Slashdot Mirror
Sea Sponges Master Nano-technology
Mick Ohrberg writes "It has been discovered that sea sponges utilizes a biomolecular mechanism to direct nanofabrication of silica to create microscopic glass fibers. It's a protein that acts as a catalyst for the formation of glass from the biomineral. What's it all lead to? Hopefully a way to achieve nanostructural fabrication at low temperatures, instead of in vacuum and at high temperatures as with current technologies."
Most people don't realize the coolness of biominerals. Although engineers can make materials with better specific properties, we are still hard pressed to be able to match their combined properties. (eg: building materials with the strength/weight ratio of wood)
Nature tends to work with really lousy starting materials which ultimately limits the total performance of those materials. Nontheless, the performance that evolved biomaterials manage to eek out of those materials is quite impressive. For example - the calcium carbonate (chalk) mother of pearl of abalone shell has a total material toughness that is in the same range as nanostructured boron carbide. If we could nano/microstructure our materials after biominerals, a 10-20 fold increase in the materials properties of those materials would not be impossible to believe.
Another good example is tooth enamel. Most people think that tooth enamel is some sort of featureless white material. If you actually look at enamel under magnification, after a quick acid etch to bring out the features, it looks like burlap. It's actually a 3-D woven calcium hydroxyapatite fiber matrix composed of millions of interwoven ceramic fibers that are woven in all three dimensions in a specific fashion that prevents crack propagation. Each fiber is also composed of hundreds of tiny ceramic nanofibers - each being about 40x60 nm single crystals. There are some researchers that believe these nanocrystallites can be over 1mm in length despite their thinness.
The arrangement of the weaving of the larger fibers is uniquely tailored per tooth to maximize the overall strength of the tooth. For example, your incisors and molars and even different portions of those teeth have different weaving paterns that serve to maximize the strength of the tooth with respect to the type of chewing action that it normally sees.