Theoretical modeling, experiments and optimization of piezoelectric multimorph

• Published in: Smart materials and structures 2005-12, Vol.14 (6), p.1343-1352
• Main Authors: Lee, Seung-Yop, Ko, Byeongsik, Yang, Woosung
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; Fundamental areas of phenomenology (including applications); General equipment and techniques; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Measurement and testing methods; Physics; Servo and control equipment; robots; Solid mechanics; Structural and continuum mechanics; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...)
• ISSN: 0964-1726; 1361-665X
• DOI: 10.1088/0964-1726/14/6/026

This paper deals with the static and dynamic electromechanical responses of piezoelectric layered structures (multimorphs). Based on the Bernoulli-Euler plate model including the dynamics of piezoelectric, electrode and substrate layers, we obtain the natural frequencies, maximum displacement and resultant force of a symmetric cantilevered multimorph. The proposed theoretical model is verified by experiments using a 20-layered PZT (plumbum-zirconate-titanate) multimorph, and it is compared to the conventional bimorph model. Experimental results agree with the analytical predictions on the natural frequencies and vertical displacement. With the analytical solution for multimorph, we investigate the effects of the layer number and the layer thickness on natural frequency, maximum deflection and output force. It is found that there exists an optimum number of piezoelectric layers to maximize the transverse deflection. There also exists a specific value of the thickness ratio between piezoelectric and structure layers to maximize both the tip deflection and force.