Fundamental photopolymer additive manufacturing informed by a uniform, calibrated light engine

Photopolymer additive manufacturing (PAM) is fueling an explosion of opportunities and capabilities for US production of 3D printed products in a wide range of industries including automotive, healthcare, energy, and consumer goods. While digital light processing (DLP), a subset of PAM, relies heavily on patterned light sources with up to millions of individual pixels in the 1 µm to 100 µm length scale, recent research has revealed the dramatic dependence of the polymerization process on slight variations in photo-exposure conditions. Reliance by the PAM industry on non-uniform, poorly-characterized light engines can convolve exposure variability with fundamental photochemistry and photo-physics, hindering advancements. Specifically, a lack of single pixel characterization and multi-pixel uniformity in the light engine hinders fundamental characterization of the photopolymerization reactions that underpin PAM. By developing a uniform, well-characterized light engine, this work provides a foundation to inform the comprehensive models required to improve the fidelity and integrity of PAM products. This presentation will provide an overview of the development of a state-of-the-art light engine, comparing prints from commercially available DLP systems to those from the uniform light-engine, and highlight the need for rigorous characterization of sources to streamline PAM resin development for reliable, high performance PAM.