Building A Scale Sensitive Enough To Weigh A Virus

Cornell University researchers already have been able to detect the mass of a single cell using submicroscopic devices. Now they're zeroing in on viruses. And the scale of their work is becoming so indescribably small that they have moved beyond the prefixes "nano" "pico" and "femto" to "atto." And just in sight is "zepto." Members of the Cornell research group headed by engineering professor Harold Craighead report they have used tiny oscillating cantilevers to detect masses as small as 6 attograms by noting the change an added mass produces in the frequency of vibration.