FLASH

Direct electron detectors (DEDs) have revolutionized electron microscopy, offering near-perfect detective quantum efficiency and fast acquisition rates. These advancements have been instrumental in facilitating more accurate nano-analysis at ever lower electron doses, including the inception of 4D-Scanning Transmission Electron Microscopy (4D-STEM). However, critical challenges remain for the study of beam-sensitive, poorly crystallized, and nanoscale materials, where beam damage imposes significant limitations. The FLASH project aims to overcome these barriers by integrating next-generation DEDs, innovative scanning strategies, and advanced data analysis techniques to enable transformative insights into fragile materials critical to energy, catalysis, and fundamental science. This project will enhance 4D-STEM capabilities by implementing the event-based TIMEPIX3 detector, achieving acquisition speeds over 10 million frames per second—a 500-fold improvement over conventional detectors. Novel scanning strategies, such as Lissajous trajectories, will minimize beam damage by distributing dose more uniformly, while compressed sensing will enable sparse data acquisition. In this way we will acquire 4D-STEM datasets in under 1 ms, enabling unprecedented resolution in beam-sensitive materials and faster in-situ studies. FLASH will also pioneer Precession Electron Diffraction (PED) with DEDs to achieve quantitative nanocrystallography at unparalleled angular precision (0.03°–0.1°). Enhancements to PED-based Pair Distribution Function (ePDF) analysis will extend the measurable scattering vector range (Q) to 20–25 Å?¹, providing synchrotron-level resolution for nanoscale and poorly crystallized systems and enabling the characterization of short-range atomic order in materials previously inaccessible to electron microscopy. To further reduce electron dose, FLASH will develop advanced data analysis pipelines optimized for low-count datasets, enabling accurate analysis at minimal doses. FLASH’s innovations will have far-reaching impacts on materials characterization and beyond. The technical procedures developed within the FLASH project are first validated and then applied to different beam-sensitive nanomaterials, such as bimetallic nanoparticles, doped polymer films and extra-terrestrial materials. These advancements are particularly relevant in the context of the European Green Deal, where improved materials design is essential for sustainable energy conversion, efficient electronic devices, and environmentally friendly chemical processes. Beyond scientific breakthroughs, FLASH will contribute to the development of open-source software tools for data processing, ensuring its methodologies are widely accessible and reproducible. By releasing experimental datasets and metadata under open licenses, FLASH will also support machine-learning-assisted materials discovery, providing high-quality benchmarks for validating interatomic potentials and training AI models. This open-science approach will accelerate the development of new materials and inspire similar initiatives across the research community. This proposal is submitted under the international collaboration agreement between ANR and the São Paulo State Science Funding Agency (FAPESP-Brazil), with a co-coordinator at the University of Campinas (UNICAMP). An important aspect of this project is training of young researchers, all hired students will be co-directed by French and Brazilian researchers and spend significant time in the other participating laboratories. The project’s findings will be disseminated through high-impact publications and at international conferences ensuring global visibility and fostering collaboration. By combining instrumentation innovation, data-driven discovery, and international collaboration, FLASH will establish new standards in electron microscopy, advancing both fundamental research and industrial applications.