Ultrathin thermoacoustic films can turn entire walls and clothes into loudspeakers

Evidence

The thin film heats air in proportion to the current passed through it. If freestanding, both sides of the film are in phase, making it a monopole source. The film does not move during sound production and can also be attached to any insulating surface that does not accept heat readily. A key point is that the films can be made cheaply and quite large; they are also stretchable and flexible. Whole walls and even clothes could become loudspeakers. The Beijing group has already demonstrated a waving flag playing music. — Eric J. Heller, Why You Hear What You Hear- An…, 736

Categorization

• CANDY: A waving flag playing music via a cheap thin film is a delightful, tweetable image.