I watched a tv program not long ago where they were talking to the inventor Trevor Baylis.
This guy was the man that invented the wind up radio.
His latest invention is using Piezoelectric materials in the sole of a shoe, so when walking it charges your phone.
http://news.zdnet.co.uk/hardware/mobile/0,39020360,2076250,00.htm
He did a nice demonstration by using a little Piezo speaker that you can buy from any electronic store and placing a meter over across it, as it was bent back and forth indeed it created a voltage shown on the meters LCD display.
This was a couple of months back and I remember doing a quick search on Google and came across an article where someone was proposing an idea where Piezo sheets could be hung inside tunnels and as the cars pass through, the wind created from the cars could bend the sheets and create power.
Does anyone have any resources where Piezo sheets have been used in commercial applications?
Regards
Sean.