Topology optimization of active piezocomposite metamaterials considering manufacturable feature sizes and impedance matching

Abstract

Piezoelectric devices are utilized for sensing, actuation and energy harvesting applications, and have seen a large increase on industrial and academic interest in the last decades. Generally, piezoelectric materials are either ceramics, which have the greatest piezoelectric properties, but are stiff and brittle, or polymers, which are malleable and easier to manufacture, but have generally poor piezoelectric properties. Therefore, it is of interest to develop piezocomposite materials, combining piezoelectric and conventional materials, seeking to harness the positive attributes of both classes of materials. This can be performed using topology optimization by optimizing the microstructure of a piezocomposite unit cell, which is currently being performed by the researcher in his D. Sc. project. But additional issues arise from this methodology; in order to increase the efficiency of resulting piezoelectric devices, mechanical impedance matching has to be taken into account. Furthermore, since the fabrication of piezocomposites of complex shapes is quite difficult to perform, even with the recent advances on additive manufacturing (AM) technologies, it would significantly increase the applicability of the research if the relevant manufacturing constraints could be considered. Thus, this project seeks to apply the knowledge of the researchers at TU Delft on the ongoing research at Unicamp by expanding on the already implemented numerical framework developed by the researcher to account for the aforementioned constraints, considering the mechanical impedance between the optimized material and a reference host structure and utilizing the Moving Morphable Components method for a more precise control of piezoelectric structural shape, orientation and feature sizes inside the unit cell. (AU)