World's most sensitive scale weighs atoms to the nearest proton

Most of the things that we measure aren't critical and we can have a pretty large margin of error and be okay. For instance if you're weighing yourself a pound low or high isn't a big deal. However, when scientists are weighing very small and low mass objects such as atoms, a tiny margin of error is too much. That's where the world's most sensitive scales come into play with the ability to weigh to the nearest yoctogram.

I've never even heard of a yoctogram. These scales are sensitive enough that if you were to place an atom on the scale, it could weigh it to the nearest proton. Previously, the most sensitive scale could weigh to 100 yoctograms, which works out to something called 1/10 of a zeptogram. That has all changed with these new scales developed by Adrian Bachtold and colleagues at the Catalan Institute of Nanotechnology in Barcelona, Spain.

The scale's sensor uses short nanotube's to give the best resolution and measurement capability. The equipment works at low temperatures in a vacuum to minimize interference from other atoms. To remove any stray atoms that might be sitting on the sensor, the nanotube's are heated temporarily to disrupt any bonds to other atoms. The sensor was able to weigh an atom of xenon to the nearest yoctogram, or 10 to the -24 grams. That feat makes it the first scale capable of detecting a single proton.

"The yoctogram mass sensitivity achieved by the Catalan team is certainly spectacular ‐ the challenge ahead will be to routinely manufacture nanotube sensors at low cost," says Rachel McKendry, a nanoscientist at University College London.

[via New Scientist]