Advances in vat photopolymerization 3D printing: Multifunctional materials, process innovations, and emerging applications

Additive manufacturing (AM), commonly referred to as 3D printing, enables the on-demand conversion of computer-aided design (CAD) models into physical objects, eliminating the need for expensive moulds, dies, or lithographic masks. Among the various AM techniques, light-based vat photopolymerization (VPP) stands out for its focus on polymer-based pure and composite materials. The VPP offers exceptional versatility in printing formats, speed, and precision. Known for its rapid fabrication, high dimensional accuracy, and superior surface finish, VPP is especially well-suited for creating complex geometries. VPP operates by curing photopolymer resins using specific wavelengths of light, typically via vector scanning or mask projection methods. Remarkably, VPP is also adaptable to powder-polymer composite slurry systems and preceramic polymer liquids, enabling additional functionalities and widespread use in lightweight structural components, architectural designs, and optical devices. The integration of nanomaterials (NMs) into VPP-based 3D printing has further expanded its capabilities, enhancing mechanical, thermal, optical, magnetic, catalytic, sensing, and electrical properties. This review provides a comprehensive overview of VPP technology, detailing its underlying principles and recent advancements in materials development, particularly nanocomposites. It also examines key factors influencing the performance of VPP systems and explores their potential applications across sectors such as biomedicine, catalysis, renewable energy, sensing, and aerospace. Finally, the review addresses current challenges and outlines future prospects for VPP-based material systems. This review bridges critical gaps by correlating material design with process scalability and application-specific performance, offering valuable insights into the optimization of VPP for diverse industrial applications.