New imaging method sharpens electron microscope resolution beyond atomic limits

Led by Arthur Blackburn, co-director of UVic's Advanced Microscopy Facility, the team achieved sub-Angstrom resolution - less than one ten-billionth of a meter - on a compact, low-energy scanning electron microscope (SEM). Such clarity was previously attainable only through much larger and more expensive transmission electron microscopes (TEMs).

"This work shows that high-resolution imaging doesn't have to rely on expensive, complex equipment. We've demonstrated that a relatively simple SEM, when paired with advanced computational techniques, can achieve a resolution that rivals or even surpasses traditional methods," said Blackburn, who also holds the Hitachi High-Tech Canada Research Chair in Advanced Electron Microscopy.

The advance, detailed in Nature Communications, makes high-resolution imaging far more accessible to laboratories worldwide by reducing the cost, space, and specialized expertise typically required.

The UVic team achieved their breakthrough through a technique known as ptychography, which reconstructs images from overlapping diffraction patterns of scattered electrons. By applying this approach at 20 keV on a low-energy SEM, they achieved a resolution of just 0.67 Angstrom - smaller than a single atom and about one ten-thousandth the width of a human hair.

According to Blackburn, the method could revolutionize research across materials science, nanotechnology, and structural biology. "The advance will most immediately benefit the research and production of 2D materials, which are promising in the development of next-generation electronics," he said. "Long term, it could also assist in determining the structure of small proteins, leading to advances in health and disease research."

The study was conducted in collaboration with Hitachi High-Tech Canada and supported by the Natural Sciences and Engineering Research Council of Canada (NSERC).

Research Report:Sub-angstrom resolution ptychography in a scanning electron microscope at 20 keV