Research, Mobility and Mentoring: An Interview with Berardi Sensale

Berardi Sensale-Rodriguez is an electrical engineer and researcher whose work focuses on emerging technologies in electronics and photonics. Originally from Uruguay, his academic journey has taken him through different countries and research environments, where he has developed a particular interest in terahertz technologies and new materials. He is currently carrying out his research at the Universitat Politècnica de Catalunya (UPC) · Barcelona Tech. In this interview, Berardi talks about his research career, what led him to his field and the experiences that have shaped his journey as a researcher.

What motivated you to choose your current research field?

I did my Electrical Engineering degree in Uruguay, where I became very interested in electronics, particularly analog circuit design. At the same time, through working with numerical methods, I developed a strong interest in electromagnetics. I think that combination naturally drew me toward the more physical side of electrical engineering, understanding not only how to design a circuit or a system, but also the underlying physics that makes a device work.

In 2009, I moved to the United States to pursue my PhD at the University of Notre Dame. At the time, Notre Dame had a major research program in low-power electronics and was the hub of one of a handful of large U.S. centers funded by the Semiconductor Research Corporation to explore new paradigms for electronics. That environment exposed me to an aspect of electrical engineering that I had not really appreciated before: the materials.

My PhD advisor, Prof. Grace Xing, who is now at Cornell, was then a young assistant professor exploring a remarkably broad range of research directions. Working with her, I learned a lot about electronic and optical materials and the physics behind them. Following one of her main areas of expertise, I began working with gallium nitride, or GaN, and became particularly interested in the modeling and characterization of high-frequency devices.

Around that time, Notre Dame also hired Lei Liu, a young research professor who had come from the University of Virginia and had deep expertise in terahertz devices, particularly Schottky-diode detectors. Together with Grace, we began exploring whether GaN devices could operate at terahertz frequencies by exploiting electron plasma waves, building on ideas originally proposed by Michael Shur and Mikhail Dyakonov in the 1990s. When I started reading their papers, I was fascinated by the elegance of the underlying physics. That was really the point at which terahertz research captured my imagination.

At almost exactly the same time, graphene and other two-dimensional materials were beginning to emerge in the physics and electronics communities. I started thinking about how the unusual electronic properties of these new materials could be exploited at terahertz frequencies. What made Notre Dame particularly exciting was that I had the opportunity not only to propose these ideas theoretically, but also to demonstrate devices experimentally, working with an excellent group of students and researchers, including Rusen Yan, Tian Fang, Subrina Rafique, Kristof Tahy, Vlad Protasenko, and others.

In retrospect, I was very fortunate to be in the right place at the right time. I became one of the early researchers exploring graphene for terahertz applications and demonstrating such devices experimentally. Soon afterward, the field expanded enormously, with important contributions from researchers around the world, including Josep Jornet, a former UPC student who was then doing his PhD at Georgia Tech, and Julien Perruisseau-Carrier, who was a young professor at EPFL.

So my path into terahertz research was not really the result of a single decision. It was the convergence of several interests: electronics, electromagnetics, materials, and device physics, combined with the people I happened to meet and a moment when several new technologies were emerging simultaneously. What kept me in the field of terahertz technologies was that combination; there is beautiful fundamental physics, but at the same time there is enormous room to turn that physics into devices and systems that do not exist yet.

Reflecting on your career so far, what accomplishments are you most proud of?

I am very proud of the research accomplishments that my students and I have achieved over the years. We have introduced new ideas, demonstrated devices that had not been demonstrated before, published work that has had an impact on the field, and explored research directions that sometimes started as rather unconventional ideas. Of course, seeing an idea that began on a whiteboard eventually become an experiment that works, and then seeing other researchers build upon it, is enormously rewarding.

But if I had to identify what I am most proud of, I actually would not choose a particular paper, device, grant, or research result. I would choose the human side of my career: mentoring students and seeing them develop into independent researchers and professionals.

Over the years, I have graduated eight PhD students, in addition to working with many master's and undergraduate students and postdoctoral researchers. A PhD is a very long journey, and you get to see an extraordinary transformation. Students may arrive with a strong academic background but relatively little experience defining their own research problems. Initially, they naturally depend a lot on their advisor. As an advisor, you suggest the questions, help interpret results, identify what went wrong, and decide what direction to take next. But gradually that relationship changes.

For me, one of the most satisfying moments as an advisor is when I realize that this transition has happened: when a student comes into my office and tells me what they think we should do next, when they disagree with my interpretation and can explain why, or when they have developed expertise in an area to the point that I am learning from them. At that stage, they are no longer simply carrying out research under my supervision. They have become independent researchers.

So when I look back at my career so far, I certainly value the scientific accomplishments, and I hope there will be many more. But the accomplishment that gives me the greatest sense of pride is seeing the students I have mentored become independent professionals, knowing that I played some role in helping them get there. In the end, I think that is one of the most lasting contributions we can make as academics.

How have your motivations changed as your career has progressed?

Interestingly, I don’t think my fundamental motivation has changed very much. Perhaps that has something to do with growing up with two parents who were engineering professors and researchers, but from a very early age I was fascinated by science and engineering and by understanding how things work.

What has driven me throughout my career is really the pursuit of understanding, the beauty that I find in discovering something that is true, in understanding why something behaves the way it does, or in taking an idea and seeing whether it can actually work. The specific problems I work on have changed over the years, and my responsibilities have certainly changed as I have become a professor and a mentor, but that underlying curiosity has remained remarkably constant.

I am fortunate that I genuinely have fun doing what I do. Research has never felt to me simply like a profession or a sequence of career objectives. It is something deeply intertwined with how I experience life: being curious, asking questions, creating things, and trying to understand a little more than what I understood before.

What competency areas do you think researchers need to develop, and therefore, universities should offer more training in?

One area that I did not really appreciate at the beginning of my career, but that I have come to value greatly over the years, is entrepreneurship. As scientists and engineers, this is something we are generally not trained in. We learn how to develop new technologies and solve difficult technical problems, but not necessarily how to translate those innovations into something that can have an impact outside the laboratory. As my career has progressed, I have become increasingly interested in that translation process and in understanding what it takes to bring a research idea into a real-world application. I now see entrepreneurship as an important complement to scientific and engineering research, particularly when we want our discoveries to move beyond the academic environment.

Have you participated in any professional development programs, and how have they influenced your career growth?

One program that I participated in a couple of years ago, and that I found particularly interesting and useful, was the I-Corps (Innovation Corps) program of the U.S. National Science Foundation (NSF). I participated in the program as the lead of an NSF Partnerships for Innovation (PFI) project whose goal was to transition a technology we had developed at the university into real-world products.

The technology involved flat optical lenses with extended depth of focus, which we developed together with my colleague Prof. Rajesh Menon, then also at the University of Utah and founder of a startup: Oblate Optics. The PFI project gave us the opportunity to explore not only the technical development of the technology, but also what would actually be required to move it from the laboratory toward commercialization.

One of the most valuable parts of that experience was learning the customer-discovery process. I found it fascinating because the methodology is, in many ways, very familiar to the methods we use in our research. You begin with hypotheses about who your customers are, what problem you are solving for them, and why your technology might be valuable, and then you test those hypotheses by going out and interviewing people. You listen, collect evidence, and then validate, reject, or modify your assumptions. In that sense, you are applying something very similar to the scientific method, but to questions about markets and commercialization rather than physics or engineering.

That was quite eye-opening for me. As researchers, we tend to start with a technology that we find exciting and then ask, “Where could this be useful?” I-Corps teaches you to approach the problem from almost the opposite direction: first understand what people actually need and what problems they are trying to solve, and then determine whether your technology provides a meaningful solution.

Since participating in the program, I have made a much greater effort to engage with people in industry, not simply to tell them about our research, but especially to listen to them. I have found it remarkable how much you can learn from those conversations and how significantly they can change the way you think about a technology, its applications, and even the research questions themselves. That shift in perspective has probably been the most lasting influence of the I-Corps experience on my career.

What qualities and skills do you think a good mentor should have?

I would highlight two things: listening and patience. As mentors, we need to listen to our students and get to know them well enough to understand how best to mentor them based on who they are, how they learn, and the kinds of roles they may pursue in the future.

Different students have different strengths, and it is important to match those strengths with the research they do. I have found that when students struggle with a project, sometimes it is simply because the project is not the right match for their skills or way of thinking. Taking the time to observe and listen to your students and postdocs is therefore essential.

The other quality is patience. I am very proud of every PhD student and postdoc I have mentored, but with many of them, especially at the beginning, things were not always easy. Having patience, giving people opportunities to grow, and remembering that they are there to learn are essential to helping them eventually become successful and independent researchers.

Have you had, even informally, a mentor figure in your postdoctoral career?

I actually did not follow the traditional postdoctoral path. When I graduated, back in 2013, I moved directly from my PhD at the University of Notre Dame to an Assistant Professor position at the University of Utah. Nevertheless, I have had several mentors throughout my career, and they are among the people to whom I am most grateful.

My PhD advisor, Grace Xing, was fundamental in helping me become the researcher I am today. Grace gave me tremendous opportunities to flourish. She gave me the freedom to explore my own research ideas, believed in those ideas, and connected me with people both within and outside her group who could help bring them to fruition.

I also learned how to write scientifically from her. She would literally spend hours writing with me. As a student, she also taught me how to write research proposals. I helped her prepare two proposals, one to the NSF and another to the Navy, both of which were funded, and that experience became extremely valuable when I moved to the University of Utah and began writing my own proposals. In fact, when I was interviewing for faculty positions, I already had a draft of what would eventually become my NSF CAREER proposal, which is somewhat analogous to an ERC Starting Grant in Europe.

Once I became a faculty member at Utah, I was again fortunate to find excellent mentors among the mid- and senior-career faculty, including Gianluca Lazzi, who was then department chair and later moved to USC, as well as Cindy Furse, Mike Scarpulla, and Steve Blair. I remember going through iteration after iteration of my proposal with Gianluca. He also helped create an opportunity for me to meet Dimitris Pavlidis at the NSF and discuss my research ideas with him.

That support had a very tangible impact. During my first year as an Assistant Professor, I was able to secure two projects as principal investigator: my CAREER award and an unsolicited NSF project. That really set the tone for the early years of my career, allowing me to build a sizable research group from the beginning and to fund experiments and equipment well beyond what my university startup funds alone would have allowed.

Do you think that geographical and/or intersectoral mobility is valued at the university?

Yes, absolutely. In fact, geographical mobility has been part of my life almost from the beginning. Shortly after I was born, my parents moved from Uruguay to Brazil to pursue their PhDs at the Universidade Federal do Rio Grande do Sul (UFRGS). My father, who is also named Berardi, did his PhD there with Guillermo Creus, an Argentine professor originally from Rosario who, as I recall, had also studied in the United States before moving to Brazil. So this idea of researchers moving between countries, institutions, and academic cultures was something I grew up with.

My own connection with UPC actually began through that same kind of mobility. The first time I visited UPC was in 1996, when I was 11 years old. My father was spending part of his sabbatical here. Both of my parents are professors at the Universidad de la República in Uruguay, and over the years they returned frequently to UPC, collaborating extensively with Prof. Antonio Aguado.

So international mobility and academic exchange are actually how I first came to know UPC.

Later, my own career took me from Uruguay to the United States, and now, many years later, it has brought me back to the UPC and Barcelona. For me, mobility is much more than simply changing institutions or countries. It exposes you to different ways of thinking and doing research, creates collaborations that can last for decades, and opens opportunities that would be very difficult to create by remaining in a single environment. My own family's experience, and now my own career, are very much examples of that.

Can you give an example from your university where coming from another country has been a favorable factor for your hiring?

My own case is a very direct example. I am coming to UPC through the ATRAE program, whose purpose is precisely to attract established researchers who have developed their careers abroad. Programs like ATRAE, ICREA, and Beatriz Galindo are extremely important because they create real opportunities for researchers like me, who have built their early and mid-careers in other countries, to bring that experience back to Spain.

I think these programs are not only valuable but necessary. Talent mobility works in both directions. UPC has been very successful in producing graduates who have gone on to leadership positions around the world, and those international networks also help attract people back. In fact, when I began considering moving from the U.S. to Spain, two of the first people I contacted were two great colleagues who are also UPC alumni, Josep Jornet and Benjamin Sanchez. That cycle of sending talent out, maintaining those connections, and creating opportunities to bring experience and talent in is enormously valuable for a university.

What initiatives can universities implement to better support multicultural integration among researchers?

Language programs are a great example. I am currently taking the Basic 1 Catalan course at UPC, which the university offers free of charge to its staff, and I am really enjoying it. After only two weeks, I already notice an enormous difference; I even set RAC1 in my car so that I am constantly listening to Catalan while driving!

For international researchers, language is an important part of integration. One way to build on initiatives like this would be to offer greater flexibility in schedules and formats, particularly for researchers who travel frequently. Making it easier to combine language learning with academic responsibilities can go a long way toward helping people feel part of the local community.

How have language skills impacted your professional development and career opportunities?

I believe language and communication skills are critically important for success in a research career. As researchers, we constantly need to “sell” our ideas, not in a commercial sense, but by convincing others that a problem is important, that an approach is worth pursuing, or that a discovery matters. We do this when writing proposals for research funding, publishing papers, presenting at conferences, teaching students, or participating in panels and discussions.

In my own career, the ability to communicate what I think has been very important. Research is ultimately not only about having good ideas; it is also about being able to explain those ideas clearly, logically, and compellingly to very different audiences. You may need to explain the same research very differently to another expert in your field, to a funding agency, to a student, to someone in industry, or to the general public.

This is why one of the strongest recommendations I would give to early-career researchers is to invest seriously in their communication skills. Learn to write well, learn to present well, and learn to adapt your message to your audience. You can have an extraordinary idea, but if you cannot communicate why it is important, it becomes much more difficult for that idea to have the impact it deserves.

We would like to thank Berardi Sensale for generously sharing his time, experience and insights with us. His reflections on his research career and professional journey provide a valuable perspective for researchers and professionals considering their own paths in research.