One of the greatest difficulties of understanding the universe in the past has been that you can only examine those things that naturally exist. In addition the materials couldn’t do anything that couldn’t be done in nature. Metamaterials are a modern tool for both engineers and scientists allowing them to explore the possibilities of materials and matter in ways that you simply could never find in nature.
Metamaterials are by definition artificially created materials which have been engineered to do things that cannot be found in nature. They are able to among other things cause electromagnetic waves to interact with the materials allowing them to guide the waves. This can be compared to how a lens can focus light, but are not limited to the same limitations as naturally occurring materials¹.
One of the most primary effects that has been useful to use metamaterials to effectively create invisibility. It does this by changing how the material interacts with light rather than having it pass through it like air or glass. Instead, this material actually guide the light around the object. In this way you could make nearly any material invisible at any size and by coating other materials make nearly anything invisible. This has helped scientists understanding the nature of light and expanding hugely the possibilities of engineering².
The military engineers are naturally the most interested in the immediate advantages of this part of metamaterials. The ability to become invisible to light could also be used to make a plane even more invisible to radar than the current stealth planes. Expanding this out there are possibilities for buildings that can be hidden completely from sight. This is valuable for the military as well, but could also be useful in other ways as it becomes less costly. An unsightly factory could be stopped from hurting the view of a landscape or you could create windows in places where typical glass would be a structural weakness.
This ability to guide electromagnetic waves could also be useful in antennas³. These are able to bend radio waves more than normal as well which allows cell phone engineers to make smaller antennas. This type of ability could also be useful in the growing importance of wireless internet.
Metamaterials allow scientists to understand better the nature of matter by examining things that are not easy to otherwise see and learn better how things like light can be affected by material and the potentials for engineers are nearly endless as the ability to change how things look and react.
1- http://science.howstuffworks.com/invisible-tank1.htm
2- http://discovermagazine.com/2009/apr/10-metamaterial-revolution-new-science-making-anything-disappear
3- http://www.smallnetbuilder.com/content/view/30274/100/
