A comparative analysis of piezoelectric bending-mode actuators

During the last several years novel piezoelectric bending actuators have been developed: RAINBOW, CERAMBOW, CRESCENT, d(33) bimorph and THUNDER A comparative experimental investigation of electromechanical characteristics of these devices along with conventional d(31) bimorph and unimorph actuators was conducted in this work. All transducers were fabricated from soft piezoelectric ceramics. The experimental results show that d(33) bimorph and unimorph elements have superior quasistatic characteristics as compared to other type of bending-mode actuators. All these piezoelectric devices demonstrate a significant dependence of electromechanical performance on the magnitude of the driving electric field. It was found that the decrease in the mechanical quality factor and resonant frequency of bending vibrations in d(31) unimorph, RAINBOW, CRESCENT (CERAMBOW) and THUNDER with increasing electric field is much smaller than that in bimorph and d(33) unimorph actuators. The dependence of the behavior of these devices on the operating conditions governs the selection of a particular device for a specific application.