Carbon Nanotube Speakers

A CNT thin film loudspeaker that is being periodically stretched up to 200% of its original size in the direction perpendicular to the aligned direction of CNTs. The sound intensity variation is almost not noticeable during stretching.

A single layer of CNT thin film put on a flag forms a flexible loudspeaker dancing in wind. The dimension of the flag CNT thin film loudspeaker is 8 cm by 14.5 cm.

The thermal expansion and contraction of the air in the vicinity of the thin film produces sound, not the mechanical movement of the thin film itself.

Lin Xiao et al., " Flexible, Stretchable, Transparent Carbon Nanotube Thin Film Loudspeakers," NanoLetters, 8, 4539–4545 (2008).