A new type of actuator is presented in the paper that integrates the IDEs into a conventional piezoelectric sheet. The electrodes and polarization play a key role in the strain. Adopting constitutive equations of piezoelectric theory and variation principles in elasticity theory, the piezoelectric component dynamic equation was deduced. Several finite element models of the IDEs piezoelectric actuator were established in ANSYS. The effect of branch electrodes on the strain of the actuator was analyzed. The results show that the strain can be bigger than that of the conventional piezoelectric sheet by decreasing the gap and increasing the width of electrodes. According to the FEM result, some IDEs piezoelectric actuators were prepared. The distribution of the static electric field inside the actuator was researched to determine the polarization voltage. The 2671 high voltage power and DU-20 temperature-controlled oil bath was applied to explore the polarization process. The effect of the voltage, time and temperature on the strain of the actuator was researched by a TF2000 and SIOS laser interferometer. The results show that the optimum polarization is 800 V, for 60 min and at 150 ℃. The strain of the IDEs piezoelectric actuator is 1.87 times that of the conventional piezoelectric actuator. The actuators could prove to be helpful applications for micro-nano devices.

A new piezoelectric actuator combining interdigitated ring electrodes and a PZT-52(Lead Zirconate Titanate) disk was investigated for the large displacement requirements of piezoelectric actuators. Finite element models were established according to the structural characteristics of the actuator and static analysis was carried out based on ANSYS software. Then Ø25 mm × 2 mm samples were prepared. The displacement detection system was established, and the influence of electrode structure on radial displacement was studied experimentally. A comparison between the experimental results and the finite element analysis confirmed that the finite element model was correct. The results showed that the effect of electrode width on displacement was small. With decrease in electrode center distance and increase in the number of electrodes pairs, the radial displacement increased correspondingly. The peak of radial displacement was 1.63 μm under a 200 V voltage excitation voltage of 0.2 Hz. This was 2.5 times that for a conventional electrode piezo disk with the same structure. The actuator demonstrated better displacement properties. The piezoelectric disk could be valuable in applications involving micro-nano devices.