Low voltage (Bi, Sc)(Pb, Ti)O3 based piezoelectric multilayer actuators for high temperature applications

Abstract:
As the PZT (Pb(Zr, Ti)O3) ceramics has long been studied for decades, the PZT related materials are widely applied in many products such as piezoelectric actuators, linear motors and so on. However, one drawback for PZT is its relative low curie temperature. Therefore the conventional PZT products can only be applied at relatively low temperature (<150 °C). A new kind of piezoelectric materials with high curie temperature and depolarization temperature BSPT ((Bi, Sc)(Pb, Ti)O3) can be used to solve this problem. In this work, the piezoelectric actuator chip made by BSPT materials can work at 250 °C without performance degradation. The multilayer technology is also introduced to reduce the operation voltage down to 150V, while can be even down to 45V. The manufactured BSPT actuator chip with multilayer structure can achieve the stroke of as high as 4 µm at external voltage of 150V which is higher than other single layer products. When we stack three or more BSPT chips together, the BSPT stack actuator can even achieve the stoke of more than 10 µm. As the chemical activity of Pt is much lower than that of Ag and Pd, we use Pt inner electrode instead of Ag/Pd inner electrode to enhance the stability and the lifetime of BSPT actuators, which indicates that our product can also work at extreme environment. In brief, our research provides a new idea in the high temperature piezoelectric motion control applications such as high temperature gas valve, glue dispensing device, nano or micro positioner and so on.