Fabrication of Ceramic-polymer Piezo-composites with Triply Periodic Minimal Interfaces via Digital Light Processing

The geometry of the phase interface in co-continuous piezoelectric composites is critical in improving their piezoelectric properties. However, conventional co-continuous piezoelectric composites are mostly simple structures such as wood stacks or honeycombs, which are prone to stress concentrations at the joints, thus reducing the fatigue service performance and force–electric conversion efficiency of piezoelectric composites. Such simple structures limit further improvements in the overall performance of co-continuous piezoelectric composites. In this study, based on the digital light processing 3D printing method, we investigated the influence of three different structures–the gyroid, diamond, and woodpile interfaces–on the piezoelectric and mechanical properties of co-continuous ceramic/polymer piezoelectric composites. These findings demonstrate that the gyroid and diamond interfaces outperformed the ceramic skeleton of the woodpile interface in terms of both mechanical and electrical properties. When the ceramic volume percentage was 50%, the piezo-composite of the gyroid surface exhibited the greatest hydrostatic figure of merit (HFOM), reaching 4.23×10⁻¹² Pa⁻¹, and its piezoelectric coefficient ($d_{33}$) and relative dielectric constant (${\epsilon }_r$) reached 115 pC/N and 748, respectively. The research results lay the foundation for the application of co-continuous piezoelectric composites in underwater communication and detection.