Design of wide bandwidth metamaterial for biosensor and wireless application

. A., Kishor K., Sinha R.

In this paper, we present an analysis and design of a metamaterial as the perfect absorber and refractive index sensor in the far-infrared (IR) region, utilizing the finite element method (FEM). The structure consists of a metal resonator on a silicon dielectric with a bottom copper layer beneath the dielectric. Our results demonstrate that the designed structure achieves nearly perfect absorption of transverse electric (TE) polarization at a resonance wavelength of λ r =9.40µm. This occurs because of the perfect impedance matching condition, which achieves a 99.47% absorption efficiency. This condition is also sensitive to the angle of incidence and causes minimal reflection at the resonating wavelength of λ r . This characteristic makes the designed metamaterial structure suitable for use as a sensor. The structure enables maximum electric field confinement in the gap region (g) of the split ring resonator (SRR) at the metal-dielectric interface. The resonance wavelength can be effectively tuned and optimized by varying the gap size (g), dielectric material, dielectric thickness (t d ), copper layer thickness (t c ), and incident angle of the metamaterial absorber (MA). The absorption peak shows a highly sensitive response to changes in the refractive index of the surrounding medium, with a sensitivity of 1600 nm/RIU. This absorber, with its excellent absorption in the far-IR spectrum, holds promising potential for applications in energy harvesting and IR sensing.

Sharma V., Kalra Y., Sinha R.K.

Abstract Chiral metasurfaces provide ultracompact devices for polarization modification and detection. In this paper, high linear dichroism (LD) and dual band circular dichroism (CD) using superstructural chiral structure with inbuilt resonance cavities based on metal perovskite metal layer is proposed. Under circularly polarised incident waves, the metasurface exhibits a dual-band CD with a maximum value of 0.81. On the other hand, the suggested design also accomplishes efficient LD of 0.95. Additionally, independent control over each resonance wavelength may be attained by modifying parameters inside each resonance cavities. This will significantly contribute to the advancement of tunable dichroic devices and flat polarization optical components in optical integrated systems.

Gupta R., Dwivedi R.P., Sbeah Z.A., Sorathiya V., Alwabli A., Alghamdi A., Faragallah O.S.

This paper presents a plasmonic metamaterial sensor utilizing gold resonator gratings with different radii for the cylindrical gratings. The sensor is simulated using the finite element method (FEM) in the infrared wavelength range of 0.7 to 2.5 µm. The sensor structure consists of six layers, with the gold resonator on the top, beneath it a Ge–Sb–Te (GST) substrate sandwiched between two silicon (Si) substrates and then a MXene substrate sandwiched between two SiO2 substrates. The design exhibits distinct reflectance characteristics across the proposed range, which is suitable for different sensing applications. A comparison is made between the two states of GST (amorphous and crystalline) to investigate the sensitivity of the device. Geometrical parameters, including the height of GST and Si, are optimized, changing the oblique incident of light, and three types of comparisons are conducted. Firstly, a sensitivity comparison is made between this work and previously published research. Secondly, a quality factor and figure of merit comparison is performed. Lastly, a sensitivity comparison is made between different sensing techniques and the technique employed in this work. After optimizing the design parameters, the device demonstrates the highest detection sensitivity, yielding results of sensitivity equal to 800 nm /RIU. The proposed design-based metamaterial can be utilized as a lab-on-chip sensor.

Sbeah Z., Sorathiya V., Chauhan D., Alwabli A., Jaffar A.Y., Alghamdi A., Faragallah O.S.

This work presents the design and numerical simulation of a multilayered surface plasmon resonance (SPR) sensor incorporating borophene and germanium (Ge)-antimony (Sb) telluride (Te) (GST) as active plasmonic materials. The sensor design is modelled in two dimensions (2D) and exhibits a broad refractive index detection range, from 1 to 2.5 µm/RIU. The proposed design utilizes a top-analyte configuration, where the target analyte is placed directly on the sensor surface for interaction. Various metals like Ag (silver), Au (gold), Al (aluminium), and Cu (copper) are considered for investigation of the influence of the middle metal layer on the overall optical response. The GST layer is modelled as a two-state material, accounting for its amorphous (aGST) and crystalline (cGST) phases. It allows for exploring the sensor’s tunability based on the GST material’s phase state. Furthermore, comprehensive optimization and validation processes are conducted for various device parameters, including layer thicknesses, widths, and the type of metal employed. These optimizations aim to achieve optimal sensor performance regarding sensitivity and overall functionality. Notably, the simulations reveal distinct bandwidths and resonant regions for both aGST and cGST phases of the GST layer. In conclusion, this proposed sensor provides potential application in biomolecular and chemical testing due to its tunable characteristics and broad refractive index detection range.

Sharma V., Kalra Y., Sinha R.K.

Metalenses can potentially reduce the size and complexity of existing cameras, displays, and other optical devices, owing to their capability of flexible manipulation of the polarization, amplitude, and phase of light. However, a high meta-atom aspect ratio is still a drawback as it causes difficulty in fabrication of metalens. In this paper, we present the first demonstration of a human-eye inspired metalens with a much lower and constant meta-atom aspect ratio while maintaining the polarization under an arbitrarily polarized excitation in the near-infrared waveband.

Ankit, Baitha M.N., Kishor K., Sinha R.K.

In this paper, design and fabrication of a dual-band near-zero index metamaterial (MTM) structure using copper on an epoxy resin fiber (FR-4) dielectric substrate is reported for refractive index sensing applications. The primary objective is to achieve dual-band operation spanning a 1–15 GHz frequency range, with a specific focus on achieving a broad bandwidth in the C-band. The resonance of the MTM structure was ascribed to the coupling of plane electromagnetic waves with surface plasmon polaritons on the structure, resulting in a quadrupole plasmon resonance mode. Furthermore, transmission characteristics of the fabricated MTM structure were experimentally measured and found to align closely with the simulated results obtained through the finite element method in COMSOL Multiphysics. The designed MTM structure demonstrates negative and near-zero permittivity at resonance frequencies, enabling left-handed and near-zero index behavior in dual microwave frequency bands. Under room temperature conditions, the MTM sensor exhibited sensitivities of 1 GHz/RIU and 3 GHz/RIU at resonance frequencies of 2.7 and 7.3 GHz, respectively. Consequently, the MTM structure exhibits significant potential for diverse applications, serving as a valuable component in sensors, detectors, and optoelectronic devices operating in the GHz region.

Agarwal P., Kishor K., Sinha R.K.

Ankit, Kishor K., Sinha R.K.

Abstract We propose modeling and design of a low-loss all-dielectric metasurface (DM), comprised of Silicon on Insulator (SiO2) substrate to demonstrate a perfect reflector in the visible spectrum. The proposed metasurface unit cell consists of V and W shapes arranged in a mirror image configuration, with nanometre-sized gaps (g) between them. A narrow peak with a nearly 100% reflectance and a broad perfect reflectance spectrum is observed within the visible region (400–700 nm) of the electromagnetic spectrum. The effective electromagnetic parameters were also analyzed for electric and magnetic dipole resonance. The electric and magnetic field distributions at the resonant wavelength were also analyzed for the proposed structure. By altering the gap region ‘g’, the thickness of the dielectric Silica layer (ts ), and the Si resonator (t m), the proposed structure exhibits tunable characteristics. We have successfully illustrated the consistent position of the scattering parameter’s response, regardless of the structure’s rotation, concluding the homogeneity of the designed structure across the entire visible spectrum. The all-DM exhibits a unique combination of features, including a distinct and wide reflectance spectrum as well as a tuned and enhanced electric field which makes it an ideal platform for the applications in filters, color printing, low-loss slow-light devices, and nonlinear optics.

Ankit, Kishor K., Sinha R.K.

This paper delves into the intricacies of designing, fabricating, and characterizing a metasurface exhibiting epsilon-negative (ENG) and near-zero index (NZI) properties. Specifically, it focuses on an eye-shaped coupled circular split ring resonator (CC-SRR) metasurface, crafted from copper on an epoxy resin fiber (FR-4) dielectric substrate material. The design is further optimized to induce resonance frequencies at approximately 7.5, 8.8, and 13.4 GHz within the C, X, and Ku bands, respectively. Utilizing the COMSOL Multiphysics and CST Microwave Studio simulation tools, the structural design is developed to ascertain its electromagnetic properties across the 1–15 GHz frequency spectrum. Experimental measurements of the transmission characteristics of the fabricated metasurface align closely with the simulated results. The electromagnetic field distributions of the proposed metasurface structure are scrutinized, revealing tunable characteristics contingent upon variations in the thickness ( $${t}_{s}$$ ) of the dielectric substrate material and the copper resonator thickness ( $${t}_{m}$$ ). Additionally, a theoretical model employing an equivalent circuit, featuring various inductor (L) and capacitor (C) components, is presented to compare against simulated results for the targeted resonance frequencies.

Chen Z., Lin Y., Salehi H., Che Z., Zhu Y., Ding J., Sheng B., Zhu R., Jiao P.

Dadouche N., Mezache Z., Tao J., Ali E., Alsharef M., Alwabli A., Jaffar A., Alzahrani A., Berazguia A.

The early detection and diagnosis of cancer presents significant challenges in today’s healthcare. So, this research, suggests an original experimental biosensor for cell cancer detection using a corona-shaped metamaterial resonator. This resonator is designed to detect cancer markers with high sensitivity, selectivity, and linearity properties. By exploiting the unique properties of the corona metamaterial structure in the GHz regime, the resonator provides enhanced interaction of electromagnetic waves and improved detection skills. Through careful experimental, simulation, and optimization studies, we accurately demonstrate the resonator’s ability to detect cancer. The proposed detection system is capable of real-time non-invasive cancer detection, allowing for rapid intervention and better patient outcomes. The sensitivity value was confirmed through simulation, estimated at 0.1825 GHz/RIU. The results of two different simulation methods are used: the simulation software CST Studio Suite (version 2017) based on the finite element method (FEM), and the simulation software ADS (version 2019) based on the equivalent circuit method, thereby increasing confidence in the convergence of simulation and measurement results. This work opens new avenues for developing advanced detection technologies in the field of oncology, and paves the way for more effective cancer diagnosis. The experimental study verified that this realized sensor has very small frequency shifts, significantly small electrical dimension and miniaturization, high sensitivity, and good linearity. The suggested configurations showed a capacity for sensing cancer cells in the GHz regime.

Sbeah Z.A., Adhikari R., Sorathiya V., Chauhan D., Ponomarev R.S., Dwivedi R.P.

This paper presents a plasmonic metamaterial sensor utilizing an I-shaped gold resonator. The sensor is simulated using the finite-element method (FEM) to detect gas and liquid (ethanol solutions) in the infrared wavelength range of 0.5–2.5 µm. The sensor structure consists of three layers, with a VO2 substrate sandwiched between a bottom SiO2 substrate and a top gold resonator. The design exhibits distinct absorption characteristics across the range of 0.5–2.5 µm, tailored for different gas and liquid sensing applications. A comparison is made between the two states of VO2 to investigate the sensitivity of the device. Geometrical parameters, including height and width, are optimized, and three types of comparisons are conducted. First, a sensitivity comparison is made between this work and previously published research. Second, a Quality factor and Figure of Merit comparison is performed. Finally, a sensitivity comparison is made between different sensing techniques and the technique employed in this work. After optimizing the design parameters, the device demonstrates the highest detection sensitivity for gas and ethanol solutions, yielding results of 2800 (nm/RIU) and 2600 (nm/RIU), respectively. The proposed I-shaped gold-based metamaterial exhibits the potential to be utilized as a lab-on-chip biosensor.

Ankit, Kishor K., Sinha R.K.

This paper reports the design and performance characteristics of perfect reflector tunable metamaterial (MTM). The reported MTM parameters are optimized to achieve nearly 100 % reflection at resonance wavelength (λr) 1550 nm. The propagation characteristic of the proposed MTM structure was obtained by the finite element method (FEM). The electromagnetic parameters such as effective permittivity (εeff.), effective permeability (µeff.), and effective refractive index (ηeff.) are calculated using Nicolson-Ross-Weir (NRW) method and analysed for the 1400–1700 nm wavelength range. It has been observed that the proposed MTM structure exhibits µ-negative (MNG) metamaterial characteristics as well as a negative effective refractive index at λr. Further, it has also been shown that by varying the number of arrays of unit cells and using a mirror image of the unit cell, the operating wavelength can be easily tuned as required for different applications. The overall perfect reflectance and the tunable performance of the proposed MTM has a potential applications in the design and development of compact photonic devices such as optical resonators and antennas.

Agarwal P., Kishor K., Sinha R.K.

Terahertz (THz) metasurface sensors have recently received considerable attention. We report an ultrasensitive dual-band metasurface (DBM) sensor in this work. The reported DBM sensor is a micro-rod periodic structure based on all InSb semiconducting material . The DBM is realized for the dual-band resonance behaviour at 1.911 THz and 1.985 THz. The corresponding Q factor for the DBM sensor is obtained at the higher side, around 174.36 and 181.11 at room temperature (T = 300 K). The geometrical parameters dependency for the resonance frequency of the proposed DBM is analysed and reported. Further, the refractive index sensitivity is observed by varying the surrounding’s refractive index from 1.00 to 1.05 (aqueous glucose solution). It is reported that, at room temperature, the proposed DBM sensor shows a sensitivity of 1800 GHz/RIU and 1900 GHz/RIU at the corresponding resonance frequencies 1.911 THz and 1.985 THz respectively. The temperature sensitivity of the proposed DBM is also explored and reported. Furthermore, the figure of merit (FOM) of the proposed DBM sensor is 164 and 173 respectively at corresponding resonance frequencies. So, the reported DBM structure could also find potential applications in the THz region as sensors, detectors, and other optoelectronic devices . • Terahertz (THz) metasurface sensors have recently received considerable attention due to its sensing applications. • A dual-band metasurface (DBM) sensor has been proposed based on all Indium Antimonide (InSb) that can simultaneously work as a temperature and refractive index (RI) sensor in the THz region. • The proposed DBM shows high Q factor of 174.36 and 181.11 corresponding to the resonance frequencies 1.911 THz and 1.985 THz respectively. • The sensitivity is 1800 GHz/RIU and 1900 GHz/RIU respectively when it is used as refractive index sensor. • The proposed design of ultrasensitive DBM sensor could be an alternative strategy for high-quality multi-function sensors for medical diagnostics and biochemical sensing.

Sbeah Z.A., Adhikari R., Sorathiya V., Chauhan D., Rashed A.N., Chang S.H., Dwivedi R.P.

In this paper, a biosensor based on a Y-shape gold resonator metamaterial structure is simulated to detect biomaterials, such as hemoglobin and urine, using Ge–Sb–Te (GST) as a phase changing material in the infrared wavelength range from 1.2 µm to 1.7 µm. Here, the Y-shaped resonator is placed on top of the GST layer. Simulation results shows that the maximum detection sensitivities for hemoglobin and urine are 2453 nm/RIU and 3986 nm/RIU, respectively. However, maximum sensitivity of 4096 nm/RIU is achieved for urine after optimizing the design parameters. A comparison is made based on the absorption responses with the variation of wavelengths for the two different phases of GST, which are crystalline GST and amorphous GST. In other words, the proposed Y-shape gold-based metamaterial shows the potential ability to be used as a lab-on-chip biosensor.