Because the scale’s radio signal is constant, the vibrations are as well. A steady stream of electrons passes through the nanotube and then jumps through the electric field. If an object to be weighed is attached to the nanotube, the additional mass changes the tube’s resonant frequency so that it no longer vibrates in sync with the radio wave, and electrons can no longer jump from the nanotube to the positive electrode. The heavier the object that is placed on the nanotube, the more its resonant frequency changes.
The researchers were able to determine that a frequency change of 0.104 megahertz corresponded to a mass of 4.9 x 10″“24 kilograms. In fact, the scale is capable of weighing materials lighter than one atom of gold. During this research, Zettl realised that some of the nanotube’s frequencies fell within the commercial radio band, spawning the idea for the nanoradio.
Read more: For the full article, see Science Illustrated magazine, July/August 2010 Australian edition.
