A novel multifunctional piezoelectric composite device for mechatronics systems by using one single PZT ring

Piezoelectric ceramics are fascinating function materials and have good electromechanical coupling properties that can be used to develop various types of composite devices. Recently, piezoelectric composite devices with multifunctional demands have been extensively desired due to the remarkable developments of mechatronics systems. This paper focuses on developing a novel multifunctional composite device by using one single PZT ring, in which a piezoelectric actuator, a sensor and an energy harvester are embedded. The composite device is mainly composed of a rotary rotor and a piezoelectric vibrator, the piezoelectric vibrator is formed by a metal elastomer mechanically bonded together with a piezoelectric ceramic ring. The piezoelectric ceramic ring is polarized into three regions to produce the actuating, sensing and energy harvesting functions. The mathematical model of the composite device was derived and validated by experiment. A prototype was fabricated and the experiments including the mechanical, energetic and transient characteristics were performed and discussed. The results indicate that the composite device reaches the maximum torque, no-load speed and mechanical power of 0.674 Nm, 118 rpm and 2.65 W when it is excited by a voltage signal with amplitude 67 V and frequency 40 kHz; the results also show that the maximum extracted power of the composite device reaches 305 mW when the load resistance is 11.6 k omega, the composite device has a rapid response speed with startup time less than 5 ms and shutdown time less than 1 ms.