Projects

Development of an in-operando electrochemical stage for the Quattro scanning electron microscope

An electrochemical stage integrated to the scanning electron microscope Quattro from Thermo Fisher Scientific is now available to all Québec Researchers. This allows taking electrochemical measures in situ or in operando, particularly for the cyclovoltametry of solid electroactive materials and the cycling of battery prototypes. Quattro's users can also access the glove box (BAG) of the central XPS installations at Polytechnique Montréal, which assures transfer of air or water sensitive samples to the Quattro in controlled conditions.

Developping this infrastructure was realized jointly by members of the Dollé Group, including Steve Rousselet (University of Montréal), and professionals from CM². Their work was focused on commissionning and validating the electrochemical module, as well as resolving technical difficulties met with the stage, even though the design was initially adapted by Thermo Fisher for this type of measures. This process needed suplementary methodological development, electrochemical tests, programmation adjusting and a rigorous performance monitoring.

The electrochemical system of the Quattro platform is now fully operational, and the Dollé team succeded in doing tests in real conditions on lithium metal batteries. (M. Costalin et coll. J. Electrochem. Soc. 172 030505 (2025) and (idem. 171 100505 (2025)). The interface between BAG and SEM, including the transfer system, was completed in January 2023. This functionality, allowing the introduction of samples without air exposure, is then a recent evolution of the Quattro electron microscope. Adapating BAG to the transfer module was done by the technical staff of University of Montréal.

EBSD measurements for non-conductive materials

EBSD measurements of non-conductive materials are not possible in high-vacuum microscopes due to sample charging. The deposition of conductive coatings, such as carbon or gold, is necessary to reduce charging; however, these coatings prevent the acquisition of indexable Kikuchi patterns needed for EBSD analysis.

The aim of the current research project is to develop a methodology for the formation of conductive coatings that are thick enough to eliminate charging while remaining thin enough to allow the acquisition of high-quality Kikuchi patterns.

A set of non-conductive samples will be polished and ion milled to a surface quality suitable for EBSD measurement. Carbon and gold coatings will then be deposited to a thickness sufficient to suppress charging and to form a dense, uniform conductive layer.

Subsequently, the coating thickness will be gradually reduced by ion milling to improve the quality of the Kikuchi patterns. After each milling step, the quality of the resulting Kikuchi patterns will be evaluated until the best performance is reached.

During this project the following parameters will be studied:

• Ion Milling Parameters for Surface preparation of polished samples
• Parameters for the deposition of the carbon and gold layers (deposition time, stand-off distance )
• Parameters for the thickness reduction of conductive coatings (ion milling angle and time)
• Electron microscope parameters for EBSD Testing (beam voltage and amperage, size of the aperture, exposure time)

The preliminary experiments for this methodology demonstrated very promising results.

Analaysis by separation of variables in SEM/TEM multimodal datasets

This project involves developing artificial intelligence tools to perform multimodal data segmentation (multiple signals from electron detectors and EDX/EELS spectrometers). This data would come from 2D images or tomogams acquired using the FIB-SEM electron microscope or the transmission electron microscope. The objective is to develop and validate hyperspectral decomposition algorithms using various strategies, such as latent variable decomposition or neural networks, by leveraging the latest generation of AI librairies. To enable broader use of the tools across the network, a version with a graphical user interface will be developed and made available to the RQMEM, along with traning on its use.

Development of advanced high energy TKD and low energy EBSD for the high resolution characterization of microstructures

This project aims at enhancing advanced EBSD capabilities through the development of high-energy TKD and low-energy EBSD methodologies. High-energy TKD will be applied to alloys with relatively high density (steels, superalloys, Ti alloys) and provides spatial resolution superior to that of conventional EBSD, which is essential for ultrafine microstructures. Low-energy EBSD will optimize low-energy acquisition, where reduced penetration and limited scattering improve surface sensitivity and resolution for bulk samples. A systematic comparison of the two methods will define their advantages, limitations, and applications depending on the allow. The performance of several EBSD detectors will be evaluated to optimize measurement conditions. TKD samples will be prepared using FIB, while bulk samples will undergo ion polishing and UV cleaning. Measurements will cover various strains and geometries, and pattern quality, step size, and indexing will be evaluated at ÉTS and in the network.

Nanostructured and metalloproteined hydrogels : identification of observation conditions to measure in HRTEM and cryo-FIB

The complex interactions between biological hydrogels (e.g., mucus) and synthetic hydrogels (e.g., hydrogels for topical applications) and nanoparticles containing active ingredients (pharmacological, vaccine, or genetic) must be measured in several fields of health sciences (ophthalmology, immunology, cancer, etc.). However, visualizing the interactions between nanoparticles and hydrogels—whether biological or synthetic—poses a significant challenge in electron microscopy. First, hydrogels are fragile, water-saturated structures (over 98%), and preparing them for observation under an electron beam requires specific techniques (e.g., cryosectioning followed by lyophilization for HRTEM observation; cryopreparation for cryo-FIB-SEM observation, etc.). Because these organic samples are fragile, the specimens must be observed under modes, conditions, and parameters (e.g., energy, focusing, magnification) that ensure low radiation doses. Furthermore, natural hydrogels such as mucus—found on the cornea, nasal, oral, gastric, intestinal, and vaginal walls, etc.— may contain high levels of metalloproteins. However, the concentrations of Fe, Mg, Mn, Cu, Ca, and Zn ions—the primary ions found in metalloproteins—must be sufficiently high to be detectable in sections of lyophilized or cryopreserved hydrogels observed by HRTEM or cryo-FIB-SEM. The concentration thresholds at which these metals would be detectable by EDS in such specimens must be determined. In this project, synthetic hydrogels based on bovine mucins—which mimic the characteristics of certain human mucus—will be co-formulated with lipid nanoparticles (representative of several drug delivery systems) and common metalloproteins (e.g., hemoglobin (Fe), hemocyanin (Cu), and Zn-finger proteins). For HRTEM analysis, the hydrogels will be prepared by cryo-ultramicrotomy and lyophilized (U. Laval), while for FIB-SEM, the hydrogels will be cryopreserved at McGill. The samples will be examined by HRTEM (including EDS) and by cryo-FIB-SEM. This project will enable the evaluation of all specimen preparation, dose, and signal constraints involved in the observation of this type of complex specimen.

Development of an experimental method on PFIB to obtain 3D reconstruction images including image taking, EDS maps and EBSD maps of hard materials

The project consists in visualizing in 3D the nano/microstructure of "hard" materials. The goal is to obtain images of several regions of the sample, in addition to chemical maps using X-ray spectrometry (EDS) and crystallographic maps using EBSD.

These informations are first collected from a section of the sample.Then, the PFIB electron microscope beam allows to strip in a controlled fashion and relatively quickly the sample surface to obtain the same informations, but from a section below the initial surface. These sequences of striping and data acquisition are repeated for a given number of cycles to eventually construct and visualize the 3D nano/microstructure of materials. This includes the visualization of nano/microstructural constituents and their chemical composition and the crystalline structure and so the visualization of spatial phase distributions. It is also possible to determine the morphometric parameters of these phases (size, quantity and shape) by analysing images. These reconstructions can need many consecutive days of machine time including night and weekend depending on the needed spatial resolution and the size of the region of interest.

Up to now, we successfully obtained images of biological samples from professor Natalie Reznikov from McGill with whom we have a collaboration. Prof Reznikov's group then treats the images to represent the 3D images on Dragonfly software. No results of this type has yet been obtained by including chemical informations (EDS maps) and cristallographic informations (EBSD maps) of hard materials. Many problems need to be solved including the unexpected stop of data acquisition due to a system problem with the operation of Thermofisher's PFIB (during image acquisition), obtained image alignment in a given section of the sample (to generate a mosaic of this section) and the mosaic aligment of different sections (to generate a 3D reconstruction and analysis of the images and EDS and EBSD maps).

The first objective of this project is then to obtain these informations in a robust and reproducible way. The subsequent objective will be to reconstruct the 3D information with the Dragonfly software and/or Avizo, We will evaluate these softwares as part of this project. Finally, we will obtain mophometrical parameters.

Imaging Beam-sensitive and Low-contrast Soft Materials with iDPC and 4D-STEM

The characterization of nanostructures of beam-sensitive (i.e., metal-organic framework) and low-contrast soft materials (i.e., macromolecules) are vital for understanding their functional properties and guiding their applications. However, achieving high-resolution imaging of their nanostructures by electron microscopy has been historically challenging due to their extreme sensitivity to electron beam irradiation and the inherently low contrast of light elements. Recent advances in integrated-differential potential contrast (iDPC) and four-dimensional scanning transmission electron microscopy (4D-STEM) offer opportunities to overcome these limitations. iDPC utilizes electrostatic potential sensitivity to produce high signal-to-noise, phase-rich images of both light and heavy elements under low-dose conditions, while 4D-STEM records complete electron diffraction patterns at every probe position, enabling the reconstruction of nanostructures with unprecedented precision.

Ce projet exploite les instruments à la fine pointe pour développer des techniques avancées d’iDPC et de 4D-STEM, incluant le MÉT Talos au Facility of Electron Microscopy Research (FEMR, McGIll) et le microscope électronique en transmission Spectra à l’Institut Interdisciplinaire d’Innovation Technologique (3iT, Université de Sherbrooke), tous deux équipés avec des détecteurs DPC/iDPC à quatre quadrans, en plus du SU9000 à McGill équipé de détecteurs 4D-STEM. Ensemble, ces plateformes offrent un environnement expérimental exceptionnel pour l’acquisition de données rapide, de haute résolution et à faible dose, adapté à la sensibilité de faisceau des matériaux souples. En intégrant ces techniques complémentaires et favoriser les collaborations entre les institutions au Québec, ce travail a pour objectif de mettre en place un cadre robuste pour l’imagerie permettant de visualiser et d’interpréter de manière fiable les nanostructures de systèmes de matériaux jusqu’alors difficiles à étudier.

EDS and EELS Talos, Spectra and SU9000 benchmarking and optimization

Le RQMÉM soutient la collaboration entre le FEMR de McGill et la plateforme de microscopie de l’Université de Sherbrooke. McGill opère un microscope électronique Talos alors que UdeS héberge un système Spectra dont l’optique corrigée permet une microscopie STEM analytique plus performante. Le financement va supporter les visites du personnel de FEMR à Sherbrooke pour des formations pratiques, incluant des sessions avec les spécialistes de Thermo Fisher, qui vont informer directement sur l’optimisation de l’instrument Talos à McGill.

Specifically, the project will benchmark Talos EDS capabilities against Spectra performance, as well as McGill-based Hitachi SU-9000, establishing quantitative reference data to guide future upgrades and operating protocols. This will help build a clear framework for sample workflow between the platforms. After this benchmarking is established, McGill samples that currently exceed the Talos’ limits will be analyzed there during subsequent visits.

Besides EDS, we have developed EELS analysis on the Talos and established limitations in a number of cases, requiring the use of the Spectra. We wish to study plasmonic materials sensitive to beam damage preventing reliable EELS acquisition (e.g., TiN), structures with multiple plasmon modes requiring higher energy resolution (e.g., Au nanorods), and Gd-containing samples for which current EELS and EDS detection thresholds are insufficient.

This initiative will immediately enhance characterization capabilities in Quebec and foster long-term sharing of expertise between the two institutions.