Can piezoelectric crystals produce electricity from compression only ? When continuous compression and tensile forces on them generate AC voltage source, can only compression force give me a DC voltage source ? Is there a chance that the crystal will initially act as a Voltage source but soon re-adjust itself to get its acquired polarity neutralized ? If so, how long typically can the polarity last ? And I would also be glad if i could get some data for my project. specifically: 1.What is the minimum pressure required for any piezoelectric crystal to generate electricity ? 2. How much Volts can i expect from that pressure?