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A novel piezoelectric stack for rotary motion using d 15 working mode is proposed, fabricated, and tested in this article to achieve the high stiffness and high precision of rotation. This piezoelectric stack is fabricated by bonding process from only two components—lead zirconate titanate ceramics and electrodes, which is beneficial to realize the simple structure. A theoretical model based on the shear deformation theory is established to predict the static output performances. And the simulation with the finite-element method is adopted to evaluate the dynamic characteristics. An experimental system is built to verify the design and study the performances of the piezoelectric stack. The experimental results indicate that the static output angle changes from −13.25 to +13.33 μ rad, whereas the exciting voltage changes from −300 to +300 V, with good linear relationship and high repeatability accuracy. Under the condition of changing the exciting voltage by the step of 0.5 V, the stable resolution is measured to be higher than 0.022 μ rad. The large load capacity and width frequency response are verified, which reflect the high stiffness of the proposed piezoelectric stack. The proposed piezoelectric stack achieves accurate and stable rotary output motion with high resolution, rapid response, and large load capacity. Besides, the stack has regular shape and simple structure, and therefore, it is suitable to be integrated in the equipment in the fields of micro–nano manipulations, piezoelectric ultrasonic motors, etc.

A piezoelectric robot with four parallel legs operating in rowing mechanism was presented and tested. The driving feet of the legs moved in a triangular trajectory, and a pair of legs on the same axis operated like rowing to move the robot step-by-step through the static friction forces between the driving feet and platform. A kinematic model with respect to the motion of the piezoelectric legs was established based on the Timoshenko beam theory and Galerkin procedure, which was used to design and optimize the structure of the robot. A prototype was fabricated and its experimental system was established. The motion trajectory of one driving foot was measured, which agreed well with the calculated results using the kinematic model in terms of both magnitudes and trajectory. A nanopositioning ability was achieved with a resolution of 16 nm. The experiment results showed that the output speed was linearly related to the voltages of the excitation signals, and motions along any directions could be achieved by changing the applied voltages. The prototype achieved maximum output speeds of 584 and 614 μ m/s along the X and Y axes, respectively, under voltage of 400 Vp-p and frequency of 100 Hz. Furthermore, a carrying capacity of 25 kg was achieved. The proposed piezoelectric robot could be used to transport heavy devices with nanopositioning accuracy.