Electromechanical properties of ultra-low porous auxetic piezocomposite: from the perspective of Poisson's ratio

In this study, the ultra-low porous auxetic piezoelectric composite made of lead zirconate titanate (PZT) and hollow polyvinylidine difluoride (PVDF) is first proposed by combining additive and subtractive approaches. The electromechanical properties of the auxetic piezoelectric composite are investigated by finite element analysis. It is found that the ultra-low porosity in the composite may lead to great extensibility along with the excellent figures of merit obtained in conventional highly porous piezoelectric ceramics. The small amount of additional PVDF can greatly tune the electromechanical properties of composite and effectively reduce the maximum stress of PZT. To elucidate the role of Poisson's ratio on the electromechanical properties of piezoelectric materials, the relationship expressions among some electromechanical coefficients are derived. Moreover, the semi-empirical expression of longitudinal compliance coefficients and a simple strategy for predicting some electromechanical coefficients are presented to instruct design and application of the ultra-low porous auxetic piezoelectric materials.

Automated summary

This study introduces an ultra-low porous auxetic piezoelectric composite made of PZT and hollow PVDF, showing that a small amount of additional PVDF can effectively tune the electromechanical properties of the composite and reduce the maximum stress of PZT. By deriving expressions for the relationship among some electromechanical coefficients, the role of Poisson's ratio in the electromechanical properties of piezoelectric materials is elucidated. These findings provide insight for the design and application of ultra-low porous auxetic piezoelectric materials.