Abstract

Addressing Key Challenges in Multi-Material and Multi-scale Digital Projection Stereolithography

Pranav Soman, Professor, Biomedical and Chemical Engineering , Syracuse University

This presentation will include two research projects conducted at Syracuse University and few outreach slides related to opportunities at NSF for the Additive Manufacturing community. First project, entitled, Multi-material Gradient Printing Using Meniscus-enabled Projection Stereolithography (MAPS) addresses current challenges related to vat based multi-material printing associated with hardware modifications, control systems, cross-contamination, waste, and resin properties. MAPS is a vat-free method that relies on generating and maintaining a resin meniscus between a cross-linked structure and bottom window to print lateral, vertical, discrete, or gradient multi-material 3D structures with no waste and user-defined mixing between layers. We show that MAPS can print 3D structures with gradient properties in mechanical stiffness, opacity, surface energy, cell densities, and magnetic properties. Second project, entitled Multipath projection stereolithography (MPS) addresses the inherent tradeoffs between print resolution, design complexity, and built sizes. Inspired by microscopes that could switch objectives to achieve multi-scale imaging, we report a new optical printer coined as MPS specifically designed for printing microfluidic devices. MPS is designed to switch between high- and low-resolution optical paths to generate centimeter sized constructs (3cm x 6cm) with a feature resolution of ~10µm. Using a test-case of micromixers, we show user-defined CAD models can be directly input to an automated slicing software to define printing of low-resolution features with embedded micro-scale fins. A new computational model, validated using experimental results, was used to simulate various fin designs and experiments were conducted to verify simulated mixing efficiencies.