{TAIL ~ The actuator mechanism} is preferably {HEAD ~ a piezoelectric actuator}, however a variety of actuator mechanisms can be used 
{ TAIL ~ The actuator mechanism } is preferably { HEAD ~ a piezoelectric actuator } , however a variety of actuator mechanisms can be used
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH