Journal of Engineering Science and Technology Review 14 (4) (2021) 153 - 160 Research Article Simulation of Piezoelectric Stack Actuators for Loss Component Mark Christian P. Espinosa, Paola N. Calub, Rodney B. Javier* and Sheryl Dinglasan Fenol College of Engineering and Information Technology, Cavite State University, Indang, Cavite, Philippines Received 26 May 2021; Accepted 22 September 2021 ___________________________________________________________________________________________ Abstract Piezoelectric actuators (PEA) are widely utilized now for ultra-precision positioning and actuation in the micro/nanotechnology manufacturing industry. To ensure that these devices perform efficiently and to improve the system and prevent unnecessary inaccuracies it may trigger, it is better to understand its loss phenomenology. Piezoelectric devices have three losses: dielectric, mechanical, and piezoelectric. In this study, behaviour of PEA was simulated using COMSOL Multiphysics to characterize each loss and determine its effect on mechanical response, electrical impedance and percentage loss. The quality factor of the PEA was also calculated with different combined loss. The simulation study showed that each loss has its own influence on the said constituents especially over the frequency sweep. It was also proved that resonant frequency is invariant to the losses, thus, making it an extensive property of the PZT material. Keywords: Piezoelectric Actuator, Loss Phenomenology, COMSOL Multiphysics, Quality Factor, Actuators ___________________________________________________________________________________________ 1. Introduction The extensive study of piezoelectric actuators (PEA) for micro-positioning applications made a lot a progress through some times due to six main advantages given by Li & Chen (2013) [1] and Chi & Xi (2014) [2] such as not omission of a rotating mechanism, ultrahigh precision positioning, instant response, very large output force, lower power dissipation and design aesthetic. It contributed a lot in enabling micro/nanotechnology and ultra-precision manufacturing systems. It is then necessary to enhance the efficiency and performance of this component to increase the mechanical factor and clarify its loss phenomenology [3]. Hysteresis is an innate nonlinear property of piezoelectric devices that influence its control performance and efficiency. Displacement of PEAs depends on not only the current control inputs but also the historical inputs because of the existence of hysteresis [4-5]. According to Zhuang et al. (2014) [6], hysteresis losses in piezoelectrics are considered to have three types in general: dielectric, mechanical (elastic), and piezoelectric losses where they can be classified into intensive or extensive factor upon the boundary conditions [2, 6, 7, 8] Several hysteresis models, as indispensable parts in improving the performance of PEA, have been proposed to describe the hysteresis effect [4, 9]. Chi & Xi (2014) [2] categorizes these models into two types: physics-based models and phenomenological models. Physics-based models utilize the relationship of energy, the displacement and etc. such as Zhang & Damjanovic (2020) [5] described using the Quasi-Rayleigh model while phenomenological models directly uses mathematical models starting from the characteristics of the hysteresis curve which a lot of reference have explained it [10, 11] In this paper, the loss phenomenology of the piezoelectric actuator (dielectric, mechanical, piezoelectric) is modeled and simulated using COMSOL Multiphysics software. Each loss is defined for specific factors: mechanical damping coefficient (QM) for mechanical loss, dissipation factor (tan δ) for dielectric loss and piezoelectric loss or coupling loss factor (tan ϕ) for piezoelectric loss. The mechanical response, electrical impedance as well as the percentage loss for each loss is demonstrated over the frequency sweep of 1 kHz to 1 MHz. The mechanical response indicates the effect of each loss on the displacement of the PEA while the electrical impedance shows the behavior of the electrical resonances and the anti-resonances. Mechanical quality factors are basically related to the losses and play a significant role for its study [5, 12]. A higher mechanical quality factor increases the efficiency and reduces heat generation [7]. For PEAs, the resonances and anti- resonances are considered as the maximum and minimum point of admittance which characterizes as the quality factor under resonance (Qa) and anti-resonance (Qb). In the study, the quality factors where obtained over the frequency sweep of the combined material loss configurations. Fig. 1. Thors lab PK4FQ2 discrete piezoelectric rectangular stack. 2. Methods 2.1 Geometric Description A discrete multilayer piezoelectric stack actuator with both flat ends was modelled in the simulation platform of JOURNAL OF Engineering Science and Technology Review www.jestr.org Jestr r ______________ *E-mail address: rdnyjavier@cvsu.edu.ph ISSN: 1791-2377 © 2021 School of Science, IHU. All rights reserved. doi:10.25103/jestr.144.19