Micro and Nanoelectronics Devices, Circuits and Systems

The structural, optical, and magnetic characteristics of undoped and Ni-doped ZnO [Zn(1−x) NixO] films synthesised by the sol-gel technique were reported in this work. The films’ polycrystalline nature is confirmed by X-ray diffraction structural investigation. The intensity of the corresponding diffraction peak (101) increases with increasing Ni doping concentrations. The average crystallite size of the films ranges from 13 to 21 nm. The optical studies of ZnO film have shown a high transmittance (~80%) in the visible range with a large bandgap (Eg ~ 3.23 eV). The optical bandgap is initiated to be reducing (Eg ~ 1.75 eV) abruptly for the [Zn(1−x) NixO] film. The vibrating sample magnetometer analysis exhibit the diamagnetic properties of the film after Ni doping. The Ni-doped ZnO films seem to be a viable option for solar applications.

In the present work, HIT-CBTSSe tandem solar cell device model was developed using Silvaco TCAD simulator. As a first step, HIT and CBTSSe solar cells were modeled and validated. As a next step, the tandem structure is modeled using ITO as tunneling material between CBTSSe top cell and HIT bottom cells. Tandem structure is modeled and simulated, and it initially yields efficiency of 14.53%. The photon absorption profile and the external quantum efficiency are analyzed and the unequal absorption between the top and bottom modules is found to limit the efficiency. The model is optimized, and the maximum attainable efficiency is 22.2%.

This paper reports on the effects of different dielectrics on recessed-gate gallium oxide MOSFETs in terms of analog and RF performance. Different gate dielectrics like $${\text {SiO}}_{2}, {\text {Al}}_{2}{\text {O}}_{3}$$ SiO 2 , Al 2 O 3 and $${\text {HfO}}_{2} $$ HfO 2 are considered as gate dielectric material, and their effects are analysed. High-k dielectric $${\text {HfO}}_{2} $$ HfO 2 provides better electrical performance compared to other dielectric materials. High-k dielectric offers good threshold voltage and better DIBL, output conductance, low leakage current with increased drain current response which can be traded-off with a bit increased intrinsic capacitance, GBW and low cut-off frequency. High-k dielectric-based gallium oxide MOSFETs show its potential applications in high-voltage, high-power switching applications with a good $$ I_{\text {on}}/I_{\text {off}} $$ I on / I off ratio of $$6.75\times 10^{9}$$ 6.75 × 10 9 .

In this paper, extended gate Gate-All-Around Tunnel FET (EG-GAA-TFET) is designed. Various temperatures like 300, 400, and 500 K are used for variation of gm, gm2, gm3, and cut-off frequency (fT) with Vgs. The temperature’s influence on ION, IOFF, subthreshold slope (SS), ION/IOFF, and threshold voltage (Vth) are also studied. The ON-current and transconductance (gm) are found to be better for higher temperatures (T = 500 K). The leakage current, subthreshold slope, and current ratio are better for lower temperatures, whereas the threshold voltage (Vth) is improved for higher temperatures. The cut-off-frequency (fT) is better at higher temperatures for lower gate voltage than better at higher gate voltage. Additionally, the designed device also shows better linearity performance at higher temperatures.

This work optimized the performance parameters of the Graded-Channel Gate-Stack Double-Gate (GC-GS-DG) MOSFET using a meta-heuristic technique. The meta-heuristic algorithm applied for this study is PSO with Constriction Factor and Inertia Weight Approach (PSO-CFIWA). The drawbacks of PSO are the premature convergence and stagnation problem. The PSO-CFIWA eliminates these drawbacks. Both the current at OFF-state (IOFF) and subthreshold swing (SS) are considered in the formulation of overall objective/cost function (CF). The weighted sum approach method is used to obtain the overall CF. Compared with the previous literature, the PSO-CFIWA shows much better results in device design.

Transistors are the foundation for electronic circuits and are continuously modifying in design from their insertion into the semiconductor industry to follow Moore’s law. The scaling of conventional bulk metal oxide semiconductor field-effect transistors (MOSFETs) improves IC performance in driving capability and switching speed up to a specific limit. The limiting factors in the bulk MOSFET downscaling are power consumption due to short-channel effects (SCEs) like drain-induced barrier lowering, gate-induced drain leakage, Vth roll-off, leakage current, and subthreshold slope degradation. New device architectures like silicon on insulator MOSFET (SOI MOSFET), double-gate MOSFET (DG MOSFET) are emerged to continue the scaling trends which have low leakage and low threshold voltage without any degradation in the performance. In this paper, we make a comparative study on the electrical characteristics of the conventional planar MOSFET, SOI MOSFET, and DG MOSFET. We extract the electrical characteristics of the above structures by using the nanoHUB tool and show that for the same design parameters DG MOSFET exhibits large Ion current as well as low DIBL, and low subthreshold swing as compared with SOI and bulk MOSFET. From the graph obtained, the values of Ion, Ioff subthreshold slope are calculated, and it has been proved that due to the presence of two gates in DG MOSFET on either side of the channel, which makes the gate-to-channel coupling doubled resulting in the suppression of SCEs and higher Ion.

In this article, we are explaining the electromagnetic models to simulate the effect of plasmon coupling at metal cathode and to analyze the OLED with nano-grated cathode for reduction of surface plasmon loss. The modeling and analysis of the bottom-emitting organic light-emitting diode (OLED) using nano-grating metal cathode structures is presented. OLED is modeled and simulated by using finite difference time domain (FDTD) approach. The light extraction efficiency (LEE) has been improved by introducing nano-grating cathode structure that reduces surface plasmon (SP) losses. The proposed OLED without grated cathode and the device with nano-grated cathode comparison is shown. The intensity of far field is also studied for various cathode materials on an OLED device. It was found to be optimum for a wavelength of 540 nm for aluminum as a cathode material.

The present paper shows the normally-On AlN/ β-Ga2O3 HEMT designed with Si3N4 as a dielectric between gate and AlN layer. The insertion of the dielectric Si3N4 enhances the efficiency and reliability of the conventional HEMT reducing the gate leakage current and short channel effects. The proposed device is simulated in a Commercial Silvaco Technology Computer Aided Design (TCAD) to obtain the important DC and RF characteristics such as drain current, transconductance, gate leakage current, capacitance and cut-off frequency. The simulated results are satisfactory and the device can be useful for high frequency and low power applications.

We modulate the electronic properties of symmetric as well as asymmetric Al0.3Ga0.7As/GaAs double quantum well (DQW)-based FET structure. The asymmetry in the DQW structure is achieved by considering doping only in the side barrier toward the surface. The subband energies En, areal electron densities n, and subband occupancy of electrons Nn are obtained from the self-consistent solution of Schrodinger and Poisson equation. Here, we analyze the impact of applied electric field F on En, n, Nn, and the potential profile V(z) for different doping concentrations ND. For F = 0, n is equally distributed in each well for symmetric doped structure. When F is applied along the growth direction, the electrons shift from the right to the left side well close to the substrate. Hence, the interface roughness and remote columbic scattering reduce leading to improve the transport properties, e.g., mobility and enhancing the device performance. We also compared the distribution of n and variation of Nn in symmetric and asymmetric structures with applied F.

Aluminium gallium nitride/gallium nitride (AlGaN/GaN) (AlGaN/GaN) have become a major focus for all electronic devices based on GaN, due to the beneficial merger of material properties, including a good thermal conductivity, a wide band gap, high peak and saturated electron velocity, high critical breakdown field, and the capability to set up high-quality hetero-interfaces that forms a high sheet density two-dimensional electron gas (2DEG). Various structures have been proposed to increase the breakdown voltage (Vbr) of the device. One of them is introduction of a field plate (FP). In this paper, various types of FPs are considered and compared with respect to the Vbr characteristics and analogue characteristics.

The p-type AlGaN electron barrier layer (EBL) has been widely used to suppress electron leakage from the active region of AlGaN-based deep ultraviolet (UV) light-emitting diodes (LEDs). However, the conventional EBL can reduce the electron leakage partially and invertedly affects the hole injection due to the formation of positive polarization sheet charges at the hetero-interface. Recently, EBL-free LED structures have received significant attention due to the improved carrier transportation and reduced electron leakage. In this context, we present a novel band-engineered EBL-free AlGaN UV LED structure that uses polarization-controlled composition-graded convex quantum barriers (QBs) instead of traditional QBs and analyzed its performance theoretically. Our proposed structure opens a new path to control the electron leakage due to both a gradual increase in the effective conduction band barrier height and mitigated electrostatic field in the active region. As a result, the internal quantum efficiency and output power of the reported EBL-free structure are boosted significantly compared to the traditional AlGaN UV LED at ~260 nm emission wavelength. Experimental demonstration of such a unique LED design can show the way to generate high-power deep UV light sources for practical applications.

Novel semiconductor materials to be used as absorber materials in solar cell, and their thermodynamic behavior needs to be analyzed at large as solar cell devices undergo temperature variations. Therefore, density functional theory-based analysis has been carried out to examine the thermodynamic properties of novel quaternary chalcogenide material Ag2SrSn(S/Se)4 in its kesterite and stannite structures, in 0–1100 K temperature range at 0 GPa pressure. Ag2SrSnS4 (Sta) has the highest calculated melting point of 638 K and hardest amount all four structures. Vibrational heat capacity at constant volume (Cv) for all four structures is saturated at 199.45 Jmol−1 K−1. Vibrational entropy increases with increase in temperature. It is observed that stannite structures of both materials are prone to dimension changes with temperature, due to higher value of coefficient of thermal expansion (α). The change in internal energy of the crystal is linear with respect to temperature.

The impact of adsorption of benzene molecule on pristine and doped (Mn, Fe) MoSe2 monolayer is shown in this paper. The benzene, being a non-magnetic molecule by nature, has health-threatening effects on human body. The adsorption of benzene is focused on two configurations, namely pristine and doped MoSe2 monolayer. The higher adsorption energy is witnessed for Fe-doped MoSe2 monolayer. Likewise, the charge transfer also excels for Fe-doped MoSe2 monolayer in benzene adsorption rather than the other configurations. However, the individual charge transfer between surrounding atoms is higher for Mn atom. To show the capability of MoSe2 monolayer to detach the adsorbed benzene molecule, the recovery time is estimated. It is observed that with higher adsorption energy, the recovery time is increased. It is difficult to remove the adsorbed molecule from the surface at lower temperature, so to facilitate easy removal, the temperature is increased to high value of 498 K. Thus, it is concluded that MoSe2 monolayer is suitable for designing of green sensors with lower recovery time and high adsorption energy.

In this article, we propose to develop dye-sensitized solar cells (DSSCs) based on vertically aligned TiO2-nanowire (NW) and Ag nanoparticle (NP) assisted vertically aligned TiO2-NW (TAT) photoanode fabricated by the glancing angle deposition (GLAD) technique on FTO substrates. The scanning electron microscope (SEM) analysis reveals that the Ag-NP assisted vertically aligned TiO2-NW photoanode was deposited on FTO substrates. The average length and diameter of the NW have been measured to be ~ 350 nm and ~ 90–100 nm, respectively. And, the X-ray diffraction (XRD) investigation reveals the presence of small crystals of TiO2 and Ag from the weak peaks. Further, the absorption spectrum analysis shows that the incorporation of Ag-NP in TiO2-NW increases the intensity of absorption in the visible region. The calculated bandgap of the annealed Ag-NP (30 nm)-assisted TiO2-NW (TAT@30 nm) sample using photoluminescence (PL) analysis is ~3.12 eV. Finally, the performance of two types of DSSC devices based on TiO2-NW and TAT@30 nm photoanode was analyzed. It is observed that the TiO2-NW-based DSSC device shows better performance in terms of photo-conversion efficiency compared to the TAT@30 nm photoanode-based device.

In this paper, a simple E-beam evaporation process was used to manufacture TiO2 thin film (TF) on a Si substrate for multiband photodetection. The existence of tiny crystal grains of anatase and rutile TiO2 is shown by XRD examination of the As-deposited TiO2-TF sample. The absorbance of annealed TiO2-TF is increased in the UV region and extends into the visible range with maxima at ~400 nm and ~570 nm. The bandgap of annealed TiO2-TF derived from the Tauc plot is ~3.2 eV, which is similar to the bandgap of annealed TiO2-TF extracted from the Gaussian-fitted PL spectra. Finally, the TiO2-TF/Si-based photodetector device operated at −3 V under low-intensity green light has an excellent responsivity value of ~0.496 A/W, which is quite intriguing. Furthermore, the photodetector devices developed had a rise and fall times of ~0.154 and ~0.123 s, respectively. As a result, this low-cost E-beam evaporation approach might be used to make visible light detectors based on TiO2-TF for optoelectronic applications.

The emerging novel device tunnel field-effect transistor (TFET) has fascinated the scientific community with its distinct features such as lower subthreshold slope (SS), small leakage currents and minimized short channel effects. Hence, TFET was found to be an appropriate device for low power and high-frequency applications. The prime objective of this manuscript is to elaborate on recent significant contributions made by the researchers to surpass its limitations such as ambipolar behavior, low ION/IOFF ratio and to improve subthreshold swing (SS). The influence of temperature (200–400 K) and ferroelectric material on the device performance was also reviewed in detail.

The paper reports design and analysis of the non-uniform body with dual material TFET-based digital inverter. The analysis includes the transient characteristics of the inverter in appearance and non-appearance of interface trap charges. Gaussian distribution of interface trap charge with various concentrations has been taken into account. Further, different delay parameters of the circuit have been calculated, and it is observed that fall time delay of the circuit is less than that of rise time delay. Finally, it is found that the propagation delays of the proposed TFET-based digital inverter are 9.75 ps and 6 ps in occurrence and non-occurrence of interface trap charges, respectively.

With the advancement in integrated circuit (IC) miniaturization, limiting the power usage has become a significant issue for both academia and industrial researchers. Negative capacitance field-effect transistors (NCFETs) have recently grabbed a lot of attention compared to several established ultralow-power devices with sub-threshold swing (SS) less than 60 mV/decade. In every device, the channel plays a crucial role in the transport mechanisms of the device, thus impacting its performance and operational attributes. In this work, we analyze the effects of different channel materials such as gallium nitride (GaN), gallium arsenide (GaAs), and silicon (Si) on the transfer characteristics of single-gate NCFET in the presence of spacer. In addition, the effects of these materials on the trans-conductance are also studied. The simulation results reveal that the GaAs-based channel provides a better ON–OFF current (ION-IOFF) ratio and trans-conductance, but SS performance degrades badly. Furthermore, it has been observed that the Si-based channel offers improved SS in comparison with the other two materials. Several key performance metrics of the device such as ON-current, OFF-current, and SS are investigated, and the comparison of various parameters of the device based on different channel materials is summarized.

This paper presents the sensitivity analysis of an AlGaN/GaN single gate MOSHEMT with a tapered high-κ dielectric with a cavity under the gate for neutral biomolecules. The device performance exhibits an enhanced gm and reduced leakage current by using a tapered dielectric on a single gate MOSHEMT over a conventional dielectric single gate MOSHEMT. Variation in drain current, transconductance, and threshold voltage plays an important role when heterostructures are used for biosensing applications. This has been exploited in studying device sensitivity toward neutral biomolecules by using dielectric modulation. The simulated reference MOSHEMT with a tapered dielectric exhibited a maximum drain current of 1474 mA/mm and a high transconductance of 814.6 mA/mm while the MOSHEMT with a conventional dielectric exhibited a maximum drain current of 651.4 mA/mm and maximum transconductance of 771.6 mS/mm. With neutral biomolecule in the cavity, the maximum variation in drain current, transconductance, and threshold voltage was obtained for glucose oxidase as 310 mA/mm, 0.06 V, and 73.7 mS/mm, respectively. All simulations have been carried out using the 2D simulator Visual Technology Computer-Aided Design tool.

Graded composition in the barriers of multi-quantum was depicted and incorporated upon a c-plane GaN/AlGaN light emitting diodes (LEDs) constructed above a sapphire substrate for carrier transportation enhancement and lowering of efficiency droop. Because of their potential applications in various fields, ultra-violet LEDs formed on gallium nitride (GaN) materials have been the topic of interest for various researchers. The simulation outcomes exhibit that optimized light emitting diode having an aluminum constitution graded between 26% and ~2% in per triangular barrier demonstrates largest internal quantum efficiency (IQE) (38%) around 100 A/cm2 indicating significant rise compared to the conventional device having square barriers. This improvement has been ascribed to the modified energy band structures that upgrade the uniformity during transportation of carriers and also enhance the recombination rate in every GaN quantum well. As a result of this, the IQE of the device improves. The simulated LED device with graded quantum barrier structure acquires lower series resistance and substantially minimized efficiency droop characteristics of nearly 3.6% with respect to 11.8% for conventional device, supporting carrier enhancement (both electron as well as hole) transport in our designed device.

Plant extract can be the alternated cost-effective and ecofriendly source of electrolyte for the electrochemical cell. In this study, six types of plant extract electrolyte have been used on the electrochemical cell, and the electrical performances of six bio-electrochemical cells were investigated. The highest average voltage (1.14 V), current (21.25 mA) were obtained for PKL extract cell, and the lowest performances were found for aloe vera cell. The power and capacity were also calculated for this all cell. All electrical performances of PKL extract cell were more significant than other plants extract electrolyte cells. The electrical performances of all of these bio-electrochemical cells have been graphically represented in this paper. This comparative study regarding the performances of different electrochemical cells may open a promising platform for ecofriendly, cost-effective power production.

A systematical innovative model using CZTSe which is earth-abundant and non-toxic material based on p/n junction and silver-doped CZTSe which increases crystallization quality of CZTSe kesterite material with CZTSe as BSF layer of p+/p/n junction solar cell was modeled toward high photovoltaic characteristic. It is observed that the configuration of CdS/ACZTSe/CZTSe exploits enhancement of depletion region using the primary absorber layer (ACZTSe) and (CZTSe) BSF layer which reduces the recombination rate and enhances the short circuit current Jsc. In our model, carriers are improved through the absorber layer. There is a substantial decrease in recombination losses after using ACZTSe as the active layer and CZTSe as p+ layers. We endeavor further ACZTSe thicknesses thus determining the optimum obtainable performance of 35.21% at its 3.0 µm ACZTSe thickness with 0.7093 V open-circuit voltage, 57.05 mA/cm2 power in a short circuit, and the fill factor 87.0% under AM1.5 global illumination and more than 80\% of quantum efficiency is achieved. This proposal's modeling advances the efficiency of ACZTSe kesterite solar cells.

Steep subthreshold slope and high current on–off ratio are among the major challenges of tunnel field-effect transistors (TFETs) for low-power complementary metal-oxide-semiconductor (CMOS) device applications. This work presents the performance comparison of Si and Ge double-gate tunnel field-effect-transistors (DGTFETs) based on DC and RF analysis. As compared to Si-based DGTFET, the Ge-based DGTFET depicts an improved performance such as high ION of ~8.61 × 10−5 A/μm, low IOFF of ~1.33 × 10−12 A/μm, ION/IOFF ratio of ~6.4 × 107, good sub-threshold swing of ~24.4 mV/dec, and better RF performance revealed from transconductance, parasitic capacitances, cut-off frequency, transit time, power delay product, and transconductance generation efficiency. Therefore, Ge-based TFET is a superior candidate for low-power CMOS device applications.

A recent doping-less (DL) charge plasma tunnel FET (TFET) structure has been suggested to diminish ambipolar features with improved analog/RF figure of merits (FoMs) Additionally, the DL arrangement gives fabrication ease and security against random dopant fluctuations (RDFs) on the contrary with the conventional-doped TFET. Here, dual (front and back gate) n+-pockets have been formed by inserting tunneling electrodes only close to source/channel junction. An assessment of the performances of proposed electrostatically doped dual pocket vertical TFET (ED-DP-V-TFET) configuration with conventional lateral and single-pocket TFET has been performed in terms of device characteristics. The proposed model suggests superior performance over its TFET contender. Besides, the suggested model is investigated for analog/RF FoMs with the variation of WF of tunneling electrode (TE) and oxide thickness (Tox) under TE using ATLAS device simulation software. Simulated results confirm the efficacy of the proposed structure in the RF/analog domain.

GaN HEMT is chosen for many high frequency applications such as Power Amplifiers because of its desirable properties. Most semiconductors fail at high frequency applications because of their thermal and bias limitations. It is very difficult to operate the amplifier at high frequency and high power ratings. The HEMT transistors can operate at high electric fields and high frequencies. The heterojunction structure provides more no of free electrons without any doping which significantly improves the mobility and the current. The hetero-structure also blocks the current flow in unwanted directions. This paper explains about GaN HEMT transistor and its practical application as a Power Amplifier. CREE CGH40010F GaN (10 W) device is chosen and developed at the schematic level. The schematic provides 15.5 dB gain and 66% efficiency.

The structural, electronic, and optical properties of transition metal dicalcogenide (WS2) semiconductors were calculated using DFT calculations. For the first time, the anisotropy and birefringence of WS2 are calculated in different energy regions. The estimated structural and electronic properties are in consider with the reported values.

In this paper, zinc sulfide (ZnS) is taken as a suitable buffer layer in the copper zinc tin sulfide (CZTS) solar cell. The solar cell parameters have been calculated by considering the thickness and the bandgap of the ZnS layer using SCAPS 1D software. This proposed device model witnessed a good performance in all the parameters such as an efficiency of 22.08% with open-circuit voltage of 0.93 V, short-circuit current of 28.27 mA/cm2, and fill-factor of 82.61% through ZnS as a buffer layer for the copper zinc tin sulfide (CZTS) solar cell. When the absorber layer thickness is between 2 and 4 μm, we can obtain the high efficiency. By choosing the ZnS bandgap between 3.1 and 3.25 eV, the efficiency will be higher as obtained in the proposed study.

The improvement in DC and RF characteristics of Quantum Well base in GaAs HBT (Hetero Junction Bipolar Transistor) is presented. Based on an experimentally validated model of the Silvaco TCAD tool, the properties of the GaAs HBT are simulated. Our results are indicative that Quantum Well base in HBT has the best DC characteristics like the current gain (760) and the lowest offset voltage (5.9 mV). However, the RF performance of the HBT is observed to be poor with the unity gain cut-off frequency recording a value of fT = 1 MHz.

Approximate computing pervades for different error-tolerant applications to accomplish low-power and higher frequency. A programmable accuracy-controlled multiplier (ACM) is proposed to control the accuracy by generating partial products. The accuracy will be controlled by setting up the control bits to mux out the actual multiplier and/or approximate multiplier out. The trade-off in power and area is observed at different error rate. The experiment is demonstrated for image compression using discrete cosine transform (DCT) method to measure the SNR for standard cameraman gray image. This work is resulted with mean error distance (MED) of 3.12 and 23.825 dB SNR. The core logic resulted in maximum 31.63% reduction in static power and 7.48% reduction in critical path delay for approximate multiplier. The core area is reduced up to 27.79%, and an improvement in SNR is achieved up to 3.44% at a cost of 20.84% area over head while synthesized using 45 nm.

Many processor architectures, such as digital signal processors and microprocessors, rely on arithmetic circuits. The efficient implementation and design of arithmetic units necessitates the creation of binary adder structures in a similar manner. A ripple carry adder has a tiny surface area yet is slower. Carry propagation is also one of the reasons why the total for each bit is generated sequentially after the preceding carry arrives. The primary idea behind this study is to replace the RCA in a normal CSLA with a binary to excess-1 converter (BEC) to achieve high speed, area efficiency, and low power consumption. The following architectures are implemented using Verilog HDL as a programming language, and their simulation results are also shown.

Dynamic random access memory (DRAM) has performed the basic element for designing in embedded system. Various DRAM cell topologies in deep submicron level are designed and analyzed in this study. Memory blocks have become a critical component for overall system performance in today’s digital data processors and controllers. Selecting a DRAM cell structure from the many options increases design time and effort greatly. DRAM topologies in two, three, four transistor are implemented on 32 nm technology scale. A three-transistor and one-diode-based DRAM topology is also designed and compared with all the structures. The three-transistors and one-diode implementation shows significantly better retention time with comparable average power consumptions. The power dissipation, retention time, and read and write access times of the cells are compared. Tanner EDA is used to perform all design and simulation work.

In this paper, we demonstrate a register-transfer level schematic of a vending machine that facilitates understanding of the actual design and precise circuit analysis. The proposed design shows minimum power consumption for a good range of frequencies. Modeling the machine is done using the finite state machine technique, which uses a list of its states. Subsequent steps include optimization techniques, deriving Boolean expressions, and describing the design (behavioral modeling) using Verilog HDL in Xilinx VIVADO and Xilinx ISE. As a result, we get a readable RTL schematic of a vending machine that accepts three currencies and operates on three different products. For the proposed design, reduced power consumption of 33.59 mW and a reduced gate delay of 1.024 ns at a frequency of 5 MHz are estimated. Design in this paper shows a brief RTL schematic of a fully functional vending machine using mealy finite state machine (FSM). An advantage of this approach is that one can know the flow of signals from input to output. With this, managing the power and timing of the device becomes flexible. One can sort out the requirement of a particular block in the device. In turn, actual power management can be achieved. This paper aims to design a fully functional vending machine in-depth, to the point where a designer can feel the actual hardware producing logic of his interest.

Recent days sensing technology in the memory play a vital role, in the “Von Neumann Bottleneck” method, there should be a specified memory was given for the read and write operations. The Sense Amplifier is a key circuit in the edge of power efficient, high-speed random-access memories. This paper describes the design of sense amplifier for a given random access memory and more elaborately on Resistive RAM. Reading of the memory is most important in all memories and it is time-consuming, this paper aims to improve the speed of reading in the memories especially in Resistive RAM. Resistive RAM was built on 1Resistor-1Transistor configurations, the data is stored in the form of resistance, and which is non-volatile in nature. From the resistor we can retrieve the data which is in the form of resistance using the time-based sense amplifier. The sense amplified designed to optimize the delay and to improve the speed of sensing. The schematic of sense amplifier is verified using PYXIS environment with 130 nm CMOS-technology node and it works fine and helps us to improve the reading operations efficiently in the Resistive RAM. These are used in many applications and different fields like security, neuromorphic computing, and non-volatile logic system.

This paper presents optimization of cantilever-based radio frequency (RF) micro-electro-mechanical system (MEMS) technology switches using artificial neural network (ANN)-based prediction algorithms, i.e., linear vector quantization network. We have created a literature survey-based train dataset and finite element method (FEM) simulation-based test datasets for cantilever structure-based RF MEMS switches. The dataset training is done with different algorithms, i.e., Bayesian regularization and extracted performance indices.

This paper discusses a new reconfigurable bidirectional RF transducer, i.e., antenna where both frequency and pattern are reconfigured. The antenna involves with the T-shaped rectangular patch where it will be joined by two latitudinal slits. The slits will linked to a pin diode to gain the essential frequency bands. The design was micro-machined on 70 mm * 70 mm substrate with FR4 as a material and designed using HFSS tool. The frequency reconfiguration can be perceived in between at 4.5, 5.8, 11.4, and 13.6 GHz which are used for the WLAN communications. The reconfiguration of pattern is about − 15°, 15°, 30° angle will be seen in the radiation patterns at the same bands.

In this paper, we propose a gallium nitride (GaN) high-electron-mobility transistor-based (HEMT) sensor and developed circuit for point of care detection of mercury contamination in water. The platform, GaN HEMT, has been fabricated for three different epitaxial structures and four different device designs. The drain current of GaN HEMTs for various designs for a specific epitaxial structure has been recorded at a $$V_{\text {ds}}$$ V ds of + 5 V where a 2x50-25ID device design performs better than the other three. The sensor is developed on the 2x50-25ID design and tested in continuous running mode that is able to detect nM level of concentrations of mercury in water. The sensor exhibits a drain current change of 6.66% at a $$V_{\text {ds}}$$ V ds of + 5 V when immersed into 1 nano-molar solution of the mercury with reference to the drain current obtained in normal DI water. The developed handheld system also shows a good response to the mercury contaminated water, and the the performance is reasonably close to the on chip detection. The packaged sensor and circuit is portable and can work stand alone for the detection of the mercury.

Many studies have shown that most MEMS devices use light beams whose deflection response is the main focus before choosing it for specific applications. This paper deals with the simulation of the MEMS-based cantilever beam for low-pressure detection. COMSOL 5.4 multiphysics FEM model is used to study the behavior of beam and compared with the conventional cantilever beam. Both are analyzed with two different materials SiO2 and SU-8. The change in the deflection has been analyzed with various pressure values applied on the cantilever beam. Through simulation and analysis results, it is observed that the deflection of the proposed beam is good at lower pressure values.

The currently under-deployment 5G, as well as the future 6G and Super-IoT paradigms, is demanding and will go on demanding for high-performance, frequency agile, and reliable RF passive components, ranging from simple switches to articulated devices, phase shifters, impedance matching tuners, RF power step attenuators, filters, and so on, with pronounced characteristics of reconfigurability and/or tunability. RF-MEMS is one of the most suitable technologies able to meet these challenges, as its recent market absorption is demonstrating. In this paper, we discuss a novel design of switched capacitor/varactor entirely designed in RF-MEMS technology, optimized against a mitigation of the activation (pull-in) voltage, as well as an increase of the ON-state capacitance. In particular, multi-physical simulations are reported and discussed, after having validated the Finite Element Method (FEM) tools against experimental datasets. Moreover, physical samples are currently under fabrication and will be reported in the final paper.

A variable MEMS capacitor for Ka band frequency is designed having high capacitance ratio, less pull-in voltage, less stress misses, and better quality factor. MEMS varactor can be used as a tuning device to tune the frequency of a resonator. MEMS varactor is placed over the Substrate-Integrated Waveguide (SIW)-based resonator. The SIW resonator is designed over a single-layered Rogers RT/Duroid 6002 having dielectric constant $$\varepsilon_{r}$$ ε r  = 2.94 and tanδ = 0.0012 whose substrate thickness is of 508 μm. The gap between SIW top layer and MEMS structure is 3 μm. MEMS varactor structures with holes and without holes are simulated. Meanders are used to support the membrane, which makes displacement more uniform. The serpentine-structured meanders are suitable as it decreases the pull-in voltage. Pull-in voltage of 0.84 V is achieved. The RF behavior of the MEMS variable capacitor depends on UP and DOWN capacitance and air gap between the two plates. The UP capacitance of 3.69 pF and resonance frequency of 39.5 kHz were achieved. When DC voltage is applied to the bottom fixed plate, the DOWN capacitance increases to 166.59 pF. A high Capacitance ratio of 45.14 is achieved. RF analysis of the device is done at 1–40 GHz. Return loss is noted as − 12.21 dB at 27 GHz. The low insertion loss of − 1.97 dB at 27 GHz for the proposed MEMS varactor has made the design suitable for the Ka communication band. This device is first of its kind in the Ka band communication where a minor change in structural parameters will have a huge impact over the response.

An overview on design of MEMS accelerometer involving parallel plate mechanical suspension is analysed. It is built using single-crystal isotropic silicon on the platform ‘COMSOL Multiphysics’. Stepwise analysis is performed to know the effect of structural parameters on Von Mises stress, displacement, eigenfrequency, change in capacitance and also frequency response bringing in the concept of finite element analysis (FEA) by considering g in the range of 0–500 m/s2. All the relations between capacitance and acceleration are interpreted by plotting a graph considering various values, and its application can be well defined in detecting mechanical properties efficiently.

Wireless sensor industry is driven by challenging paradigm of the Internet of things (IoT) devices and the 5th generation of wireless communications (5G). However, the near field devices have a lot of potential due to their low-power consumption, with the downside of covering a typically shorter range. This paper addresses the challenge of increasing the range by utilizing a modulated scattering technique (MST)-based wireless sensor integrated with a micro-switch realized in microelectromechanical systems (MEMS) technology for radio frequency (RF) applications. Our hybrid MST-RF-MEMS sensor prototype has been reviewed in real-time outdoor scenarios for environmental parameter sensing as well as for an indoor air quality monitoring system. The employed RF-MEMS switch is highly miniaturized and exhibits good performances and RF characteristics for frequencies up to 110 GHz. Numerically designed proposed MST-RF-MEMS prototype sensor has been fabricated and experimentally assessed. The achieved results are adequate and prove that the prototype RF-MEMS based sensor significantly increases the addressed communication range. The integration of the MST and RF-MEMS switch in the sensor system reveals its essential role for designing the next generation near field sensors in the millimetre and sub-millimetre frequency bands, where standard RF switches are unable to operate.

Nowadays, it has become indispensable to precisely detect the fat concentrations in milk to maintain a healthy life. To address this issue, we propose a biophotonics sensor, which works on Tamm plasmon polariton (TPP) technique. The proposed structure is comprised of metal (Ag) integrated 1D photonic crystal (PhC) structure, where the PhC is realized with an alternate arrangements of SiO2 and porous GaN. The numerical computations are performed employing the well-established transfer matrix method. Various parameters of the structure like number of period of the PhC, and thickness of the metal layer are sensibly selected in order to accomplish maximum sensing performance. The reflection spectrum is investigated for different fat concentrations in the range 0–33.3%. An optimum sensitivity of 214.28 nm RIU−1 and quality factor of 622.64 is reported, which can be considered as noteworthy performance in the present research scenario. Moreover, the simple structural analysis and cost-effective fabrication techniques make the suggested sensor an apt contender for developing bio-sensing devices.

This paper presents a reliability analysis of thermally actuated MEMS micromirror devices. The various factors affecting the reliability of the MEMS micromirror device were analyzed and discussed. The reliability distribution function and lifetime of the MEMS micromirror were analyzed. The series and parallel model reliability model for MEMS micromirror were reported. The p-out-of-n redundancy model was considered to increase reliability for the MEMS micromirror device. This model gives more redundancy to it, and the failure of one or more devices does not affect the system performance.

The challenging characteristics addressed by the 5G standard rely on widespread coverage and services enabled by adaptive beamforming operated by cells and base stations. To this end, basic radio frequency (RF) components and systems are subjected to a constant push toward miniaturization, reconfigurability, frequency agility, and low-power consumption. In case of high-performance RF passives, these needs can be satisfied by RF-MEMS technology (i.e. RF-micro-electro-mechanical-systems), and this will be the starting point of this paper. In this paper, an overview concerning the state of the art of RF-MEMS components and compounds involved in beamforming networks is provided, with a special attention toward hybrid architectures as key feature of realistic massive-multiple-input-multiple-output (mMIMO) systems. In light of the current frontiers for RF-MEMS in the framework of hybrid architectures, switches, phase shifters, and an attenuator realized at Fondazione Bruno Kessler (FBK) are presented as suitable building blocks for future compact modules and beamforming architectures, in which RF-MEMS could play an effective and predominant role.

Bio-voltaic cell is a cell where plant extract is used as electrolyte. In this report, a bio-voltaic cell is proposed where silver nanoparticles (Ag NPs) have been used to accelerate the performances of voltaic cell. The role of Ag NPs on cell was investigated by monitoring the voltage, current, capacity, and voltage regulation of bio-voltaic cell. Ag NPs were synthesized through a rapid green approach by using the Bryophyllum.pinnatum (B. pinnatum) leaves extract and the formation of NPs is confirmed by the UV–visible spectrometer, XRD, FTIR, and FESEM analyses. The Ag NPs were applied on the bio-voltaic cell to examine the electrical performances of the cell. The Ag NPs showed significant role to reduce the voltage regulation, and increase the capacity of voltaic cell. The electrical performances of bio-voltaic cell were significantly improved after using NPs on cell. This study will serve as a promising platform to integrate the efficiency of the bio-voltaic cell.

The design of three different type of diaphragm shapes such as circular, square and hexagonal are optimized for piezoelectric micromachined ultrasonic transducers (PMUT) applications. The width of PMUT diaphragm is crucial for determining the operating frequency and sensitivity of the devices. The influence of diaphragm width on mechanical and electrical properties of PMUT devices are obtained using Eigen frequency and static stationary analysis. The width of diaphragm varied from 100 to 1000 µm and the applied pressure assorted from (0.1–500) Pa for optimization of diaphragm dimensions. Square, hexagonal membranes exhibit higher resonance frequency (~5–6 kHz) and sensitivity compared to the circular diaphragm. However, circular diaphragm produces a more deformation compared to the square and hexagonal shapes. The square shaped diaphragm suitable for sensing application, circular diaphragm mainly suitable for actuation applications and hexagonal diaphragm acts as an intermediary between square and circular diaphragms.

In this work, PKL has been biosynthesized for getting good performance using PKL electrochemical cell. AgNPs have been used in the electrochemical cell as a biosynthesized of the PKL extract. Firstly, PKL extract was produced from the PKL and then AgNPs were produced. A comparative study was done for using AgNPs and non-using of AgNPs in the PKL electrochemical cell. The open circuit voltage, load voltage, voltage efficiency and voltage regulation have been studied using AgNPs and without AgNPs. It was found the maximum Voc, VL, voltage efficiency and the voltage regulation were 5.92 V, 5.45 V, 92.06% and 37.53%, respectively, for without using any AgNPs. Whereas the minimum open circuit voltage, load voltage, voltage efficiency and voltage regulation were 5.90 V, 4.29 V, 72.21% and 8.62%, respectively, for without using any AgNPs. Again, the maximum open circuit voltage, load voltage, voltage efficiency and the voltage regulation were 6.10 V, 5.89 V, 96.56% and 5.38%, respectively, for using any AgNPs. Whereas the minimum open circuit voltage, load voltage, voltage efficiency and voltage regulation were 6.02 V,5.79 V, 95.51% and 3.57%, respectively, for using any AgNPs. It is found that AgNPs are better to use power production in the electrochemical cell.

This paper designs and simulates piezoelectric beams giving higher output power at lower vibrations by varying the structural geometry and seismic proof mass positions on the piezoelectric beam. A total of seven different MEMS Piezoelectric (PZT-5H) energy harvesters (devices) with non-traditional geometries which can work under ambient conditions with low frequencies are studied. Device 7 with a segmented tapered beam is the most efficient design, which showed a maximum output voltage of 7.9 V attained at the frequency of 98.62 Hz. The method incorporated in accomplishing the aims of this work is mainly the Finite Element Method (FEM). Eigen frequency analysis of the beam is performed to know the different Eigen modes of the beam. Frequency domain study is performed to obtain the output voltage, power, and energy as a function of the vibration frequency. The results obtained are in terms of displacement, electric potential, and other electrical and mechanical outputs. The obtained observations are compared and found that the piezoelectric beams with seismic proof mass-produce higher output levels than the other beams.

The human body is complex but very interesting to discover. The human body has many unsolved riddles which yet haven’t been answered and sometimes even astonishes scientists and doctors when something new is discovered. The whole review consists of the functionality of the kidney; it causes of dysfunction, methods of detection, replacement techniques, and kidney-on-chip. Since every organ in the human body malfunctions due to various complications in its working which leads to various diseases. About, 13% of the world’s population is affected by kidney diseases. Since replacement techniques like dialysis and kidney transplantation are costly and sometimes, not available also due to lack of donors (in case of kidney transplantation). Researchers and scientists are trying to develop the kidney’s function artificially which is termed kidney-on-chip which is a revolutionary idea.

The development of radio frequency (RF) passive components for modern 5G/6G applications, ranging from simple switches to complex network architectures, do often require simulating the system by the finite element method (FEM). FEM is useful when is difficult if not impossible to determine an analytical equation that describes the system of interest starting from the physical laws that describe the phenomena. Therefore, by dividing the complex geometries in a finite number of smaller elements (composing the mesh) physical equations can be easily applied in their analytical form. This approach can be called mechanistic, brutally solves the partial differential equations on each element of the geometry. The overall results are approximated numerical solutions of the problem in which the numerical solution of the single element is passed as input to the bordering elements to build the overall solution of the system. The application on a large number of elements gives an approximate numerical solution in which the relationship with the geometry of the architecture is lost. Using a statistical approach called response surface method (RSM) at the end of a set of simulation, it is possible to partially reconstruct the relationship between the geometrical features and the outcome. Following this approach, we tackled a problem related to radio frequency microelectromechanical system (RF-MEMS) reconfigurable power attenuators. In this specific case, we studied the response of the S21—scattering parameter (attenuation) and the VSWR—voltage standing wave ratio (reflection) to the change of three degrees of freedom (factors), two related to the geometry, and one to the material.