This paper presents the detailed design configuration and investigation of a small-scale dual-band metamaterial absorber (MTMA) for solid and liquid sensing applications. The overall dimension of the MTMA unit cell is 10 × 10 × 1.57 mm³ and constitutes an affordable FR-4 substrate. The absorber exhibits dual absorption peaks at 3.470 GHz for the S-band and 7.219 GHz for the C-band, respectively. Both absorption characteristics have been validated through comprehensive simulation and experimental procedures. The dual-band absorption rate exceeded 99% during simulations, and experimental validation showed an absorption rate above 98%. For sensing applications, various solid materials, including different Rogers substrates ( RT 5880, RT 5870, RT 4003 and RT 4835) and liquids such as sunflower and crown oil, were utilized. Our findings indicate that the proposed MTMA achieves a maximum Q-factor of 191 and a sensitivity of up to 2.5 for both solid and liquid sensing applications compared to previous studies. The simulation and experimental validation of the result indicate that suggested MTMA can be effectively used in different sensing applications such as the medical and communications industry.

This research presents the design and analysis of a compact metamaterial (MTM)-based star-shaped split-ring resonator (SRR) enclosed in a square, constructed on a cost-effective substrate for liquid chemical sensing applications. The designed structure has dimensions of 10 × 10 mm² and is optimized for detecting adulteration in edible oils. When the sample holder is filled with different percentages of oil samples, the resonance frequency of the MTM-based SRR sensor shift significantly. The measured results demonstrate that the proposed SRR sensor is superior in terms of sensitivity and quality factor compared to studies in the literature. The proposed sensor shows superior performance in sensitivity and quality factor (Q-factor) compared to existing sensors in the literature. It exhibits a remarkable sensitivity of 0.92 with a frequency shift of 760 MHz for adulteration detection, which is higher than sensors with shifts ranging from 140 to 600 MHz reported in previous studies. Additionally, the design has a high Q-factor of 149, indicating its efficiency in determining adulteration in edible oils. Additionally, the error rate in detecting adulteration is minimal at 3.1%, a significant improvement over prior sensors, which have error rates as high as 8%. These enhancements highlight the sensor’s potential in applications requiring precise, efficient, and cost-effective detection of edible oil adulteration, thus offering a significant advancement in both performance and practical utility over traditional methods.

This article presents a novel real-time meta-material (MM) sensor based on a non-invasive method that operates in microwave frequency ranges at 8.524 GHz to measure blood glucose levels with quality factor 184 is designed and fabricated. A cross enclosed between two square shapes produces a strong interaction between glucose samples and electromagnetic waves. In this study, 5 were tested noninvasively using the proposed glucose resonant sensor with a range of glucose-level changes from 50 to 130 mg/dL. For this range of glucose-level changes, the frequency detection resolution is 5.06 MHz/(mg/dL), respectively. Despite simulations, fabrication procedures (F.P.) have been carried out for more precise result verification. For the purpose of qualitative analysis, the proposed MM sensor is considered a viable candidate for determining glucose levels.

This research provides a detailed explanation of the design, simulation, and experimental of quad-square metamaterial-based negative-index unit cells for S-band applications. The Computer Simulation Technology 2022 licensee version was utilized to design and obtain numerical results for the unit cell. The proposed unit cell for the metamaterial has dimensions of 5 × 5 × 1.57 mm3. The substrate chosen was FR-4, resulting in a substantial effective medium ratio value of 19.07. A series of systematic parametric studies were conducted to optimize the quad square metamaterial structure. Key parameters, such as substrate types, unit cell arrays, thicknesses of substrate, and split gaps, were varied to determine their impact on the structure. The validated equivalent circuit result was compared to the simulated results, showing a significant agreement. The demonstrated correlation between simulation and experimental data highlights the dependability of the proposed quad-square metamaterial, positioning it as a viable option for a range of electromagnetic applications, such as communication systems, sensors, and imaging devices.

This study presents the design and analysis of a Quad-band perfect metamaterial absorber (PMMA) with five distinct absorption peaks, achieving absorption rates consistently above 96%. The absorption performance is thoroughly examined by varying the structural parameters to elucidate the mechanisms underlying the multi-band absorption. Additionally, we investigate the sensing capabilities of the absorber by analyzing its response to changes in the refractive index and thickness of the analyte. Sensitivity and figure of Merit (FOM) are utilized to evaluate the sensing performance. The sensor demonstrates refractive index and thickness sensitivities of 1.5 THz RIU⁻¹ and 0.5 THz RIU⁻¹, respectively, with corresponding FOMs of 97.424 and 91.633. These results surpass those of prior terahertz regime designs, highlighting the superior sensing capabilities of the proposed absorber. The proposed design is promising for sensing, filtering, and stealth technology applications.