Core-shell structure-induced high displacement response in piezoelectric ceramics: A theoretical design

摘要： In this work, a series of piezoelectric composites with core-shell structure are proposed to pursue high displacement response under a low applied electric field. The shell and core consist of piezoelectric and non-piezoelectric material, respectively. A finite element method (FEM) is introduced to simulate the distribution of local electric field and the displacement response. The results show that the largest piezoelectric displacement response of these core-shell structural composites reaches twenty-five times larger than that of pure piezoelectric ceramic under the applied electric field of 2 kV/mm, which can be explained by the fact that the local electric field inside the shell is enhanced up to dozens of times as large as the applied electric field. It is also suggested that the displacement response of piezoelectric composites can be heightened by adopting smaller shell volume fraction, or increasing the permittivity or decreasing the Young's modulus of the core.