Study of Large-Displacement Actuators Made of Antiferroelectric Ceramics and Its Integration with SMA

Abstract

A new type of large-displacement actuator called RAINBOW (Reduced And Internally Biased Oxide Wafer) was fabricated by a chemical reduction of PSZT antiferroelectric ceramics. It is found that PSZT was easily reduced and the optimal conditions for producing RAINBOW samples were determined to be 870°C for 2∼3 hours. The AFE-FE phase transitions occur at lower field strength for these reduced antiferroelectric ceramics compared with normal ones. Larger axial displacement (about 190 μm) were obtained from the samples. Furthermore, the possibility of the integration between antiferroelectric ceramics and SMA was also explored. PVD (Physical Vapor Deposition) method was applied to depose SMA (shape memory alloy) films on the reduced layers of the ceramic patches. Experimental results show that this integrated material has better mechanical properties and SMA films do contribute actuation to the whole composite actuating structure. So the integration method for these two kinds of functional materials is a reasonable idea to manufacture actuators with better performance.

Keywords:

• Antiferroelectric ceramics
• actuator
• shape memory alloy
• PVD

Acknowledgments

This work was supported by Natural Science Foundation of China (Grant No 50802043).