“There is a bit of materials science in everything”
Stella Laperrousaz at the MT180 finals at the University of Fribourg © CUSO
EPFL PhD student Stella Laperrousaz’s crowd-pleasing comparison of her research on electronic fibers to one of Switzerland’s most famous exports won her the audience prize at the My Thesis in 180 Seconds Competition Switzerland 2024.
Laperrousaz’s talk, entitled « Développement de fibres électroniques et optoélectroniques souples par étirage à chaud » ("Development of flexible electronic and optoelectronic fibers by thermal drawing") used fondue as an analogy to explain her research in the Laboratory of Photonic Materials and Fiber Devices (FIMAP) in EPFL’s School of Engineering.In just three minutes, she described the challenges of developing composite elastomer fibers, which are made using a technique called thermal drawing: materials with different properties are combined to make a structure called a preform, which is then heated in an oven and pulled into long fibers – just as melted cheese is pulled from a fondue pot with chunks of bread.
Jurors at the Swiss MT180 finals, held at the University of Fribourg on June 20th, judged contestants on the clarity, accuracy, and effectiveness of their presentations. The CHF750 audience prize was awarded based on the votes of attendees. In the end, it was Laperrousaz’s culinary comparison that left them hungry for more.
Finding the right recipe
As a secondary school student near Annecy, France, Stella Laperrousaz enjoyed all her subjects, from math and physics to theater and philosophy. This made choosing a university program challenging, but after a visit to the EPFL Open Days in 2015, she realized that she could turn the breadth of her interests to her advantage with materials science.
“There is a bit of materials science in everything, even if we don’t often think about it. I thought that studying materials science for my bachelor and master degrees would keep as many doors open as possible, and I definitely don’t regret it,” she says.
Materials science is always about compromise!”
The end of Laperrousaz’s master’s studies coincided with the start of the pandemic in 2020, limiting her options for further study abroad. It was then that she discovered an opportunity to do a master’s project in the FIMAP lab, led by Fabien Sorin. The research involved developing a balanced ‘recipe’ that would yield soft fibers for applications such as smart textiles, and smart medical devices like catheters.
“I was mixing elastomers with electrically conductive particles to create fibers. The idea is to have a fiber that is both stretchable and electrically conductive: materials science is always about compromise!”
In the FIMAP lab, Laperrousaz felt well supported while still being able to pursue her research interests independently, so she decided to stay on for a PhD under Professor Sorin’s supervision. Now in her third year, she is experimenting with optoelectronic ‘ingredients’ like semiconducting materials. The conductivity of such materials changes when they are exposed to light, opening up new possibilities for functionalized fibers.
Athletics is a lot like doing research: maybe you will fail, but if you try again, you might surprise yourself.
A breath of fresh air
On the heels of the pandemic, Laperrousaz was feeling cooped up and in need of social interaction. So, she combined the start of her PhD with her first foray into team rugby, joining the Lausanne University Club (LUC) for two trainings per week plus competitions.
“This was a really good balance for me. I needed a breath of fresh air, but athletics also teaches you communication and resilience. It is a lot like doing research: maybe you will fail, but if you try again, you might surprise yourself.”
It was also the desire to hone her communication skills that first piqued Laperrousaz’s interest in the MT180 competition; that, and the success of one of her close friends, fellow School of Engineering PhD student Eva Baur.
“Communication is an essential skill as a scientist, and I figured that it would also be really important if one day I decide to teach,” she says. Indeed, Laperrousaz has not definitively chosen a career path yet, and is considering both academia and industry – she is particularly interested in biomedical technologies. As she heads into the fourth year of her PhD in September, Laperrousaz will continue her research on the ideal combination of materials for optoelectronic fibers. But does she have a favorite fondue blend as well? “Even though I am French, I still love the Swiss fondue “moitié-moitié” best!” she laughs.