Sunny Sharma

Indian Institute of Information Technology Allahabad | iiita · Electronics & Communication Engg. (ECE)

The present work demonstrates the potential of the proposed Bayesian optimization (BO). It is based on neural architecture search (NAS) for the classification of gases/odors for data-sets of diverse applications and complexities in terms of the number of analytes, features and data-points. NAS is an aspect of automated machine learning (AutoML), wh...

The present work illustrates the potential of Polypyrrole (PPy) coated nanofibers based flexible sensor for low concentration (sub-ppm) ammonia detection. The sensor has been fabricated on synthesized novel flexible Polyvinylpyrrolidone (PVP)/Chitosan based substrate using electrospinning of Thermoplastic Polyurethane (TPU) nanofibers, followed by...

One dimensional (1-D) nano-structures are expected to be the most suitable candidates for analyte sensing, owing to their high surface area to volume ratio. In the present work, SnO2-ZnO composite solutions with different viscosity have been synthesized and thickness of electrospun nanofibers is optimized to obtain uniformly distributed nanofibers...

In robotic and autonomous vehicle applications, sensor systems play a critical role. Machine learning (ML), data science, artificial intelligence (AI), and the internet of things (IoT) are all advancing, which opens up new possibilities for autonomous vehicles. For vehicle control, traffic monitoring, and traffic management applications, the integr...

This paper proposes an energy-efficient hybrid medium access control protocol based on precise control of duty cycle. To save energy, the proposed protocol optimally adjusts the trans-receiver radio's turn-on and off time. By estimating slot utilization, both the cluster head and the sensing devices save energy. During the reserved slot duration, e...

We demonstrate functional switching of electromagnetic induced transparency (EIT) in terahertz (THz) metasurface. We first simulated and fabricated two metasurfaces that have light difference in their unit cell design. THz time domain spectroscopy of fabricated metasurfaces shows that two metasurfaces have almost similar transmission spectra but on...

Here, we report the design and simulation of phase-change material-based tunable photonic crystal nanocavities. The shifting and switching in resonant modes are investigated in waveguide built from photonic crystal nanocavities with a hexagonal structure. To represent different resonant modes, a single defect is created in the center of the structu...

Development of clean and sustainable renewable energy sources is imperative to deal with the future energy crises. Various technologies have been developed in this context, for example, water electrolysis, reversible fuel cell and metal‐air batteries etc. However, the sluggish kinetics of oxygen evolution reaction (OER) occurring at the anode of th...

We demonstrate active switching of Fano resonance in a THz metasurface comprised of phase change material/gold patterns. Dynamic interplay between Fano and dipolar resonance attributed to ultrafast phase-transition of Ge2Sb2Te5 promises applications in sensors.

The present work demonstrates the potential of metal sulphide SnS–ZnS composite towards detection of low concentration (sub ppm) ethanol at room temperature (27 °C). The fabricated sensor has shown excellent performance in terms of % response of 56.58% at 100 ppb owing to the low crystallite size observed from the x-ray diffraction (XRD) characteri...

We demonstrate active switching of EIT in a THz metasurface comprising of phase change material/gold patterns. Dynamic interchange between EIT and dipolar resonance due to ultrafast phase-transition of Ge 2 Sb 2 Te 5 promises applications in slow light devices.

Demand for railway transportation is persistently expanding step by step. Due to the high load on the railway track, manual monitoring of the track is not preferable. In this chapter, we will discuss the ongoing research of wireless sensor network (WSN)-based real-time inspection of railway tracks. The energy-efficient WSN is one of the important c...

This work proposes an energy-efficient duty-cycle-based hybrid medium access control protocol. The proposed protocol optimally adjusts the turn-on and off time of the trans-receiver radio to save energy consumption. Both cluster head and sensing devices save energy by estimating the utilization of slots. In reserved slot duration, each sensor devic...

In the present work, an optimization of absorption for phase-change materials (PCMs) is proposed by arranging two anti-reflective coating (ARC) materials in distributed blocks within a single layer, i.e., in the same plane. PCMs such as Ge2Sb2Te5 generally exhibit two stable states known as amorphous and crystalline which can be interchanged throug...

BaMn x Ti 1-x O 3 thin film on a silicon substrate has been prepared through the sol-gel spin coating process. The ferroelectric BaMn x Ti 1-x O 3 film shows the predominant perovskite ABO 3 structure for x = 0.2 and 0.3 for the annealing temperature of 650°C under nitrogen ambient. The metal contact on top and silicon substrate at the bottom of th...

We demonstrate a polarization-sensitive planar metamaterial which exhibits strong toroidal dipole resonance producing high Q-factor response in the terahertz frequency range. A detailed numerical study is carried out on the toroidal resonance origin in the unit cell along with dimensional optimization in the frequency range from 0.2 THz to 2.25 THz...

Yttrium (Y) doped SnO 2 nanofibers were successfully synthesized and used for detecting low ammonia concentrations at room temperature (RT). Electrospinning followed by calcination method was used to synthesize the Y doped SnO 2 nanofibers for various Y concentrations, among which 5wt .% Y doped SnO 2 nanofibers (average diameter ~90 nm) demonstrat...

In this work, a room temperature (RT) operated acetone (C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> O) sensor having good sensing characteristics like good % response, fast response an...

In this work, energy-efficient adaptive duty cycle guaranteed time slot algorithm is proposed for beacon-enabled standard medium access control protocol to efficiently handle low, medium and high data traffic loads. The proposed protocol can efficiently handle high traffic load by effective utilization of slots. The protocol can dynamically update...

The standard IEEE 802.15.4 fails to perform optimally for railway monitoring applications due to the deficiency of guaranteed time slots (GTSs). In the present work, an adaptive GTS allocation algorithm (AGAA) is proposed which efficiently deals with a deficiency of GTSs and slot underutilization problem. The proposed AGAA algorithm saves unutilize...

In the present work, we have proposed an analytical Markov-chain model of the modified slotted Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) IEEE 802.15.4 Medium Access Control (MAC) protocol, which efficiently utilizes the Guaranteed Time Slots (GTSs) under saturated traffic conditions. The five dimensional Markov chain model based a...

Hierarchically ZnO nanoarchitecture synthesized through coprecipitation technique. Growth process has been analyzed by varying pH from 5.5 to 13 along with post heat treatment process through the observation of surface morphology from 2D plates, triangular, hexagonal rods, needles, and finally to hierarchical. X-ray diffraction (XRD) reveals many i...

The present study reports room temperature ethanol sensing with improvement in response and recovery times using Ag-doped SnO2–ZnO composite nanofibers. A comparative study of nanofibers of solo SnO2, SnO2–ZnO nanocomposite and Ag-doped SnO2–ZnO nanocomposite is presented. Nanofibers of tin oxide and zinc oxide are deposited on low-cost aluminum el...

In this paper, we present a novel room temperature (RT) operated SnO2-ZnO-Fe2O3 based tri-composite analyte sensor with dual behavior having detection ability up to ~1 ppb with substantial % response (R) to detect ammonia and ethanol vapors. The tri-composite is synthesized via sol-gel spin coating technique and characterized using X-ray diffractio...

This study analysed GaN nanophosphors based white light‐emitting diodes (WLEDs) with ultraviolet (UV) excitation. Graphene quantum dots (GQDs) used as a charge transfer medium to enhance the performance in terms of luminous efficacy and colour quality. The improvement in colour rendering and colour temperature has been observed with the increase in...

In the present work, a new protocol is proposed i.e. application-specific hybrid medium access control (ASHMAC) to efficiently handle data traffic generation in the railway track condition monitoring system. ASHMAC protocol is an improved version of the bit-map-assisted (BMA) medium access control (MAC) protocol by which it can efficiently handle c...

Heterostructures (HS) have always been in attraction due to their inherited properties and different important applications. Integration of a phase-change material (PCM) with HS can tremendously extend the operating and application range using the “phase-tuning” of PCM for any optoelectronic devices. In the present study, we report a detailed study...

Thin film of Barium–Strontium–Titanate (BaxSr1−xTiO3) has been fabricated through sol–gel spin-coating process with optimized value of ‘x’ for non-volatile memory application. The Metal–Ferroelectric–Semiconductor (MFS) thin-film structures have been prepared using Barium–Strontium–Titanate (BST) with various Barium/Strontium (Ba/Sr) molar concentr...

In the present work, Ge2Sb2Te5 (GST) material is investigated for detection in visible range (specifically at 632 nm wavelength) for spectroscopic photodetection and visible-light communication applications. Thin film of GST phase-change chalcogenide material was deposited by RF sputtering method and thickness was optimized by varying the RF power...

In the original article Mirgender Kumar’s first name is spelled wrong.

In the present work, Ge2Sb2Te5 (GST) material is investigated for detection in visible range (specifically at 632 nm wavelength) for spectroscopic photodetection and visible-light communication applications. Thin film of GST phase-change chalcogenide material was deposited by RF sputtering method and thickness was optimized by varying the RF power...

In this study, we conducted finite difference time domain simulation investigations of the transient responses of silicon-on-insulator waveguide-based vertical photodetectors using the phase-change material Ge2Sb2Te5 (GST) as a sensing element on the Si core. The charge transport characteristics comprising the carrier and displacement current were...

The present work proposes a duty-cycle-enabled energy-efficient bit-map-assisted (DCE-EBMA) medium access control (MAC) protocol. The proposed protocol efficiently utilizes the data slots by the adaptive duty-cycle approach. The algorithm adaptively updates the duty cycle of the sensor nodes and makes the system energy efficient. Simulation analysi...

A metasurface for use in multiscale applications in the near-infrared (NIR) range is proposed herein. A detailed study is carried out on a polarization-insensitive, single-layered, reconfigurable swastika-like metasurface for NIR switching. Using germanium antimony telluride (Ge2Sb2Te5) as a phase-change material, the metasurface works as a NIR swi...

In the present work, a metal-ferroelectric-semiconductor (MFS) structure for non-volatile memory application using barium titanate (BaTiO3) thin film is proposed. Sol–gel method is used to prepare the material, while deposition is done through spin-coating. A thin layer of BaTiO3 (BTO) film on a silicon substrate with MFS structure is fabricated fo...

In this work, non-conducting electrospun thermoplastic polyurethane (TPU) nanofibers have been successfully embellished with the filler materials viz. ferric oxide (Fe2O3) and polypyrrole (PPy) to synthesize the conducting TPU/Fe2O3 and TPU/Fe2O3/PPy nanocomposites. The electrical, morphological, elemental analysis and structural characteristics of...

Present work proposes an Adaptive Bit-Map-Assisted (ABMA) Medium Access Control (MAC) protocol. ABMA is a modified form of Energy-efficient Bit-Map-Assisted (E-BMA) MAC protocol by which it can efficiently utilize the data slots with low overhead traffic. In ABMA MAC protocol, cluster head adaptively varies allotment of data slots to the sensor nod...

Ethanol sensing performance of the NiO sensor has been investigated from room temperature (RT) to optimum temperature (Topt.). A low cost sol-gel spin coating technique has been employed to develop the surfactant embellished NiO sensor for ethanol sensing. The scanning electron microscopy (SEM) results have evidenced the layer surface having cracks...

The effect of UV illumination (254 nm) has significantly improved the sensing parameters viz. response/recovery times and % response, of SnO2-polypyrrole (PPy) composite based ammonia sensor. A facile and costeffective sol-gel spin coating technique followed by vapor phase polymerization is applied for developing the sensor for ultra-low ammonia co...

The impulse response for a phase-change material Ge2Sb2Te5 (GST)-based photodetector integrated with a silicon-on-insulator (SOI) waveguide is simulated using finite difference time domain method. The current is calculated by solving the drift-diffusion model for short pulse (∼10 fs) excitation for both of the stable phases. Full width at half-maxi...

In this paper, we report the light-matter interaction properties of crystalline and amorphous Ge2Sb2Te5 (GST) through design and simulation on different substrates based on finite difference time domain method (FDTD). The absorption, reflectance and transmission coefficients of GST have been investigated for various thicknesses of GST on different...

Ultra-sensitive, highly selective, fast responsive and extreme low-ppb ammonia (NH3) sensor working at room temperature (RT) has been developed using SnO2/polypyrrole nanocomposite. Porous SnO2 nanofibers having diameter in range ˜70–150 nm were deposited using electrospinning technique, followed by vapor phase polymerization of pyrrole to develop...

The present work investigates the baseline resistance stability with a novel Ag doped $\rm SnO_{2}/ZnO$ nanocomposite for ethanol detection. A facile and cost effective sol-gel spin coating technique was used to fabricate a progression series of gas sensors using Ag (2 % wt.) doping in each SnO2/ZnO composites viz. $\rm SnO_2$ (100 % wt.)/ZnO (...

Present work reveals the investigations done on crystalline Ge 2 Sb 2 Te 5 (c-GST) based vertical photodetector for telecommunication wavelength (1550 nm) by optimizing the device dimensions on Silicon platform. Simulation studies done for the optimized structure reveal that the c-GST can be the promising material for the photo-detection applicatio...

The application of metal oxides based gas sensors in the field of food and fruits quality measurement can significantly reduce the spoilage of food by monitoring the quality. In the present work, rotten apple has been monitored by detecting the ethylene (C2H4) gas efflux using a thin film Ni–SnO2 sensor. The sensor is prepared by simple and cost-ef...

In this work, a SnO2 gas sensor with high specific surface area and hydroxylation property has shown enhanced sensitivity and selectivity for ammonia (NH3) detection at room temperature (RT). SnO2 thin film layer composed of nanograins of size ~ 8–24 nm is synthesized by dual step method including RF sputtering technique, followed by oxygen (O2) pl...

SnO2 nanostructured thin film based gas sensor is fabricated by sol-gel spin coating technique. The performance of the fabricated sensor has been investigated for analytes viz. ammonia (NH3) solution, acetone (C3H6O), methanol (CH3OH) and 2-propanol (C3H8O) at room temperature (RT) with humidity level ~55% RH for concentration range 500 ppb-500 ppm...

Lifetime maximization is an important issue while designing wireless sensor network. One of the ways to increase the lifetime of WSN is to reduce the energy demand of the sensor nodes and cluster head nodes, which can be decreased by filtering out redundant data traffic. A Two-Layer Hierarchal Aggregation (TLHA) protocol has been proposed, which fi...

In this letter, phosphor-converted white light-emitting diodes (LEDs) were analyzed based on single-crystalline (SC) ZnO film/Graphene quantum dots (GQDs) as phosphors with ultraviolet (UV) excitation. Color rendering index (CRI) and correlated color temperature (CCT) are found to be improved with injection current. The luminous efficiency of 245 l...

In this paper, zinc oxide (ZnO) thin film sensor has been fabricated using different sol–gel spin coating route to detect very low concentration (2 ppm) of ethanol vapors at room temperature (RT). The sensor shows appreciable response ~60% for 100 ppm of ethanol (C2H5OH) vapors at RT under humidity level ~55% RH. Various sensing parameters viz. % r...

IEEE 802.15.4 MAC protocol utilizes superframe structure for the data transmission in an energyefficient manner. In industrial applications, data generation rate of sensor nodes is abrupt in nature. Due to which, buffer overflow is started in few of the sensor nodes and hence overall throughput decreases. A new algorithm has been proposed in the pr...

Manifold higher response for ammonia detection has been accomplished by the influence of oxygen (O2) plasma treatment on sol-gel spin coated nanostructured SnO2 sensor. The response of the sensor increases with the O2 plasma treatment. The response of the sensor is investigated at room temperature for different plasma treatment durations and compar...

Doping in metal oxides provides a promising scope in the field of gas sensing allowing sensor’s surface modification which finally leads to improved results. We herein demonstrate a room temperate (RT) operated Ag doped SnO2 thin film sensor prepared by sol-gel spin coating technique for ethanol detection. It is observed that the fabricated sensor...

Here, we report design and simulations of a vertical photodetector based on amorphous Ge <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Sb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Te <sub xmlns:mml="http://www.w3.org/1998/Math/MathM...

In the present work, a two-layer optimized railway monitoring system using Wi-Fi and ZigBee interfaced wireless sensor network has been proposed for optimized bandwidth and power requirements. In the proposed network, a two-layer structure i.e. wireless local area network (WLAN) and wireless personal area network (WPAN) of wireless sensor network (...

In the present study, reverse body biasing and self-controllable-voltage-level (SVL) switch are used to reduce the leakage current in SRAM cell when the circuit is in stand-by mode, resulting in increase in threshold voltage of the transistors. In active mode, threshold voltages of transistors get decreased due to forward body bias which incorporat...

The effect of RF oxygen plasma treatment on SiO2 surfaces has been investigated and compared with nonplasma treated sensors. Eight samples of thermally grown ∼ 120 Å SiO2 film are treated with a different RF O2 plasma power and time. All sensors have been tested for different concentrations of H2 at 25 °C. It is observed that the sensitivity of sen...

This work presents the results of the experiments performed to classify the gases/odors with K-means clustering, hierarchical clustering and self organizing map using thick film gas sensor array responses. Already published responses of thick film sensor array for different gases/odors viz. H2, LPG, acetone and 2-propanol are used. Principal Compon...

Tin oxide based gas sensor elements were fabricated in integrated array form with different dopants using thick film fabrication technology. Four sensor elements including undoped tin oxide, palladium (Pd)-doped, platinum (Pt)-doped and zinc oxide (ZnO)-doped were integrated in form of single array where a common electrode was used for all the four...

A gridded gate Pt/SiO2/Si MOS capacitor has been fabricated for detection of Hydrogen (H-2) and Hydrogen Sulphide (H2S) gases. The MOS device was fabricated on P-type Si <100> (1-6 Omega cm) wafer with thermal oxide layer of thickness about 100 angstrom, whereas, Platinum (Pt) gate of similar to 350 angstrom was deposited by thermal evaporation tec...

A gridded Pt/SiO2/Si MOS sensor for hydrogen detection has been fabricated on p-type ⟨100⟩ Si wafer having resistivity (1–6 Ω cm). The SiO2 and Platinum (Pt) gate thickness were kept about 10 nm and 35 nm. The performance of Pt gate MOS sensor was evaluated through C-V characteristics (capacitance vs voltage) upon exposure to H2 (250 ppm–4000ppm) a...

This paper is a continuation of our previous work in which a new feature technique called average slope multiplication (ASM) was proposed to classify the individual gases/odors using dynamic responses of sensor array. The ASM method is used to quantify the individual gases/odors in this paper. Back propagation algorithm based two different neural n...

In the present study, an experiment to identify various gases/odors has been presented. This approach is based on the dynamic responses of a thick film gas sensor array. The dynamic response of the gas sensor array for four gases viz. LPG, CCl4, CO and C3H7OH was first transformed into well separated data using modified transformed cluster analysis...

This paper proposes a new method for classification of gases/odors called average slope multiplication (ASM) using dynamic characteristics of thick film gas sensor array. The instantaneous values of the extracted dynamic response/recovery plots for various test gases viz., LPG, CCl4, CO, and C3H7OH were correlated to its neighboring response plots...

This paper presents the performance comparison of linear discriminant analysis (LDA) versus principal component analysis (PCA) as feature extraction tools for qualitative classification of gases/odors using their responses obtained from the thick film sensor array. A multilayer feed-forward neural network (MLNN) with different training functions wa...

This paper discusses the robustness of the artificial immune recognition system (AIRS) for the gases/odors identification problem. The steady state responses of a thick-film sensor array with four sensor elements with exposure of four gases, viz., H2, CO, CH4, and LPG, are used as input data. The AIRS algorithm with its versions including AIRS1, AI...

In the present study, transformed cluster analysis (TCA) has been described in steps for better understanding of sensor responses for the identification of individual gases/odors. The effect of data preprocessing technique (TCA) for identification of odors/gases using published data obtained from responses of tin-oxide thick film gas sensor array,...

The present study discusses the results of an experiment performed for the qualitative classification of gases/odors using their responses obtained from the thick film gas sensor array. A multilayer feed-forward neural network (MLFNN) with different training functions has been utilized as a neural classifier. The input data used for the classificat...

The Pt/SiO2/Si MOS Capacitor was fabricated on p-type �100� (1–6�cm) Si wafer with thermally grown oxide layer (SiO2) of thickness about 33 ° A. The Platinum (Pt) gate with thickness 350°Awas deposited by vacuum evaporation technique. The C-V and sensitivity vs Bias voltage (V) responses of the sensor were measured at different concentration of Hyd...