, , Clayton Kostelecky, K. Womer
Piezoelectric ceramics are desirable actuator materials for many biomedical applications due to their ability to generate precise, controlled motion with applied voltage. Herein, we report the fabrication of miniature piezoelectric ceramic actuators and their subsequent performance testing under high electric fields. The actuators were produced by tape casting sub-micron lead zirconate titanate (PZT) powder, followed by electroding, laminating, and dicing to form multilayer devices. The resulting devices consisted of 10 active (i.e., PZT) layers, each of which was approximately 50 ¿¿m thick. To evaluate the effect of microstructure on performance, the multilayer components were heated to 1175-1325 ¿XC and soaked at temperature for 24 minutes. Fatigue resistance was then determined by monitoring the change in net polarization during continuous cyclic operation. Actuators sintered at lower temperatures possessed smaller-grained microstructures and exhibited improved fatigue resistance. In these specimens, polarization decreased by less than 15 % compared to more than 50 % for devices processed at higher temperatures. These results indicate that sintering control can be used to minimize performance degradation, improve reliability, and promote long-term stability.
Proc. World Congress on Biomimetics, Artificial Muscles and Nano-Bio
December 6-8, 2004
actuators, fatigue resistance, multilayer fabrication, piezoelectric ceramics