SUMMARY

Stereolithography (SLA) 3D printing is a vat photopolymerization additive manufacturing process that utilizes photocurable resin, which requires sacrificial supporting structures on part overhangs, increasing material waste and post-processing time. This study details a novel process for conducting top-down SLA 3D printing from a thin resin layer located above a static immiscible supporting fluid, which reduces or eliminates the need for solid supports. The support fluid prevents deflection from buoyant and gravitational forces on thin overhangs from anchored parts due to minute density differences between the supporting fluid and cured resin, while reducing the volume of resin necessary to print compared to traditional top-down SLA. Using this process, printed geometry has been experimentally demonstrated with overhangs of up to 90 degrees. Additionally, necessary material properties of both fluids and process parameters of the system have been identified for the system’s feasibility and broader adaptation.
Fluid Interface Supported Printing is a design concept for the fabrication of three-dimensional structures based on stereolithographic processes, in which photopolymer resin is used to fabricate features from the controlled exposure of UV light in a fluid interface system. FISP utilizes the principles of stereolithography to guide the development of its systems, and this study details the exploration of those principles in relation to relevant gaps in literature. The motivation for this study is to explore the possible reduction of support structures necessary in the fabrication of three-dimensional parts through the reduction of forces associated with gravity and surface tension in stereolithography.