Metamaterials Provide Novel EM Capabilities (.PDF Download)

Sept. 6, 2017
Metamaterials Provide Novel EM Capabilities (.PDF Download)

Metamaterials are engineered materials that are capable of characteristics not found in naturally occurring materials. They can be fabricated with negative refractivity, which causes an electromagnetic (EM) wave to reflect in a direction opposite of what might be expected. Since metamaterials can be structured to affect sound and light waves as well, a great deal of experimentation has been performed with these materials to control audio sound levels and even to control the amount of light reflecting from an object, possibly to the point of invisibility—having all light reflecting away from a viewer. One of the attractions for performing research on metamaterials, which can be produced by three-dimensional (3D) metal printers, is that they can render an object invisible to sound, light, and EM waves, enabling them to be used as a “cloaking” device against radar detection.

Metamaterials are composites formed with an artificial periodic structure. It is the configurations of these periodic structures that result in “unnatural” material characteristics, including the modification of a material’s electrical permittivity (ε) and magnetic permeability (μ). By designing the configuration of the periodic structures, the dispersion, refraction, and reflection of an EM wave can be controlled.