Hot nanotube sheets produce music on demand - tech - 31 October 2008 - New Scientist
Video: Flexible sheets of carbon nanotubes perform as speakers with little modification

Sheets made of carbon nanotubes behave like a loudspeaker when zapped with a varying electric current, say Chinese researchers. The discovery could lead to new generation of cheap, flat speakers.

Since the early 1990s, nanotubes have been intensively studied by researchers across the globe. The tiny structures are widely touted as potential drug delivery devices but might also be useful in more exotic gadgets including artificial photosynthesis devices and space elevators. But no one has thought to test their acoustic properties until now.

Shoushan Fan and his research team at Tsinghua University in Beijing, China, working with colleagues at Beijing Normal University, created a thin sheet by roughly aligning many 10-nanometer-diameter carbon nanotubes. When they sent an audio frequency current through the sheet, they discovered it acted as a loudspeaker.

A standard loudspeaker consists of three basic elements - a speaker cone, a voice coil and a magnet. The cone and coil are attached and sit in a permanent magnetic field created by the magnet. When an audio frequency current passes through the voice coil, it creates a temporary magnetic field, and the coil and cone shift relative to the permanent magnetic field. Those shifts induce vibrations in the air molecules near the speaker cone, generating sound.

There are two short videos on VIMEO of Ben Fry introducing Processing at the recent Flourish festival

Processing Workshop at Flourish '09 (pt1) from Morgellon on Vimeo.