Design of piezoelectric transducers and MEMS based on functionally graded material concepts and topological optimization

Abstract

Piezoelectric materials produce displacements when an electric potential is applied, and electric potential when they are subjected to forces or pressure. They are used in mechanical precision and mechatronics applications. Functionally Graded Materials (FGM) are composite advanced materials, which are made by changing gradually the properties with position. FGM combines the advantages of desirable features of each constitutive phase. For instance, high temperature resistance of ceramics with high mechanical resistance of metals. The application of FGM concept to piezoelectric transducer design allows designing composite transducers without interface between materials (e.g. PZT and Aluminum), due to the continuous change of property values. Thus, large improvements can be achieved in their performance characteristics, mainly, smoothing the mechanical stress distribution and increasing the fatigue-lifetime. Furthermore, recent works about piezoelectric FGM show lack of computational methods to model these transducers and evaluate their performance based on property gradation function. This suggests the use of optimization techniques for designing theses devices. Based on these ideas, this work propose the development of FEM and topology optimization algorithms to design new FGM piezoelectric transducers (sensors and actuators) with better performance, to explore the FGM potential by designing novel piezoelectric transducers and MEMS. Two-design focus will be considered: a) FGM piezoelectric transducer design with regard to their dynamic characteristics (resonance frequency and specific vibration modes), by optimizing the continuous gradation of the piezoelectric properties and, b) FGM piezoelectric transducer design, by maximizing a desired output displacement, through FGM compliant structure design actuated by piezoelectric ceramics. The work will be conducted in partnership with Prof. Gláucio H. Paulino, from Department of Civil and Environmental Engineering – University of Illinois at Urbana-Champaign (UIUC) – USA.