The influence of structural parameters on the actuation performance of piezoelectric fiber composites

Piezoelectric fiber composites with interdigitated electrodes have attracted increasing interest in a variety of areas due to their unique performances. Viscous plastic processing technique was utilized for the fabrication of... [ view full abstract ]

Piezoelectric fiber composites with interdigitated electrodes have attracted increasing interest in a variety of areas due to their unique performances. Viscous plastic processing technique was utilized for the fabrication of composite with customized feature sizes. The structural parameters, e.g., electrode finger spacing, fiber thickness, interlayer thickness and volume fraction of piezoceramic fiber, showed great influence on the free strain performance of composites, which were verified by both finite element analysis and experimental measurement. Electric field distributions along the longitudinal direction of piezoceramic fiber were used to discuss the actuation mechanism of piezoelectric fiber composites. The results revealed that PFCs had the optimal free strain performance, i.e., 1900 με and 930 με in the longitudinal and transverse directions at interlayer thickness, electrode spacing, PZT fiber thickness and volume fraction of 0 μm, 500 μm, 200 μm and 80%, which demonstrated high level of actuation capability and anisotropy. With the decrease of electrode spacing, the positive effect of increased homogeneous of electric field strength enhanced free strain performance, compared with negative effect of decreased volume fraction of homogeneous electric field. The free strain value decreased sharply to 700 με at interlayer thickness of 4 μm compared with that of 1900 με at interlayer thickness of 0 μm, which could be attribute to a high proportion of absorbed voltage by interlayer capacitor with low permittivity. As fiber thickness decreased, the positive effect of both increasing homogeneous electric field strength and volume fraction of active zone increased significantly, jointly improved the free strain performance of PFCs. And the free strain performance could be nonlinearly enhanced by increasing volume fraction of PZT fiber.