The world's smallest guitar is 10 micrometers long -- about the size of a single cell -- with six strings each about 50 nanometers, or 100 atoms, wide. Made by Cornell University researchers from crystalline silicon, it demonstrates a new technology for a new generation of electromechanical devices.

The guitar has six strings, each string about 50 nanometers wide, the width of about 100 atoms. If plucked -- by an atomic force microscope, for example -- the strings would resonate, but at inaudible frequencies.

The entire structure is about 10 micrometers long, about the size of a single human blood cell.

A nanometer is one-billionth of a meter. For comparison, the diameter of a human hair is about 200 micrometers, or 200,000 nanometers.