Enough Atoms for a Cannonball? Or Just a Small Splash?
Physicists at the University of California, Berkeley have developed a nanomechanical sensor -- a cantilevered carbon nanotube -- that can weigh an atom, replacing a large mass spectrometer.
The mass is determined by sending a radio-frequency signal to the nanotube and measuring its resonant frequency, which changes when different atoms are stuck to it.
Also see:
An atomic-resolution nanomechanical mass sensor, Nature Nanotechnology, July 20, 2008:
Unlike traditional mass spectrometers, nanomechanical mass spectrometers do not require the potentially destructive ionization of the test sample, are more sensitive to large molecules, and could eventually be incorporated on a chip.
(Source: http://www.nytimes.com/2008/07/22/science/22obweig.html?ref=science)
