CEA-Leti Demonstrates Battery-Operated EPR Spectrometer on 22-nm Chip, Enabling Portable Paramagnetic Sensing

In a recent press release, CEA-Leti announced that a team of researchers from their institution and CEA-IRIG validated what they describe as the first chip-scale, battery-operated electron paramagnetic resonance (EPR) spectrometer.¹ According to the research team, this EPR-on-a-chip miniaturized spectrometer is able to deliver better scan speed, improved wide spectral coverage, and high sensitivity.¹

The researchers presented their work on February 18^th at the IEEE International Solid‑State Circuits Conference in San Francisco, California, discussing their findings and explaining how replacing the bulky electromagnets of conventional EPR instruments with faster frequency-scanned architecture can improve paramagnetic analysis. The result is that the researchers found a new way to enable high-precision paramagnetic analysis outside centralized laboratories.¹ This result reflects a current trend of making spectrometers portable to expand where analysis can be conducted.²

EPR spectroscopy is widely used to detect unpaired electrons in radicals, metal complexes, and defects in solids, providing insights into chemical reactions, materials degradation, and biological processes.^1,3 However, traditional systems rely on large electromagnets and microwave hardware, limiting their deployment to specialized facilities. The new “EPR-on-a-chip” approach integrates the full spectrometer onto a 22-nm CMOS circuit powered at milliwatt levels, opening possibilities for portable and embedded sensing.¹

According to the researchers, the chip achieves a scan rate of 1,400 THz/s across a 100-Gauss equivalent spectral span with 120 µM concentration sensitivity while consuming 96 mW.¹ The system can scan the full spectral range in 200 ns, which the researchers note is better than existing miniaturized EPR devices that typically sacrifice spectral range or sensitivity to achieve faster scans.¹ The combination of speed and bandwidth allows observation of fast-passage effects and short-lived reaction intermediates that are difficult to capture with conventional instruments.

The device’s sensitivity is enabled by an injection-locked phase-detection architecture that encodes the EPR signal as a phase shift rather than an amplitude or frequency change. The team also integrated microwave generation, detection, and control onto a single chip.

“Our goal is to create a compact, portable EPR spectrometer that operates on just a few watts of power, enabling on-site analysis in environments where conventional instruments simply cannot operate," said Serge Gambarelli, research director at CEA-IRIG and EPR spectroscopy expert.¹

Alexandre Siligaris, senior research engineer at CEA-Leti, added that adapting RF frequency-synthesis architectures allowed the integration of a complete EPR system in advanced 22-nm technology.

“By adapting RF and frequency-synthesis architectures originally developed for telecommunications, we were able to integrate a complete EPR system on a single 22 nm chip," said Alexandre Siligaris, senior research engineer at CEA-Leti.​¹

The circuit was fabricated in 22-nm fully depleted silicon-on-insulator (FDSOI) technology by GlobalFoundries, and it is described as the first scientific instrument realized in this advanced node.¹ The 4.4 mm² chip is mounted on a printed circuit board and positioned within a 0.5-tesla permanent magnet, with the sample deposited directly on the chip surface.¹

This work is part of CEA’s Moonshot µ-RPE program. This program’s main objective is to develop a deployable spectrometer platform for applications in healthcare diagnostics, materials characterization, and environmental monitoring.¹ Portable EPR could enable on-site detection of reactive species in industrial processes, embedded monitoring within energy-storage systems, or distributed sensing networks for environmental safety.¹

The next steps in this work involve integrating planar magnet technology under investigation by CEA-Liten. This is intended to expand application flexibility and reduce system size further.¹ The advance highlights how Europe is investing resources in advanced microelectronics for scientific instrumentation. CEA positions the work as an important step in demonstrating that high-performance spectrometry can be miniaturized using state-of-the-art semiconductor technology.¹

References

1. CEA-Leti, CEA-Leti Validates First Ultra-Fast, Battery-Operated EPR Spectrometer at Chip Scale. CEA-Leti. Available at: https://www.leti-cea.com/cea-tech/leti/english/Pages/What's-On/Press%20release/CEA-Leti-Validates-First-Ultra-Fast-Battery-Operated-EPR-Spectrometer-at-Chip-Scale.aspx (accessed 2026-02-24).
2. Crocombe, R.; Kammrath, B.; Leary, P. E. Portable Raman Spectrometers: How Small Can They Get? Spectrosc. Suppl. 2023, 38 (s6), 32–40. DOI: 10.56530/spectroscopy.cn5172t4
3. Argonne National Laboratory, Advanced Electron Paramagnetic Resonance (EPR) Facility. ANL.gov. Available at: https://www.anl.gov/cse/advanced-electron-paramagnetic-resonance-epr-facility#:~:text=EPR%20spectroscopy%20is%20a%20technique%20that%20is,*%20Organic%20photovoltaic%20materials%20*%20Metallo%2Dorganic%20frameworks (accessed 2026-02-24)