Tuning the Resonant Properties of 3D Metamaterial Unit Cells via Anisotropic Coupling Mechanisms

A 3D cubic metamaterial with tunable resonant properties was fabricated and characterised experimentally. The cube comprises spiral resonators with high quality factors fabricated using Field’s metal injection. Investigating these spirals in a planar configuration shows that the coupling between them changes depending on their relative orientation. This anisotropy was utilised in a 3D cube, allowing to tune the number of resonant peaks appearing during excitation.