Mélanie Piétri, an alumna of the Nikola Tesla Department of Teaching and Research (DER) and a doctoral student

Mélanie Piétri, an alumna of the Nikola Tesla Department of Teaching and Research (DER) (electronics, electrical energy, and automation), is a doctoral student in 2023 at the LuMIn (Light, Matter, and Interfaces) and LMF (Formal Methods Laboratory). 

‘’ENS Paris-Saclay is a place where multiple disciplines coexist side by side geographically. This allows for internship or thesis opportunities at the interface between several disciplines while having specialists located in the same place. These two specificities are much less common in engineering schools or business schools, for example.’’

What is your academic journey at ENS Paris-Saclay?

I joined ENS Paris-Saclay as part of the SAPHIRE program in 2019 after a curriculum in preparatory classes MPSI and PSI (2016 to 2019). I then chose the Nikola Tesla department (formerly EEA). In my second year, I studied in the Master 1 E3A (electronics, electrical energy, and automation). At the same time, I completed the Master 1 D2PFO (double degree in fundamental physics), which corresponds to the condensed physics magistère of Orsay and evening classes. During my third year, I completed the Master 2 FESup PSEE (physics of electrical energy and electronic systems). 

Finally, in my last year, I chose to study in the Master 2 MVA (mathematics, vision, learning).

After this Master 2, I stayed at ENS Paris-Saclay for my thesis at the LuMIn (Light, Matter, and Interfaces) and LMF (Formal Methods Laboratory).

Did you know from the beginning what you wanted to do when you entered ENS Paris-Saclay?

I didn't know from the beginning what I wanted to do when I entered ENS Paris-Saclay. Choosing the department was not easy. I oscillated between industrial sciences, fundamental physics, or a gap year in the mathematics department. 

I chose the SAPHIRE program because it allowed me to keep a bit of these three aspects and was also in line with my preparatory classes. The SAPHIRE program allowed me to get in touch with several disciplines such as applied physics, through electrical, mechanical, and civil engineering, but also with more theoretical physics (through an optional unit in quantum mechanics, for example) or applied mathematics (signal processing, differential equations, distribution...). 

During the SAPHIRE program, I took an optional unit on the applications of electrical engineering to biology in the biomedical or bioenergy fields. These fields of application interested me a lot, so I oriented my master's research internships and thesis towards these themes.

Which specific year did you follow?

During my third year, I followed the Master 2 FESup with the aim of passing the external aggregation competition in industrial engineering sciences (SII) with a specialization in electrical engineering, in which I ranked 5th. 

I really enjoyed this training, which allowed me to discover more about the world of education. 

What particularly struck me was preparing lessons and experiments for the design of teaching sessions, both at the preparatory class level and at the high school, technical college, and vocational school levels. One of the specific tests for the SII aggregation is the preparation of an industrial dossier. The objective is to work with a company on an engineering issue. In return, the company provides us with documentation on the studied system, allowing us to create a teaching sequence at a given level, with the system at its core. I particularly enjoyed preparing for this test because it allowed me to create a 3-week course in high school for my part. It was also an opportunity to work with department teachers on the design of practical work experiments.

You were very involved in the school's associative life. Are you still? And what did these associative commitments bring you?

Indeed, associations were an integral part of my curriculum at ENS Paris-Saclay. I always participated in various events organized by the BDE or in the school's institutional life through the student life commissions (CVE), the board of directors (CA), or the scientific council (CS).

I also previously worked with the POSI group on the prevention of sexual and sexist violence as well as on the representation of women in sciences. These topics are particularly close to my heart, and I intend to continue investing in them, especially through artistic productions that I create every year as part of Mixed Engineering Sciences (SPI). I have maintained connections with several clubs and associations of the school, including the Disk Jockens club (DJs who animate the Kokarde parties), the organizing association of the Gala, or the BDE. Currently, I also plan to get involved in the association of doctoral students of the school, ADEPS.

I consider that associative activities have brought me a lot. I would even say that associative commitment at ENS Paris-Saclay was as important as academic activities in my curriculum and education. Associative commitment taught me to debate with several people, speak in public, develop projects, manage problems or conflicts... It allows you to meet many other students from various disciplinary fields, leading to very interesting conversations both professionally and personally.

Did you always want to do research from the beginning of your studies?

I had no knowledge of the world of research before joining the school. In preparatory classes, my goal was to enter an engineering school through the Mines Ponts entrance exam. I became interested in ENS Paris-Saclay only during my second year when I was unexpectedly admitted. I did not consider myself at this level of competition. Research and teaching are career prospects that I only considered during my time at the school. 

What is your doctoral topic?

I am working on the 'Predictive Modeling of the Synergistic Effect of a Microalgae/Bacteria Co-Culture for Enhancing Bioenergy Processes - from Microfluidic Systems to Photobioreactors.'

The goal is to use microalgae to produce lipids that can then be converted into biofuels. Research has shown that these microalgae can produce more lipids when cultivated with certain bacteria in the same environment. In this project, my role is to understand the interactions between the two types of microorganisms and mathematically model them. These interactions are being studied both in microsystems to observe interactions at the scale of a single cell, and in a photobioreactor, which is better suited for industrial-scale exploitation of microalgae. The experiments are conducted within the LuMIn laboratory and the IDA (Institut d'Alembert) platforms.

The mathematical model I am developing in collaboration with the LMF laboratory aims to predict the quantity of lipids that can be produced based on physical and biological parameters such as temperature, nutrient levels, light intensity, and carbon dioxide concentration.

I chose this topic for its connection to current energy transition issues. It aligns with academic research goals with potential applications in industrial research and engineering. It is also a multidisciplinary subject that allows me to reinvest what I have learned in the field of applied physics within the Nikola Tesla department and the knowledge acquired in applied mathematics during my final year in the MVA Master's program.

What do you plan to do in the future?

As for future plans, I currently envision maintaining both teaching and research in my future career. In teaching, I greatly enjoy the challenge of taking a scientific subject and making it more accessible for students to transmit knowledge, skills, and perhaps inspire interest in a scientific career. In research, what appeals to me is that one never gets bored; there is always something to investigate, understand, model, especially in multidisciplinary domains. 

Therefore, the role of a lecturer seems to perfectly combine these two aspects.

Could you tell us what the school has brought you during these 4 years of study?

Across all departments, ENS students can pursue very different paths, even within the same department. I find it quite challenging to reconcile in a single expression what we have in common. The common foundation that the school provides could be translated into scientific curiosity, the desire to learn and transmit... which seems to characterize a large part of the school's students but not necessarily all of them. I find it more relevant to speak of common skills acquired in the training rather than a 'normalian spirit'.

During these 4 years of study, I have acquired both theoretical and experimental skills in my department: electrical and computer engineering. The school has also allowed me to study in broader multidisciplinary fields (fundamental physics, applied mathematics). The curriculum was also an opportunity to do internships abroad (in Ljubljana, Slovenia during my M2 internship).

The school has also brought me many encounters, both professionally and personally. On the professional side, I have met researchers who are very strong in their field, but also very dedicated teachers who have conveyed to me the beauty of this profession. I have forged friendships with people from different cohorts and departments that I hope to maintain in the long term.

What advice would you give to students who are hesitant to come to ENS Paris-Saclay?

I think one should not censor oneself by thinking that ENS Paris-Saclay is a school that is too difficult to integrate because of the demanding entrance exam. Even though we are not all equal in terms of intuition, or some students may have advantages, it is hard work and discipline that always pay off.

At the school, we are in small cohorts, which allows us to quickly forge bonds with other students (through classes and associative events) but also with teachers. ENS Paris-Saclay is also a place where multiple disciplines coexist geographically. This allows for opportunities for internships or theses at the interface between several disciplines while having specialists located in the same place. These two specificities are much less common in an engineering school or a business school, for example.

Finally, if you are curious to understand scientific subjects in depth and to investigate them thoroughly, I think you are in the right place.