The atomic microscope would allow the surface of biological samples, for example, to be probed in a way that is impossible with other state-of-the-art microscopes. Electron microscopes can produce highly magnified images, but they have serious drawbacks. The samples must conduct electricity; electrons penetrate into the sample, leading to an image that doesn't accurately represent the surface; and, worst of all, the very-high-energy electron beams can obliterate the precious samples.

An atomic microscope with a low-energy beam of helium atoms could get around these problems. Neutral helium can bounce off any surface and the beam would be deflected by the electrons at the very edge of the sample, giving a true image of the surface. But an atomic microscope demands a focused beam of helium atoms, which requires a mirror that reflects the beam with very little scattering of the atoms. The new flat mirror is atomically smooth, even after it has warmed up to room temperature, and it can reflect 15% of incoming helium atoms.