Harnessing the Ion Bombardment process to create novel nanostructures


The rapidly evolving field of micro- and nano-fabrication is the meeting ground of physics, chemistry, biology, medicine, and engineering.

Conventional lithography techniques are widely used to fabricate microstructures commercially. However, such techniques have limitations at the nano level. Research in areas related to nanofabrication is therefore crucial in order to develop and improve novel manufacturing techniques.

This is where Vivek Garg, a research scholar with the IITB-Monash Research Academy, is hoping to make a significant contribution.

“My research is based on Focused Ion Beam (FIB) process for nanofabrication and its application in creating novel nanostructures,” explains Vivek. “The aim is to model ion-material interactions followed by rapid computation ion beam-based material removal (milling or etching), in order to create 2D/3D structures at both micro- and nano-scale for diverse applications like anti-reflection, colour filters, and sensors, to name a few.”

The Academy is a collaboration between India and Australia that endeavours to strengthen scientific relationships between the two countries. Graduate research scholars like Vivek study for a dually-badged PhD from both IIT Bombay and Monash University, spending time at both institutions to enrich their research experience.

Says Vivek, “FIB is a promising technique due to its capability range and diverse applications”.

For instance, it can be used for:

  • milling, thus making it suitable for micro- / nano-machining,
  • deposition, allowing for additive nanomanufacturing applications, and
  • imaging, which makes it even more powerful for microscopy analysis and materials applications.

Vivek plans to develop a reliable modelling methodology to predict optimized FIB process parameters for milling, which is expected to lead to robust and accurate 2D/3D structures at the micro- / nano-scale. He is currently working on ion induced, in-situ controlled manipulation of nanostructures and investigation through molecular dynamics simulations, in order to arrive at a feasible methodology. This work will be critical for 3D nanofabrication with promising nanoscale-controlled manipulation, strain engineering of nanostructures, opening new avenues in the diverse field of ion beams and applications beyond material science for realization of future nanoscale devices.

Optimization of Focused Ion Beam (FIB) milling process: Simulation results for a spherical profile obtained from optimization algorithm at a beam current of 20 pA and pixel size of 3 nm (a) Designed spherical profile, (b) Simulated spherical profile, (c) Error between the designed and simulated profile [1]

Rapid prototyping of subwavelength silicon nanostructures for light trapping and antireflection Properties (a) Scanning electron microscopic (SEM) image of fabricated designed Si Gaussian pillar nanostructures, (b) Antireflection properties exhibited through fabricated pillars and comparison with simulation results, (c) Optical absorption per unit volume exhibiting light trapping [2]

Structural colour printing with FIB: (a) Direct fabrication of subwavelength nanostructures for multicolour generation, (b) A wide colour palette shown with optical microscopic images of fabricated colour filters, (c) Nanoscale structural color printing: few examples, such as butterfly, Kangaroo, letters, shown via SEM image and including corresponding optical microscopic image showing generation of unique structural colours [3], [4]

Microscopic Gardening: Tiny Blossoms of Silicon
The image shows scanning electron micrograph of silicon nanoflowers realized with focused ion beam in conjunction with wet chemical etching methods. The bulk structuration of Si substrate, based on the ion implantation design and area, allows fabrication of exotic functional and 3D micro/nanostructures on Si substrate exhibiting unique optical properties for applications in nanophotonics and physical sciences (Image scale bar 400 nm)

Prof Murali Sastry, CEO of the IITB-Monash Research Academy and a leading nanomaterial scientist says, “Nanofabrication is an art. Future applications require materials with improved electronic, magnetic, optical, and mechanical properties. Many of these properties are defined by the structure and composition in the size range below 100 nm. It is most important to maintain the material integrity and composition as we move towards the nano-scale, which is what makes Vivek’s project so challenging.”

Oftentimes, it pays to think small when we need to think big!

Research scholar: Vivek Garg, IITB-Monash Research Academy
Project title: Focused Ion Beam (FIB) Fabrication of Novel 2D/3D Nanoscale Structures: Process Modeling and Applications
Supervisors: Prof. Rakesh G. Mote, Prof. Jing Fu
Contact details: vivekgarg@iitb.ac.in, vivek.garg@monash.edu

 

[1] V. Garg, R. G. Mote, and J. Fu, “Focused Ion Beam Fabrication: Process Development and Optimization Strategy for Optical Applications,” in Precision Product-Process Design and Optimization, Springer, Singapore, 2018, pp. 189–209.
[2] V. Garg, R. G. Mote, and J. Fu, “FIB fabrication of highly ordered vertical Gaussian pillar nanostructures on silicon,” in 2017 IEEE 17th International Conference on Nanotechnology (IEEE-NANO), 2017, pp. 707–712.
[3] V. Garg, R. G. Mote, and J. Fu, “Coloring with Focused Ion Beam Fabricated Nanostructures,” Microscopy and Microanalysis, vol. 24, no. S1, pp. 856–857, Aug. 2018.
[4] V. Garg, R. G. Mote, and J. Fu, “Focused Ion Beam Direct Fabrication of Subwavelength Nanostructures on Silicon for Multicolor Generation,” Advanced Materials Technologies, vol. 3, no. 8, p. 1800100, Aug. 2018.

 

Automatic Q&A Generation from Text


Asking relevant and intelligent questions has always been an integral part of human learning, as it can help assess the learner’s understanding of a piece of text. However, compiling questions manually is arduous. Automated question generation (QG) systems can help, as they have the ability to generate questions quicker and on a larger scale.

A typical scenario is evaluating students on reading comprehension, where it becomes tedious for a teacher to manually create questions, find answers to these questions, and then evaluate answer papers after the test has been administered. All these complex tasks can now be automated using an automatic question and answer generation system.

This is why research scholar Vishwajeet Kumar’s project titled, ‘Automatic Question and Answer Generation from Text’ has tremendous potential in a scenario where scientists are closely examining the efficacy of neural network-based methods in question generation from text.

“A compact Question Generation system would be able to generate meaningful, syntactically correct, semantically sound, and natural questions from text. The questions that work best are those that have supporting answers present in the text,” explains Vishwajeet, who has enrolled for a PhD programme in the IITB-Monash Research Academy,

 Early attempts at automated question generation depended heavily on a strict, limited, ad-hoc, and hand-crafted set of rules. These rules focus mainly on the syntactic structure of the text and are limited only to sentences of simple structures. Recently, the success of sequence-to-sequence learning models has opened up possibilities of looking beyond a fixed set of rules for the task of question generation.

 An automatic question generation system has applications in areas as diverse as FAQ generation, intelligent tutoring systems, and virtual assistants. Question generation can be naturally applied in the educational setting such as online courses, automated help systems, and search engines. It can also be applied in a wide variety of other domains — including chatbot systems (e.g. for customer interaction) and health care for analysing mental health.

Explaining his work so far, Vishwajeet says, “We present a system to automatically generate question and answer from text. Our system follows a two-stage process to generate question-answer pairs from the text. In the first stage, we present alternatives for encoding the span of the pivotal answer in the sentence using Pointer Networks. In the next stage, we employ sequence-to-sequence models for question generation, enhanced with rich linguistic features. Finally, global attention and answer encoding are used for generating the question most relevant to the answer.”

The IITB-Monash Research Academy is a collaboration between India and Australia that endeavours to strengthen scientific relationships between the two countries. Graduate research scholars like Vishawajeet study for a dually-badged PhD from both IIT Bombay and Monash University, spending time at both institutions to enrich their research experience.

Says Prof. Murali Sastry, CEO of the IITB-Monash Research Academy, “More and more institutions are moving from classroom teaching to online courses using platforms like MOOC, EDX, etc. For those administering such online courses, generating meaningful questions manually is a tedious task. The work of researchers like Vishwajeet shows us that asking meaningful and intelligent questions will improve the ability to answer them!”

Research scholar: Vishwajeet Kumar, IITB-Monash Research Academy

Project title: Automatic Question and Answer Generation from Text

Supervisors: Prof.Ganesh Ramakrishnan and Prof. Yuan-Fang Li

Contact details: vishwajeet@cse.iitb.ac.in

The above story was written by Mr Krishna Warrier based on inputs from the research student, his supervisors, and IITB-Monash Research Academy. Copyright IITB-Monash Research Academy.

 

 

 

 

Nanostructure fabrication inspired by sand dune ripples


What can nanotechnologists learn from ripples on sand dunes?

A lot, smiles Bhaveshkumar Kamaliya, a research scholar with the IITB-Monash Research Academy — who is convinced that if he can mimic the macro-scaled ripples or wave-patterns seen on sand dunes to a nanoscale, it will help him study interactions of ion beams with surfaces of different materials, and perhaps even create self-organized nanostructures.

Nano-scaled structures strongly improve optical, electrical, and magnetic properties of materials. This has led to the study and development of many nanostructure-based devices; however nano-structuring poses a tremendous challenge as the fabrication process for such devices is not available due to limitations of conventional photolithography and electron beam lithography techniques.

“My project has two key aspects,” explains Bhavesh, “(i) experimental investigations for the formation of nanoripples, nanodots, and other complex nanostructures by varying parameters of energetic ion beams, and (ii) molecular dynamics simulations and modelling for understanding, validating and predicting experimental outcomes.”

“The self-organized nanoripples have the potential to serve as functional nanostructures and exhibit novel structures required for photovoltaics, surface plasmons, photonics, bio-sensing, etc.,” says Bhavesh. “Controlling the topography at the nanoscale is challenging and studying the mechanism behind the phenomena could help develop new and complex materials.”

His work is likely to offer the scientific community a systematic understanding of the mechanism behind self-organized nanostructures induced by Focused Ion Beam (FIB) irradiation. It could even lead to the fabrication of an efficient photovoltaic-based energy harvesting device or surface plasmon-based bio-sensing device.

Nanorippled Germanium: (a) Scanning electron micrograph (false coloured) of nanoripples on germanium surface induced by focused ion beam irradiation, (b) mechanism of enhanced light absorption due to multiple reflections through nanoripples and (3) experimentally measured light absorption from nanorippled germanium and bare germanium surface. (Reference: B. Kamaliya, R. Mote, M. Aslam, and J. Fu, APL Materials 6, 036106 (2018); doi: 10.1063/1.5021735).

The Academy is a collaboration between India and Australia that endeavours to strengthen scientific relationships between the two countries. Graduate research scholars like Bhavesh study for a dually-badged PhD from both IIT Bombay and Monash University, spending time at both institutions to enrich their research experience.

Prof Murali Sastry, CEO of the IITB-Monash Research Academy, and a reputed nanomaterial scientist, is excited. “The Academy is an opportunity for industry in Australia and India, as well as for IIT Bombay and Monash University, to train the next generation of rich talent in India. It has the potential to be a significant research institution. Talent from the Academy should become much sought after around the globe. This project could open new avenues on controlling nanoripples orientation and high-efficiency germanium-based photovoltaic applications.”

Indeed. We hope Bhavesh’s work will cause significant ripples — both literal and metaphorical.

Research scholar: Bhaveshkumar Kamaliya, IITB-Monash Research Academy
Project title: Study of Ion Beam Interaction with Materials and Nanostructure Fabrication
Supervisors: Prof Mohammed Aslam, Prof Rakesh G. Mote and Prof Jing Fu
Contact details: rakesh.mote@iitb.ac.in, bkamaliya@gmail.com

 

The above story was written by Mr Krishna Warrier based on inputs from the research student, his supervisors, and IITB-Monash Research Academy. Copyright IITB-Monash Research Academy.

Rediscovering colonial Bengal’s Muslim women writers


Muslim women writers in Bengali were reasonably prolific in colonial Bengal. However, contemporary readers of Bengali literature are unaware of their work in both fiction and non-fiction. How is it that the writing of an entire demographic has failed to become institutionalised in the widely-researched field of Bangla sahityer itihas or Bengali literary history?

This is the primary question that drives my PhD programme at the IITB-Monash Research Academy. As a corollary, I also ask how we may disinherit the priorities that created these exclusions, and suggest productive paradigms through which colonial Bengal’s Muslim women writers can be read in the twenty-first century.

To begin with, we will need to go back in time a little.

The Bengali literary canon revolves largely around the work of Hindu male writers. Yes, Muslim male writers find mention in certain titles of Bengali literary history by male Muslim historians, but the only Bengali Muslim woman writer whose work has been recognised to some extent is Rokeya Sakhawat Hossain.

This is not to say that Hindu and Brahmo women writers are institutionalised to any recognizable extent within the field of Bangla sahityer itihas either. However, the work of such women writers has been brought to the forefront by a dedicated group of feminist literary scholars working within a field that can be described as early Bengali women’s writing. These scholars have mined the writing of Hindu and Brahmo women writers from colonial Bengal to examine the ways in which Bengali women’s subject hood was produced within the anti-colonial nationalist narrative.

The work of the Muslim women writers that I work on do not fit into these existing paradigms of scholarship. I, therefore, work at the intersection of Bangla sahityer itihas and early Bengali women’s writing to examine how canons are formed and how canonical exclusion operates.

Some of the questions that have dogged me for long are:

– Who is to say what is ‘good’ literature?
– Who is heard when they speak along these lines?
– Who are the gatekeepers of the Bengali literary sphere and how do they operate?

My work focuses on the specific case of colonial Bengal’s Muslim women writers to answer questions that are fundamental to the field of literary study in any language.

Shamsunnahar Mahmud

Rokeya Sakhawat Hossain

 

My research relies on two key methodical aspects among others—archival research and translation. During the summer of 2017, I discovered the work of the Muslim women writers I have chosen to focus on in five libraries in and around Kolkata. More work by such women writers exist in libraries in Dhaka. However, these works are not yet catalogued under a label such as ‘colonial Bengali Muslim women’s writing.’ So my work in the archives will help to carve out such a category and will create a repository of works fitting such a description. The work of future researchers can further enrich this inaugural repository.

All my primary material is in Bengali. This consists of eight texts ranging between the length of 60 and 400 pages. I have translated all this material into English and will be publishing some of them soon. As a result, this material will be made available to a much larger reading public than such work has commanded ever before. Hopefully, English-language translations of these works will also generate more research interest in the field of Bengali Muslim women’s writing.

Literary canons are built through deliberate exclusion of the writing of people on the periphery. Canon-making is neither unconscious, nor neutral. The onus is on readers to recognize this, learn about the systems of representation and circulation that its biases and omissions indicate, and remedy it as best they can.
Feminists and representatives of religious, caste-based, racial and sexual minorities have, in the last few decades, called for revision of literary canons to include previously undiscovered, but prolific and insightful, writers. However, as a prerequisite to this task, it is necessary to map the exclusionary gestures through which such canons operate and to question whether it would be better to expand canons, revise them, or abjure the idea of canons altogether. My work will hopefully go some way in answering such questions.
As graduate research scholars of the IITB-Monash Research Academy, we study for a dually-badged PhD from IIT Bombay and Monash University, spending time at both institutions to enrich our research experience. The Academy is a collaboration between India and Australia that endeavours to strengthen academic relationships between the two countries.

Research scholar: Sreejata Paul, IITB-Monash Research Academy

Project title: Gender and public sphere

Supervisors: Dr Paulomi Chakraborty and Dr Mridula Nath Chakraborty

Contact details: sreejatapaul@gmail.com

The above story was written by Sreejata Paul. Copyright IITB-Monash Research Academy.

How internal friction affects polymer dynamics


Imagine that you are waiting underneath an umbrella at an uncovered bus-stop on a stormy, rainy evening. As the bus rolls into position, you try to fold the umbrella before boarding. The wind and rain make it difficult to do so, and you can feel the driver staring at you impatiently. As the wind slows down a jot, you realize that your umbrella is rusty, making the task of folding it even more difficult. You finally manage to fold the umbrella, amid the increasing number of cold stares from the bus, and slump gratefully in the seat closest to the entrance.

Such a resistance to folding is experienced by all protein molecules which have to fold correctly into their correct 3-D shape, starting from their respective 1-D structures.

When protein molecules are synthesized by RNA, they are simply a linear sequence of amino acid building blocks. In order to perform the function for which they were synthesized, the protein molecule needs to ‘fold’ or reorient itself into the requisite three-dimensional shape. An excellent discussion on the structure of proteins can be found here.

Proteins not only experience an external resistance to folding from the solvent they are present in (water, mostly), they also experience an ‘internal’ resistance to folding (like the rust in the umbrella). This ‘internal friction’ in polymer molecules is a key focus of my PhD research. [Protein folding, taken in its entirety, is a much larger question, and I do not work on the protein-folding problem.] The biological consequences of internal friction, especially in connection with the protein-folding problem, has begun to receive a lot of academic attention recently.

Now, proteins are just a type of polymer: long chain molecules that are composed of several repeating units. At a fine enough level of detail, the chemistry of these building blocks will begin to matter: there is a significant difference between the bond that joins a carbon atom to a hydrogen atom, and a nitrogen-hydrogen bond.

My research training involves the use of statistical mechanical principles, and a tool called Brownian Dynamics (BD) simulations, wherein polymer molecules are modeled as beads connected by springs, without going into the finer chemical details of the molecule. Such a calculated and deliberate neglect of detail prevents us from answering certain questions about the polymer molecules (“what should be the shape of the drug molecule that binds specifically to site #27 of the molecule?”) but offers payback in terms of insight about specific universal properties of polymers. These universal properties could be biophysical or rheological in nature.

Total shear stress, τp,yx, as a function of the shear rate for various values of ϵ and h*. Error bars are smaller than the symbol size.

                                               Source: R. Kailasham, R. Chakrabarti, and J. R. Prakash, J. Chem. Phys. 149, 094903 (2018)

In a recent publication, we study the rheological response of a dilute polymer solution with internal friction.

As graduate research scholars of the IITB-Monash Research Academy, we study for a dually-badged PhD from IIT Bombay and Monash University, spending time at both institutions to enrich our research experience. The Academy is a collaboration between India and Australia that endeavours to strengthen relationships between the two countries. According to its CEO, Prof Murali Sastry, “The IITB-Monash Research Academy was conceived as a unique model for how two leading, globally focussed academic organisations can come together in the spirit of collaboration to deliver solutions and outcomes to grand challenge research questions facing industry and society.”

He was spot on. This project will firstly enhance our ability to understand mechanisms in biological systems such as the cellular environment. It will also contribute to enabling aspects of the Strategic Research Priority ‘Living in a changing environment’ and understanding the fundamental molecular aspects of Biodiversity—all of which is essential for harnessing biomolecular processes whether in health care or biotechnology.

Research scholar: Kailasham Ramalingam, IITB-Monash Research Academy

Project title: Theoretical and computational study of polymers in the semi-dilute regime in presence of shear flow, crowding and internal viscosity

Supervisors: Dr. Rajarshi Chakrabarti and Dr. Ravi Jagadeeshan

Contact details:kailasham29@gmail.com

 This story was written by Kailasham Ramalingam. Copyright IITB-Monash Research Academy.

 

Using an enzyme to battle the Big C


Cancer is arguably the biggest medical mystery the world is trying to solve today. And researchers like Debopriya Sadhukan from the IITB-Monash Research Academy are attempting to understand the chemistry of cancer, which will hopefully help design better drugs to beat this dreaded disease.

Debopriya’s project is titled ‘Understanding the reaction mechanism of C5-cytosine DNA methyl transferase’.

Possible sites for DNA methylation

“DNA methylation—a process by which methyl groups are added to the DNA molecule—plays a crucial role in carcinogenesis,” she explains, “for it controls gene expression and maintains genome integrity. In tumour cells the normal methylation pattern is disrupted by hypomethylation or region-specific hypermethylation. In such cells, the methylation pattern is controlled by the enzyme C5-cytosine DNA methyltransferase. But how the enzyme catalyses the reaction is still a mystery. We are therefore trying to understand the working mechanism of this enzyme.”

Some of the questions researchers in this field are grappling with are:

i) How is the cysteine residue de-protonated?
ii) What is the role of the Glu119 residue?
iii) What is the nature of the base that will abstract the proton from the 5-position of cytosine?

Says Debopriya, “We are trying to understand the reaction mechanism of this enzyme by a completely different approach so that we can give a much better and easier explanation of the mechanism. In mammals this methylation mostly occurs at the 5-position of cytosine, so our work is solely focused on the reaction mechanism of C5- cytosine DNA methyl transferase. We adopted a simple approach. If the deprotonation energy of the C5-H bond is equal to or less than the protonation energy of the base, then the base will be able to abstract the proton from the 5- position of cytosine. So, we calculated the deprotonation energy of the C5-H bond in the presence of different moieties of the active site and the protonation energy of different bases in both gas phase and in a solution. Though we have not yet been able to close in on a suitable base whose protonation energy is more than the deprotonation energy of the C5-H bond, we found that the difference in deprotonation energy and protonation energy decreases when one increases the dielectric constant of the solvent. This is encouraging!”

Scheme-1: General Reaction Mechanism for DNA Methylation

The IITB-Monash Research Academy is a collaboration between India and Australia that endeavours to strengthen scientific relationships between the two countries. Graduate research scholars like Debopriya study for a dually-badged PhD from both IIT Bombay and Monash University, spending time at both institutions to enrich their research experience.

Says Prof Murali Sastry, CEO of the IITB-Monash Research Academy, “Today’s research challenges require a strongly multi-disciplinary approach. And the way in which this Academy has been set up makes it possible for such multi-disciplinary investigations to be carried out. This gives me immense hope that our research scholars will create significant science, societal and industry impact in the future. According to data from the National Cancer Institute, there are 458.4 new cases of cancer per 100,000 men and women per year. What could be more gratifying than if the work by researchers like Debopriya can help reduce that number?”

Research scholar: Debopriya Sadhukan, IITB-Monash Research Academy

Project title: Understanding the reaction mechanism of C5-cytosine DNA methyl transferase.

Supervisors: Prof. G. Naresh Patwari, Dr. Ekaterina Pas

Contact details: oli.debopriya@gmail.com

The above story was written by Mr Krishna Warrier based on inputs from the research student, his supervisors, and IITB-Monash Research Academy. Copyright IITB-Monash Research Academy.

Improving coverage control laws for multi-robot systems


Consider the following applications:

  • Monitoring the temperature/current or oil spills in a part of the ocean.
  • Attempting to ascertain the presence of nuclear radiation in a particular region.
  • Deploying a network of unmanned (UAVs) in a reconnaissance mission to measure enemy presence in a region.

In each, there is a need to distribute autonomous agents functioning as sensors to optimally cover an unknown environment. Algorithm design for such agents usually faces two challenges. The first is location optimization — to resolve how the agents should be ideally distributed in order to achieve optimum sensing capabilities. The second, and more important, is to ascertain the requirements in communication in order to achieve the desired optimum coverage configuration in a robust manner (for instance intervals between messages, communication topology).

Rihab Abdul Razak, a research scholar with the IITB-Monash Research Academy, is working on a project titled, ‘New models and algorithms for decentralized and adaptive coverage control in multi-robot systems’ to help resolve these challenges.

He aims to study advances in decentralized coverage control. This is an important coordinated control problem wherein a set of robots identify optimal techniques to cover an unknown environment for the purpose of sensing.

Says Rihab, “The phenomenon to be sensed by the robots is described by a mathematical function over the region to be covered. Each robot is capable of measuring the value of the function at its position. Controllers for mobile robots have been developed so that the robots realign themselves in an optimal sensing configuration. The problem is solved by optimizing the locational optimization cost function with respect to the agent positions, and developing controllers for the robots so that they converge to the optimum of the cost function. The controllers are decentralized so that the controllers for each robot in the group work based on information local to the robot and do not require global information.”

Most of the work done in this field so far uses simple agent models to design controllers. “We aim to design controllers for more realistic agent models,” explains Rihab. “Also, we focus on adaptive algorithms where all the information about the environment may not be known, and the algorithms developed need to adapt to these unknown quantities.”

The Academy is a collaboration between India and Australia that endeavours to strengthen scientific relationships between the two countries. Graduate research scholars like Rihab study for a dually-badged PhD from both IIT Bombay and Monash University, spending time at both institutions to enrich their research experience.

Says Prof Murali Sastry, CEO of the IITB-Monash Research Academy, “Rihab’s work has wide-ranging applications, including rescue and recovery, radiation and nuclear spill detection, underwater oil exploration, etc. The goal is to improve existing coverage control laws.”

Research scholar: Rihab Abdul Razak, IITB-Monash Research Academy

Project title: New models and algorithms for decentralized and adaptive coverage control in multi-robot systems

Supervisors: Dr. Srikant Sukumar, Dr. Hoam Chung

Contact details: tarihab@gmail.com

The above story was written by Mr Krishna Warrier based on inputs from the research student, his supervisors, and IITB-Monash Research Academy. Copyright IITB-Monash Research Academy.

Seeking a new material to monitor hydrogen


The demand for hydrogen on a commercial scale is growing rapidly. This colourless, highly combustible gas is not only a large industrial and laboratory commodity, but also has the potential to be used as fuel, and this could increase the demand to more than 2 trillion cubic metres per year. Therefore it is necessary to have a dedicated sensing system with low saturation, high sensitivity and affordability to measure hydrogen.

Arif Ibrahim, a research scholar with the IITB-Monash Research Academy, is hoping to develop precisely such a system as part of his project, ‘Nano-confined multi component metal hydride system for hydrogen sensing application’.

“Current measuring technologies use various principles — like Resistive, Optical, Bubble Testing, Catalytic Combustion, and Electrochemical,” says Arif. “We hope to come up with a thin-film-based hydrogen gas sensor using carbon-based material, which performs continuous monitoring with appropriate electronic arrangement.”

Hydrogen cannot be detected by human senses, making the use of suitable detection devices necessary. It is highly inflammable, and since hydrogen leaks can be hazardous if not detected quickly, reliable detection systems need to be tested, and their performance validated, so that they can be effectively deployed wherever hydrogen is produced, stored, distributed, or used.

Says Arif, “We have so far come up with a novel material that shows better response with pd dispersion into the matrix of that material and hydrogen gas can be sensed and continuously monitored with its lower limit by using any either resistive- or optical-based detection system. The biggest challenge is to get a proper thin film with thickness that lies under the 2D regime.”

The IITB-Monash Research Academy is a collaboration between India and Australia that endeavours to strengthen scientific relationships between the two countries. Graduate research scholars like Arif study for a dually-badged PhD from both IIT Bombay and Monash University, spending time at both institutions to enrich their research experience.

The image shows the detection principle in resistive as well as optical domain. In resistive sensing approach material is deposited on the top of conductive electrode i.e. gold, silver then sensing is done on the basis of change in resistivity with respect to exposure in the hydrogen rich environment. Similarly optical approaches are based on the change in the reflectivity of the material subjected to hydrogen gas

Says Prof Murali Sastry, CEO of the IITB-Monash Research Academy, “Hydrogen is not a primary energy source such as coal or gas but is an energy carrier (similar to electricity) and can store and deliver energy in a widely useable form. It is one of the most promising alternative fuels for future transport applications. When produced from renewable sources it provides pollution-free transport, without carbon dioxide (CO2) emissions, and decreases our dependence on dwindling oil reserves. If Arif is able to develop a sensing system for hydrogen that’s reliable and robust, the scope is tremendous.”

Arif Ibrahim

Research scholar: Arif Ibrahim, IITB-Monash Research Academy

Project title: Nano-confined multi component metal hydride system for hydrogen sensing application

Supervisors: Prof. S P Duttagupta, Prof. A Sarkar, Prof. Sankara Sarma V Tatiparti, Prof. Raman Singh, Prof. Gita Pendharkar

Contact details: er.arifibrahim@gmail.com

The above story was written by Mr Krishna Warrier based on inputs from the research student, his supervisors, and IITB-Monash Research Academy. Copyright IITB-Monash Research Academy.

Tracking nanoparticle movement deep inside our lungs


Lung disease is the third leading cause of deaths worldwide, according to a study by the World Health Organization. The respiratory system is prone to numerous diseases like asthma, bronchitis, pneumonia, and cancer. Many of these are caused by nanoparticles that deposit on the inner surfaces in our lungs.

• How does our breathing pattern affect the transport and deposition of these nanoparticles?
• Does our breathing rate during different activities like sleeping, running or walking have any significant effect on this?
• What are the differences in the breathing profiles of healthy persons and those with diseases?
• Can predicting nanoparticle movement in the lung help combat lung disease?

These are some of the questions that Chitresh Bhargava, a research scholar with the IITB-Monash Research Academy, is seeking answers to as part of his PhD project titled ‘Deep in the Lung: Nanoparticles transport and deposition in alveolar flows’.

“The transfer of desirable (drugs) or undesirable aerosols (pollutants) in the lung occurs with the exchange of oxygen and carbon dioxide in small sacs known as alveoli (more than 300 million in number). Understanding the transport and deposition of such nanoparticles is of deep interest to me,” says Chitresh. “It enables us to study health effects — both from the point of view of potential risks due to pollutants and safety to pharmaceutical drug delivery.”

Previous studies suggest that factors such as the particle size and carrier airflow pattern determine the deposition fraction in regions such as nasal pharyngeal, bronchioles and alveoli. “It has been reported that a fine particle size (approximately 20 nm) has a deposition fraction of 90% in the alveoli”, which suggests that diffusion is the main mechanism of particle deposition. However, studies reveal that diffusion cannot be the only reason. Convective transport plays a vital role as well in the transport of particles along the conducting airways.”

During his research, Chitresh will simulate and analyze fluid flow and particle deposition in various complex alveolar models of the pulmonary tract through computational fluid dynamics (CFD). “In a series of studies, we will employ the CFD approach as it allows us to consider flows that are very difficult to model experimentally even for very small particles. However, CFD has not yet been used extensively to study alveolar deposition. Limitations such as failure to incorporate the accurate shape of the alveoli, expansion-contraction of the alveoli during breathing, and the impact of breathing rate on the transport and deposition of aerosols have influenced us to work on a more accurate method to track particles in the alveoli.”

Airflow simulation in an alveolated duct 3D model for Reynolds number 0.01. The streamline profile shows re-circulation of air in alveoli

The IITB-Monash Research Academy is a collaboration between India and Australia that endeavours to strengthen scientific relationships between the two countries. Graduate research scholars like Chitresh study for a dually-badged PhD from both IIT Bombay and Monash University, spending time at both institutions to enrich their research experience.

Says Prof Murali Sastry, CEO of the IITB-Monash Research Academy, “Extensive research is being conducted to ascertain new drugs and drug delivery systems for pulmonary delivery that are more efficient and safe. It is first important, though, to understand the mechanism of transport and deposition of the particulate matter in the human lung rather than directly switching to the drug delivery system for treatment of a number of diseases. Thus, the prediction of the particle deposition in the human pulmonary tract is of vital importance to evaluate the risks associated with exposure to air pollutants. We hope Chitresh’s research will lead to a novel understanding of transport and deposition mechanisms that occur in alveolar flows, which, in turn, will help us all breathe a little easier!”

 

Research scholar: Chitresh Kumar Bhargava, IITB-Monash Research Academy

Project title: Deep in the Lung: Nanoparticles transport and deposition in alveolar flows

Supervisors: Prof. Devang V. Khakhar, Prof. Murray Rudman and Dr. Guy Metcalfe

Contact details: chitreshbhargava29@gmail.com

The above story was written by Mr Krishna Warrier based on inputs from the research student, his supervisors, and IITB-Monash Research Academy. Copyright IITB-Monash Research Academy.

Making robotic surgeries more efficient and interactive


Aspiring surgeons find surgical simulators very helpful as a training tool. However, most of these simulators use simplified tool-tissue interaction because of the real-time feedback required. This problem can be overcome if finite models are developed.

Abhishek Mukherjee, a research scholar with the IITB-Monash Research Academy, is therefore working on a project titled ‘Modeling of the interaction of soft tissues and cells with their environment’.

It is well-documented that during surgery the tissue response is a function of force (applied by the surgeon), tool position, and the path taken by the surgeon. Abhishek is attempting to develop tool-tissue interaction models to predict feedback which could directly be fed to the haptic device if the simulations can be conducted in real time. And just in case real time computations are slow, realistic simulations could be carried out offline and fitted into meta-models, which could then be used for feedback from the haptic device.

“A part of my project deals with modeling the interaction between a robotic surgical tool and tissue to characterize the mechanical properties of the tissue. Through this, we may be able to detect the presence of a tumor embedded in it,” says Abhishek excitedly. “And then there’s the other part, where I plan to model stresses on cells when they migrate through 3D channels. This is likely to give us more insight into the physics behind such processes. Cancerous cells take more time to migrate than healthy ones, and thus might serve as a bio-indicator. Bio-mechanical interactions are complex because they cannot simply be analyzed from a mechanical standpoint — there are several biological processes involved too. I relish the possibility that I get to unravel some of nature’s best kept secrets by understanding how bio-mechanisms work. The model that we have developed could make robotic surgeries more efficient and interactive.”

A three-dimensional computational model of an indentation process to detect an embedded cancerous nodule. The colours indicate stress development in the system with red indicating high stress and blue low stress conditions.

The IITB-Monash Research Academy is a collaboration between India and Australia that endeavours to strengthen scientific relationships between the two countries. Graduate research scholars like Abhishek study for a dually-badged PhD from both IIT Bombay and Monash University, spending time at both institutions to enrich their research experience.

Says Prof Murali Sastry, CEO of the IITB-Monash Research Academy, “The first part of Abhishek’s project holds a lot of promise for efficient robotic surgery in that there is a major push to make robotic surgery more interactive and make robots ‘feel’. Unfortunately, mathematical models to do are still to be developed. Robotic surgeries are currently done based on distance estimation to the target organs, but incorporating a touch or force sensation would make the process more intuitive and interactive for the surgeons operating on it remotely. The second part of the project is important to understand the physical phenomenon behind cell migration through constricted spaces. This could give more insight into understanding the dislocation of cancer cells from their primary location to lodging themselves in a separate location to give rise to secondary tumors. Understanding these phenomena could go a long way in treating cancers.”

Abhishek Mukherjee

Research scholar: Abhishek Mukherjee, IITB-Monash Research Academy

Project title: Modeling of the interaction of soft tissues and cells with their environment

Supervisors: Prof Ramesh Singh, Prof Shamik Sen, Prof Abhishek Gupta, Prof Wenyi Yan

Contact details: abhmukh@gmail.com

 

The above story was written by Mr Krishna Warrier based on inputs from the research student, his supervisors, and IITB-Monash Research Academy. Copyright IITB-Monash Research Academy.