Spray-Drying-Assisted Digital Light Processing for Highly Dense and Precise Three-dimensional Printed Barium Titanate Ceramic Structures

Abstract

Photopolymerization-based ceramic 3D printing, known as digital light processing (DLP), offers a valuable platform for rapidly prototyping previously unattainable intricate architectures without the need for additional molds. However, the presence of ceramic particles in photocurable suspensions introduces challenges, including elevated viscosity and diminished curing depth due to light-ceramic particle interactions. This ultimately compromises the efficacy of the photocuring process, resulting in undesirable geometric inaccuracies. In this study, meticulously engineered lead-free ferroelectric barium titanate (BaTiO3, BTO) ceramic granules, produced through a spray-drying process, optimize ceramic suspension formulation. This approach enhances ceramic flowability and involves the judicious addition of a binder, yielding a uniform redispersion of ceramic particles within the matrix, while maintaining a bimodal particle size distribution with reduced diameters. Supported by both experimental and numerical simulations, this improves the rheological and curing properties, enabling the successful fabrication of highly dense, complex 3D-printed BTO structures with excellent shape fidelity. Moreover, by carefully designing the thermal profiles, DLP 3D-printed BTO ceramics exhibit impressive shape retention after debinding and sintering while demonstrating ferroelectric and dielectric performances comparable to their non-3D-printed counterparts. This study presents a transformative approach that unlocks the full potential of ceramic 3D DLP printing. Granulated BaTiO3 (BTO) ceramics extracted from a spray-drying process are utilized to formulate uniformly re-dispersed ceramic suspension, particularly optimized for digital light processing (DLP) 3D printing. This novel approach significantly enhances the shape precision of DLP 3D-printed BTO architectures with high density and, subsequently, improves their dielectric and ferroelectric performance, comparable to Non-3D-printed BTO ceramics. image