Welcome to the webpage of Innovative Materials & Physics for Advanced Convergent Technologies (IMPACT) Lab: At the IMPACT Lab, we delve into the fascinating world of Innovative Materials and Physics to pioneer Advanced Convergent Technologies for next-generation energy, sensing, and computing solutions. Our research is fundamentally driven by a deep understanding of condensed matter physics, with a strong emphasis on exploring and engineering novel material properties.

Our Core Focus: Making an IMPACT

 

The IMPACT Lab is dedicated to the design, synthesis, and characterization of cutting-edge functional materials with an eye on applications. We aim to bridge the gap between fundamental physics and tangible technological advancements. Our key research thrusts include:

 * Innovative Materials Synthesis & Characterization: We specialize in the bottom-up fabrication of a diverse range of materials, including 2D materials, thermoelectric materials, light harvesting and functional nanostructures (nanoparticles, thin films, heterostructures), high performance polymers, hydrogels and metal-organic-frameworks. While at one end our approach involves advanced thin-film deposition techniques such as sputtering and pulsed laser deposition (PLD), alongside wet chemical methods for nanoparticle synthesis, at the other end we are interested in scalable solutions based on biomass. We employ a comprehensive suite of characterization techniques, including X-ray diffraction (XRD), various microscopy methods (SEM, TEM, AFM/MFM), and detailed investigation of electrical transport, piezoelectric and optical properties besides surface wettability, strength and robustness to environmental weathering.

 * Physics-Driven Device Exploration: Understanding the underlying physics of phenomena like resistive switching, spin-Seebeck effect, anomalous Nernst effect, exchange bias, and magnetoelectric coupling is central to our work. We investigate these phenomena in our synthesized materials with the goal of developing novel device paradigms. This includes exploring materials for efficient energy harvesting (thermoelectrics, solar cells – though solar cells were a past interest, the material science aspect is relevant), highly sensitive magnetic field sensors, advanced data storage (spintronics, MRAM), and novel computing architectures.

 * Advanced Convergent Technologies: The "convergent" aspect of IMPACT highlights our interest in materials and phenomena that sit at the crossroads of different technological domains. For instance:

   * Energy Solutions: We explore materials for waste heat recovery (thermoelectrics) and investigate the fundamental physics that could lead to more efficient energy conversion. Our work on multiferroics and magnetoelectrics also has implications for low-power electronic devices.

   * Sensing Applications: The strong sensitivity of magnetic and electronic properties to external stimuli in materials like magnetoelectrics, piezoelectric, and specifically designed nanostructures positions them as ideal candidates for advanced sensors (e.g., magnetic field sensors, multifunctional sensors).

   * Next-Generation Computing: Our research in the field of neuromorphic computing involves successfully emulating key biological learning and memory dynamics—including short-term potentiation/depression (STP/STD), long-term potentiation/depression (LTP/LTD), and spike-rate-dependent plasticity (SRDP)—in thin-film based synaptic devices. This work bridges the gap between biological neural networks and artificial hardware, and directly contributes to the quest for faster, smaller, and more energy-efficient computing and memory devices.

 

Our Approach: From Fundamental Physics to Societal Impact

 

The IMPACT Lab fosters a vibrant research environment where fundamental scientific questions meet real-world applications. We are committed to:

 * Exploring novel physical phenomena in condensed matter systems.

 * Developing new materials with tailored functionalities.

 * Fabricating and testing prototype devices.

 * Training the next generation of scientists and engineers to make a significant IMPACT in materials science and applied physics.

IMPACT Lab is poised to contribute significantly to the development of innovative solutions for some of the most pressing technological challenges of our time.

 

Integrated Sustainable Energy Solutions: The Role of Biomass Valorization

Furthering our commitment to Advanced Convergent Technologies for societal IMPACT, the lab, in collaboration with other domain experts, also explores integrated and sustainable energy solutions. A notable area of this collaborative work involves the valorization of biomass through gasification. This approach aligns with our goal of contributing to robust energy solutions, particularly for off-grid and agricultural applications (in collaboration with TFTL lead by Dr. Rishi Raj).

Key aspects of this collaborative research include:

 * Biomass Gasification for Energy Generation: We have investigated the design, fabrication, and performance of innovative biomass gasification systems. These systems are aimed at efficiently converting agricultural waste and other biomass resources into combustible gases, which can then be used for thermal applications like hot water generation or to power other processes. This research directly addresses the need for decentralized energy generation and waste utilization.

 * Application-Driven System Development: Our collaborative efforts have focused on developing practical systems with tangible benefits. This includes projects like agricultural waste-based gasifier heating systems for innovative cooling technologies (e.g., GreenCHILLTM) and off-the-grid climate control units for agricultural produce storage. These projects demonstrate a pathway from fundamental understanding to real-world sustainable technology.

 * Interdisciplinary Convergence for Sustainability: These initiatives showcase the "convergent" nature of the IMPACT Lab's philosophy, where expertise in materials physics intersects with mechanical engineering and thermal sciences to create holistic solutions. For example, our work on "Biomass-gasification-based atmospheric water harvesting" (published in Energy, 2018) and "Design, fabrication, and performance evaluation of a novel biomass-gasification-based hot water generation system" (Energy, 2019) exemplifies this synergy.

By engaging in such collaborative research, the IMPACT Lab extends its reach beyond conventional condensed matter physics to contribute to broader sustainable development goals, ensuring that our innovations in materials and physics find pathways to practical and impactful energy technologies.

 



some RESEARCH Contributions


Our current interest lies in Physics Motivated Sustainable Functional Materials and Technologies. Given below is a brief description of work in my research group:

(I) Fundamental Research

(A) Resistive Switching Devices and On-chip Artifical Neurons:

Background:Intrinsically neuromorphic devices were conceptualized about four decades ago but initial demonstrations of the same have only appeared recently. These developments have been fueled by the promising applications of the resistive switching devices (RSDs) in the development of artificial neurons. The present focus of the community engaged in furthering this work is directed towards the development of new materials for RSDs as well as for developing algorithms focusing on implementation of neuromorphic computing based on RSDs. Materials and devices that demonstrate key physical effects including non-linearity, plasticity, excitation, and extinction.
[Students: Indranil Maity, Richa Bharti; Collaborators: Dr. A. K. Mukherjee, Dr. A. Bandyopadhyay, Dr. S. J. Ray]

Our Key Contributions:
(a) Graphene mediated Resistive Switching in Complex Oxides. [AIP link]
(b) Enhanced Stability and Low-Operational Voltage using Defect Engineering. [Springer link]
(c) Improvement in Resistive Switching Characteristics using Dendritic Nano-inclusions. [Springer link1]
(d) Resistive Switching Phenomena in Complex Oxides. [Springer link]  [AIP link] [Elsevier link] [Elsevier link1]
(e) Resistive Switching as a Probe for Secondary Phase inclusion. [Springer link] 

(B) Force Sensing and Rheology in Micro-fluidic Channels:

Background: Rheology refers to the study of how materials flow and deform under applied forces. In microfluidic devices, we explore the rheological properties of fluids at a microscopic scale. These properties include viscosity, elasticity, and viscoelasticity. Understanding them helps us predict how fluids will behave within confined channels. Many fluids encountered in microfluidics are not simple Newtonian liquids. They contain macromolecules, particles, droplets, or other components that impart complex rheology. Examples of complex fluids include: (a) Polymer solutions and melts: These exhibit non-Newtonian behavior due to polymer entanglements, (b) Suspensions: Mixtures of solid particles in a liquid, (c) Biological fluids: Blood, cell suspensions, or protein solutions, (d) Surfactant solutions: Containing surface-active molecules, (e) Microfluidic channels provide an ideal platform to study complex fluid behavior. The confined geometry allows us to observe phenomena that might not occur in bulk system. It is worthwhile to investigate flow patterns, shear stresses, and particle interactions within these channels. Microfluidic rheology finds applications in biomedical devices, Lab-n-a-chip systems, Characterization of polymers, gels, and colloidal suspensions, and in optimizing mixing and reaction kinetics. We have started our work in this direction with the design and development of force sensors for micro-fluidic environments. [Students: Khashti Datt Pandey; Collaborators: Dr. Atul Thakur]

Our Key Contributions:
(a) Image-guided micro-force sensor. [Sensors and Actuators A: Physical link]
(b) Biomechanical parameter estimation using untethered non-prehensile magnetic microbot. [Springer-Nature link]


(C) Physics and machine Learning:

Background: Statistical physics and machine learning intersect in fascinating ways. While deep learning has yielded impressive practical results, the underlying theoretical understanding lags behind. Here, the statistical mechanics of disordered systems offers insights. Statistical physics inspires machine learning algorithms, leveraging mean-field theory and variants. Machine learning techniques find use in theoretical physics, particle physics, cosmology, quantum computing, and materials science. Bridging theory and technology, statistical physics enriches our understanding of artificial intelligence. The synergy between these fields promises exciting developments! [Students: Mohak Shukla]

Our Key Contributions:
(a) Similarities between RG and Auto-encoders. [Elsevier link]

(C) Graphene Oxide and related systems as sustainable functional materials:

Background:Graphene oxide (GO), a monolayer sheet of graphite oxide, is a wonder material that has tremendous application potential. Primarily, it serves as a precursor for making reduced graphene oxide (rGO) which has superlative properties close to graphene in addition to the benefit of scalable synthesis. Besides this, the remarkable physical and chemical properties of GO makes it a highly sought after material for applications in a wide variety of areas including electronics, biomedicine, energy and environment.GO has promising biological applications demonstrated at laboratory scale which include drug delivery, antibacterial coatings, photo-thermal cancer therapy, and selective differentiation of mesenchymal and neuronal stem cells. Key environmental applications of GO include contaminant adsorption, water decontamination, solar desalination and environmental sensing. GO also finds niche applications in areas including tribology and energy storage. GO has been shown to be a highly flexible nanomaterial with a high stiffness. However, realizing all this in practice hinges on developing a safe, economic and scalable method for making GO. Here, residues from the gasification process of natural biomass appears as a potential source for high quality carbon nanomaterials for potential large scale applications. The current emphasis is on using these cabon nanomaterials for improving properties of structural materials.
[Students: Ankush Kumar, Pranay Ranjan (Graduated), Apurva Sinha (Graduated); Collaborators: Dr. T. Rajagopala Rao, Dr. S. K. Samanta, Dr. A. K. Chakraborty, Dr. J. Balakrishnan]

Our Key Contributions:
(a) Demonstration of a non-explosive, scalable technique for inexpensive high yield synthesis of GO. [npg link1]
(b) Elucidate the potential of GO based Photovoltaic devices. [npg link] [Elsevier link]
(c) GO and rGO for dye adsorption and separation of a mixture of cationic dyes. [Elsevier link1] [Elsevier link2]
(d) Sensing capabilities of GO and rGO. [Springer link] [AIP link]
(e) Origin and Nature of Magnetism in GO and related systems. [IoP Science link]
(f)What is not quite right with GO and rGO? [Springer link]

(D) Thermoelectric Materials based on Oxides and their nano-composites:

Background: Thermoelectric (TE) materials help convert waste heat into useful electric power. In addition, the compact structure of TE devices are attractive for noise free refrigeration, e.g., in critical healthcare applications. Besides these there exist a host of other niche applications including power sources for deep space expedition. The utility of a TE material is evaluated using a dimensionless quantity called figure of merit, zT (= S2σ/κT ), where S is Seebeck coefficient, σ is electrical conductivity and κ is thermal conductivity which consists of electronic part of thermal conductivity and lattice part of thermal conductivity. Bi2Te3, PbTe and related materials have been found to exhibit excellent TE properties. However, these materials are toxic and undergo degradation at high temperatures limiting their large scale applications. In this context, complex oxide materials present themselves as viable alternative materials which are chemically inert and thermally stable. However, the known complex oxide materials are found to have very small S and a correspondingly a small zT.  Due to interesting interplay between charge, orbital and spin degrees of freedom in these materials, its physical properties can be tuned. This provides an opportunity to explore complex oxide materials with different compositions with a promise of finding an ideal TE candidate. Besides this, the use of Physics motivated strategies at nanoscale, there is huge promise for bulk nanostructured TE materials (viz., TE nanocomposites). The experimental work in our group is inspired by fundamental theoretical ideas propounded by the research groups of: (a) S. Maekawa  on the importance of spin state degeneracies in determining thermopower, and (ii) L. D. Hicks and M. S. Dresselhaus on the  role of quantum well structures in enhancing thermopower. [Students: Ashutosh Kumar (Graduated); Collaborators: Dr. D. Sivaprahsam, Prof. C. V. Tomy]

Our Key Contributions:
(a) Improving thermoelectric properties of lanthanum cobaltate via suitable co-substitution. [Elsevier link]
(b) Manganite-Cobaltate composite route to improved thermoelectic behavior. [Elsevier link]
(c) Magnetic field induced tuning of thermal transport poperties in Cobaltates. [IoP Science Link]
(d) Composite of Cobaltates with different carrier densities for improved thermoelectric properties. [IoP Science link]
(e) Colossal Thermopower in 3D superlattices based on Oxides. [Elsevier link]

(E) Theoretical and Experimental Studies in Cu2ZnSnS4 (CZTS) Solar Cells:

Background: Despite tremendous promise due to their earth abundant ingredients and solution processable material preparation, the solar cell family based on Cu2SnZnS4 (CZTS) absorber materials suffers key challenges impacting its efficiency and eventual deployment. At the outset the physical origin of these challenges needs to be understood.  We are addressing some of these concerns in our lab. [Students: Atul Kumar (Graduated)]

Our Key Contributions:
(a) Role of Contact Work Function, Back Surface Field and Conduction Band Offset in CZTS Solar Cell. [IoP Science link]
(b) Improving Opto-electrical Properties of CZTS using suitable Nano-compositing Strategies. [Springer link]
(c) Comprehensive Loss Modeling in CZTS Solar Cells: I-V characteristics as a simple probe of loss mechanisms. [Elsevier Link]



Technology Development Research
In the following technology development works, we are trying to provide necessary Physics based interventions in key ongoing developmental projects in the Engineering Departments both at IIT Patna and elsewhere.

(A) Developing Off-grid Atmospheric Water Harvesting System:

Background: We are working on the design and development of an all-season optimal atmospheric water harvester having a cooling power requirement of 3 Ton/10 kW with a flexibility for both grid based and off-grid operations. Due to constantly depleting ground water resources and industrial contamination of water bodies, shortage of reliable supplies of fresh water is a looming crisis across the world; mitigating it is therefore a global challenge. An increasing water demand for cities, industrial plants, agriculture and for the extraction of fossil fuels are straining an already burdened system. Nearly 1 billion people lack access to safe drinking water and sanitation due to lack of availability of clean water. Furthermore, the development of efficient modular water generation systems for rural, urban, tribal, national security, and disaster response scenario is highly desirable. Airborne moisture is a source of plentiful amount of freshwater that is accessible everywhere and can be harvested with a suitable off-grid energy source (biomass, solar energy, etc). Production of practically useful quantity of freshwater under a wide range of weather conditions and in an energy-efficient manner is therefore a very exciting research problem. In past, methods including radiative cooling, sorption-based water harvesting and solar distillation have been extensively studied. However, these studies lacked on crucial fronts including issues related to all weather condition operation, scalability and efficient system integration. We are also working towards developing robust and safe superhydrophobic coatings through environmental friendly approaches for the purpose.  Developing a scalable, cost-effective way to produce atmospheric water with all weather condition operation for the community is the prime goal of this work. [Students: Abhash Shukla, Bathina Chaitanya (Graduated), Sunil, Rabindranath Sarangi; Collaborator: Dr. Rishi Raj, Dr. V. Bahadur; Industry Partner: Shri Anurag Agarwal (New Leaf Dynamic Technologies Pvt. Ltd.)]
Link to Engineering Department Colleagues Homepage

Our Key Contributions:
(a) A Survey on Scope of Biomass Gasification Based Atmospheric Water Harvesting in India. [Elsevier link]
(b) Robust and safe superhydrophobic coating through environmental friendly approach. [Elsevier link]
(c) System and Method for Extraction Atmospheric Moisture (Abhash Shukla, Sunil, R. Raj and Ajay D. Thakur). [Indian Patent: 496332]

(B) Developing Biomass Gasification Based Off-grid Cold Storage System:

Background: We have developed a Novel Biomass-Gasification Based Hot Water Generation System (under the aegis of Ucchatar Aavishkar Yojana (UAY), Govt. of India) to run the Ammonia-CaCl2 cycle of the existing product GreenCHILLTM  of New Leaf Dynamic Technologies Pvt. Ltd. (our Industry partner). This has lead to the development of one of its kind Biomass-Gasification based Cold Storage System for preserving Farm products. We are working on further development of the climate control chamber so as to extend the ambit of this application (under IMPRINT-II).  [Students: Sunil, Rahul Sinha, Bathina Chaitanya (Graduated); Collaborator: Dr. Rishi Raj, Sri Anurag Agrawal, Dr. V. Bahadur]
Link to Engineering Department Colleagues Homepage

Our Key Contributions:
(a) Design, Fabrication and Performance Evaluation of a Novel Biomass-Gasification Based Hot Water Generation System. [Elsevier link]
(b) Demonstration of long-term cyclic sorption of ammonia in modified expanded graphite-calcium chloride composites for practical applications [Elsevier link]

(C) Developing Magnetic-Microrobotic Setup for Cell Manipulation:

Background: We are working on the design and development of magnetically actuated microbot for Cell manipulation applications. [Students: Dharmveer Agarwal, Kishan, Pranav, Aditya, Akash, Shivam, Dharmveer, Yuvaraj; Collaborator: Dr. Atul Thakur (Note: My role here has been in looking at some of the physics aspects of the problems)]
Link to Engineering Department Colleagues Homepage

 Our Key Contributions:
(a) Automated Non-prehensile Magnetic-Micromanipulation [ASME link]
(b) Single Cell Magnetic-Manipulation [RAS link]
(b) Magnetic Micro-robot based Micro-Manipulation of Cell Surrogates in Fluidic Channels [JMBR link]
(b) Bomechanical parameter estimation [JMBR link]

(D) Collaborative effort towards Low Global Warming Potential of refrigerants and refrigeration systems:

Background: As part of the collaborative efforts under the Ozone Cell of the Ministry of Environment, Forest and Climate Change, we are involved in research activities on low global warming potential alternative refrigerants and refrigeration systems. This work is aimed at addressing the Kigali amendment to the Montreal Protocol on Climate change, [Students: Abhash Shukla, Md Qadeer; Collaborator: Dr. Rishi Raj]

key RESEARCH contributions in past


  • Improving Thermoelectric Performance Metrics in several Chalcogenide Materials: We have studied a number of chalcogenide material systems for their thermoelectric properties and have explored ways to enhance their figure of merit in both polycrystalline and single crystal samples. [Springer link] [Science Direct link] [Elsevier link]
  • Pinning Mechanism in Iron Based Superconductors: We demonstrated  the existence of delta-l pinning mechanism in Fe-based superconductors. [link1]   [link2]
  • Vortex Matter in Thin Films with Nano-Engineered Disorder: We have explored the nature of vortex lattice matching phenomena in nano-engineered thin films of superconductors.[link]
  • Vortex Lattice Spinodal:We demonstrated a contact-less technique to determine the vortex lattice spinodal using third harmonic ac susceptibility. [link]
  • Modulation in state of partial order of vortex matter: We investigated the healing of transient disordered vortex states injected into a superconducting sample during the field ramping process in isothermal M-H measurements as a prescription to comprehend the modulation in the state of order of the underlying equilibrium vortex state in weakly pinned single crystals of a wide variety of superconductors. [link]
  • Role of Quenched Random Disorder on Vortex Phase Diagram: We explored the presence of a two-peak feature spanning the peak effect (PE) region in the ac susceptibility data and the magnetization hysteresis measurements over a wide fieldtemperature regime in weakly pinned single crystals of 2H-NbSe2 with different degrees of quenched random disorder. [link]

 


COLLABORATORS (Present and Past)



  • T. Rajagopala Rao (IIT Patna)
  • S. K. Samanta (IIT Patna)


LINKS

 

projects implemented at IIT Patna

 

Sl

Project Title

PI Name

Co-PI Name

Amount

Status

Date of Start

Date of Completion

Funding Agency

1

CZTS based flexible solar cells

Dr. Ajay D. Thakur

Dr. A. K. Thakur

1416000

Completed

09-May-2014

08-May-2015

SRIRU, CEE IIT Patna

2

Design and Development of an Agricultural Waste Based Gasifier Heating System for GreenCHILLTM

Dr. Rishi Raj

Dr. Ajay D. Thakur

9507000

Completed

17-Aug-2016

16-Aug-2018

MHRD, SERB and Industry UAY

3

Spin transport in 2D material/perovskites (LSMO) heterostructures

Dr. Jayakumar Balakrishnan

Dr. Ajay D. Thakur

3179000

Completed

08-Jun-2016

07-Jun-2019

DST Nanomission

4

Persistent Light Emitting Phosphors for Solid State Lighting Applications

 

Dr. P Kumari

 

Dr. A. K. Choudhary,

Dr. D. K. Sinha, Dr. Ajay D. Thakur

(Co-PI from mentor Institute)

1098000

Completed

18-June-2019

30-Sep-2020

TEQIP collaborative research scheme III

5

Development of an agricultural waste based off-the-grid climate control unit for storage and processing of agricultural produce

Dr. Rishi Raj

Dr. Ajay D. Thakur

9835540

Completed

22-Feb-2019

7-January-2023

IMPRINT-II

6

Psychrometry Driven Design and Fabrication of An All Season Optima Atmospheric Water Harvester

Dr. Rishi Raj

Dr. Ajay D. Thakur

3240260

Completed

03-Dec-2020

02-Dec-2023

DST(TMD)

7

Developing inorganic-organic hybrid thin film architectures as artificial neurons for non-von Neumann architectures

Dr. Ajay D. Thakur

NA

3197832

Ongoing

20-Feb-2023

19-Feb-2026

SERB

8.

Collaboration for research activities on low global warming potential alternative chemicals to substances controlled under the Montreal Protocol

Dr. Rishi.Raj

Dr, Ajay D. Thakur

5000000

Ongoing

10-Apr-2023

9-Apr-2028

Ministry of Environment, Forest and Climate Change

© Copyright Ajay D. Thakur