2026 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2026): Fabrication, Processing, and Functional Applications of Architected
Program Organizers: David Leigh, University of Texas at Austin
Tuesday 1:30 PM
August 4, 2026
Room: Comal
Location: AT&T Center
1:30 PM
Evaluation of TPMS-Based Lattices for Casting in Additively Manufactured Sand Molds using Process Simulation: Joseph Fisher1; C. R. Hasbrouck1; Joseph Bartolai1; 1Pennsylvania State University
TPMS-based lattices enable design opportunities for improving performance in structural and thermal applications, but their complex curvature, overhangs, varying thickness, and relatively thin walls make production using large format metal additive processes challenging. Sand casting is a mature and scalable process, but we cannot feasibly produce molds of TPMS-based lattices with traditional metalcasting patterns. Using binder jetting, sand molds with the overhangs and blind features needed for lattices can be produced directly without patterns. However, casting lattice structures comes with other potential concerns. The large surface area and tortuous paths for metal flow can lead to misruns, cold shuts, and other defects. This work studies the relative castability of different TPMS-based lattices to inform future sand casting design efforts. We compare both skeletal and surface TPMS-based lattices at matched volume fractions using otherwise identical part and gating design, simulating mold fill and solidification to assess defect formation and overall castability.
1:50 PM
Feasibility of Fabricating Metal Schwarz TPMS Structures Using Metal MEX Additive Manufacturing: Prakash Rai1; Bahram Asiabanpour1; 1Texas State University
This study investigates the technical and economic feasibility of fabricating Schwarz Triply Periodic Minimal Surface (TPMS) structures using Metal Material Extrusion (MEX) as a cost-effective alternative to conventional metal additive manufacturing methods. A parametric Schwarz TPMS geometry was developed through implicit modeling, with optimized unit cell size and lattice thickness to ensure structural stability and fabrication compatibility. The work focuses on the design and manufacturability of metallic TPMS structures by evaluating printing, debinding, and sintering conditions required for defect-free fabrication while preserving geometric integrity. Key printing parameters, debinding and sintering temperature profiles, were systematically analyzed to minimize cracking, distortion, and dimensional inaccuracies. The results demonstrate the potential of Metal MEX for producing complex metal TPMS geometries with improved accessibility and lower production cost, while offering suitability for atmospheric water generation (AWG) applications due to their high surface-area-to-volume ratio and enhanced heat and mass transfer characteristics.
2:10 PM
Stable Multilayer VTP Tubular Structures: Kelsey Snapp1; Brett Emery2; Jeffrey Lipton2; 1DEVCOM SC (Army); 2Northeastern University
Fabricating fine-scale cellular and lattice structures via extrusion-based additive manufacturing remains challenging due to inherent resolution constraints of the hardware. Viscous thread printing (VTP) exploits the predictable coiling instability of a viscous filament deposited from a translating nozzle, enabling cellular geometries at the scale of the printer's native capability. By controlling nozzle height and translation speed, various patterns can be produced. Of particular interest are translating coils that, when tightly overlapped, form tube-like three-dimensional structures from a single printed layer. However, these tubular structures are highly sensitive to surface irregularities, causing subsequent layers printed atop them fail to produce clean tube geometries due to the uneven surface of the preceding layer. This study systematically investigates VTP process parameters to identify conditions that yield consistent tubular structures robust enough for successful multilayer fabrication.
2:30 PM
Additive Manufacturing of Hair-like Materials: Design Principles, Process Constraints, and Manufacturing Strategies: Itzel Chavez Martinez1; Caleb Yuen1; Cade Clonts1; Zack Okun1; Andrew Sarrasin1; Alexander Potts1; Morgan Nunez1; Afsana Nizamudeen1; Ryan Duong1; Heather Emady1; Cahit Ozturk1; Dhruv Bhate1; 1Arizona State University
Whereas cellular materials such as honeycomb and lattices have received significant interest in the additive manufacturing (AM) community, these are just one of several classes of nature-inspired discrete architected materials. This work takes aim at one such understudied class of these materials: hair. Hair and hair-like materials have a wide functional basis in nature, from particle trapping to sensing – yet few engineering applications leverage this finest of nature’s innovations. This week reviews the literature that has been published on using AM processes (primarily fused deposition modeling and vat photopolymerization) to fabricate these slender, high aspect ratio structures, as well as the authors’ own studies in this area, to identify design principles, process constraints and manufacturing strategies when using AM to fabricate hair-like materials (HLM). The aim of this paper is to serve as a starting point for any researchers interested in using AM for the development of HLM.
2:50 PM
Cellular-Based Mechanical Interface (CMI) for Multi-Material Extrusion: Design Effectiveness of Triply-Periodic Minimal Surfaces (TPMS): Li Yang1; Aodirte Ghosh1; 1University of Louisville
Cellular-based mechanical interface (CMI) for multi-material bonding overcomes various challenges associated with the low compatibility of material pairs for multi-material extrusion processes. By incorporating cellular structure designs in the interface design, tailored mechanical properties could be potentially achieved, which allows for the design of multi-material interfaces with properties that are partially decoupled from the intrinsic material compatibility. In this research, the design characteristics of triply-periodic minimal surface (TPMS)-based CMIs were investigated via both experimental study and numerical simulations. Multiple TPMS designs including the gyroid, Schwartz-D and diamond were investigated, and the relationship between level set field parameters and the resulting interface properties were investigated. The results provide the foundational understanding of the design effectiveness of TMPS-based CMI designs. Furthermore, the results also allowed for the comparison of the differences of design characteristics between surface-based cellular designs and strut-based surface designs that were previously reported.
3:10 PM
Evaluating the Effects of Additively Manufactured Lattice Design on Electromagnetic Interference Shielding: Felix Cooper1; Nicholas Meisel2; Joseph Kubalak1; 1Penn State University Applied Research Laboratory; 2Penn State University
Electromagnetic interference (EMI) can disrupt electronics functionality, making EMI shielding essential in device packaging. Furthermore, lightweight solutions enable protection in weight-sensitive applications. Although material extrusion (MEX) additive manufacturing (AM) offers a limited range of EMI-shielding materials, it enables geometric complexity to produce low-cost, fast-turnaround solutions that boost EMI shielding through customizable designs. This study builds on prior EMI shield research and fabricates shields using MEX AM lattices. It uses short carbon fiber reinforced polymers and examines how lattice design variables affect EMI attenuation. Compared to other studies, this work examines a lower frequency range (0.3-1.5 GHz), used by communication, navigation, and various satellite and radio systems. Preliminary results show increased SE with decreased pore size and minimal effect from the addition of a conductive layer. The findings of this study will inform design guidelines for EMI shields tailored for specific frequency ranges and geometric requirements.