Authors : Alexander Vinogradov, Yegor Matveev Yegor, Roman Lubchenko and Pavel Titov
Abstract: This study presents the theoretical results of a comparative analysis of axisymmetric models of piezo actuators with a bimorph and unimorph structures. The unimorph actuator contains ring elements that are fastened to a round metal base. The bimorph actuator has two bound identical piezo ceramic disks with a thin-film electrode between them: the outer surfaces of the disks are covered with thin silver ring electrodes. Different voltages are applied to the ring parts which deforms the bend and creates a system of ring protuberances and depressions. Such actuators are relatively new in piezo engineering-literature does not describe a methodology of their design or comparative analysis. This research is relevant for the choice of an optimal scheme of further development. Quasi-static models are constructed according to the circuits of initiation of bend strains in the multilayer piezoelectric structures (disks, rings and membranes). Special software for their calculation was developed. The results of modeling of bimorphs and unimorphs with ring electrodes were obtained via. the analytical methods and the finite element methods; test models were compared to known designs. The study found that a unimorph with a base with an optimized thickness had greater strains than the bimorph did. Furthermore, the bimorph contained two times as many double-ended electrodes which complicated its structure and limited its application in micropumps without additional protective means which reduce its energy efficiency. As a result, the preferred model is that of a unimorph that serves as a piezo actuator for the creation of annular waves.
Alexander Vinogradov, Yegor Matveev Yegor, Roman Lubchenko and Pavel Titov, 2018. A Comparison of Axisymmetric Models of Multilayer Piezo Actuators for the Creation of Annular Strain Waves. Journal of Engineering and Applied Sciences, 13: 940-953.