Department of Electrical Engineering

Indian Institute of Technology Hyderabad (IITH) is a premier institute of science and technology established in 2008. IITH has been consistently ranked in the&nbsp;<a href="https://iith.ac.in/reports/" rel="noopener noreferrer">top 10 institutes</a>&nbsp;in India for Engineering&nbsp;<a href="https://www.nirfindia.org/2021/EngineeringRanking.html" rel="noopener noreferrer" target="_blank">according to NIRF</a>&nbsp;making it one of the most coveted schools for science and technology in the country.

IITH offers&nbsp;<a href="https://iith.ac.in/academics/under-graduate/">undergraduate programs</a>&nbsp;in all the classical engineering disciplines, applied sciences, design, as well as several modern interdisciplinary areas. Students are given a flexibility to explore a broad set of areas, and potentially pursue a minor or double major in a discipline that is not their own. Students who wish to seek a deeper understanding of their own discipline are strongly encouraged to get involved in cutting-edge research with the help of a faculty to mentor them, and earn an Honors in their own field.

The very foundation of IIT Hyderabad is based on&nbsp;<a href="https://iith.ac.in/research/">research and innovation</a>. The vibrant research culture is evident from the number of patents and publications that IITH produces consistently every year. IITH offers&nbsp;<a href="https://iith.ac.in/academics/programmes-offered/">graduate programs</a>&nbsp;at both a masters, and a doctoral level, in several diverse areas. There are separate programs for technology, design, science, and liberal arts. The&nbsp;<a href="https://iith.ac.in/academics/post-graduate/">MTech program</a>&nbsp;is offered in various modes and durations to cater to the ever-growing need of postgraduate level professionals in the country.

IITH encourages and supports&nbsp;<a href="https://iic-iith.netlify.app/index.html" rel="noopener noreferrer" target="_blank">innovation and entrepreneurship</a>&nbsp;at every stage. The minor program in entrepreneurship is open to all students of IITH, and many of the courses are offered by industrialists who are entrepreneurs themselves. There are various&nbsp;<a href="https://iith.ac.in/research/centres-incubators/">innovation centers and incubators</a>&nbsp;that promote entrepreneurship and help mentor young innovators. IITH has been very successful in building tie-ups with leading academic institutions around the globe.

IITH enjoys a very special relationship with Japanese universities and industries that goes beyond academic and research collaborations. In fact, some of the iconic buildings in IITH campus will carry the signature of Japanese architecture.

IITH creates a unique holistic ecosystem for education that offers interactive learning, a very flexible academic structure, cutting-edge research, strong industry collaboration, and entrepreneurship. This is an environment which enables students and faculty to translate their dreams into realities.

IIT Hyderabad

Folic acid (which is converted to folate (i.e., vitamin B9) in the body) is a water-soluble molecule that is constantly lost and reintegrated daily, and physiological folate deficiencies can cause degenerative conditions, such as megaloblastic anaemia and neural tube defects. Herein, we report the one-step solid-state synthesis of NbFeO4 nanoparticles, which were used to prepare an electrochemical transistor for the highly selective, nanomolar detection of folic acid (FA) in human blood serum samples. Raman spectra and X-ray diffraction (XRD) patterns revealed the combination of monoclinic and orthorhombic phase formations with NbO6 octahedral sites. The NbFeO4-based electrochemical transistor (ECT) exhibits an excellent sensitivity of 0.009 nM cm−2 in the linear range of 1-100 nM as well as a low limit of detection (LOD) of 0.66 nM at an applied potential of 0.6 V. In addition, this sensor shows high selectivity towards FA in the presence of interfering species such as glucose (GS), ascorbic acid (AA), urea and uric acid (UA). The outstanding performance of the sensor can be ascribed to the presence of NbO6 octahedral sites in the NbFeO4 structure which interact with folate (the oxidized form of FA) through Nb4+/Nb5+ niobium states, resulting in an increase in the oxidation peak current. This novel inorganic electrochemical transistor platform can be used to develop high performance, non-enzymatic electrochemical transistors for a wide range of bioanalytical applications. © 2023 The Royal Society of Chemistry.

World University root node

New Journal of Chemistry

Facile one-step synthesis of a niobium iron oxide based electrochemical transistor for rapid, label-free detection of folic acid in human blood serum samples

To address the energy needs of the modern world, there is an increasing demand for low-cost energy storage systems with high energy and high power densities. Due to their extraordinary ability to store energy, nanocomposite electrodes have a significant role in supercapacitor applications. The current work describes a simple, one-step hydrothermal synthesis of crystalline BCO nanoflakes (NFs) that is inexpensive and effective for use as a supercapacitor electrode material. The crystal structure and phase formation of BCO material were identified with the help of XRD and FTIR analysis, respectively. FE-SEM analysis is used to confirm that the hierarchical BCO nanoflakes are made of bismuth wrapped around copper. Using a half-cell arrangement and a 6 M KOH electrolyte, the as-fabricated Bi2CuO4 (BCO) nanoflakes-based symmetric supercapacitor displays a specific capacity of 1842 C/g at 3 A/g current density. The trasatti method demonstrates the synergetic charge storage redox behavior of 92.9 % and capacitive behavior of 7.1 %, respectively. The cyclic stability shows an outstanding 88 % capacitance retention over 10,000 cycles in a two-electrode system. The symmetric cell with BCO material exhibits a high specific capacity of 652 C/g at 1 A/g current density with 41 Wh kg−1 energy and power density of 899 W kg−1, respectively. © 2023 Elsevier Ltd

Journal of Energy Storage

One-step hydrothermal synthesis of Bi2CuO4 nanoflakes: An excellent electrode material for symmetric supercapacitors

Sustainable and stable photodetectors with self-powering nature and superior performance are necessary to address the growing demand for flexible and wearable optoelectronic devices. This work demonstrates a flexible, self-powered, coaxial p-n heterojunction photodetector using SnS2/SnS on an Ag fiber substrate by coupling the photoexcitation property, semiconductor nature, and piezoelectric effect. Detailed characterization studies confirm the formation of hexagonal and orthorhombic crystal planes of SnS2 and SnS nanoflakes, respectively, with a piezoelectric coefficient (d33) of 175 pm/V for SnS2. The photoabsorption is maximum in the visible region with a direct band gap of 2.1 eV. The electrical studies display a tunable photoresponse under zero-bias conditions. Upon compressive strain of 0.43%, the photoresponse increases by 36%. The Ion/Ioff ratio of the fabricated photodetector was 102 at a zero bias, and the rise and decay times shorter than 1 s were obtained. The maximum external quantum efficiency of the fabricated photodetector was found to be 54.2%, owing to the superior piezo-phototronic properties. The band diagram and the charge transfer mechanism are studied to investigate the piezo-phototronic effect. The uniform strain on the Ag fiber substrate and the piezo-potential distribution upon compressive and tensile strain promotes carrier separation in the coaxial interfaces of the p-n junction. The demonstrated strategy provides a direction for developing fiber-based photodetectors with self-powering behavior and enhanced photoresponsivity for next-generation smart wearable textile-based applications. © 2023 American Chemical Society.

ACS Applied Nano Materials

Coaxial SnS2/SnS Nanostructures on the Ag Fiber Substrate for Flexible Self-Powered Photodetectors

Since lead-based piezoelectric nanogenerators (PENGs) possess serious health risks, environmental problems, proper disposal issues, and biocompatibility concerns, this work presents the fabrication of a flexible piezoelectric nanogenerator utilizing lead-free orthorhombic AlFeO3 nanorods for biomechanical energy scavenging to sustainably power electronics. Hydrothermal technique is used to synthesize the AlFeO3 nanorods and the PENG was fabricated on Indium tin oxide (ITO) coated Polyethylene terephthalate (PET) flexible film with AlFeO3 nanorods interspersed in polydimethylsiloxane (PDMS). transmission electron microscopy proved that the AlFeO3 nanoparticles are of nanorods shape. Through x-ray Diffraction, it is validated that AlFeO3 nanorods have orthorhombic phase and crystalline structure. A high piezoelectric charge coefficient (d 33 ) of 400 pm V-1 is obtained from the piezoelectric force microscopy of AlFeO3 nanorods. With optimized concentration of AlFeO3 in the polymer matrix, an open circuit voltage (V OC) of 30.5 V, current density (J C) of 0.7888 ±0.0001 μA cm-2 and an instantaneous power density of 240.6 mW m-2 are obtained under the application of a force of 1.25 kgf. To investigate the nanogenerator's practical utility, the PENG is used for lighting multiple LEDs, charging of a capacitor and as a pedometer via biomechanical energy harvesting. Hence, it can be employed for developing various self-powered wearable electronics such as flexible skin, artificial cutaneous sensors, etc. © 2023 IOP Publishing Ltd.

Nanotechnology

A high performance lead-free flexible piezoelectric nanogenerator based on AlFeO3nanorods interspersed in PDMS matrix for biomechanical energy scavenging to sustainably power electronics

Urea and nitrate-based fuel cells have emerged as promising electricity generation devices. However, most of these catalysts are expensive and limited in supply, which limits their practical applications. Hence, metal-organic frameworks (MOF) have been explored as catalysts due to their low cost, easy preparation, and high redox activity. Here, we synthesize nickel-based MOF (Ni-MOF) via one-pot solvothermal technique as bifunctional electrocatalyst for the direct urea and nitrate fuel cell. The as-synthesized Ni-MOF is deposited on nickel foam (NF) and used as working electrode (Ni-MOF/NF) which demonstrates a peak current density of 188 mA/cm2 for urea oxidation reaction (UOR) and −14 mA/cm2 for nitrate reduction reaction (NRR) at an onset potential of ∼ 1.58 V (vs RHE), and ∼ 1.12 V (vs RHE), respectively The enhanced functionality of the Ni-MOF/NF electrode can be attributed to the high catalytic efficacy of the Ni-MOF. This is mainly due to the presence of multiple oxidation states of N (i.e., Ni2+/3+) and excellent electronic conductivity of the organic ligands in MOF structure. Moreover, Ni-MOF/NF electrodes retain ∼ 71.2% and ∼ 83.9% capacity after 20000 s of UOR and NRR, respectively. This efficacy of the as-fabricated electrocatalyst proves MOF as a promising platform for direct fuel cell applications. © 2023 Society of Powder Technology Japan

Advanced Powder Technology

Solvothermal synthesis of hybrid nanoarchitectonics nickel-metal organic framework modified nickel foam as a bifunctional electrocatalyst for direct urea and nitrate fuel cell

High output and non-interrupted power supply from fabric-based nanogenerators still remain a major challenge in developing self-powered wearable electronic applications. Addressing this, we demonstrate a low-cost, lead-free triboelectric nanogenerator based on hydrothermally grown Titanium (Ti) functionalized Molybdenum Disulfide (MoS2) interspersed polypropylene (PP) cloth and sandwiched with Nylon cloth for a highly sensitive respiration sensor and self-powered ammonia gas sensor. The nanogenerator with the device configuration Cu/Ti@MoS2/PP: Nylon /Ag is attached to a respiratory mask, and the open-circuit voltage (Voc) and short-circuit current density (JSC) during respiration cycles were obtained as 29.3 V and 42.7 µA/cm2 respectively. A significant difference in the breath pattern of human respiration cycles. Further, a fully self-powered ammonia gas sensor was demonstrated by integrating the triboelectric nanogenerator with Ti@MoS2/PP ammonia sensor. The self-powered Ti- MoS2 on PP cloth-based gas sensor driven by TENG displays an excellent response with a wide dynamic sensing range of ammonia gas from 200 ppb to 2600 ppb at room temperature, with a high sensitivity, selectivity and a rapid response time. This study explores the bifunctional nature of Ti@MoS2 nanoparticles as a respiratory mask and a self-powered ammonia gas sensor fabricated with excellent potential for self-powered health diagnostic applications. © 2023 Elsevier B.V.

Sensors and Actuators B: Chemical

Ti@MoS2 incorporated Polypropylene/Nylon fabric-based porous, breathable triboelectric nanogenerator as respiration sensor and ammonia gas sensor applications

The high worldwide mortality and disproportionate impact of cardiovascular diseases have emerged as the most significant global health burden, unfortunately, unmet by the traditional detection methods. Therefore, developing a rapid, sensitive, selective, and rugged biosensor for the precise classification/quantification of cardiac biomarkers is a stepping stone for the future generation of cardiac healthcare. We demonstrate a facile, time-efficient, and scalable biosensor for classifying the FDI approved gold standard cardiac biomarker Troponin-I (cTnI) in untreated human serum matrix, built-on 2-D SnS2 and 1-D MWCNT composite transducer and decision-tree based explainable machine learning (ML) algorithm. The proposed methodology is further enhanced using an inimitable Operating-Voltage-Selection-Algorithm (OVSA), which boosts ML accuracy to ∼100%. The near-perfect classification is realized by strategically incorporating this two-step algorithm-first the OVSA, then the heuristic and ML approaches on the selected dataset. Dynamic concentrations of the biomarker (100 fg/mL to 100 ng/mL) are estimated with high sensitivity, ∼71 (ΔR/R) (ng/mL)−1cm−2 and low limit of detection (0.02 fg/mL), aiding to the prediction and prognosis of acute myocardial infarction. The hyperparameter tuning and feature engineering improve the decision process of the ML algorithm, fostering robustness against data variability. Feature importance indices, namely the Gini index, Permutation Importance, and SHAP values, portray ‘Voltage’ as the most important feature, further justifying our insight into the OVSA. The biosensor's specificity, selectivity, reproducibility and stability are effectively demonstrated with the sampling to result reporting time of just 20 min, establishing it as a potential candidate for clinical testing. © 2022 Elsevier B.V.

Biosensors and Bioelectronics

Near perfect classification of cardiac biomarker Troponin-I in human serum assisted by SnS2-CNT composite, explainable ML, and operating-voltage-selection-algorithm

Age-related macular degeneration (AMD) is a progressive chronic neurodegenerative retinal disease leading to vision loss, irreversible blindness, and visual impairment in older adults worldwide. Complement component 3 (C3) protein has been identified as the most predominant biomarker towards early diagnosis of AMD; therefore, there is an utmost requirement for non-invasive detection of C3 protein in the tear fluids of AMD patients. Considering this, we report an insightful electrochemical sensor capable of detecting clinically relevant concentrations ranging from 10 fg/mL to 1 μg/mL using electrospun indium-doped zinc oxide (InZnO) nanofibers as the transducing layer. The InZnO nanofibers have facilitated high anti-C3 antibody loading of 3.42 × 10−9 mol/cm2 and enhanced the overall charge transport mechanism at the sensor interface. The biofunctionalization process of the biosensor was investigated thoroughly using X-ray photoelectron spectroscopy (XPS) as well as different electrochemical techniques. The target C3 proteins were captured on the fabricated biosensor surface and determined through changes in charge transfer resistance (R CT) while executing electrochemical impedance spectroscopy (EIS) and peak current (I p) in the case of cyclic voltammetry (CV) and differential pulse voltammetry (DPV), respectively. The InZnO nanofiber-based nano-biosensor demonstrated a very low limit of detections (LODs) of 5.214 fg/mL and 0.241 fg/mL with an excellent sensitivity of 4.6709 (ΔR/R) (g/mL)−1 cm−2 and 54.4939 (ΔI p/I p)% (g/mL)−1 cm−2 for EIS and DPV techniques, respectively. By virtue of high antibody loading, ultrasensitive and ultra-selective capability, the indium-doped ZnO nanofibers show huge potential to be used as a high-performance diagnostic platform for AMD diagnosis. Graphical abstract: [Figure not available: see fulltext.]. © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.

Microchimica Acta

Electrochemical nano‐biosensor based on electrospun indium zinc oxide nanofibers for the determination of complement component 3 protein

Recently, a large body of work has revealed a very accurate deep learning established movement categorization algorithmic technique for assistive technology applications. However, minimum seriousness is given to its relative hardware execution. But direct mapping these algorithms onto battery-operated devices is a point of care, edge devices would not yield optimum results necessitating an algorithm-architectural holistic design methodology. In the current study, we offered a method for creating reconfigurable VLSI architectures for deep learning established gesture recognition for rehabilitative technology applications. The ZYNQ ultrascale + MPSoC zcu102 FPGA was used to implement the design. The on- chip power requirements for LoCoMo-Net and MyoNet on FPGA are 3.5 and 5 Watts, respectively. Furthermore, gesture recognition on the FPGA takes both networks at 1.876 ms and 61.988 ms, respectively. The accuracy comparison of the most advanced networks is carried out on the CPU, GPU, FPGA, and ASIC platforms. The suggested architecture was further synthesized utilizing GF 40-nm technology, which resulted in a 2.5× improvement in performance in terms of speed and a 12- 15× decrease in power consumption compared to FPGA in 2.046∼ mm2 of space and 300.8423 mW of power at 1.21 V. © 2013 IEEE.

IEEE Access

Reconfigurable VLSI Design Architecture for Deep Learning Established Forelimb and Hindlimb Gesture Recognition for Rehabilitation Application

Transferrin (TRF) is a type of glycoprotein present in blood plasma that plays a vital role in facilitating the absorption, storage, and movement of iron(III) ions within the circulatory system of multiple vertebrates. Herein, we report one-pot solvothermal synthesis of Copper Metal-Organic Framework nanosheets modified nickel foam (Cu-MOF/NF) for electrochemical detection of transferrin (TRF) in simulated human blood serum. The crystal structure of the Cu-MOF nanosheets was determined through X-ray diffraction (XRD), while Raman spectroscopy and Fourier-transform infrared spectroscopy (FTIR) analysis were employed to investigate the vibrational modes and the presence of surface OH groups, respectively. The nanosheet morphology of the Cu-MOF was observed and characterized using scanning electron microscopy (SEM) micrographs.The as-fabricated Cu-MOF/NF exhibits a sensitivity of 1.36 mA/x (x = mg.mL−1cm−2) for a linear range of concentrations from 1 mg mL−1 – 100 mg mL−1 with a low limit of detection (LOD) of 0.81 mg mL−1. The sensor exhibited good selectivity for TRF, even in the presence of interfering ions such as bovine serum albumin, ascorbic acid, uric acid, and urea, with concentrations 100-fold higher than TRF. The porous nickel foam with high conductivity, offers numerous active sites and pathways for ion transport, as well as pathways for electron transport during electrochemical catalytic reactions. This performance of the sensor is attributed to Cu 2+/Cu+ redox couple at the octahedral sites of the Cu-MOF facilitating the electro-oxidation of TRF and charge-carrier delocalization during the catalytic reaction. The as-fabricated sensor is successful in the determination of trace level TRF concentration the human blood serum with excellent recovery percentages of 108.33% This proves Cu-MOF/NF as a promising platform for various electrochemical analytical applications. © 2023 Elsevier Ltd and Techna Group S.r.l.

Ceramics International

Cu-MOF nanosheets modified nickel foam: A versatile platform for highly sensitive electrochemical detection of transferrin in simulated human blood serum