Composite Materials used in advanced models

Carbon fiber
 (alternately called graphite fiber) is a material consisting of extremely thin fibers about 0.0002-0.0004 inches (0.005-0.010 mm) in diameter and composed mostly of carbon atoms. The carbon atoms are bonded together in microscopic crystals that are more or less aligned parallel to the long axis of the fiber. The crystal alignment makes the fiber incredibly strong for its size. Several thousand carbon fibers are twisted together to form a yarn, which may be used by itself or woven into a fabric. Carbon fiber can be combined with a plastic resin and wound or molded to form composite materials carbon fiber reinforced plastic (also referenced as carbon fiber) to provide a high strength-to-weight ratio material. The density of carbon fiber is also considerably lower than the density of steel, making it ideal for applications requiring low weight. The properties of carbon fiber such as high tensile strength, low weight, and low thermal expansion make it very popular in aerospace, military, and motor sports, along with other competition sports. The unique appearance of carbon fiber also makes it popular for stylistic purposes.

 
¼ micron  diameter carbon filament (running from bottom left to top right) compared to a human hair.
Fiberglass
 
 (also called fiberglass and glass fiber) is material made from extremely fine >fibers of glass. It is used as a reinforcing agent for many polymer products; the resulting composite material, properly known as fiber-reinforced polymer (FRP) or glass-reinforced plastic (GRP), is called “fiberglass” in popular usage.

 Aramid=Kevlar
 
  Aramid fibers are a class of heat-resistant and strong synthetic fibers. They are used in aerospace and military applications, for ballistic rated body armor fabric, and as an substitute .They are fibers in which the chain molecules are highly oriented along the fiber axis, so the strength of the chemical bond can be exploited.
 Kevlar is the registered name fore Aramid.