3D Maps of Delicate Surfaces Acquired by Helium Atoms

Scientists have developed “heliometric stereo,” a new technique that creates quantitative 3D maps using a Scanning Helium Microscope (SHeM) [1].

This method overcomes the limitations of traditional 3D mapping tools (like electron microscopes) that can damage delicate samples. SHeM uses a gentle, non-damaging beam of neutral helium atoms that only interacts with the absolute surface.

The technique works by combining multiple 2D images, each taken from a different detection angle. By measuring the change in signal brightness, which depends on the local surface angle, a complete 3D profile can be calculated.

The team demonstrated this on two setups:

• A single-detector machine, by rotating the sample .
• A multi-detector machine, which acquired the images simultaneously and was  times faster.

Both methods produced accurate 3D reconstructions, opening a “new frontier” for measuring soft or sensitive materials.

[1] J. Appl. Phys. 138, 044902 (2025)