Department of Electrical Engineering

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Flexibility in curriculum, in all its academic programs, encompassing elements of teaching, research, creativity, innovation and entrepreneurship is the most unique feature of IIT Jodhpur. The Department of Science and Technology (DST), under the National Mission on Cyber Physical Systems, has identified IIT Jodhpur as a Technology &amp; Innovation Hub in the area of Augmented Reality and Virtual Reality. The institute has also been nominated as the coordinator for the Jodhpur City and Knowledge Cluster by the Office of Principal Scientific Adviser, Government of India.

The sprawling 852-acre IIT Jodhpur campus is a majestic tribute to the deep-rooted diverse cultural heritage of the region. The campus is an architectural masterpiece, which is slated to become an international exemplar of sustainability with net-zero energy, and advanced water and waste management strategies.&rdquo;

IIT Jodhpur

In this work, a TCAD based approach is presented to model electrical behavior of TIPS-Pentacene: polymer blend organic field-effect transistors (OFETs). Stress induced and temperature induced effects are also captured, thereby accurately modeling the device behavior under different operating conditions. The framework is validated against experimental results and is then used to estimate the effect of temperature on characteristics of inverter circuit using this device. © 2017 IEEE.

World University root node

2017 IEEE 12th Nanotechnology Materials and Devices Conference, NMDC 2017

Comprehensive analysis of TIPS-Pentacene: Polymer blend organic field-effect transistor for device and circuit simulation

A nucleation controlled one-step process to synthesize MoS2–MoO3 hybrid microflowers using vapor transport process and its application in efficient NO2 sensing at room temperature are reported. The morphology and crystal structure of the microflowers are characterized by scanning electron microscope (SEM), Raman, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy techniques. A cathodoluminence mapping reveals that the core of the microflower consists of MoO3, and the flower petals as well as nanosheet are composed of a few layers of MoS2. Further, the MoS2–MoO3 hybrid microflower sensor exhibits a high sensitivity of ≈33.6% with a complete recovery to 10 ppm NO2 at room temperature without any extra stimulus like optical or thermal source. Unlike many earlier reports on MoS2 sensor, this advanced approach shows that the sensor is exhibited a low response time (≈19 s) with complete recovery at room tepmerature and excellent selectivity toward NO2 against various other gases. The efficient conventional sensing of the sensor is attributed to a combination of high hole injection from MoO3 to MoS2 and modulation of a potential barrier at MoS2–MoO3 interface during adsorption/desorption of NO2. It is believed that the modified properties of MoS2 by such composite could be used for various advanced device applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Advanced Materials Interfaces

Growth of MoS2–MoO3 Hybrid Microflowers via Controlled Vapor Transport Process for Efficient Gas Sensing at Room Temperature

We demonstrate a highly selective and reversible NO2 resistive gas sensor using vertically aligned MoS2 (VA-MoS2) flake networks. We synthesized horizontally and vertically aligned MoS2 flakes on SiO2/Si substrate using a kinetically controlled rapid growth CVD process. Uniformly interconnected MoS2 flakes and their orientation were confirmed by scanning electron microscopy, x-ray diffraction, Raman spectroscopy and x-ray photoelectron spectroscopy. The VA-MoS2 gas sensor showed two times higher response to NO2 compared to horizontally aligned MoS2 at room temperature. Moreover, the sensors exhibited a dramatically improved complete recovery upon NO2 exposure at its low optimum operating temperatures (100 C). In addition, the sensing performance of the sensors was investigated with exposure to various gases such as NH3, CO2, H2, CH4 and H2S. It was observed that high response to gas directly correlates with the strong interaction of gas molecules on edge sites of the VA-MoS2. The VA-MoS2 gas sensor exhibited high response with good reversibility and selectivity towards NO2 as a result of the high aspect ratio as well as high adsorption energy on exposed edge sites. © 2018 IOP Publishing Ltd.

Nanotechnology

Highly selective and reversible NO2 gas sensor using vertically aligned MoS2 flake networks

We demonstrate RF sputtered Ni-doped ZnO nanostructures for detection of extremely low concentration (1 ppm) of hydrogen gas at moderate operating temperature of 75 °C. Structural, morphological, electrical and hydrogen sensing behavior of the Ni-doped ZnO nanostructures strongly depends on doping concentration. Ni doping exceptionally enhances the sensing response and reduces the operating temperature of the sensor as compared to undoped ZnO. The major role of the Ni-doping is to create more active sites for chemisorbed oxygen on the surface of sensor and, correspondingly, to improve the sensing response. The 4 at% of Ni-doped ZnO exhibits the highest response (∼69%) for 1% H2 at 150 °C, which are ∼1.5 times higher than for the undoped ZnO. This is ascribed to lowest activation energy ∼6.47 KJ/mol. Diminishing of the relative response was observed in 6% Ni- doped ZnO due to separation of NiO phase. © 2017 Elsevier B.V.

Sensors and Actuators, B: Chemical

Efficient hydrogen sensor based on Ni-doped ZnO nanostructures by RF sputtering

To exploit the role of alignment of MoS2 flake in chemical sensing, here, we have synthesized the horizontally and vertically aligned MoS2 flake network using conventional chemical vapor deposition technique. The morphology and number of layers were confirmed by SEM and Raman spectroscopy, respectively. The sensing performance of horizontally aligned and vertically aligned flake network was investigated to NO2 at room temperature. Vertically aligned MoS2 based sensor showed higher sensitivity ~51.54 % and ~63.2 % compared to horizontally aligned MoS2 sensor' sensitivity of ~35.32 % and ~45.2 % to 50 ppm and 100 ppm NO2, respectively. This high sensitivity attributed to the high aspect ratio and high adsorption energy on the edge site of vertically aligned MoS2. © 2018 Author(s).

AIP Conference Proceedings

NO2 sensing at room temperature using vertically aligned MoS2 flakes network

This study introduces a quick, highly efficient and a single sensor based maximum power point (MPP) tracking (MPPT) for partially shaded solar photovoltaic (PV) system. For this purpose, a novel 'human psychology optimisation' (HPO) algorithm is proposed, which is based on psychological and mental states of an ambitious person. The main objective of the HPO algorithm is the maximum extraction of the power from PV panel and efficiently supplying it to the load (battery). In this study, a single (current) sensor based MPPT for battery charging, by using HPO and some recent state-of-the-art MPPT algorithms, is tested on MATLAB simulation and verified on a developed prototype of the partially shaded solar PV system. The efficient battery charging and quickly reaching the MPP by HPO w.r.t. all other algorithms, in steady-state as well as in dynamic conditions, show the superiority over all the recent state-of-the-art control methods. Moreover, due to the single sensor, the cost of the MPPT system is reduced, as well as due to HPO the computational burden is very less, so it can be easily implemented on the low-cost microcontroller. © The Institution of Engineering and Technology.

IET Generation, Transmission and Distribution

Single sensor based MPPT for partially shaded solar photovoltaic by using human psychology optimisation algorithm

This study introduces a mathematical trajectory based 'Weibull Pareto sine-cosine optimisation (WPSCO)' algorithm for the maximum power point tracking (MPPT) in the dynamics as well as in steady-state conditions of a partially shaded (PS) solar photovoltaic (PV) system. This 'WPSCO' technique is used for quick and oscillation-free tracking of the global best peak position in a very less number of steps, which is necessary to work in real-time atmospheric conditions. The unique advantage of this algorithm for MPPT problem in PS condition is as it is free from common and generalised problem of the other evolutionary techniques such as longer convergence duration, a large number of search particles, steady-state oscillation, unnecessary computational burden etc., which create power loss and oscillations in output. This hybrid algorithm is tested on different types of PV characteristics of the PS solar PV array by using MATLAB simulator and verified on a developed hardware of the solar PV system. Moreover, the tracking ability is compared with the state-of-the-art methods. The satisfactory steadystate and dynamic performances of the WPSCO algorithm under variable irradiance and temperature levels show the superiority over the state-of-the-art control methods. © 2016 The Institution of Engineering and Technology.

IET Renewable Power Generation

Peak power detection of PS solar PV panel by using WPSCO

A super-pixel based on-chip compression is proposed in this paper. The compression is achieved by reading only one sample for each super-pixel. The proposed technique and the corresponding circuit are simulated in MATLAB and UMC 180 nm CMOS technology, respectively. Higher values of PSNR are observed as compared to the state-of-the-art on-chip compression techniques. For the compression factor of 2, the implemented design results in 49% of power saving. © 2017 IEEE.

EDSSC 2017 - 13th IEEE International Conference on Electron Devices and Solid-State Circuits

A super-pixel based on-chip image compression for high speed CMOS image sensors

Evidently, development of lab-on-a-chip platform to monitor various physical parameters, such as density, pressure, diffusivity, viscosity etc., has enormous potential and wide-ranging applications in the diagnostics and medical fields. Although, various microviscometers have been developed in the past, they still possess limited applications due to their lack of reproducibility in measurements and limit-of-detection. In the present work, we describe the experimental validation of a 3D printed microviscometer for measuring adulteration of gasoline (petrol) with diesel and kerosene. The device analyzes the change in dynamic viscosity based on width occupancy of the fluids inside a microchannel. This microviscometer has been designed and fabricated using the Stereolithography (SLA) based Digital Light Processing (DLP) 3D printer. The tests were conducted on samples of several blending ratios of petrol, diesel and kerosene, and the results were found within an accuracy of 0.95. This device possesses several advantages like ease of operation, simple design and automation capabilities. Further, the device is amenable to be implemented in various applications where viscosity is the monitoring parameter. Copyright © 2017 American Scientific Publishers All rights reserved.

Sensor Letters

Stereolithographic 3D printed microfluidic viscometer for rapid detection of automobile fuel adulteration

This paper studies synchronization in a multi-agent system, which is defined as a situation where all the agents in a group are required to achieve a common velocity direction. The agents are assumed to be coupled through controller gains that are not necessarily identical or homogeneous, which addresses a practical scenario where the gains may vary nominally due to minor implementation errors or drastically due to major faults or errors. The paper analyzes the effect of heterogeneous gains on the common velocity direction at which the system of agents synchronizes. Conditions under which heterogeneous controller gains result in a synchronized formation are derived and it is shown that the resulting common velocity direction lies in the conic hull of the initial velocity vectors of agents. A detailed analysis of the two agents system shows that there exists a less restrictive condition on heterogeneous gains that results in synchronization. Effect of saturation is also studied for two cases when the controller gains are bounded and when the control efforts are bounded. Both all-to-all and limited communication topologies are considered. Simulations are given to support the theoretical findings. © 2017, Springer Science+Business Media Dordrecht.