Dr. Sridhar S

@vit.ac.in

Assistant Professor (Sr. Grade-2), Department of Physics
Vellore Institute of Technology-Vellore Campus

EDUCATION

Ph.D., Fiber Bragg Grating Sensors, Graduated in 2019, Indian Institute of Science, Bangalore, India
M.Sc. Engineering, Fiber Bragg Grating Sensors, Graduated in 2019,Indian Institute of Science, Bangalore, India
M., Graduated in 2013, Pondicherry University, Pondicherry
B.Sc. Physics, Graduated in 2011,Bishop Heber college, Bharathidasan University, Tiruchirappalli, Tamil Nadu

RESEARCH, TEACHING, or OTHER INTERESTS

Multidisciplinary
12

Scopus Publications

260

Scholar Citations

6

Scholar h-index

6

Scholar i10-index

Scopus Publications

  • Daksha: on alert for high energy transients
    Varun Bhalerao, Santosh Vadawale, Shriharsh Tendulkar, Dipankar Bhattacharya, Vikram Rana, Hitesh Kumar L. Adalja, Hrishikesh Belatikar, Mahesh Bhaganagare, Gulab Dewangan, Abhijeet Ghodgaonkar, Shiv Kumar Goyal, Suresh Gunasekaran, Guruprasad P J, Jayprakash G. Koyande, Salil Kulkarni, APK Kutty, Tinkal Ladiya, Suddhasatta Mahapatra, Deepak Marla, Sujay Mate, N.P.S. Mithun, Rakesh Mote, Sanjoli Narang, Ayush Nema, Sudhanshu Nimbalkar, Archana Pai, Sourav Palit, Arpit Patel, Jinaykumar Patel, Priya Pradeep, Prabhu Ramachandran, B.S. Bharath Saiguhan, Divita Saraogi, Disha Sawant, M. Shanmugam, Piyush Sharma, Amit Shetye, Nishant Singh, Shreeya Singh, Akshat Singhal, S. Sreekumar, Srividhya Sridhar, Rahul Srinivasan, Siddharth Tallur, Neeraj K. Tiwari, Amrutha Lakshmi Vadladi, C. S. Vaishnava, Sandeep Vishwakarma, Gaurav Waratkar
    Experimental Astronomy, 2024
  • Science with the Daksha high energy transients mission
    Varun Bhalerao, Disha Sawant, Archana Pai, Shriharsh Tendulkar, Santosh Vadawale, Dipankar Bhattacharya, Vikram Rana, Hitesh Kumar L. Adalja, G C Anupama, Suman Bala, Smaranika Banerjee, Judhajeet Basu, Hrishikesh Belatikar, Paz Beniamini, Mahesh Bhaganagare, Ankush Bhaskar, Soumyadeep Bhattacharjee, Sukanta Bose, Brad Cenko, Mehul Vijay Chanda, Gulab Dewangan, Vishal Dixit, Anirban Dutta, Priyanka Gawade, Abhijeet Ghodgaonkar, Shiv Kumar Goyal, Suresh Gunasekaran, Manikantan Hemanth, Kenta Hotokezaka, Shabnam Iyyani, P. J. Guruprasad, Mansi Kasliwal, Jayprakash G. Koyande, Salil Kulkarni, APK Kutty, Tinkal Ladiya, Suddhasatta Mahapatra, Deepak Marla, Sujay Mate, Advait Mehla, N. P. S. Mithun, Surhud More, Rakesh Mote, Dipanjan Mukherjee, Sanjoli Narang, Shyama Narendranath, Ayush Nema, Sudhanshu Nimbalkar, Samaya Nissanke, Sourav Palit, Jinaykumar Patel, Arpit Patel, Biswajit Paul, Priya Pradeep, Prabhu Ramachandran, Kinjal Roy, B.S. Bharath Saiguhan, Joseph Saji, M. Saleem, Divita Saraogi, Parth Sastry, M. Shanmugam, Piyush Sharma, Amit Shetye, Nishant Singh, Shreeya Singh, Akshat Singhal, S. Sreekumar, Srividhya Sridhar, Rahul Srinivasan, Siddharth Tallur, Neeraj K. Tiwari, Amrutha Lakshmi Vadladi, C.S. Vaishnava, Sandeep Vishwakarma, Gaurav Waratkar
    Experimental Astronomy, 2024
  • The interplay of intra- and inter-layer interactions in bending rigidity of ultrathin 2D materials
    Yingchun Jiang, Srividhya Sridhar, Zihan Liu, Dingli Wang, Huimin Zhou, Jia Deng, Huck Beng Chew, Changhong Ke
    Applied Physics Letters, 2023
    Continuum mechanics break down in bending stiffness calculations of mono- and few-layered two-dimensional (2D) van der Waals crystal sheets, because their layered atomistic structures are uniquely characterized by strong in-plane bonding coupled with weak interlayer interactions. Here, we elucidate how the bending rigidities of pristine mono- and few-layered molybdenum disulfide (MoS2), graphene, and hexagonal boron nitride (hBN) are governed by their structural geometry and intra- and inter-layer bonding interactions. Atomic force microscopy experiments on the self-folded conformations of these 2D materials on flat substrates show that the bending rigidity of MoS2 significantly exceeds those of graphene or hBN of comparable layers, despite its much lower tensile modulus. Even on a per-thickness basis, MoS2 is found to possess similar bending stiffness to hBN and is much stiffer than graphene. Density functional theory calculations suggest that this high bending rigidity of MoS2 is due to its large interlayer thickness and strong interlayer shear, which prevail over its weak in-plane bonding.
  • A Study on MoS Nanolayer Coated Etched Fiber Bragg Grating Strain Sensor
    S. Sridhar, Suneetha Sebastian, Ajay K. Sood, Sundarrajan Asokan
    IEEE Sensors Journal, 2021
    In this paper, we report on the comprehensive study on Molybdenum disulfide (MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) nanolayer coated etched Fiber Bragg Grating (eFBG) strain sensor. MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanolayer is coated using Physical Vapor Deposition (PVD) of Molybdenum (Mo) on eFBGs followed by sulfurization of the same in an inert atmosphere at 450° C. Such coating technique provides a direct control over the coating thickness of MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , thereby enabling a study based on the effect of nanolayer coating thickness on the intrinsic strain sensitivity as well as the power of the back reflected Bragg wavelength of eFBG in the 0.78eV spectral region. High uniformity of MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanolayer coating ensures consistent, repeatable and highly linear FBG strain sensors with a correlation coefficient of 0.988 in the range of 0 to 2500 με. A maximum intrinsic strain sensitivity of ~6.65 pm/με with a resolution of ~150 nε have been achieved with optimized MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> coated eFBG sensors. This kind of consistent, highly sensitive and linear strain sensors when incorporated with proper packaging schemes can be particularly useful for applications demanding high sensitivity of FBG sensors such detection of seismic vibrations, underwater acoustic signals, low amplitude accelerations, etc.
  • Fiber Bragg Grating-Based Pulse Monitoring Device for Real-Time Non-Invasive Blood Pressure Measurement - A Feasibility Study
    N. Vajresh Kumar, Shweta Pant, S. Sridhar, Vinay Marulasiddappa, S. Srivatzen, Sundarrajan Asokan
    IEEE Sensors Journal, 2021
    The real-time, continuous, beat-to-beat blood pressure (BP) monitoring is vital in clinical scenarios such as operations theatres, ambulances etc. In the present study, a non-invasive BP monitoring methodology based on Fiber Bragg Grating sensors is reported. The design and development of Fiber Bragg Grating based Pulse Monitoring Device (FBGPM) is demonstrated which is capable of acquiring the radial arterial pulse pressure waveform effectively in real time. The Radial Arterial Pulse Pressure Waveform is acquired on beat to beat basis employing developed FBGPM in a clinical environment. Further, the recorded radial arterial pulse pressure waveform is processed to obtain systolic and diastolic BP by utilizing a standard non-invasive BP measurement device as a reference. The BP values obtained through FBGPM are then compared with the BP values obtained through an Intra-Arterial (IA) probe. The FBGPM is a chemically and electrically inert device which makes it an effective candidate for monitoring the real-time BP. The focus of the study is to demonstrate the feasibility of deploying developed FBGPM device in clinical environment to acquire beat-to-beat BP and subsequently compare the present device to the IA probe method of BP acquisition.
  • Hydrostatic Pressure Response of Mo Coated Etched Fiber Bragg Grating Sensor in Side-Hole Packaging
    Suneetha Sebastian, Sandhya Avvaru, Supriya Sridhar, Kiran Michael, S. Asokan
    2019 Conference on Lasers and Electro Optics CLEO 2019 Proceedings, 2019
    We demonstrate side-hole packaged; nanolayer Molybdenum (Mo) coated etched Fiber Bragg Grating (eFBG) as hydrostatic pressure sensor. Pressure sensitivity enhancement of nearly 2000 times is observed with such a simple, ruggedized and packaged sensor system. © 2019 The Author (s).
  • Temperature sensor based on multi-layer MoS2 coated etched fiber Bragg grating
    S. Sridhar, Suneetha Sebastian, S. Asokan
    Applied Optics, 2019
    The development of an etched fiber Bragg grating (eFBG)-based temperature sensor with a uniform multi-layer molybdenum-di-sulphide (MoS2) coating is presented in this paper. Multi-layer MoS2 has been coated on clad etched FBG sensors by DC magnetron sputtering of molybdenum (Mo) and subsequent sulfurization. The dependence of temperature sensitivity on the coating thickness of MoS2 on eFBGs has been tested from room temperature to 100&#x00B0;C. It has been found that MoS2 coated clad etched FBG sensors with a coating thickness of around 10&#x00A0;nm exhibit a maximum temperature sensitivity of &#x223C;95&#x2009;&#x2009;pm/&#x00B0;C (almost one order higher than that of bare fiber Bragg gratings), with a resolution of &#x223C;0.01&#x00B0;C obtained using an FBG interrogator with 1&#x00A0;pm resolution.
  • Highly sensitive fiber Bragg grating-based pressure sensor using side-hole packaging
    Suneetha Sebastian, S. Sridhar, P. Shiva Prasad, S. Asokan
    Applied Optics, 2019
    In this work, an analysis of pressure response of a fiber Bragg grating (FBG) sensor in a side-hole package is presented using the finite element method. Various parameters of the side-hole packaging such as hole radius, the distance of separation between them, the radius and length of the package, and the choice of the package material are considered and optimized in order to promote maximum pressure sensitivity of the FBG sensor. This investigation on optimization of the side-hole package parameters gives rise to pressure sensitivity of nearly 105 times as compared with the bare FBG sensor, with the numerical values of 3&#x00A0;pm/MPa for a bare FBG sensor to &#x223C;280,000&#x2009;&#x2009;pm/MPa for an optimized side-hole package FBG sensor. Such high-pressure sensitivity of an FBG sensor is being reported for the very first time in this work, to the best of our knowledge, and can be considered as the initial step toward the realization of a highly sensitive hydrophone based on FBG for sensing underwater acoustic signals.
  • Hydrostatic pressure response of Mo coated etched fiber Bragg grating sensor in side-hole packaging
    Suneetha Sebastian, Sandhya Avvaru, Sridhar S, Kiran Michael, S Asokan
    Optics Infobase Conference Papers, 2019
  • Multilayer MoS 2 Coated Etched Fiber Bragg Grating Based Hydrophone
    Suneetha Sebastian, S Sridhar, Rachel A Jilin, Sandhya A V Varu, A Sreejith, S Asokan
    Proceedings of IEEE Sensors, 2018
    This paper demonstrates multilayer Molybdenum disulfide (MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) coated etched Fiber Bragg Grating (eFBG) as highly sensitive hydrophone. Multilayer coating of MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> on eFBG is achieved using sputtering of Molybdenum (Mo) followed by sulfurization at 450°C in an inert gas atmosphere. MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> coated eFBG subjected to underwater acoustic pressure showed an increase in pressure sensitivity of nearly 20 times at 231Hz in comparison with bare FBG sensors.
  • Temperature dependent compressive behavior of graphene mediated three-dimensional cellular assembly
    Rituparna Ghosh, Siva K. Reddy, S. Sridhar, Abha Misra
    Carbon, 2016
  • Highly dense ZnO nanowires grown on graphene foam for ultraviolet photodetection
    Buddha Deka Boruah, Anwesha Mukherjee, S. Sridhar, Abha Misra
    ACS Applied Materials and Interfaces, 2015

RECENT SCHOLAR PUBLICATIONS

  • Fiber Bragg Grating Based Pulse Monitoring Device for Real-Time Non-Invasive Blood Pressure Measurement–A Feasibility Study
    NV Kumar, S Pant, S Sridhar, V Marulasiddappa, S Srivatzen, S Asokan
    IEEE Sensors Journal , 2021
    2021
    Citations: 32
  • A Study on MoS2 Nanolayer Coated Etched Fiber Bragg Grating Strain Sensor
    S Sridhar, S Sebastian, AK Sood, S Asokan
    IEEE Sensors Journal , 2021
    2021
    Citations: 13
  • Hydrostatic Pressure Response of Mo Coated Etched Fiber Bragg Grating Sensor in Side-Hole Packaging
    S Sebastian, S Avvaru, S Sridhar, K Michael, S Asokan
    CLEO: Applications and Technology, JTh2A. 95 , 2019
    2019
    Citations: 6
  • Temperature sensor based on multi-layer MoS 2 coated etched fiber Bragg grating
    S Sridhar, S Sebastian, S Asokan
    Applied optics 58 (3), 535-539 , 2019
    2019
    Citations: 31
  • Highly sensitive fiber Bragg grating-based pressure sensor using side-hole packaging
    S Sebastian, S Sridhar, PS Prasad, S Asokan
    Applied optics 58 (1), 115-121 , 2019
    2019
    Citations: 32
  • Multilayer MoS 2 Coated Etched Fiber Bragg Grating Based Hydrophone
    S Sebastian, S Sridhar, RA Jilin, SAV Varu, A Sreejith, S Asokan
    2018 IEEE SENSORS, 1-3 , 2018
    2018
    Citations: 3
  • Temperature dependent compressive behavior of graphene mediated three-dimensional cellular assembly
    R Ghosh, SK Reddy, S Sridhar, A Misra
    Carbon 96, 439-447 , 2016
    2016
    Citations: 24
  • Highly dense ZnO nanowires grown on graphene foam for ultraviolet photodetection
    BD Boruah, A Mukherjee, S Sridhar, A Misra
    ACS applied materials & interfaces 7 (19), 10606-10611 , 2015
    2015
    Citations: 119

MOST CITED SCHOLAR PUBLICATIONS

  • Highly dense ZnO nanowires grown on graphene foam for ultraviolet photodetection
    BD Boruah, A Mukherjee, S Sridhar, A Misra
    ACS applied materials & interfaces 7 (19), 10606-10611 , 2015
    2015
    Citations: 119
  • Fiber Bragg Grating Based Pulse Monitoring Device for Real-Time Non-Invasive Blood Pressure Measurement–A Feasibility Study
    NV Kumar, S Pant, S Sridhar, V Marulasiddappa, S Srivatzen, S Asokan
    IEEE Sensors Journal , 2021
    2021
    Citations: 32
  • Highly sensitive fiber Bragg grating-based pressure sensor using side-hole packaging
    S Sebastian, S Sridhar, PS Prasad, S Asokan
    Applied optics 58 (1), 115-121 , 2019
    2019
    Citations: 32
  • Temperature sensor based on multi-layer MoS 2 coated etched fiber Bragg grating
    S Sridhar, S Sebastian, S Asokan
    Applied optics 58 (3), 535-539 , 2019
    2019
    Citations: 31
  • Temperature dependent compressive behavior of graphene mediated three-dimensional cellular assembly
    R Ghosh, SK Reddy, S Sridhar, A Misra
    Carbon 96, 439-447 , 2016
    2016
    Citations: 24
  • A Study on MoS2 Nanolayer Coated Etched Fiber Bragg Grating Strain Sensor
    S Sridhar, S Sebastian, AK Sood, S Asokan
    IEEE Sensors Journal , 2021
    2021
    Citations: 13
  • Hydrostatic Pressure Response of Mo Coated Etched Fiber Bragg Grating Sensor in Side-Hole Packaging
    S Sebastian, S Avvaru, S Sridhar, K Michael, S Asokan
    CLEO: Applications and Technology, JTh2A. 95 , 2019
    2019
    Citations: 6
  • Multilayer MoS 2 Coated Etched Fiber Bragg Grating Based Hydrophone
    S Sebastian, S Sridhar, RA Jilin, SAV Varu, A Sreejith, S Asokan
    2018 IEEE SENSORS, 1-3 , 2018
    2018
    Citations: 3