Displacement, stiffness and load behaviour of laser-cut RAINBOW actuators

Commercial piezoceramic PZT 5A discs were reduced in air at 750 °C to produce RAINBOW actuators using graphite as the reduction substrate and ZrO 2 powder for protection. After the reduction process, the RAINBOW actuators were cut to desired shapes with a Nd–YAG laser. The effect of the laser cutting on the load, displacement, stiffness and dielectric constant characteristics of the actuators was studied for different sizes. Load capabilities of the actuators reduced as the amount of active material decreased but almost 30% of the active material could be removed without significant change in load properties. Results showed the possibilities to shape and decrease the size of the actuators and perform application specific modifications in load, displacement and stiffness properties. The effect of the laser cutting on the dielectric constant was insignificant compared with the de-poling effect of high electric field driving. Manufactured actuators were modelled with the ATILA program. Modelling gave accurate results with the original RAINBOW actuator and with sliced actuators 15 and 10 mm in width.