Signal Conditioning Piezoelectric Sensors

http://www.ti.com/lit/an/sloa033a/sloa033a.pdf

Mini Piezo Siren

http://www.rebelhosts.com/tt/te/p59.htm

Piezoelectric Tutorial From Physics to Ardurino
http://www.eng.utah.edu/~cs5968/handouts/piezo.pdf

Piezoelectric Amplifier Circuit

http://hackedgadgets.com/2009/05/06/piezoelectric-amplifier-circuit/

Sensing Amplifier Circuit