New York, September 27:

There’s a limit to how tiny gadgets, devices and machines can get, scientists have claimed.

The claim comes from an experiment performed by a University of Arizona team of optical sciences doctoral candidate John D Perreault and assistant professor of physics Alexander D Cronin. Perreault and Cronin directly measured how close speeding atoms can come to a surface before the atoms’ wavelengths change, said a stat-ement from the university.

Theirs is a first, fundamental measurement that confirms the idea that the wave of a fast-moving atom shortens and lengthens depending on its distance from a surface, an idea first proposed by pioneering quantum physicists in the late 1920s. The measurement tells nanotechnologists how small they can make extremely tiny devices before a microscopic force between atoms and surfaces, called van der Waals interaction, becomes a concern.

The result is important both for nanotechnology, where the goal is to make devices as small as tens of billionths of a metre, and for atom optics, where the goal is to use the wave nature of atoms to make more precise sensors.