The advent of graphene has opened new avenues for the design of high-performance metamaterial devices, particularly in the realm of electromagnetic absorption applications. This paper introduces a novel design for a broadband tunable graphene metamaterial absorber (GMMA) utilizing graphene. Through numerical simulations, our proposed GMMA demonstrates a absorption bandwidth of 3 THz (1.14 – 4.14 THz) with absorptivity exceeding 90% for both transverse magnetic (TM) and transverse electric (TE) modes. A comprehensive numerical analysis, using a transmission line equivalent circuit model, is conducted to find out the impedance components of all the corresponding layers, which can be significant to determine the impedance matching. The absorber exhibits wideband tunability, polarization insensitivity, and robust tolerance to structural variations, making it a promising candidate for diverse applications in the terahertz (THz) band especially in the antenna regime. Our proposed GMMA antenna can achieve a gain of 37.48 dB, a directivity of 32.81 dB, a return loss of -34 dB, and an efficiency of 99.96%. This research provides a valuable contribution to the development of tunable broadband GMMAs for THz frequencies, addressing the increasing demand for high-speed and efficient devices in the modern era of science and technology.

In this article, we present an innovative plasmonic lab-on-chip (LoC) sensor featuring three ports, utilizing a 1 × 2 demultiplexer to detect two separate samples without cross-contamination. The performance of the sensor is numerically investigated using the finite element method, yielding a maximum sensitivity of 865.9 nm per refractive index unit (RIU) and a figure of merit (FOM) of 58.4 in the 700-920 nm range. The proposed metal–insulator–metal (MIM) structure, incorporating a diamond-shaped silicon nanodot array with a perimeter of less than 100 nm, serves as a sensing surface, detecting changes in the refractive index (RI) of the surrounding medium. Our suggested sensor demonstrates an extraordinary transmission coefficient of around -18 dB, it surpasses classical optics predictions, and its nanoscale light confinement enhances interaction with analytes. Our LoC sensor, based on the MIM structure, achieves high accuracy and precision in measuring small RI changes, making it portable and suitable for on-site applications, and settings with limited resources. This sensor streamlines medical processes by rapidly detecting blood groups and diabetes levels with minimal sample volume, potentially improving patient care efficiency.

In this article, we introduce a novel comb shaped plasmonic refractive index sensor that employs a ZrN-Insulator-ZrN configuration. The sensor is constructed using Zirconium Nitride (ZrN), an alternative refractory material that offers advantages over traditional metals such as silver and gold, as ZrN is standard Complementary Metal Oxide Semiconductor (CMOS)-compatible and has tunable optical properties. The sensor has recorded a maximum sensitivity, figure of merit (FOM), and sensing resolution of 1445.46 nm/RIU, 140.96, and 6.91 × 10⁻⁷ RIU⁻¹, respectively. Beyond that, the integration of ZrN offers the sensor with various advantages, including higher hardness, thermal stability at high temperatures, better corrosion and abrasion resistance, and lower electrical resistivity, whereas traditional plasmonic metals lack these properties, curtailing the real-world use of plasmonic devices. As a result, our suggested model surpasses the typical noble material based Metal-Insulator-Metal (MIM) arrangement and offers potential for the development of highly efficient, robust, and durable nanometric sensing devices which will create a bridge between nanoelectronics and plasmonics.