Enhanced piezoelectric output performance in flexible polyvinylidene fluoride foam with a hierarchical dual-pore structure

Abstract

Piezoelectric polymer-based flexible electronic devices have attracted extensive research interest due to their wide applications in various technical fields, and their structure designs have profound effects on their output performances. In this work, a hierarchically porous polyvinylidene fluoride (PVDF) piezoelectric foam with two different types of pores was created by an efficient and simple method to achieve better mechanical flexibility and improved piezoelectric output performance. The macroscopic three-dimensional (3D) interconnected pore network structure constructed with a nickel foam template improved the material's compressibility and optimize the load transfer mode, while small pores within the 3D PVDF matrix retained by polymer melt molding further enhanced the flexibility and reduced the PVDF foam's dielectric constant. Both experiment and simulation results demonstrated that devices based on these PVDF foams exhibited stable signal outputs under thousands of cycles and enhanced sensitivity, which ensured their good performances in monitoring and sensing different human motions.