Mo u nting an d Han d ling G u i d elines
Adherence to the followingguidelines will help you obtain maximum performance and lifetime from your piezo actu- ators: Do not use metal toolsfor actuator handling. Do notscratch the coating on the side surfaces. The following precau- tions are recommended during handling of piezoelectric actua- tors:I. Piezoelectric stack actuatorswithout axial preload are sensitive to pulling forces. A preload of up to 50% of theblocking force is generallyrecommended. II. Piezoelectric stack actuatorsmay be stressed in the axial direction only. The applied force must be centered very well. Tilting and shearing forces, which can also be in-duced by parallelism errorsof the endplates, have to be avoided because they will damage the actuator. This can be ensured by the use of ball tips, flexible tips,adequate guiding mecha-nisms etc. An exception to this requirement is made for the PICA™-Shear actuators, because they operate in the shear direction. III. Piezoelectric stack actuatorscan be mounted by gluingthem between even metalor ceramic surfaces by a cold or hot curing epoxy, respectively. Ground sur- faces are preferred. Please, do not exceed the specified working temperature range No pulling force without preload. No lateral force or torque. Ball tips or flexures to decouple lateral forces or bending forces. Ball tips or flexures to decouple bending forces. of the actuator during curing. IV. The environment of all actu-ators should be as dry as possible. PICMA ® actuatorsare guarded against humid- ity by their ceramic coating.Other actuators must be pro-tected by other measures (hermetic sealing, dry air flow, etc). The combination of long-term high electric DC fields and high relative humidity values should be avoidedwith all piezoelectric actua-tors. V. It is important to shortcir-cuit the piezoelectric stackactuators during any hand-ling operation. Temperature changes and load changes will induce charges on the stack electrodes which might result in high electric fields if the leads are notshorted: Should the stackbecome charged, rapid dis- charging—especially with- out a preload—might dam- age the stack. Use a resistor for discharging. VI. Prevent any contaminationof the piezo ceramic sur-faces with conductive orcorrosive substances. Iso- propanol is recommended for cleaning. Avoid acetone and excessive ultrasonic cleaning at higher tempera- tures. Bolting between plates is not recommended. © PI 1998-2005. Subject to change w/o notice. Cat 118 05/09.17 4-48