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Rare earth elements (REEs) are vital to everything from smartphones and laptops to wind turbines and electric vehicles – but extracting them comes at a steep environmental cost. Mining one tonne of REEs can generate up to 2,000 tonnes of toxic waste, including radioactive material. French-American chemist Marie Perrin is offering a cleaner solution. At ETH Zürich, she developed a fast, scalable process to recover europium from discarded fluorescent lamps – without the pollution of conventional methods.
“Today, I’m working on bringing to market a technology that I developed during my grad studies on the recycling rare earth elements,” Perrin says. “They’re in your phone, in your computer, and in a lot of green technologies, like wind turbines and electric cars.” “We have a solution […] to source these metals from the very waste we produce,” she says.
The innovation earned her a place among the top ten Tomorrow Shapers in the European Patent Office’s 2025 Young Inventors Prize.
A golden solution to toxic waste
The patent-pending process begins by dismantling lamps to safely extract phosphor powder and remove mercury. The powder is dissolved in acid, then combined with sulphur-based molecules that trigger a redox reaction. A golden precipitate forms, rich in europium, while other elements like yttrium remain in solution. The solid is filtered, treated with ammonium oxalate to regenerate the extractant, and finally transformed into usable europium oxide.
The method also reduces the need for toxic solvents and allows closed-loop reuse of chemicals. “Our invention allows us to separate these elements more efficiently. And we do it from waste so that these critical metals are not thrown away,” she says.
A childhood passion turned global mission
Born in the US and raised in Toulouse, Perrin was drawn to chemistry from a young age – not least because both her parents are scientists. “‘My mum is a chemist, and early on, she shared her passion for chemistry, which really guided me in my studies afterwards,” she says, looking back.
Perrin’s PhD at ETH Zürich began with work on water purification rather than rare earth separation, but a shift came early in the project when, together with PhD supervisor Professor Victor Mougel, Perrin “discovered that the molecules that we were using could be used for rare earth separation”.
With support from ETH’s Technology Transfer Office, Perrin filed a patent application, published her findings in science journal Nature, and co-founded the Swiss startup REEcover with Mougel and longtime friend Maria Pujos.
In spite of REEcover’s sustainability credentials, it has not all been smooth sailing. “We reached out to many companies but struggled to make an impact at first,” Perrin recalls. “When we began to make contacts, we realised that many industries do not have power over their supply chain.”
Expanding to new rare earth sources
Initially focused on lamps, REEcover is now expanding into recovering rare earths from magnets used in electric vehicles and electronics. The team is running proof-of-concept studies to adapt the method to other waste streams, aiming to push industry towards circular models.
For Perrin, this is not science for science’s sake. “Our generation faces many challenges, from global pandemics to climate change,” she says. “If you have an idea, be bold, be creative and keep pushing the boundaries of human knowledge.”
