprising scientists from Bell Labs, the Weizmann Institute of Science in Israel and the Natural History Museum of Los Angeles County, and will be described in an article to be published in the August 23rd issue of Nature.
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