BST/PVDF-ABS composites with high dielectric tunability prepared via FDM additive manufacturing

Barium-strontium titanate (BST) /Polyvinylidene fluoride (PVDF)-based composites have attracted significant attention due to their excellent dielectric properties and processability applied in aviation and medicine electronic devices. However, due to the limitations of traditional preparation processes, it is difficult for these composites to form complex structures. In this work, Ba_0.6Sr_0.4TiO₃/PVDF-ABS composites were prepared via Fused Deposition Modeling (FDM) additive manufacturing. The influences of different matrix compositions on the microstructure, dielectric properties, and mechanical properties of composites were studied. A multi-layer capacitor with mortise and tenon structure was fabricated by FDM processing to demonstrate its application. The results showed that samples prepared by FDM had uniformly dispersed fillers and exhibited good dielectric properties. With the increase of ABS content, the dielectric constant, the dielectric loss, and the dielectric tunability decreased, while the breakdown strength increased. When the BST content is 20 vol%, PVDF content is 48 vol%, and ABS content is 32 vol%, the BST/PVDF-ABS composites exhibited the best performance. The composites demonstrated a dielectric constant of 18, a dielectric loss of 0.021, a dielectric tunability of 39.26 % at 19.5 kV/mm, and a tensile strength of 34.5 MPa. A multi-layer capacitor with mortise-and-tenon structure was obtained by FDM and exhibited a capacitance of 112.8 pF. Its capacitance showed a high tunability and can be changed from 112.8 pF to 87.1 pF under DC bias. This work provides ideas for the fabrication of electronic devices by using Ba_0.6Sr_0.4TiO₃/PVDF-ABS dielectric composites and FDM additive manufacturing.