Answers to real world problems come from ideas leveraging a wide variety of fields and an innovative mindset that implements them into actual working devices.

Rajas Poorna, our next pathbreaker, PhD student in BioEngineering at Georgia Tech, researches low-cost (“frugal”) technologies for healthcare, based on fundamental physics.

Rajas talks to Shyam Krishnamurthy from The Interview Portal about being attracted to interdisciplinary research (Physics and Biology) with a focus on addressing healthcare challenges that are cost-effective and time-effective.

For students, find your niche and become the best version of yourself by working on challenging projects and opportunities !

Rajas, Your background?

I did my primary education in Bangalore, then moved to Mysore until undergrad. In 11th and 12th, I studied PCMCs (Physics, Chemistry, Mathematics, Computer Science), while preparing for JEE and KVPY via FIITJEE’s integrated course.

I was always curious about the world and read as many science books as I could get my hands on until 7th, when the internet came around. Then, I browsed through Wikipedia instead.

My parents are both doctors, but since I was very excited about science and building machines, I wanted to be somewhere at the intersection of “scientist” and “engineer”.

What did you do for graduation/post graduation?

When I finally had to choose between doing a B. Tech at an IIT vs doing a B.S. at IISc, I chose IISc and eventually majored in physics and took a minor in biology. I always wanted to become a physicist (so that I could build new and powerful machines!), and Mother Nature is obviously very clever, so I thought it would be wise to learn engineering techniques from her, hence biology. I later continued at IISc for a Master’s in physics.

What made you choose such an offbeat, unconventional and uncommon career?

One major driver for me was probably this series of books that my parents had bought me when I was very young, the “Time Life Early Learning Series”. These books were so colourful, so high quality, and were filled with answers to the kinds of questions children ask, like “Why is the sky blue?”, or “How do trees grow?”, or “Why does my dad shave in the morning?”. I feel like these books had a powerful impact on the way I saw the world because they taught me that answers to real-world questions do not fall into easy boundaries like “physics” and “biology” and “chemistry” and so on; we need all of them to explain the world and satisfy our curiosity.

As I grew up, fictional hackers, who could build just about anything, that too out of garbage, were my inspiration, and I would try to build useful things at home from whatever I could find. 

I must especially thank my mother for her initiative and support. She would put me into every available competitive exam at school, and that prepared me to take on the toughest ones (NTSE, JEE, and KVPY) that finally enabled my career. In 9th and 10th, I met some of the most excellent and interested science teachers ever via the BASE Foundation Science and Technology program, and here, my physics teacher, Krishnamurthy sir, taught me how to be scientifically rigorous: a skill that has been extremely important to this day.

In the 2nd year of undergrad, I came across this TED talk titled, “Lifesaving scientific tools made of paper” by Prof. Manu Prakash at Stanford, and he demonstrated, among other things, a centrifuge made of paper that could spin at 125,000 rpm, or roughly 2,000 times per second! They used these in health centers in Africa that lacked electricity to centrifuge blood and diagnose malaria, at less than a rupee per test! He showed me that this kind of innovation could actually save lives. So far, I had built a handful of interesting devices out of, essentially, garbage, and I felt an immediate connection to that. I felt that I could leverage my interests to actually save lives, and this guided me to a career in Frugal Science.

How did you plan the steps to get into the career you wanted? Or how did you make a transition to a new career? Tell us about your career path

At IISc, I met many highly capable individuals from all over the country. I had been mostly successful in the past, but I knew it would hit my confidence hard if I was not able to succeed at least moderately here. People around me had already won medals at events like the International Physics Olympiad. It was going to be hard to beat such people at their subjects, and it was going to continue to be an uphill battle in the future – trying to beat the best in the world at their game.

So, I decided that I was going to find some other worthwhile game, but one that others around me were ignoring. The physics enthusiasts around me, for instance, tended to hate biology because there was so much to memorise. And the biologists often chose biology because they weren’t very good at math. But I was good at both! That was my aha moment – very few people would be preparing to work on the (obviously very valuable) intersection between physics and biology. Now, if I added another intersection and incorporated my love of building things (which very few physicists around me were interested in) into this field, then I would have very few competitors anywhere in the world, let alone IISc.

I got an excellent opportunity to get started with this through our college fest, Pravega, where I volunteered to build a game of Laser Tag. Laser Tag is a game where people use laser “guns” to “shoot” sensors on players’ bodies, and the winner is the one who “kills” as many opponents as possible. I was to develop the whole thing from scratch – the guns, suits, sensors, and even the code. Through this, I learned how to build something so (relatively) complex from scratch, how large projects take much, much longer than expected, and, eventually, how to take help from others. Ultimately, Laser Tag was a hit at Pravega.

During my 2nd year, I wanted to redo Laser Tag to fix all the issues from last time. I also wanted to teach people all the skills that I had learned, so that they wouldn’t have to struggle the way I did. So rather than building everything mostly by myself, I recruited 35 of my juniors, and I taught them how to design and build it themselves.

By the end of Laser Tag 2.0, I had found a team of 5 capable and interested juniors who could take on an engineering challenge. We participated in iGEM, an international synthetic biology competition, and built a cheap device to automate bacterial “growth curves”, which tell you how fast the bacterium of your interest grows and matures. Microbiologists use this curve to time many procedures, like how a chef would use different cooking times for different grains. But this was a tediously manual and error-prone process that could sometimes take several days and lots of skipped sleep. We put serious work into documenting how someone else could replicate our work, and for the quality of our work and documentation, as well as its potential impact, we were nominated for the “Best Hardware” prize at iGEM. This put us in the top 5 of 186 teams, above teams like MIT and Stanford! This greatly boosted my confidence.

For Laser Tag, I wanted to have WiFi guns, suits, etc., and used a chip called the “ESP8266”. I mentioned this in a conversation with my electronics professor, Prof. Rajan Kanhirodan, who had not yet come across this chip, and he offered me a project during my 2nd year summer. This project then led to my Bachelor’s thesis work, and my first paper!

Through this game, through this plaything, I had gained so much! I had learned electronics, hand tools, coding, teaching, obtaining parts, project management, delegation, and event planning, and it also led to my first big break! A friend of mine even switched from theoretical physics to aerospace engineering after his experiences here! It essentially kickstarted both of our careers. It just goes to show how far passion can take you if you aim it at the right thing at the right time, provided that you are in the right place.

For my Bachelor’s thesis, my work was with Prof. Kanhirodan in “Diffuse Optical Tomography”. What I was trying to accomplish was, in layman’s terms, something like 3D ultrasound imaging, but in colour, and lower resolution. The idea is that if you pass light through multiple points on the tissue surface and collect this light at multiple other points, you can model the scattering and absorption of this light throughout the tissue and thus create a 3D image. If you use multiple wavelengths of near-infrared light, you can create a false colour image with the oxygen concentration and use this to detect cancer.

I was working on a device already built by a senior in the lab which could scan a plastic tissue substitute (“phantom”) in ~40 minutes. But 40 minutes is too long for a patient to wait perfectly still for a scan, and thus, my job was to reduce the scan time to within, say, 5 minutes. The previous device only used one light source and one light detector at a time and was thus slow. I developed hardware to read from all 24 light detectors simultaneously, and this brought the scan time down to ~5 minutes. Then, I developed a way using “frequency multiplexing” to use 6 light sources simultaneously. This essentially involved turning each light source on and off at different frequencies, and “listening” for all these frequencies simultaneously at each light detector. This finally brought the scan time down to 1 second, which made it much more robust and patient friendly. 

After this, I continued for a Master’s in IISc and came across a very interesting project in Prof. Bhushan Toley’s lab – a device that would perform PCR in a village. PCR is a method to detect DNA, and can hence be used to diagnose COVID, tuberculosis, typhoid, etc., and the project is thus obviously very valuable for India. I also found an excellent environment to do this in Prof. Sai Siva Gorthi’s lab, but they did not have a specific project for me. I proposed a collaboration between the two, and this led to a very successful project, where I built a device that can not only do PCR in a village, running off a simple USB power bank, but can do it in 7 minutes (normal machines take ~1 hour), and costs <500 rupees. This led to 2 patents, and I continued there after my Master’s as a Senior Research Fellow to finish the project properly.

Towards the end of my Master’s, COVID struck, and I had to go back home and could not work on my PCR project. My mother runs a pathology lab, and we had to figure out how to collect blood samples from patients without risking COVID transmission between the lab technicians and patients. N95 masks were almost impossible to obtain, and we could not use standard COVID nasal swab “booths” because the gloves were too thick for drawing blood. These also often used expensive air filters to prevent COVID transmission. To solve this, I worked with the technicians to design and build (with the help of a carpenter) a booth specifically for collecting blood samples. I used veterinary gloves thin enough to feel for a vein, and computer fans and long pipes to take the air breathed by the technician far away, removing the need for expensive filters. Finally, I used a simple USB power bank to keep the fans running, and hence keep the booth safe, even in case there was a power cut. The booth was built using materials easily available in a small town, such as a metal slot shelf, fibre board, and acrylic, and costed <₹20,000; just over a month’s worth of PPE kits.

Soon after this, I started applying seriously for PhD opportunities in the US and mailed as many professors as I could. I prepared a good CV and Statement of Purpose, taking help from many online sources and references. I also took help from peers who had succeeded in their PhD applications and were much better than me at showcasing themselves. I applied to one place in Europe which had an early deadline: this forced me to prepare a full draft well in advance for the US applications. This was not a very good draft, and I did not get in. But I could see the flaws in my Statement of Purpose and corrected them for my US applications.

Eventually, Prof. Saad Bhamla, who was one of the original inventors of the paper centrifuge that I mentioned above, replied to my email, and this led to a discussion about my interests and motivations, and, finally, to my admission to Georgia Tech for a fully funded PhD in Bioengineering!

How did you get your first break? 

Laser Tag was such an amazing opportunity for me, and it opened so many doors that I still haven’t had the time to walk through all of them. I wanted to identify who shot whom in the laser guns, so I planned on turning the lasers on and off with different frequencies, but I needed an efficient, robust algorithm that could detect these frequencies on an Arduino, which has very little processing power. I came up with one during a course in Digital Signal Processing, and I still haven’t had time to publish it! 

What were the some of challenges you faced? How did you address them?

Challenge 1: Towards the end of my bachelor’s degree, I was not yet sure that I wanted to do a PhD, and I did not want to do a PhD simply because it was the path of least resistance, and everyone around me was doing it. I wanted to ensure that I had a very good reason for doing it. But if I got into the best places, that would be a good enough reason. 

So I applied to just 3 highly selective universities (Harvard, Stanford, and University of Washington). They were highly ranked programs that combined biology, engineering, physics, and medicine, and I could actively incorporate medicine into my career this way. But I did not get into any of them. This was at least in part because my Statement of Purpose (SOP) was very different from what they were expecting, which was because I had not consulted my peers, professors, or online sources nearly enough. 

To address this, I spent the next 2 years improving my CV so that I could be solid on that front, and took as much advice as I could from as many reliable people as I could for writing my SOP and CV. 

Challenge 2: Throughout this process, I had a strong fear of rejection. I had been rejected twice before from the best places, first while applying for UG, and second while applying for PhD during my Bachelor’s, and my mind was occupied by this fear. It made it feel like it could be a monumental waste of time, and I could not bring myself to see the upside of getting a PhD. This was making it hard to write properly.

To combat this, I consulted my professors and asked them to identify places that I am likely to get into, so that I can be sure that I am not over- or underestimating myself. I also took their help to find “safeties”, where I would be very likely to get admitted. I also prepared my CV as well as I could. These, along with the steps above, made the fear manageable.

Challenge 3: Applying was very stressful for me, and I felt that I could not do it while working on anything else. I had to do it full time, and so I took a full month away from work so that I could complete it. 

Tell us about your role as a PhD candidate at Georgia Tech

I am now a PhD student at Georgia Tech! I am co-advised by Prof. Saad Bhamla in the Chemical and Biomolecular Engineering department, and Prof. Marcus Cicerone in the Chemistry and Biochemistry Department. My job is primarily focused on research on low-cost (“frugal”) technologies for healthcare that use fundamental physics to greatly simplify existing technologies, and, in the process, potentially find new technologies! 

This means that I need to be able to work with ideas from a wide variety of fields and be able to implement them into actual working devices. Having a background in physics and electronics helps greatly with this. To acquire the specific skills needed for each project, I must consult the scientific literature and learn new tools, either from the literature or peers in the lab.

Our lab also works on extreme biology: insects that can jump very high, or manifest crazy collective behaviours, and so on, and my background in biology helps me understand these phenomena and possibly implement them in some frugal technology.

I also mentor high-school students from nearby schools in their own frugal engineering projects for iGEM, and my experience teaching people Laser Tag greatly helps with this, as does having a very curious younger brother!

Every day is different; some days I will focus on classes, on others, I could be mentoring students, reading the literature, working on a theory of how my device could work (or fail), building said device, discussing it with my professors, discussing others’ projects, or presenting what I am up to to my labmates!

I think that this is the perfect job for me, since every single one of these things is something I truly enjoy. The projects have immense social value and challenge me in just the right way. Half the time, they are in my domain, but the other half, I need to learn and grow, and the balance is good. And I also get the change to pass on what I know to younger students; what more could I ask for?

How does your work benefit society? 

I am working on two projects right now. The first is a $1 hearing aid. According to the WHO, over 5% of the world population requires rehabilitation to address their hearing disabilities. That is 1 in 20 people, and yet, hearing aids cost several thousand rupees for even the cheapest models. If we can do even something very basic for less than 100 rupees, that would change the lives of so many people.

The other is a new, affordable (<$100) technology for performing diagnostic tests on blood, urine, etc., using just light and no reagents. If we can get this to work, it would allow these tests to be performed at essentially no cost, even in the middle of the desert. They would not even need reliable electricity or a supply chain for reagents. 

5% of primary health care centers in India don’t even have buildings. But if we can build such a device for less than the cost of a budget smartphone, then governments can afford to roll this out everywhere, and this could then save millions of lives!

Tell us an example of a specific memorable work you did that is very close to you!

Laser Tag!

Your advice to students based on your experience?

My advice would be the following:

  1. Find an intersection of fields that you are good at and are interested in working in, and try to go there. This way, you will not have to compete with everyone else who is working in more traditional, well-known fields. The more intersections you can incorporate, the better.
  2. Find challenging projects and opportunities where you have to develop multiple skills and get in touch with many people. If you are passionate, you will be able to work through the difficulties, and other people will notice. This will help you get in touch with even more people.
  3. Observe when you are getting in your own way, and sabotaging your own progress. So many people have access to so many opportunities, but these mental blocks can prevent you from utilising them and making the most out of them.
  4. Have faith that doing the right thing for your career will help you, and doing the wrong thing will hurt you. At some point, if not today. To decide which is which, ask yourself honestly and continually, because your intuition will update itself over time, and become better able to answer bigger and bigger questions. 

Future Plans?

Eventually, I aim to become a professor, since academia will allow me to investigate diverse ideas, and industry or startups will not. But if I get my diagnostic technology to work, I will have to either establish my own startup, or find someone trustworthy who can bring it out to market. I will also have to figure out whether I should stay in the US and leverage the migrant talent pool, or go to India and help build up India’s systems.