Metamaterials leverage field and wave propagation on the mesoscopic scale, by virtue of man-made structures that are greater than a molecule but smaller than the wavelength or field variation scale. They are materials whose electromagnetic, thermal or acoustic properties arise from their intricate internal structure, rather than just the material properties of their constituent elements.
Just as each individual molecule of a material affects how waves interact with it, it is possible to engineer small discrete shapes called unit cells into the material that have the effect of tailoring its properties to suit specific needs. So long as these unit cells are sufficiently small compared to the wavelength of the signal, they appear to the signal as a continuous surface.
Before the advent of metamaterials, wave propagation through a medium was thought of as a static property of that substance, similar to hardness or color. The importance of metamaterials is that they allow engineers to manipulate wave propagation by arranging the unit cells in different ways, and by either mechanically or electrically tuning each unit cell on command. By changing the electrical or mechanical characteristics of each individual element, the properties of the material as a whole can be effectively controlled to a high degree of precision. To give an example, although gold is a good conductor and reflects yellow light, one could design a metamaterial out of gold that was an insulator and appears red in color.
This design flexibility opens up numerous technological possibilities. For example, imagine antennas that can dynamically shape their radiation pattern without moving parts and without the expense of a phased array. Likewise, metamaterials enable a host of imaging products that operate by scanning only a subset of each frame. Acoustic metamaterials open up radical new ways of controlling sound and vibration.
The Metamaterials Commercialization Center, created by the Invention Science Fund, is at the forefront of this field and is actively seeking ways of bringing these technologies out of the lab and into the marketplace. The MCC has been working with many of the leading scientists in this area for over a decade and has assembled a talented team of scientists and engineers to bring metamaterial inventions into the marketplace. Below, we discuss just a small sample of the areas in which the MCC is working. To learn more or contact us directly, please use our contact form. We look forward to hearing from you.
Beam-shaping and beam-steering antennas form the backbone of modern communications, radar, and imaging. The devices used for beam-steering ranging from to parabolic dishes to phased arrays are all examples of coherent apertures. Metamaterials can be used to form the same coherent apertures, but with key advantages in cost, size, weight, and power. Active metamaterials enable all-electronic beam-steering without mechanical rotation gimbals. The low cost of metamaterial components also brings such electronic beam-steering into range of commercial markets as well as military applications.
Natural leveraging of resonant phenomena makes metamaterials perfectly suited for application to electronic filter networks. Among the components demonstrated include couplers, filters, and other waveguide components. Metamaterial design techniques enable high performance while eliminating costly and bulky aspects of classical filters.
The same design principles that enable novel electromagnetic materials can be extended to acoustic materials, where the wavelengths of interesting phenomena tend to be quite large (due to the much lower speed of sound compared to the speed of light). This opens up a very wide range of material and fabrication possibilities: 3D printing for instance, has been used to demonstrate novel metamaterial acoustic devices.
Above microwave frequencies in the range of terahertz (THz) and infrared (IR) the variety of responses found in natural materials tends to shrink. This, in turn, affects the variety and type of devices that can be constructed from natural materials. Metamaterials with designed responses offer a compelling solution to expand the diversity of choices and realize solutions to challenging IR/THz applications.