Dr. Eden at the University of Illinois has developed a 3D microplasma photonic crystal which provides the ability to introduce or completely suppress attenuation resonances at will, in the microwave, millimeter wave, and terahertz spectral regions, while minimizing insertion loss. This complex 3D photonic crystal is comprised of a 3D-printed polymer scaffold, and free-standing arrays of polyimide capillaries.
Since the capillaries are suspended in free space on the scaffold, electromagnetic structures can be placed on or around the microtubes. One example of this involves depositing metal films onto each capillary with precise periodicity. In this way, each pair of neighboring metal film rings in the 3D array are effectively coupled and constitute a capacitor, creating extremely versatile, and tunable crystal performance.