Metamaterial-inspired 2D cavity grating with electromagnetically induced reflection as a glucose sensor

Abstract

A three-dimensional structure is designed, fabricated, and measured to achieve electromagnetically induced reflection (EIR) using metamaterial-inspired 2D cavity grating (MICG). The unit cell is composed of a orthogon ring resonator (ORR), a circle ring resonator (CRR), and the metal cavity. The physics mechanism of EIR is a weak hybridization between the ORR and CRR at 15.15 GHz, which exhibits a high reflection coefficient of 95%. We use the electric and magnetic field distributions to analyze and verify this physics mechanism. The geometric parameters of the ORR, CRR, and metal cavity have a profound influence on the reflectance spectra. In addition, the proposed MICG can be used to detect the concentration of the glucose solution (GS) as the liquid sensor, and sensitivity (S) reaches up to 3.26 GHz/RIU (refractive index unit). The figure of merit (FOM) is calculated as 8.15, which shows favorable sensing in the microwave sensor. Furthermore, the proposed MICG has potential applications to detect different liquids.