This is a picture of the world's smallest six string guitar made at the Cornell Nanofabrication Facility. It is 10 micrometers long , the size of a single cell. The whole thing was made of silicon, as a demonstration of resonance and vibration at nano-scales. Harold Craighead, the director of the facility at the time described how it works,
"When a laser hits a string, the heat makes it vibrate at extremely high frequencies, about 17 octaves—higher than a normal guitar. The so-called strings are free to move, clamped at both ends. That clamping allows us to shine light on that string, change the temperature, and generate stresses that cause the string to move. The different motions of a single string or different strings moving allow us to do something analogous to playing the guitar. When we move the light beam around, we can make tones that every once in a while sound sort of appealing”
This raises an interesting philosophical question. It looks like a guitar, but if it can’t be heard or played by a human is it a really guitar? For other philosophical guitar-related questions see air guitar .