November 8-12, 2015
The ability to pattern complex materials with high-speed and low-cost three-dimensional (3D) printing techniques is highly desirable. Here, we present progress on developing siloxane-based feedstock formulations, known as “inks,” for a unique 3D printing approach called Direct Ink Writing (DIW). DIW is a low-cost, mask-less printing route that enables rapid design and patterning of planar and three-dimensional (3D) microstructures. In this filamentary printing approach, a concentrated ink with tailored viscoelastic properties is deposited through a micro-nozzle that is translated using a multi-axis positioning stage. The ink rapidly solidifies as it is extruded so that 3D structures with fine features may be built up in a layer-by-layer fashion. We introduce the concept of tailoring the macro-scale mechanical properties by designing the 3D micro-architecture of the printed cellular silicone materials. We show the ability to obtain highly uniform or graded properties by simply adjusting the pattern design. Moreover, by understanding the materials-structure-processing property relationships, we have created a modeling-design-fabrication approach to achieve tailored mechanical properties. For example, we have created porous architectures that, in one case, are well suited for pure compression and, in a separate case, are better suited for shear environments. We expect that the ability to deterministically program mechanical performance from part-to-part and within a part will prove useful for many applications.
Eric Duoss, Todd Weisgraber, Christopher Spadaccini, and Thomas Wilson, "Additive manufacturing of cellular materials with tailored properties" in "Composites at Lake Louise (CALL 2015)", Dr. Jim Smay, Oklahoma State University, USA Eds, ECI Symposium Series, (2016). http://dc.engconfintl.org/composites_all/27