SBIR Phase I: Novel Extrusion System for Additive Manufacturing of Engineered Lattice Structures

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase I project is to support the use of sustainable materials, stronger parts, and material savings in Large Format Additive Manufacturing for the Aerospace and Defense Industry. The technology has the potential to reduce printing time and energy consumption. It could also enable the printing of complex geometries at a scale not currently accessible in the manufacturing industry. The intellectual merit of this project is to address the two biggest technical challenges customers face in the Large Format Additive Manufacturing industry: low-strength in the Z-direction, and high surface porosity. This project is developing two innovative solutions to address these technical challenges. The first innovation is using multiple independently articulated nozzles to print a part through a non-planar printing approach. During proof-of-concept experiments, this innovation has shown success for non-planar fiber alignment. It shows the potential to improve strength in the Z-direction, by custom fiber alignment in the direction of loading. For the second innovation, a nozzle design will be developed to heat printed material through the nozzles. A prototype for this technology has already shown a 30-40% increase in strength for ASTM D-638 tensile test specimens. It is hypothesized that the increase in strength is due to decrease in porosity, improved layer bonding, and polymer entanglement, which can solve the second big challenge for Large Format Additive Manufacturing. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.