PICMA
® and PICA
TM Two main types of piezo actua-tors are available: cofired PICMA
® actuators requiringabout 120 volts for full motion,
and glued PICA
TM -Stack actua-tors, requring up to 1000 volts
for full extension.The maximum electrical fieldwhich can be recommended
for reliable operation of PZT
ceramics is on the order of 1 to
2 kV/mm. To keep the operat-
ing voltage within practical lim-
its, actuators consist of thin
layers of electroactive ceramic
material which are electricallyconnected in parallel. The netpositive displacement is the
sum of the displacements of
the individual layers. The thick-
ness of the individual layers
determines the maximumoperating voltage of the actua-tor.Glued PICA
Polymer coated stacked actuator (PICA TM -Stack) and ceramic insulated cofired actuator(PICMA ® ) TM -Stack piezoelec-tric actuators consist of sepa-
rate ceramic discs with a thick-
ness of 0.2 to 1.0 mm. Thesevalues, which are limited bythe manufacturing technology,
result in nominal driving volt-
ages of up to 1000 V. In con-
trast, PICMA
® actuators aremanufactured using a cofiring
technology. This advancedprocess allow for multilayerdesigns which have individual
layer thicknesses of just 20 to
100 µm. Hence PICMA
® actua-tors require nominal voltages
of only 40 to 200 V.Both types of piezoelectricactuators can be used for many
applications: PICMA
Comparison of a long-travel, high-load piezoelectric actuator and a compact actuator for small loads
Layers in a stacked piezoelectric actuator Layers in cofired monolithic piezoelectric actuator ® actuatorsfacilitate drive electronicsdesign and can be produced at
reasonable costs in standard
sizes and large quantities. Due
to its manufacturing techno-
logy, PICA
TM -Stack actuatorscan be designed with largercross-sections for high-load
applications. They can easily
lift weights of up to several
tons. Additionally, the PICA
TM © PI 1998–2006. Subject to change without notice. This data sheet is superseded by any newrelease. The newest release is available for download at www.pi.ws. 06/10/30.0 -
Stack technology is very flexi-ble in terms of special actuator
shapes and sizes.
40