Copyright © 2007 Dorling Kindersley
Materials scientists combine atoms in new ways to produce new materials with SMART properties. Imagine a window that changes color to control the room temperature, or artificial arteries that pump blood around the body—these new materials are being developed, tested, and used now.
Most new materials are developed from existing materials. Scientists try out new combinations of elements. They apply heat and pressure to materials to impart new properties.
Different properties are needed depending on where the materials are used. Materials for use in the human body must be nontoxic and resistant to corrosion by blood and other body fluids. New packaging materials should be cheap to produce, easy to recycle, or biodegradable.
The latest carbon fiber sports rackets and bicycles are as light as wood but as strong as steel. Diamond is the hardest material—the bonds between its carbon atoms are strong because they are arranged in a 3-D structure like a honeycomb. Carbon fibers are strings of carbon atoms. The bonds between the atoms give the fibers strength and stiffness.
A material that responds to its environment, like the chameleon’s skin, is a smart material. Smart clothes could control your body temperature, light up in the dark, or even keep themselves clean.
Alloys of nickel and titanium have shape memory. The pattern of the atoms changes when the metal is bent or twisted, but when the metal is heated, the atoms spring back into their original positions. Some eyeglasses have frames made from memory alloys.
Some new polymers (plastics) conduct electricity. Electric currents may make them emit light as well. Video screens made from these polymers could be as thin and flexible as sheets of paper, and could lead to ultra-thin cell phone displays. In the future, it may be possible to spray a video screen onto a T-shirt!