Page 38 - Biomimetics: Technology Imitates Nature

Biomimetics: Technology Imitates Nature

Once the spider’s chemical miracle
can be replicated fully, then a great many
useful materials can be produced: safety
belts with the requisite elasticity, very
strong surgical sutures that leave no
scars, and bulletproof fabrics. Moreover,
no harmful or poisonous substances
need to be used in their production.
Spiders’ silk possesses the most ex-
traordinary properties. On account of its
high resistance to tension, ten times
A detailed view of the spigots. more energy is required to break spider

silk than other, similar biological materi-
als. 35
As a result, much more energy needs to be expended in order to
break a piece of spider silk of the same size as a nylon thread. One main
reason why spiders are able to produce such strong silk is that they man-
age to add assisting compounds with a regular structure by controlling
the crystallization and folding of the basic protein compounds. Since the
weaving material consists of liquid crystal, spiders expend a minimum of
energy while doing this.
The thread produced by spiders is much stronger than the known
natural or synthetic fibers. But the thread they produce cannot be collect-
ed and used directly, as can the silks of many other insects. For that rea-
son, the only current alternative is artificial production.
Researchers are engaged in wide-ranging studies on how spiders
produce their silk. Dr. Fritz Vollrath, a zoologist at the university of
Aarhus in Denmark, studied the garden spider Araneus diadematus and
succeeded in uncovering a large part of the process. He found that spiders
harden their silk by acidifying it. In particular, he examined the duct
through which the silk passes before exiting the spider's body. Before en-

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