It needs precise control so a piezo is out, I cant tell you the chemical I am using to grow the crystal or the parent police will confiscate it! But there is a certain chemical that you can grow a crystal from (like many), this particular chemical's crystal has some really neat properties if you apply high voltage spikes as it grows. I read about it in a university paper I found in dads stash, apparently you can realign the crystal structure with high voltage short pulses. This apparently gives the crystal some odd properties. The paper has never been published (no idea why) but was done by a PhD student and someone my dad knows.
Took me ages to get hold of the chemical!
Took me ages to get hold of the chemical!