Page 34 - Biomimetics : Biologically Inspired Technologies

Bar-Cohen : Biomimetics: Biologically Inspired Technologies DK3163_c001 Final Proof page 20 21.9.2005 6:40pm

20 Biomimetics: Biologically Inspired Technologies

pressurizing, and this is in contrast to nature which uses ambient conditions. Materials, such as
bone, collagen, or silk, are made inside the organism’s body without the harsh treatment that is used
to make our materials. The fabrication of biologically derived materials produces minimum waste
and no pollution, where the result is biodegradable, and can be recycled by nature. Learning how to
process such materials can make our material choices greater, and improve our ability to create
recyclable materials that can better protect the environment. There are also studies that are
improving prosthetics, which include hips, teeth, structural support of bones, and others. A brief
description of structural materials that are made by certain insects and birds is given in this section,
whereas Chapters 12 and 14 cover in greater detail the topics of biological materials and their
multifunctional characteristics.

1.6.1 Spider Web — Strong Fibers

One of biology’s best ‘‘manufacturing engineers’’ with an incredibly effective material-fabrication
capability is the spider. It fabricates the web (Figure 1.14) to make a very strong, insoluble,
continuous lightweight fiber, and the web is resistant to rain, wind, and sunlight. It is made of
very fine fibers that are barely visible allowing it to serve its function as an insect trap. The web can
carry significant amount of water droplets from fog, dew, or rain thus making it visible as shown in
Figure 1.14. The web structure in the photograph has quite an interesting geometry. It reveals the

Figure 1.14 (See color insert) The spider constructs an amazing web made of silk material that for a given
weight is five times stronger than steel.