Metamaterials are a new class of synthetic materials with properties unlike anything found in the natural world. Some have been designed to act as invisibility cloaks, others as superlenses, antenna systems, optical sensors, solar cells or highly sensitive detectors.
To understand metamaterials, you must first learn about electromagnetic energy. When you tune your radio, watch TV, send a text message, or pop popcorn in the microwave, you are using electromagnetic energy. Electromagnetic energy travels in waves and spans a broad spectrum from very long radio waves to very short gamma rays. Our eyes can only detect a very small portion of this spectrum called visible light.
Naturally occurring matter behaves based on the molecules that make it up. For instance all natural matter reflects and refracts light; how much light it reflects and refracts depends on how the electromagnetic waves of the light interact with these molecules.
Metamaterials are a structured composite material that is engineered and constructed to respond to select parts of electromagnetic energy to produce specific results. While natural substances derive their electromagnetic properties from their atomic composition, metamaterials gain theirs from deliberately designed internal structures. For example, metamaterials are created using select materials in combination, like gold and copper in different shapes and patterns to combine the properties of the materials changing how it reflects or refracts electromagnetic waves.
Metamaterials can be engineered to access a wide range of electromagnetic properties some for the very first time including negative electrical permittivity, negative magnetic permeability, and negative refraction index.
Metamaterials have a variety of applications reminiscent of science fiction, such as cloaking devices that could make an object invisible. However, the focus of Intellectual Ventures Lab’s Center for Metamaterials is on more practical applications of the material such as satellite user terminals to connect planes, trains, and automobiles to broadband service.
Check out this video (featuring apocolyptic voiceovers) on metamaterials made by the University of Southampton, UK.
Photo: David Schurig