Liquid Crystals in Metamaterials
Poised to deliver advances in electromagnetic technologies, the field of metamaterials is rapidly expanding the range of electromagnetic properties available in materials by leveraging structured composites to generate targeted response outside of what is available in conventional materials. While novel and useful electromagnetic properties are the genesis of metamaterials research , the field has expanded to include acoustic/mechanical systems  and thermal materials [3, 4] as well. Structured electromagnetic materials have a long history in research  and this latest incarnation was spurred by the work of Pendry  and Smith et al.  on creating materials with artificial negative refractive index to demonstrate phenomena predicted by Veselago  decades ago. Many excellent references for a general understanding of metamaterials are available that describe the physics and research of these interesting and potentially useful systems in great detail and we direct readers to these references for background information in order to better cover the topic at hand. In short, metamaterial systems typically rely on sub-wavelength features or inclusions, sometimes called meta-atoms, with a structurally defined response, such as a shaped metallic or dielectric inclusion that possesses a resonance, ...