A compact bimorph rotary piezoelectric actuator with customized small power supply

Inertial piezoelectric actuators are widely applied in precision devices with simple structure and accurate movement. However, existing inertial piezoelectric actuators still face the challenges of rollback motion and bulky power supply. In this work, an alternate excitation strategy and a customized small power supply for a bimorph rotary piezoelectric actuator (BRPA) are proposed to solve the problems. The BRPA prototype is designed with a bipedal symmetrical structure, measuring 35 mm in height and 32 mm in diameter, which has a maximum rotation velocity of 0.247 rad/s and a resolution of 0.66 µrad. Thanks to the bipedal symmetrical structure, the friction directions between the driving feet and the rotor can be coordinated to suppress the rollback. The rollback ratio is almost zero when the phase difference of the exciting signal is set as 180°. The customized power supply is designed and manufactured, whose size is 58 mm×56 mm×46 mm. It can output signals for the single step mode and the continuous mode, and they are adopted to excite BRPA to achieve a small stroke with one single step and a large stroke with continuous step, respectively. Then, an experimental system for optical fiber alignment is developed based on the BRPA and the customized small power supply, the experiment has verified the practicability of this work in the precision fields, especially in the miniaturized precision systems.