(17d) Rheological Characterization and Design of Highly-Filled Inks for Direct-Ink Write Additive Manufacturing

Additive manufacturing enables the creation of unique, custom-designed hardware in a relatively timely and inexpensive manner. Direct-ink write operates by extruding a particle-filled “ink” onto a substrate in a desired pattern via extrusion through a syringe. The ink is engineered with a yield stress to hold the shape of the extruded part. For applications with functional fillers, the challenge is to formulate inks with the highest possible particle loading that can still be printed. The flow behavior of the ink is strongly dependent on filler loading, size, morphology and packing fraction. We will explore how rheological characterization is more complex in the limit of highly filled inks and how rheology can inform understanding of printability.

Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.