Production of Materials with Spatially-Controlled Cross-Link Density via Vat Photopolymerization.
We describe an efficient method to produce objects comprising spatially controlled and graded cross-link densities using vat photopolymerization additive manufacturing (AM). Using a commercially available diacrylate-based photoresin, 3D printer, and digital light processing (DLP) projector, we projected grayscale images to print objects in which the varied light intensity was correlated to controlled cross-link densities and associated mechanical properties. Cylinder and bar test specimens were used to establish correlations between light intensities used for printing and cross-link density in the resulting specimens. Mechanical testing of octet truss unit cells in which the properties of the crossbars and vertices were independently modified revealed unique mechanical responses from the different compositions. From the various test geometries, we measured changes in mechanical properties such as increased strain-to-break in inhomogeneous structures in comparison with homogeneous variants.
Department of Chemistry, University of Washington , Seattle, Washington 98195, United States.
Gregory I
GI
Peterson
Department of Chemistry, University of Washington , Seattle, Washington 98195, United States.
Johanna J
JJ
Schwartz
Mechanical Engineering, University of Washington , Seattle, Washington 98195, United States.
Di
D
Zhang
Mechanical Engineering, University of Washington , Seattle, Washington 98195, United States.
Benjamin M
BM
Weiss
Mechanical Engineering, University of Washington , Seattle, Washington 98195, United States.
Mark A
MA
Ganter
Mechanical Engineering, University of Washington , Seattle, Washington 98195, United States.
Duane W
DW
Storti
Department of Chemistry, University of Washington , Seattle, Washington 98195, United States.
Andrew J
AJ
Boydston
additive manufacturing; function-based representations; graded materials; vat photopolymerization; voxel model