CEA Leti miniaturizes electron paramagnetic resonance spectrometer

02 Oct 2025

Reducing size and power demand enables portable EPR spectrometry for more diverse applications.

Leveraging its expertise in fields such as integrated circuits for telecommunications, France-based research institute CEA-Leti says it is “driving innovation in cutting-edge applications”. One of its latest projects is the miniaturization of an Electron Paramagnetic Resonance (EPR) spectrometer, a technology that, it says, “could redefine how spectrometry is used across various industries”.

EPR spectrometry is a powerful technique used to detect free radicals and metal ions. It can help analyze oxidative stress related to aging and diseases like cancer, or study material degradation in applications such as photovoltaics, fuel cells and batteries.

However, conventional EPR spectrometers are typically large, energy-intensive systems, consuming tens of kilowatts and costing up to €500,000. “Our goal is to create a compact, portable spectrometer that operates on just a few watts of power, making it easy to transport for on-site analysis,” said Serge Gambarelli, Research Engineer at CEA-Irig and an EPR spectroscopy expert.

Paradigm shift

Traditional EPR spectrometers rely on sweeping a magnetic field using an electromagnet while exciting the sample with a fixed-frequency electromagnetic wave. The innovation at CEA-Leti replaces the bulky electromagnet with a compact yet powerful permanent magnet.

“This new approach significantly reduces the size of the system while maintaining high performance,” said Jean-Baptiste David, Research Engineer on the Moonshot project at CEA-Leti. The frequency of the electromagnetic wave is then adjusted using an integrated circuit developed at CEA-Leti, thus ensuring a precise and efficient analysis.

RF integrated circuits, traditionally designed for telecommunications, are being repurposed to enable this breakthrough. “With over 15 years of expertise in frequency synthesis, we are adapting RF architectures to create a fully integrated EPR spectrometer on a single chip,” said Alexandre Siligaris, Senior Research Engineer and frequency synthesis expert at CEA-Leti.

By integrating this technology into a compact form, CEA-Leti is transforming what was once a large laboratory instrument into a versatile, field-ready tool. Developing a compact yet powerful magnetic system is crucial to the success of this miniaturized spectrometer.

“Our laboratory has over a decade of experience in magnetic materials, particularly rare-earth-based magnets,” said Céline Delafosse, Head of the Magnetic Materials and Components Laboratory at CEA-Liten.

“Typically applied in electric mobility and energy transition sectors, this expertise is now being leveraged to design the magnetic system for the micro-EPR spectrometer, demonstrating a valuable transfer of knowledge into the field of instrumentation.”

The development of this next-generation spectrometer has been made possible through strategic funding from the Carnot Commission at CEA-Leti as well as CEA’s PTC (Transversal Competence Program). Following this, the team received further funding from the Moonshot commission, highlighting the project's promising potential. The team is now implementing a two-year development phase to produce a functional prototype of the micro-EPR spectrometer.