Paper Number
AM2   Keynote                         My Program 

Session
Additive and Advanced Manufacturing

Title
Printability criterion for highly-filled inks for direct-ink write additive manufacturing

Presentation Date and Time
October 21, 2025 (Tuesday) 1:50

Track / Room
Track 5 / O’Keeffe + Milagro

Authors (Click on name to view author profile)

  1. Griebler, James J. (University of Illinois Urbana-Champaign, Chemical and Biomolecular Engineering)
  2. Kopatz, Jessica W. (Sandia National Laboratories)
  3. Rogers, Simon A. (University of Illinois Urbana-Champaign, Chemical and Biomolecular Engineering)
  4. Tappan, Alex S. (Sandia National Laboratories)
  5. Grillet, Anne M. (Sandia National Laboratories)

Author and Affiliation Lines (in printed abstract book)
James J. Griebler1, Jessica W. Kopatz2, Simon A. Rogers3, Alex S. Tappan2 and Anne M. Grillet2
1Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, IL 61801; 2Sandia National Laboratories, Albuquerque, NM 87123; 3Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, IL 61801

Speaker / Presenter 
Grillet, Anne M.

Keywords
experimental methods; additve manufacturing; applied rheology; industrial applications; particualte systems; suspensions; techniques

Text of Abstract
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 ability of an ink to be extruded onto a substrate in many layers and maintain the desired shape is what defines printability. Printability of inks has historically been investigated in an iterative manner by formulating and printing inks and then performing postmortem analysis of final parts. Our goal is to predict what range of particle loadings will print a high quality part. For applications with functional fillers, the challenge is to formulate inks with the highest possible particle loading that can still be printed. We have proposed a printability criterion based on the particle filler’s maximum packing fraction calculated from small amplitude oscillatory shear experiments. This printability criterion is demonstrated to predict the range of optimal particle loadings over a range of hard particle fillers and blends. We then utilize statistical methods to develop a filler characteristics model to predict the maximum packing fraction from particle analysis alone. These two methods paired together can significantly speed up development of new inks, increase the performance of material extrusion printing, and improve the stability of printed parts, with less wasted time and materials. 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. SAND2025-05725A