Marvin,

Your best course of action is to "let the experts do it".  Contact at least
two wirebonder manufacturers and send them samples to try.  They may even do
it for free. If the experts can't do it, then you will need to change your
surface topology.  Run the aluminum off the PZT, and on to a more stable
surface such as your substrate. If this is not possible, perhaps a designed
experiment should be performed.  I can help with this if you need it.

Good luck and best regards,

Mike Mattes
 MicroMechatronics