Enhancing Interlayer Bonding in DLP‐Printed Piezoelectric Ceramics via Controlled Secondary Curing for High Piezoelectric Performance

Digital light processing (DLP) presents a promising approach for fabricating intricately designed piezoelectric components, which are essential for developing high-sensitivity piezoelectric sensor systems. However, the inherent layer-by-layer stacking nature of DLP induces interlayer cracking in printed ceramics, which severely deteriorates their performance. This work introduces an innovative interfacial engineering strategy to print superlattice components with exceptional piezoelectric performance. A moderate exposure time improves the surface characteristics of cured layers, that initiates controlled secondary curing at material interfaces. This process strengthens interlayer bonding and consequently boosts the mechanical properties of the green body. The optimal interlayer bonding quality is observed for t-20 ceramics. Its piezoelectric constant (d₃₃) reaches an exciting 516 ± 8 pC·N^-1, which approaches the level of commercial ceramic and exceeds the values of most 3D-printed advanced piezoelectric materials. The printed superlattice component achieves an ultra-high piezoelectric response, e.g., open-circuit voltage up to 493 V at 17.3 N. The component exhibits an extremely pressure-sensitive sensitivity of 27.9 V·N^-1, along with a voltage response at a very faint load of 0.1 N. Applications in various scenarios show the component's favorable sensing characteristics and reliable non-contact dynamic monitoring capability, which opens new avenues for its applications in the sensing field.