New Type of Interactive Paper Makes and Plays Sounds
While the invention is almost entirely made of paper, a special kind of ink that contains conductive silver particles is the secret ingredient here. The ink allows an electric current to flow without any bulky wires.
Because the scientists used the paper as a billboard in their demonstration, the paper is about three centimeters (or one inch) thick. There are three layers that make up the interactive paper: a front layer with the text and images that viewers see and touch, a middle layer with conductive ink that is connected to a power supply, and a back layer of thick cardboard material.
To make the paper make a noise, a person just has to touch the front layer, and the paper works a lot like a touchpad on a laptop. When a hand applies pressure to the conductive ink on the second layer, the pressure alters the current flow, and speakers produce a sound.
Inside the paper, small cavities act as speakers to amplify the sound. The conductive ink is used to print electromagnets, which vibrate in response to different current flows, producing sound.
Researcher Mikael Gulliksson explains that the area of interactive paper is still in its early stages, and there is a lot of potential, although most aspirations are still several years away from realization. (One of these long-term goals is using semiconducting polymers to integrate all the electronics on a single piece of paper.) From this perspective, this sound-producing paper is a commercial breakthrough.
Now that the scientists have demonstrated billboards, their next area of interest is one that consumers can hold in their hands: interactive chocolate packaging. I just wonder what a chocolate bar would have to say...