“I would be my own worst student”

During his recent dissertation defense, one of Stellacci’s PhD students put up a somewhat unorthodox photograph: one of Stellacci teaching him how to ski. “I’ve always enjoyed sharing knowledge of all kinds, whether related to science, cooking or winter sports,” says the professor.

“When I joined MIT as an assistant professor in the early 2000s, some people criticized me for not having enough formal teaching experience,” he says. “But I won a teaching award just three years later!”

Today Stellacci is the head of EPFL’s Supramolecular Nano-Materials and Interfaces Laboratory (SuNMIL) and a fellow of the European Academy of Sciences. “I believe that teaching and research are inseparable,” he says, adding that he has turned down several prestigious positions because they didn’t come with teaching duties. “The roles of professor and researcher are highly complementary,” says Stellacci. “When you teach something, you make an immediate impact on students because you’re expanding their pool of knowledge. But this impact wears off over time as the students take other classes and learn from other professors.” However, when it comes to research, “it’s the opposite” – your findings generally mature as the years go by.

The roles of professor and researcher are highly complementary

Contagious enthusiasm

When asked what his secret recipe is for being such an effective teacher, Stellacci – who is also skilled in the kitchen – replies (almost) without hesitation: “Enthusiasm is the main ingredient,” he says. “It’s contagious – students can’t resist being drawn in! That puts them in the right mood to learn and participate.”

Any other secret ingredients? “I push students to go beyond their limits, to prove to themselves that they can do it,” he says. “Even if that means scaring them a little at the start of the semester. Specifically, I prioritize quality over quantity and focus on three or four key topics per semester, which determine how I structure my lectures.” Stellacci admits that he also borrows freely from the legendary Feynman Lectures on Physics.

“It’s really gratifying to watch the terrified classroom at the start of the semester evolve into a room full of proud students at the end,” he says. To make this transition happen, Stellacci encourages the young engineers to “participate as much as possible.” For his part, he aims to “get to know his students well” so he can give them the support they need in the learning process. “I realize that’s harder for professors who teach larger classes than I do.”

I recently took classes in chess and in French. They reminded me of how much I don’t like formal education

A cure for boredom

Teaching comes “so naturally” to Stellacci that he has to think a while before responding about the biggest challenges: “Let’s say that, after a few years, it gets a little tiring to repeat the same things.” Yet he’s found a simple solution to that. “I regularly change the key topics covered in my classes.” And sometimes he changes the classes themselves.

Stellacci clearly loves his role as a professor. Does he also enjoy sitting on the other side of the table? “No, I’m not a good student,” he replies. “I recently took classes in chess and in French. They reminded me of how much I don’t like formal education. If I took one of my own classes, I’d be my own worst student – the one who never speaks up!”

A bright yellow brochure

That doesn’t mean Stellacci, who is originally from southern Italy, didn’t enjoy his time in school – on the contrary. His eyes light up when he describes his early love of physics, chemistry, math and engineering.

“When I graduated from high school, I wasn’t sure how I could combine all these into a single major at university,” he says. But he found the answer as he flipped through one of the brochures he’d gotten from Politecnico di Milano – a brochure describing its materials engineering program. “I still remember the brochure’s bright yellow cover and exactly where I was when I read it,” he says. “I instantly realized that’s what I wanted to study.” Stellacci has never looked back, even if “it wasn’t easy for me to give up theoretical physics and move to a large city in northern Italy.”

After earning his master’s in materials engineering, Stellacci went on to obtain a PhD, also at Politecnico. He then moved to the US to complete a postdoc at the University of Arizona Chemistry Department. In 2002, he headed to the east coast and took an assistant professor position at the MIT Department of Materials Science and Engineering.

Starting from scratch

In 2010, he returned to Europe and joined EPFL as a full professor. This enabled him to forge even closer ties with biology, “a field I’ve developed a strong interest in over the years,” he says. After all, “life forms the building blocks of all our materials, which means that living organisms are the pinnacle of materials science.”

For now, Stellacci is on sabbatical for the 2025–2026 academic year. “I’ll have to completely redo my lectures when I start teaching again next fall,” he says, before adding without a hint of irony: “I’m looking forward to starting again from scratch!”