Tuesday, October 21, 2008

The Spider Silk

photo by shinichiro on flicker


For decades, scientist have studied the the silk produced by orb-weaving spiders.The Dragline silk is the strongest of the seven silks these spiders can spin which attracted most attention.It is tougher and more waterproof than silkworm strands, which are commonly used in clothing.

Mark Carwardine says in The Guiness Book of Animal Records 1995. "Spider silk is the strongest of all natural and man-made fibres.... It is even stronger than steel: the dragline of a European garden spider (Araneus diadematus), for example, can support a weight of 0.5 g (0.002 oz) without snapping, whereas a steel strand of similar thickness will snap under the strain of just 0.25 g (0.01 oz)."

The manufacture of industrial fibers such as Keviar requires high temperature and the use of organic solvents.In constrast,spiders produce silk at room temperature, using water as a solvent.Furthermore, dragline silk is tougher than Kevlar.

At How Stuff Works we are told. "Spider silk is extremely strong -- it is about five times stronger than steel and twice as strong as Kevlar of the same weight. Spider silk also has the ability to stretch about 30-percent longer than its original length without breaking, which makes it very resilient."

But replicating dragline silk is not easy, for the material is made inside the spider's body and the process is not yet fully understood. According to Cheryl Y. Hayashi , a biologist, that it is humbling to realize that a lot of very smart people are trying to replicate what the spider in our basements can do naturally (quoted in Chemical & Engineering News Magazine.)