Friday, June 08, 2007

Serenading Paper?

Get working on your cheesy rhymes because there may be a new market for jingle writers soon.

Researchers at the University of Sweden are using conductive ink to make sound-producing paper that responds to touch. The prototypes are billboards made entirely of paper that play music or dialogue depending on where you touch them. Watch the video

The applications are endless - commercial packaging, music sampling in record stores, aides for the blind and visual impaired, interactive books...

Right now this technology exists only for large-scale objects like billboards, but the researchers are scaling it down. A New Scientist Tech article quotes Mikael Gulliksson, lead researcher, as saying,

We are interested in scaling the technology down to produce interactive packaging for products like chocolates.

Yum, chocolate. Maybe next Valentines Day I'll get a box of Swedish chocolates that can serenade me...

The boards are created in three layers - a base made from sturdy cardboard, a middle layer screen-printed with conductive ink, and a top layer printed with the billboard design.

All of the information is digitally embedded in the paper and the touch sensors and speakers are printed directly on the middle layer. The middle layer is connected to a power supply and some microelectronics which enable the user to play, pause, and rewind the sounds as shown in the video.

I think this is great stuff. I am seriously worried, though, that if this technology becomes common every time my roommate pours food for her cat I'll have to hear the meow mix.


  1. That is bizarre. Conductive ink, I can understand. But how do you make a speaker out of paper and ink?

  2. Excellent I don't fully understand the answer to myself.

    From what I understand, printed speakers work a lot like the speakers in your car stereo – they take electrical signals and turn them into physical vibrations (sound waves).

    A basic speaker consists of an electromagnet placed inside a permanent magnetic field and connected to a diaphragm. Alternating current passing through the electromagnet causes it to flip polar orientations. Every time the polar orientation flips, the direction of the force between the electromagnet and permanent magnet also flips. This causes the coil to vibrate mechanically, producing sound waves that are amplified by the diaphragm.

    To make billboard speakers the researchers print electromagnets on paper using conductive, magnetic ink. The paper is then stretched over cone-like cavities in the board. When alternating current is applied to the printed electromagnets they vibrate, producing sound waves that are amplified by the cone-like cavities.


    If anyone has a clearer explaination please share!