Description:

A "nanobalance," a vibrating carbon nanotube that can directly weigh microscopic organisms and particles piggybacked onto it, has been demonstrated by researchers at Georgia Tech.  A mass attached at the end of a nanotube shifts its resonance frequency. If the nanotube is calibrated (i.e., its spring constant known), it is possible to measure the mass of the attached particle. In this example, the resonant frequency was 968 kHz, compared to 3.28 MHz when unloaded (calculated). The mass of this carbon sphere was then determined to be 22±6 femtograms (one fg is a quadrillionth of a gram). A direct estimate based on volume and the density of amorphous graphite gives a mass close to 30 fg.  In general, this technique can determine the mass of particles with similar dimensions in the range of femtograms to picograms (trillionths of a gram) . This includes viruses.

 

 Previous Day/Next Day

Please contact the webmaster if you would like to submit an image