Electromechanical resonators are components in many technologies. A nanometre-size version -- a resonating carbon nanotube -- has now been created that can be tuned over a range of frequencies. The simplest stringed musical I instrument is the bow, similar I to a hunter's bow -- a string stretched on a frame so that, when plucked, it resonates and produces a note whose pitch is determined by the string's tension. On page 284 of this issue, Sazonova et al. demonstrate a nanometre-scale version of a musical bow by exciting and detecting mechanical resonances in a carbon nanotube suspended between two gold electrodes. The authors show that they can tune the resonance frequency, or pitch, of the nanotube by varying a gate voltage, which serves as both an electronic tension adjustment and a means of exciting the vibrations. The vibra-tional frequencies of the nanotube are more than a thousand times higher than the audible range, so the tones produced cannot be heard. However, in an elegant demonstration of the diverse capabilities of carbon nanotubes, Sazonova et al. have used the nanotube itself as an electronic detector -- one that can 'hear' its own motion.
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