A laser beam is directed at a solar cell which is connected to a guitar amplifier. A rubber band is stretched across the beam. When the rubber band is plucked, a tone similar to the sound of an electric bass guitar becomes audible. The artists perform an entertaining hip-hop song with this instrument.
How does it work?
When the laser hits the solar cell, a voltage is produced. In the amplifier speaker, the speaker’s membrane is moved forward. When the rubber band oscillates through the beam, it interrupts the laser repeatedly; hence the output voltage of the solar cell becomes a periodic signal. The amplifier speaker membrane oscillates too, and an intense bass sound can be heard.
