Technologically speaking, the latest fiber-optic cables have nothing on a small deep-sea sponge. Scientists report today in the journal Nature that the so-called glass sponge Euplectella contains outgrowths that are similar in structure to fiber-optic cables but much less likely to break.
Euplectella is commonly called the "Venus flower-basket" because its silica skeleton forms an intricate cage, which often houses a pair of mating shrimp. Tiny projections known as spicules extend from the base of the structure (see arrow in image). These spicules are similar in size to conventional fiber-optic cable and made from the same material. When Joanna Aizenberg of Bell Laboratories/Lucent Technologies and her colleagues tested their optical properties they found that the sponge parts had a comparable index of refraction to man-made cables and would thus be equally good at transmitting information. Moreover, the spicules are surprisingly resistant to breakage, which is a problem for telecommunication wires. "You can tie a knot in this fiber [a spicule] and it doesn't break," Aizenberg notes.
The natural fibers are also advantageous because Euplectella forms them at ambient temperatures. Manufacture of fiber-optic cables, in contrast, must take place at high temperatures, which makes it difficult to add specialized impurities that could improve the light-guiding properties of the cable. (These added dopants are subsequently removed during cooling in a process called devitrification.) Euplectella, the authors conclude, should "shed light on low-temperature, biologically inspired processes that could give rise to better fiber-optical materials and networks."