First, i think lots of people will find this video to be awesome. Second, toward the end of the video they show paper embedded piezos. How do they do this? I'm thinking it's magnetic ink, on either side of the paper, but is a piezo really that simple?

http://www.youtube.com/watch?v=XESzR3MfxUE

 

I didn't notice a piezo. I did see/hear the loudspeaker made using an inked inductor; there was a magnet underneath. I noticed the strain gauge connected to the meter.

Piezo transducers are generally made from quartz crystals, which are somewhat fragile.

 

ok, then how'd they make the inductor? i wanna make one.