Weighing An Attogram

Roland Piquepaille writes "Researchers at Cornell University have reached a new level of precision by measuring objects with a mass of less than an attogram (10^-18 gram). They used a silicon cantilever oscillator to measure small dots of gold. But their real goal is to detect and identify viruses. The team also wants to reduce the size of the cantilever, extending the sensitivity well into the zeptogram (10^-21 gram) range. This summary contains more details and an image of a small gold dot resting on the silicon cantilever they used to achieve this breakthrough."