Dielectric metamaterials and composites in the age of 3D printing, and directional cloaking

The rapid evolution of additive manufacturing techniques has the potential to revolutionize a wide range of fabrication-limited fields. In this article, we apply plastic additive manufacturing to the creation of radio-frequency electromagnetic devices, demonstrating a metamaterial-like unidirectional cloak. Enabling this all-dielectric cloak is a computational boundary-optimization design approach significantly different from traditional metamaterial design techniques. For a subset of applications, the new all-dielectric cloak proves to work as well as well as previous metal-inclusive designs.