There has been a surge of interest in the uses of artificial materials to expand the range of electromagnetic properties. Artificially structured media is that which results from a macroscopic arrangement of two or more distinct materials.

The basic definition of Metamaterials in the context of the DARPA (Defense Advanced Research Projects Agency) Metamaterials Program is that they are a new class of ordered composites that exhibit exceptional properties not readily observed in nature. It should be noted that Metamaterials originally referred to artificial composites that achieve material performance beyond the limitations of conventional composites. Most scientific activities with regards to Metamaterials centers on its electromagnetic properties even if the original definition included many other material properties.