By Song Peijing from Office of Overseas Promotion
A new kind of flexible, stretchable, and transparent loudspeaker made with carbon nanotube (CNT) film was invented by a team led by Professor FAN Shoufan and Associate Professor JIANG Kaili from Tsinghua’s Department of Physics.
(A cylindrical cage-like CNT film loudspeaker which emits sound in all directions)
Based on the discovery that a piece of CNT thin film can become a practical magnet-free loudspeaker simply by applying an audio frequency current through it, the CNT film loudspeaker generates sound within a wide frequency range, high sound pressure level, and low total harmonic distortion. The CNT film loudspeaker possesses all the functions of a voice-coil loudspeaker as well as the merits of being magnet-free and without moving components. The nano-thick CNT films are flexible, stretchable, and transparent and can be tailored to any shape and size to fit various rigid or flexible insulating surfaces such as walls, roofs, windows, flagpoles or even clothes. Several CNT films can also be configured into a large-size loudspeaker.
(The CNT thin film was put on a flag to make a flexible flag loudspeaker)
The research on thin film loudspeakers was published in Nano Letters in October 2008 and generated lively discussion around the world in such journals as Nature and Physics Today. The single-element film loudspeaker opens up the possibility for new designs of acoustic devices which differ from the traditional ones.
(Photos provided by Professor Jiang Kaili)
