基于可逆畴变的压电圆环多层致动器应变响应研究

压电致动器在现代工业中发挥着非常重要的作用。然而，目前应用的压电致动器均是基于线性压电效应，最大应变一般只有0.1-0.15%，实现大的致动应变一直是该领域学者追求的目标。本文中，我们提出了两种经过特殊设计的基于可逆非180°电畴翻转的PZT圆环多层致动器，一种是径向极化、部分电极（RPPE）的4层圆环，另一种是周期性正交极化（POP）的4层圆环，以期能够实现大的致动应变，而且圆环构型层数增加时也不容易发生失稳等问题。实验结果表明，在相同的驱动电场（2kV/mm，0.1Hz）下，4层RPPE最大致动应变为0.27%，约为普通PZT圆环的2倍，但表面变形很不均匀。相比之下，4层的POP圆环致动器的最大输出应变为0.36%，是普通PZT圆环的2.7倍。这两种致动器的致动应变都是随着频率的增加而减小， RPPE致动器在超过1Hz后稳定在0.19%， POP致动器在超过5Hz后稳定在0.2%。而且， POP圆环致动器重复性能很好，经过2万次致动循环后致动应变几乎不变。这种POP PZT多层圆环致动器具有结构稳定、输出应变大等优点，在致动领域具有很好的应用前景。

Strain response of piezoelectric ring multilayer actuators based on reversible non-180 ° domain switching

Piezoelectric actuators have been playing a very important role in modern industries. However, the current used PZT acutaors are based on linear piezoelectric effect, with the maximum output strain is only 0.1-0.15%. Realization of large strain is always the goal of scholars in this field. In this work, we proposed two types of PZT ring multilayer actuators based on reversible non-180 ° domain switching. One is the radially-poled, partially electroded (RPPE) 4-layer ring, the other is the periodically orthogonal poled (POP) 4-layer rings. Experimental results show that under the same driving field (2kV / mm, 0.1Hz), the maximum actuation strain of 4-layer RPPE actuator is 0.27%, about twice that of conventional PZT ring, but the surface deformation is not uniform. As to the 4-layer POP ring actuator, the maximum output strain is 0.36%, about 2.7 times strain of conventional PZT ring, and the deformation is very uniform over the surface. The actuation strain of both actuators decreases with the increasing driving frequency. The strain of the RPPE actuator was stabilized at 0.19% when the driving frequency exceeds 1Hz, and that of the POP actuator keeps at 0.2% when the driving frequency exceeds 5Hz. Furthermore, the actuation strain of the 4-layer POP ring actuator is very stable and keeps unchanged after 20k cycles of operation. The POP ring multi-layer actuator has the advantages of large output strain and stable configuration, and may get wide applications in the actuation field.