Scale developed to weigh gold atoms

Scientist in the US have claimed to have developed a nanoelectromechanical scale system which is so sensitive it can measure - at room temperature - the mass of a single atom of gold.

Physicist Alex Zettl holds a joint appointment at the Energy Department’s Berkeley Lab and the University of California-Berkeley and led the research with researchers Kenneth Jensen and Kwanpyo Kim.

The carbon nanotube mass sensor was able to weigh separate gold atoms and also measure objects which were two-fifths the size of a gold atom in just over one second.

Mr Zettl said: "The Holy Grail of [nanoelectromechanical systems] has been to push them to a small enough size with high enough sensitivity so that they might resolve the mass of a single molecule or even single atom."

He said this has previously been difficult to achieve even at cryogenic temperatures.

Cold temperatures means thermal noise is reduced which in turn means increased sensitivity.

In other science news, water has been finally identified in soil samples from Mars.