The fabrication and deformation capabilities of two dimensionally graded DEPP FGP

Abstract

Piezoceramic functional grading methods, such as the Dual Electro/Piezo Property (DEPP) technique, can successfully produce monolithic actuators which generate higher order deformations when activated (bending, twisting, etc.) while simultaneously increasing reliability by eliminating bonding layers. By synergistically combining ceramic powder with elevated piezoelectric coefficients with a high permittivity dielectric, DEPP actuators are not constrained to the one dimensional property variations as other grading methods. This paper explores the new capability of producing multidimensionally graded piezoceramics via the DEPP technique coupled with the Micro-Fabrication by Co-eXtrusion (MFCX) process. It also presents a modeling technique based upon transfer matrix method that builds up the full actuator performance model from elemental beam models derived using an energy approach which captures all the material variations and the resulting complex electric fields. To validate both the fabrication and modeling techniques, a rippling DEPP FGP actuator was fabricated and tested with three oppositely graded regions, demonstrating two dimensional gradients through the length and thickness. This work sets the foundation for monolithic multi-dimensional FGP opening the door to a new class of applications.