Excellence in PhD Research!


Message from Prof. Murali Sastry, CEO:

“It is a matter of immense pride that 5 of the Academy students have been selected for the “Excellence in PhD Research” Award and will receive this honour at the hands of the Hon’ble Prime Minister of India, Shri Narendra Modi, during the Convocation on 11 August, 2018. They are :

  • Dr. Ramakrishna Bairi
  • Dr. Vignesh Kuduva
  • Dr. Jayesh Sonawane
  • Dr. Subhadeep Das
  • Dr. Jhumur Banerjee

On behalf of the entire IITB-Monash Research Academy, I’d like to congratulate all of the award winners and wish them the very best as they set out on their careers.

Alumnus invents tough, metal alloy


Four times stronger than stainless steel, a unique alloy blends chromium, cobalt, iron, manganese and silicon.

It’s not Black Panther’s vibranium or Captain America’s proto-adamantium shield, but a new alloy has come pretty close.

Our alumnus, a University of North Texas researcher Saurabh Nene has been working with UNT’s College of Engineering Department of Materials Science and Engineering to mix and flow material simultaneously, giving the alloy new strength.

The alloy, which has no catchy name like its fictional counterparts, is created by melting and casting the materials, then taking the thin, flat mold to start “friction stirring,” Nene said.

Nene, who has been working on this piece of research for eight months, said the process intensely deforms the metal’s makeup by forcibly inserting a rotating tool into the cold metal.

“When you insert the tool in the metal, it generates frictional heat,” Nene said “When you move the tool ahead, it starts mixing the metal. The mixing and flow of the metal creates an intense deformation.”

The only problem with using Nene’s alloys commercially is the cost. While he said he could not estimate that exactly, he is trying to change the chemistry of the alloy to replace the cobalt element. For reference, cobalt costs $78,500 per ton. Iron costs $65.

“We are still trying to look for a good substitute that is not costly but can have the same result,” Nene said. “The main goal is to maintain the properties.”

Nene, alongside lab colleagues Michael Frank, Kaimiao Liu, Brandon McWilliams and Kyu Cho of the U.S. Army Research Laboratory in Maryland, published a report July 2 in the online journal Scientific Reports.

A paper related to the topic was also published in the journal in November 2017.

Designing and developing a self-piloted airship


 
A rendered image of an airship under development

Airships, which are typically aircraft that float because they are inflated with gas lighter than air, are slower than airplanes but more efficient with regard to energy consumption. They have many uses, but being extremely light, are difficult to control. This is what motivated Sohan Suvarna, a research scholar with the IITB-Monash Research Academy, to work on a project titled, ‘Design and Development of Autonomous Airships’.

“The biggest challenge that airship operators face is the effect of crosswinds,” reveals Sohan. “These big balloons are literally at the mercy of winds. This is why they are not as popular as airplanes, in spite of being cost-effective. Several researchers have been working on developing effective control laws for these vehicles. My goal is to develop an airship with excellent lateral stability.”

For over half a century after World War II, airships were used mainly for sightseeing or advertising. Now, the uses range from surveillance—particularly in archaeological, ecological, agricultural and livestock studies—to weather forecasting, pollution control, and even as network/ Wifi routers.

While airplanes use most of their power in the generation of lift, an airship relies mainly on aerostatics for lift generation. It uses most of its power in manoeuvring and counteracting crosswinds.

Sohan’s research is multidisciplinary—requiring the amalgamation of design, simulation and implementation. The potential research outcomes are many:

• Design and fabrication of an airship capable of effective control. (One of the airships that Sohan has built can be viewed here: https://www.youtube.com/watch?v=Xet1SyeawEE)

• Development of a high fidelity versatile flight dynamics model to anticipate the flight of the airship in real time. This is like predicting how the airship would behave, given ambient conditions
• Development of a control law that could guide the airship, and
• Implementation of the developed control law and navigation algorithm into an actual airship


Sohan Suvarna’s research flight plan

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 Sohan 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 applications of an autonomous airship are limited only by imagination. Since unmanned aerial vehicles do not require a pilot onboard, their endurance is not restricted by the physiological capabilities of the pilot. Besides, in an age of diminishing energy sources and fuel-hungry jets, it wouldn’t be a bad idea to look for energy-efficient transportation.”

Sohan, incidentally, is also passionate about stargazing. For this researcher, the sky is clearly not the limit!

Sohan Suvarna
Research scholar: Sohan Suvarna, IITB-Monash Research Academy
Project title: Design and Development of Autonomous Airships
Supervisors: Prof. Rajkumar Pant, Prof. Arpita Sinha, Prof. Hoam Chung
Contact details: sohan.suvarna@monash.edu

Convalesce in the news!


Message from Prof. Murali Sastry, CEO:

“It is with immense pleasure and pride that I inform all of you that the first startup from the Academy, Convalesce, has been selected for the Acceleration Program of IndieBio this summer 2018. IndieBio is the world’s leading life science accelerator based in San Francisco providing the best support silicon valley can offer to core biotech startups. IndieBio is backed by the venture SOSV.

Each team receives $250,000 in seed funding, lab and co-working space, dedicated mentorship, and becomes part of a huge network of IndieBio alumni, investors, biotech entrepreneurs, investors, press, corporate partners, and more. Founders engage with customers and partners, pitch to investors, and turn science into a real product people pay for.

Twice a year, IndieBio typically accepts 15 startups worldwide for their acceleration program, which lasts approximately 4 months. The aim is to close the distance between science and money.

As you all know, Subhadeep Das, an alumnus of the Academy, is the brains, heart and soul behind this startup and has pursued the dream of being an entrepreneur with single minded dedication. I am personally of the opinion that the future of Indian business and indeed, science and innovation, will be driven by startups such as Convalesce. This is a moment to be cherished by us all and marks an important milestone in the journey of the Academy. Such achievements in technology, science and business will determine what impact the IITB-Monash Research Academy has not just in India and Australia but globally.

Subhadeep – on behalf of the entire Academy, please accept my warmest congratulations, and best wishes in translating your dreams into reality”.

Best Poster Presenter Award from IITB


 

Vibhuti Chhabra presented a poster titled “Thermochemical conversion of mixed municipal solid wastes” at the Chemference conference held at IITB from 18th to 20th May’18. She participated in the 3MTT competition and won the best presenter award. The poster presented the mechanism of the pyrolysis of MSW. The results were obtained from the experiments conducted at the Australian Synchrotron and Monash University. Her research project is being sponsored by JSW.

Making mobile data downloads swifter


Figure 1. Caching of content at the edge (Base stations, Access points, etc.) of a heterogeneous cellular network

We’re hoping that Lalhruaizela Chhangte completes his research quickly, for his work promises to make mobile data downloads swifter and more efficient!

“Global mobile data traffic is expected to increase nearly eightfold between 2015 and 2020; unfortunately this means network congestion will increase too. One way to effectively reduce congestion in the backhaul links of today’s IP networks is caching videos and non-voice traffic closer to mobile and wireless devices,” says this research scholar with the IITB-Monash Research Academy. “That’s what motivated me to work on my project: A Software-Defined Testbed For Real Time Network Simulation.”

 

Video is the major component of IP traffic over mobile and wireless networks. Already, it constitutes more than half the mobile and wireless data traffic. Unlike voice traffic, though, video is more predictable and delay-tolerant.

“The popularity of videos can be estimated by tracking user activity, and this can be used to identify the contents in demand,” says Lalhruaizela. “Wireless technology has dominated access networks with WiFi Access Points (APs) at the last hop. More than a billion APs were shipped in the last decade and this number is expected to increase. The latest WiFi APs either come equipped with storage capacity or have the option to add it on. This makes them capable of storing considerable amount of contents. With storage becoming cheaper and WiFi APs present abundantly in homes and workplaces, a natural proposition would be to use these devices to cache contents and serve users’ requests locally from the access point’s caches. This should help reduce the frequency of fetching contents from remote content servers, and thus mitigate congestion in the backhaul links,” he smiles. Backhaul refers to intermediate links between the core network and smaller subnetworks.

Figure 2. High level design of the SDN based caching system using APs

Lalhruaizela is working on the design and implementation of a distributed content caching system in WLAN which uses storage in low-cost wireless APs to cache and deliver contents to mobile clients. “Technically speaking,” he says, “we have designed and implemented a software defined networking (SDN) based distributed caching system over wireless APs, which minimises the need to fetch content from remote content servers. It also addresses two major WLAN challenges during content delivery—client mobility and load balancing on WiFi APs.”

Figure 3. Flow of control and data in the system as a user requests a content

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 Lalhruaizela study for a dually-badged PhD from both IIT Bombay and Monash University, spending time at both institutions to enrich their research experience.

The applications for this work are many.

Service providers that have deployed thousands of wireless access points in public places such as coffee shops, shopping malls, airports, train stations, and sports stadiums can use the idea proposed to cache contents (videos, music etc.) which are in high demand in the APs to provide faster and seamless content downloads to users.

Also, educational institutions, which deploy hundreds of wireless access points in campus buildings and hostels will hopefully be able to cache content that is frequently accessed or downloaded in the APs. This will reduce the data consumption from third party Internet service providers, and also utilise the existing storage capabilities of the wireless APs.

Says Prof Murali Sastry, CEO of the IITB-Monash Research Academy, “Due to the huge data explosion over the Internet, and the ever-increasing demand for data from users, efficient and reliable caching has become vital. At the Academy, we will certainly track Lalhruaizela’s progress closely.”

We suggest you do too!

Research scholar: Lalhruaizela Chhangte , IITB-Monash Research Academy

Project title: A software-defined testbed for real time network simulation

Supervisors: Prof. Nikhil Karamchandani, Prof. D Manjunath, Prof. Emanuele Viterbo

Contact details: hrchhangte@gmail.com

This story was written by Antara Dasgupta. Copyright IITB-Monash Research Academy

Preventing flood hazards from becoming horrific disasters


Figure 1. Bridges were ravaged by the raging river, as the Chaurabari glacial lake burst on the June 16, 2013. If an efficient flood forecasting system had existed, the fatalities could have been minimized by timely evacuation. Source: https://www.indiatoday.in/india/north/story/uttarakhand-floods-environmentalists-blame-it-on-centre-state-govt-for-man-made-disaster-167419-2013-06-20.

I was a Master’s student, studying environmental science in Dehradun, when the horrific flash floods of 2013 wiped out entire villages in the state of Uttarakhand (north India). We were locked into our hostels, which didn’t have access to food for a few days, while water in the drain-sized channel behind our university gushed on like a full-blown river. We woke up to watch the news every morning, thinly veiled fear on our faces, silently praying for the relentless rain to stop. Three days later, when it was all over, my friends and I volunteered to help the survivors, who were fast pouring into Doon from all the hill stations. The memory of the dead, and the missing whom we could not possibly help, haunts me still.

I knew then that the technology to prevent such disasters exists, where we are lacking is really in their on-ground application. They say hindsight is always 20/20 and one might have hoped that the Uttarakhand tragedy taught us something about increasing our flood resilience. Unfortunately, all evidence is currently poised against that hypothesis. My goal, therefore, is to effect change in the way we plan our forecasting systems, design effective inter-organization communications strategies, and use every piece of data we have to ensure that flood hazards don’t turn into horrific disasters.

The IITB-Monash Research Academy — where I have enrolled for a PhD project titled, ‘Towards a Comprehensive Data Assimilation Framework for Operational Hydrodynamic Flood Forecasting’ — is a collaboration between India and Australia that endeavours to strengthen scientific relationships between the two countries. Graduate research scholars here study for a dually-badged PhD from both IIT Bombay and Monash University, spending time at both institutions to enrich our research experience.

For decades researchers and planners have relied on mathematical models to provide actionable flood forecasts, which are nothing but approximations of the real world flow processes expressed as equations. These models were previously trained on historical flow data collected using river gauges and validated using the same, usually at the channel outlet. However, the global decline in gauge networks in addition to the changing nature of the flow characteristics due to climate change, have rendered the use of such approaches insufficient. Moreover, gauge validation approaches for the channel seldom analyze the performance of the model in the floodplain, which is counterintuitive, as that’s where we need timely forecasts and warnings.

Although gauge networks are getting sparser, alternative data sources like earth observation and citizen sensing observations from social media are rapidly becoming ubiquitous. Big data is already driving everything from football strategies to elections. It’s time to unleash the full potential of such datasets for humanitarian causes such as disaster management. The advent of satellite technology revolutionized the flood mapping process by providing synoptic observations of flood extent in near real time. What was unexpected was its phenomenal potential for flood forecasting applications.

In the last decade, several studies used satellite-derived flood depths to train flood models and further to improve their predictive skill. These studies primarily relied on an indirect estimation of flood water levels by intersecting the flood boundary with floodplain topography. Extracting these water levels requires making several simplistic assumptions which adds significant uncertainty to the model domain. The direct integration of satellite-derived flood extents into flood models, however, could potentially help to avoid adding this uncertainty, as the inundated area is directly observable through satellites. Further, we compensate for the lack of flood depth information from satellites, by integrating crowd-sourced water level observations. By minimizing the number of additional assumptions about the data, we hope to reduce the forecast uncertainty further.

In the course of our work, we are hoping that more accurate flood maps with corresponding estimates of uncertainty can provide flood managers and first responders with useful tools for efficient mitigation efforts, which will benefit millions of people residing in floodplains. Further, they can be useful to substantiate insurance claims and help define premium amounts for risk insurance.



Figure 2. An advanced mathematical tool called data assimilation is used to integrate flood information from physical models, satellite data, and social media to arrive at better flood forecasts.

We use a combination of satellite data and crowd-sourcing to improve model forecasting skills which could potentially mean the difference between life and death for people living in low-lying flood prone areas. Studies integrating remotely sensed flood depths with models, have reported an increase in accuracy for forecasts made more than 10 days in advance, which could positively impact disaster preparedness. In addition to improving the forecasts, we have also worked on improving the flood mapping process from satellite data, where our approach reduced the errors by more than half in some regions! We introduced a novel fuzzy flood mapping technology, which doesn’t require any ground data for the mapping, can be easily automated, and provides the desired level of confidence in the flood mapping at each pixel.

Says Prof Murali Sastry, CEO of the IITB-Monash Research Academy, “In a world where climate change and population growth have already exposed over 2.8 billion people to flooding between 1995 and 2015, it’s baffling that we don’t have more people using the power of data for the greater good. Science is only as useful as the people it benefits, and the scientific community should work towards making research actionable for end-users. The work by researchers like Antara Dasgupta can go a long way in saving millions of lives. We wish her all success.”

Research scholar: Antara Dasgupta , IITB-Monash Research Academy

Project title: Towards a Comprehensive Data Assimilation Framework for Operational Hydrodynamic Flood Forecasting

Supervisors: Dr. RAAJ Ramsankaran and Prof. Jeffrey P. Walker

Contact details: antara.dasgupta@monash.edu

This story was written by Antara Dasgupta. Copyright IITB-Monash Research Academy

Detecting gas leaks using 2D sensors


Figure 1. If gas leaks are not contained in time, they can have lethal effects

Gases are generally colourless and odourless, making it extremely difficult to detect leaks. Tiny gas leaks can quickly build up into explosive concentrations — which can cause considerable damage.

Potential hazard zones are coalmines, dumping grounds, petroleum refineries, and even dairies — which emit toxic and explosive gases like methane, nitrogen oxide, sulphur dioxide, carbon dioxide, carbon monoxide, etc.

India’s worst mining disaster occurred in Dhanbad in 1965, where over 250 miners died. Besides, big cities like Mumbai regularly report fire incidents at landfills like the Deonar dumping ground, due to methane gas leaks. Various technologies are available to detect gas leaks, but they all have limitations. This is what motivated Uzma Memon a research scholar with the IITB-Monash Research Academy, to work on a project titled, ‘2D system for greenhouse gas sensing’.

“The existing technologies for gas sensing can be divided into chemical, calorimetric, gas chromatograph, acoustic methods, and optical,” explains Uzma.
“Chemical gas sensing technology however, has a limitation of saturation and requires a working temperature of 150oC to 500oC, which can be fatal in the case of explosive gases like methane. Besides, chemical sensors are not immune to harsh environmental conditions.
“Optical sensors have far more advantages — high sensitivity, selectivity, and stability with longer life and relatively short response time. For instance, infrared-based IR detectors, which offer high accuracy and safety, but are extremely expensive and have an added disadvantage of needing to be in the line of sight.

“I am therefore working on another type of optical detector—the Terahertz-based gas sensor—which is a relatively new but promising technology as it has been known to report sensitivity in amounts as minuscule as parts per billion (ppb).”

As part of her research, Uzma is attempting to develop a resonator tuned to terahertz frequency which, when subjected to a gas environment, will indicate a change in terahertz response spectra. “My biggest challenge,” she says, “is real-time monitoring and tracking of the gases and predicting their outbreak, by simulating a 2D thin film resonator for Terahertz frequency.”

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 Uzma 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 Academy, “Today’s research challenges require a strongly multi-disciplinary approach. The way in which the Academy has been set up makes it very possible for such multi-disciplinary investigations to be carried out. This gives me immense hope that the Academy will create significant science, societal and industry impact in the future. Uzma’s work in fabricating and testing a 2D film resonator optimized at terahertz frequency to detect gas has the potential to save lives—what can be more gratifying than that!”

Research scholar: Uzma Memon , IITB-Monash Research Academy

Project title: 2D system for greenhouse gas sensing

Supervisors: Prof S P Duttaguptta , Prof A Sarkar, Prof Raman Singh

Contact details: uzb.mem@gmail.com

This 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.

Reducing radiation risk in tomography


Illustration of the tomography process for an object. For clarity, this image shows one direction: rays are being sent from top to bottom. In reality, multiple directions are employed.

Tomography is a non-invasive technique to view the internal structure of an object, by irradiating it with powerful electromagnetic rays. In comparison to the more common 2D X-ray imaging for, say, fractures, tomography involves rays sent from multiple directions. This technique finds applications in fields as varied as medicine (for diagnosis), manufacturing (to detect cracks in products), material science (to study the interaction of materials over time), and geophysics (to identify fossil fuels in the earth’s crust), among various other disciplines.

The amount of X-rays absorbed by the object depends on the material properties of the object. Rays that aren’t absorbed are then measured after propagating through the object. The process of recovering the 3D structure of the entire object from these measurements is referred to as ‘reconstruction’. The quality of reconstruction depends on the number of measurements acquired. The more the measurements, the more accurate the reconstructed volume representative of the true internal structure of the object.

However, acquiring a large number of measurements for, say, a patient, implies exposure to higher levels of the X-ray radiation, which is harmful in the long run. It can also be expensive, and may require the patient to be immobile. In order to overcome these shortcomings, current research aims to build algorithms that help reconstruct the 3D object volume reasonably well with very few measurements.

The classical Nyquist-Shannon sampling theorem asserts the need to sample data at a uniform rate of at least twice the highest frequency contained in the data. For long, this remained the guideline for computing the minimum number of measurements needed. In 2006, a new theory, ‘Compressive Sensing’, emerged. This guaranteed robust reconstruction with measurements far fewer than the Nyquist rate. Compressive Sensing exploits the fact that most naturally occurring data are usually sparse under mathematical transforms such as the Discrete Cosine Transform, wavelets, or some other unique basis. Over the last decade, the focus has been on improving the efficiency of reconstruction by using domain knowledge of the data together with Compressive Sensing routines.

It is in this context that my research fits in. It aims to drastically reduce the number of needed measurements using two ideas:

  • suitable pre-processing

  • use of prior information of the family of objects scanned, perhaps over time

Specifically, the problems I deal with include: optimal grouping of 2D slice (cross-section of 3D volume) measurements, registration of 2D slices in the Radon and Fourier domains, and effective use of prior information within the Compressive Sensing framework. My work is particularly useful in scenarios wherein a person undergoing a long-term treatment needs to get a scan at regular intervals. In such a case, the information from earlier scans can be effectively used to reduce the X-ray dosage in later scans.


Overview of the updated reconstruction process in Preeti Gopal’s research

I also intend to work on developing and selecting the best direct reconstruction technique that would serve as a good initialization for iterative reconstruction routines. In the next couple of years, I aim to further explore applications of computational image analysis.

We, graduate research scholars of the IITB-Monash Research Academy, 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 bang on target. It is fascinating to learn how interdisciplinary healthcare is. Physicians dictate what needs to be seen for diagnosis and treatment; physicists and material scientists work on building the hardware; and finally, computer scientists’ work on developing optimal algorithms to compute the desired entity from as few resources as possible. My research is on the algorithms front and aims to reduce exposure to X-ray radiation due to a scan.

Preeti Gopal

Research scholar: Preeti Gopal, IITB-Monash Research Academy

Project title: Improving tomographic reconstruction from sparse measurements

Supervisors: Dr. Ajit Rajwade, Dr. Sharat Chandran, Dr. Imants Svalbe

Contact details:gopal.preeti@gmail.com

 

This story was written by Preeti Gopal. Copyright IITB-Monash Research Academy.

Prasoon Kumar’s Defense


Successful Defense of Prasoon Kumar

Prasoon Kumar, jointly guided by Prof. Prasanna Gandhi (IIT Bombay) and Prof. Mainak Majumder (Monash University) presented his defense seminar on Monday, 2 April 2018.

His thesis title is ‘Scalable fabrication of bio-inspired, 3D micro/nanofluidic devices’.

Abstract:

The diffusion of small molecules through polymeric micro/nanosystems finds application in numerous fields such as tissue engineering, biomedical devices, membrane-separation technologies, food-packaging industries and in the removal of contaminants, solvents and such others. The performance of such devices depends on the microstructure of the polymers and the design of the micro/nanosystems that employ the polymers. The design of devices at multiple length scales that are inspired from natural systems has been proven in the manufacture of highly efficient microsystems. However, the scalable fabrication of such micro/nanosystems (with limited costs in instrumentation and operation, and minimal requirement of expertise and time) should be possible before these micro/nanosystems can be used at full throttle in the applications mentioned above.

Therefore, in the current work, we have thoroughly studied the secondary lamella of fish gills at different length scales by using computational and theoretical analysis, in order to determine the structural parameters that are responsible for their excellent gas-/solute-exchange capabilities. Our findings suggested the evolutionary conservation of a few structural factors and parametric ratios in fish gills, which is responsible for the efficient gas/solute exchange capability in every fish. Inspired by the design of secondary lamella, we have fabricated bio- inspired multiscale 3D micro/nanochannel networks in thin polymeric matrices by solvent etching of sacrificial structures that are formed by a combination of two scalable microtechnologies: electrospinning and the controlled, lifted Hele-Shaw method. The fabrication methodology presented here is a lithographyless, ultrafast, scalable process for the generating of multiscale fractal morphologies in polymeric materials. After conducting structural and dye flow characterization of the above mentioned multiscale, 3D micro/nanofluidic devices, preliminary results of their mass-transfer capabilities showed that these multiscale, 3D micro/nanofluidic devices were better in comparison to simple 3D micro/nanofluidic devices. Further, our experimental and theoretical investigation suggested that the geometry of the intermediate channel network (reservoir) plays a vital role in interfacing with a random network of nanochannels for enhanced volumetric fluid flow through them. Further, the densities and the tortuosity of the nanochannel networks also play a vital role in the volumetric fluid flow and mass-transfer capabilities of 3D micro/nanofluidic devices.

Although capillary-driven flow studies were carried out by using the 3D micro/nanofluidic devices that are mentioned above, a passive fluid pump connected to such 3D micro/nanofluidic devices is desirable in order to achieve a better rate of fluid flow. This may result in extending the applications of 3D micro/nanofluidic devices in areas such as μ-TAS, cooling of microelectronic circuits and advance drug delivery. Therefore, we have developed a passive micropump that was inspired by leaves of plants that can pump fluid at a rate comparable with that which is reported in previous literature. In this study, the manufacturing of micropumps also represents a simple, scalable and inexpensive process in which spin-coating technology is integrated with a controlled, lifted Hele-Shaw cell. The micropumps were able to emulate the structural features of leaves and the pump fluid by a coupled phenomenon of capillary action, absorption and evaporation. Further, a theoretical model was developed to describe the micropumping phenomenon. The model elucidates the role of different structural and ambient factors such as designs that are inspired from leaves, the temperature of the ambience, the density of the vascular network, the permeability of a porous substrate and such others for volumetric pumping of fluid and sustaining of the pressure head. The results predicted by the theoretical model corroborated well with the experimental findings. Eventually, the design, fabrication and characterization of the leaf-inspired micropump were successfully carried out.

In summary, in order to exploit bio-inspired micro/nanofluidic devices for mass-transfer operations, the work focused on the design and fabrication of these devices through scalable micro/nanotechnologies; this was done in order to ensure enhanced fluid flow and to study factors that affect the flow of fluid through such devices. Thus, the work will enable the development of 3D micro/nanofluidic at a large scale for applications in biomedical and chemical industry, which demand the transfer of heat and mass.