Fiber-Optic Sponge Makes Deep-Sea Lamps
Last year, it was announced that a deep-sea sponge named the Venus Flower Basket possessed glass strands similar to fiber optic cables (see 08/20/2003 headline). Now, a five-member team from Bell Labs has performed the first detailed optical analysis of the fibers. They indeed found these structures to be “remarkably similar to commercial silica optical fibers and are capable of forming an effective fiberoptical network.” Their findings are published in PNAS.1
The sponge’s fiber optics, though, are superior to man-made ones in four respects:
- Focus: “Other interesting design elements include terminal lens-like extensions located proximally and barb-like spines located along the spicule shaft. The presence of these lens structures at the end of the biofibers improves the light-collecting efficiency [that] offers an effective fiber-optical network with selected illumination points along the length of the crown-like fibrous network surrounding the cylindrical skeletal lattice.”
- Cool: “Second, the formation of the biosilica fibers occurs at ambient temperatures and pressures.” Man-made glass fibers are made at high temperatures. “Their complex structure and composition are encoded in the organism and are controlled by specialized organic molecules and cells. The low-temperature formation of silica in organisms, as an alternative to the high-temperature technological process, is a subject of extensive studies.”
- Dope: “The low-temperature synthesis brings about an extremely important feature: the ability to effectively dope the structure with impurities that increase the refractive index of silica. Our elemental analysis showed, for example, the presence of sodium ions in the entire fiber, particularly in the core. Sodium ions (and many other additives) are not commercially viable optical fiber dopants because of manufacturing challenges, including devitrification at high processing temperatures. In the case of these spicules, however, the presence of sodium ions results in the increase of the refractive index to values approaching and even exceeding that of vitreous silica.
- No Stress: “Another advantage of the low-temperature synthesis is evidenced in the lack of the polarization dependence on the refractive index. Birefringence in commercially prepared fibers often occurs as a result of the residual thermal stresses in the fibers upon their cooling. Ambient condition formation of the spicules in biological environments prevents the development of any residual thermal stress.
The authors are not sure how the sponge uses its technology. Typically, this species inhabits deep waters near hydrothermal vents, where the only light is from bioluminescent organisms or chemoluminescence. They offer a suggestion that it might act as an underwater lamp for symbiotic organisms: “Our results suggest that if such sources exist within or in close association to the basalia of E. aspergillum, their light might be efficiently used and distributed by the sponge. Such a fiberoptical lamp might potentially act as an attractant for larval or juvenile stages of these organisms and symbiotic shrimp to the host sponge.”
Their final paragraph sums up the wonder of this creature’s amazing manufacturing ability:
In conclusion, we have demonstrated an example of nature’s ability to evolve highly effective and sophisticated optical systems, comparable and in some aspects superior to man-made analogs. High fracture toughness arising from their composite structure, the presence of index-raising dopants, the degree of silica condensation, and the absence of residual stress in these fibers suggest an advantage of the protein-controlled, ambient temperature synthesis favored in nature. Whether these optical properties are biologically relevant or not, the mechanisms of the formation of silica spicules in E. aspergillum are inspiring to materials scientists and engineers. We believe, therefore, that this system represents a new route to improved, silica-based optical fibers, constructed by using a bottom-up approach.
1Aizenberg et al., “Biological glass fibers: Correlation between optical and structural properties,” Proceedings of the National Academy of Sciences USA, www.pnas.org/cgi/doi/10.1073/pnas.0307843101 (published online before print on 03/01/2004).
Mother Nature, being blind, would not make a lamp. Let’s object when scientists use the word “evolve” as a synonym for “engineer”. Nature cannot “evolve” a “highly effective and sophisticated optical system.” Highly effective and sophisticated systems are products of engineering. Engineering requires intelligence and purpose.
This sponge, first named by creationist Richard Owen in 1841, is a natural wonder. Another wonder is how Darwinists think Nature Inc. can get any manufacturing done, with their pointy-haired boss (chance) managing a crew of blind, deaf and dumb Dilberts (natural selection). The competition, Intelligent Design Unlimited, puts out a catalog that is a work of art.