Abstract: Multimaterial 3D printing promises to bring the kind of structural and functional complexity we see in nature into synthetic systems, but doing this in a single vat is still far from straightforward. This PAM JAM will cover recent progress in one-vat multimaterial vat photopolymerization (VPP), focusing on how small – and often overlooked – details in chemistry, optics, and processing can make or break these systems. Rather than swapping resins or relying on multi-step workflows, newer approaches use wavelength selectivity, reaction orthogonality, and grayscale light control to program multiple materials from a single formulation. Key practical design rules have begun to emerge, including how to think about photochemical selectivity, resin formulation beyond standard acrylates, and the coupling between light–matter interactions and reaction kinetics. These considerations directly impact interfacial integrity, mechanical gradients, and overall print fidelity. The discussion will conclude with a perspective on where the field is heading, including gaps in characterization and opportunities for integrating modeling and data-driven design, with an eye toward applications in soft robotics, biomedical devices, microelectronics, and advanced optics.

Abstract: Vat photopolymerization (VPP), particularly digital light processing (DLP), provides exceptional resolution for polymer additive manufacturing but remains limited in high‑throughput industrial deployment due to slow recoating dynamics and strong resin–window adhesion. This study introduces a novel printing interface engineered to reduce interfacial adhesion while enhancing resin flow behavior, enabling rapid layer replenishment and significantly increasing build rates. The interface architecture was evaluated through controlled experiments and integrated into automotive prototyping workflows at Nissan. Results demonstrate substantial improvements in throughput, process stability, and scalability, supporting small‑ to medium‑volume production of end‑use polymer components. Case studies highlight successful fabrication of geometrically complex automotive parts, illustrating how this interface transforms VPP from a prototyping‑centric technology into a viable production method for automotive manufacturing environments.

Abstract: Photopolymer additive manufacturing offers high resolution and surface quality, but the need to remove support structures after printing remains a major challenge. Supports limit part geometries, add manual labor, and generate waste. This talk focuses on Selective Solubility Vat Photopolymerization (SSVP), a new approach that uses a single resin and two wavelengths of light to selectively cure either a dissolvable thermoplastic or a durable, insoluble thermoset within the same print. This allows complex geometries to be fabricated with supports that can later be removed in mild solvents or in a component of the original resin itself, enabling closed-loop recycling of the dissolved support material. Several other emerging strategies for reducing the burden of support removal in photopolymer printing will also be discussed. Together, these examples show how materials design, process design, and machine design can work together to make resin 3D printed more automated, sustainable, and capable of producing complex parts.