Interconnected four split rectangular ring resonator flexible metamaterial for microwave sensing application.

Metamaterial sensors are gaining popularity for their numerous application possibilities, including sensing, imaging, energy harvesting, explosive detection, military radar, wavelength detection, and other sensor applications. This work presents a simple interconnected four-split rectangular ring resonator metamaterial (MTM) for microwave sensing applications. The novelty of the proposed MTM is reusability since it can detect sensitivity utilizing both of its sides in two distinct methods. It has an electrical size of approximately 0.178 λ × 0.178 λ. The MTM unit cell demonstrates transmission resonance with Mu Negative (MNG) metamaterial properties for both the C and X-band. It has an excellent effective medium ratio (EMR) of 5.57 at 6.7 GHz and 4.33 at 8.6 GHz, which indicates its compactness and efficacy. Two sensing methods are investigated to determine which is more effective for sensitivity measurement and its potential in microwave sensing applications. The resonance frequency fluctuates based on the permittivity and refractive index changes. The MTM unit cell amplifies this resonance with the E-field intensity. The MTM demonstrates flexibility features for various bending degrees. The measured findings demonstrate that the proposed metamaterial has excellent sensitivity, high Q-factor (Q-factor > 10), and FoM for its first method. The sensitivity, Q-factor, FoM, flexibility and good EMR results suggested that the proposed MTM is a viable solution for microwave sensing applications.