It has also to apply the correct pre-stress to the piezoelectric material in order to allow dynamic and precise motion.
In diamond shaped amplifiers, using 4 piezo crystals instead of one increases control of movement, particularly in changing temperatures.
[3] Another method of amplifying the piezo stroke is to use a lever arm, which can be a primary or a secondary amplification mechanism, and can be used to generate displacements with 10 to 40 times magnification.
Amplified piezoelectric actuators have no sliding parts due to the flexural hinges and do not require lubrication.
Controlling helicopter rotor blades using active flaps has been investigated for some time without being put into production.