a layer of {HEAD ~ a second conductive metallization} on either side of {TAIL ~ the pair} of layers of the electrodisplacive material 
a layer of { HEAD ~ a second conductive metallization } on either side of { TAIL ~ the pair } of layers of the electrodisplacive material
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH