2026 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2026): Novel Processes
Program Organizers: David Leigh, University of Texas at Austin
Tuesday 8:00 AM
August 4, 2026
Room: Zlotnick Ballroom 5
Location: AT&T Center
8:00 AM
Geometry-Dependent Sintering Nonuniformity in Radio Frequency Additive Manufacturing: A Computational Framework for Process Compensation: Matthew McCoy1; Christopher Saldaña1; Carolyn Seepersad1; 1Georgia Institute of Technology
Radio Frequency Additive Manufacturing (RFAM) is an emerging polymer sintering process that adapts RF heating, traditionally used to energize bulk material volumes, into a spatially controlled additive manufacturing platform. By selectively inkjet-depositing a lossy dopant into a nylon-12 powder-bed layerwise, RFAM enables patterned volumetric sintering driven by an RF field that couples preferentially with the dopant, melting surrounding powder in three dimensions simultaneously. Having established precise dopant patterning control through a custom-developed printer, the next frontier is computational process control. The RF field distribution is geometry-dependent, i.e., field concentration near corners and edges drives non-uniform energy deposition that varies with cross-sectional shape. HEATR (High-frequency Electrothermal Additive Thermal Resolver), a coupled electroquasistatic–transient thermal simulation framework, predicts and compensates for this behavior. HEATR informs simulation-driven strategies including functional dopant grading at the droplet scale, ILT-inspired input image pre-distortion, and rotational field averaging, establishing a computational foundation for geometry-agnostic, dimensionally faithful RFAM sintering.
8:20 AM
Physical Validation of an On-Demand Resin Characterization and Process Planning Framework: Daphne Lin1; Mohammad Zamani2; Brandon Yu1; Zoubeida Ounaies2; Carolyn Seepersad1; 1Georgia Institute of Technology; 2The Pennsylvania State University
Functional grading of materials through extrusion-based processes such as Reactive Extrusion Additive Manufacturing (REAM) enables fabrication of designs with embedded complex behaviors. The difficulty of functional grading arises from constant changes and transitions between material compositions, leading to instabilities in the printing process and decreased part quality. Additionally, experimental characterization of materials and process tuning would be too costly, as the number of potential material compositions requested in functional grading is too large. As such, an on-demand resin characterization and process planning framework was developed to functionally grade magneto-active particles for a REAM process. This work presents the framework and its validation. Leave-One-Out validation (LOOV) and rheological measurements through viscometry were conducted to validate the characterization portion of the framework. A comparison of geometric fidelity of a framework-informed print with both a naïve approach print and single-resin print was conducted to validate the process planning portion of the framework.
8:40 AM
Reactive Extrusion Additive Manufacturing (REAM) of PDMS Using a Supportive Bath: Brandon Yu1; Hongtao Song1; Carolyn Seepersad1; 1Georgia Institute of Technology
Reactive extrusion additive manufacturing (REAM) has relied on epoxy-based materials, which are rigid and unsuitable for prolonged skin contact, limiting their use in many applications. This work introduces an elastomeric alternative, Dragon Skin Very Fast polydimethylsiloxane (PDMS), to expand the material capabilities of the REAM platform. Due to its low shape integrity prior to curing, PDMS lacks the structural integrity required for unsupported printing, constraining achievable geometries. To address this limitation, an inert support bath composed of silicone oil with a fumed silica modifier is implemented. The bath is chemically compatible with both PDMS and epoxy systems and provides mechanical support during deposition. This study systematically evaluates print fidelity with and without the support bath, characterizes the rheological behavior of the bath material, and compares the mechanical properties of printed specimens. The results demonstrate the feasibility of incorporating elastomeric, biocompatible materials into REAM, enabling the fabrication of complex, compliant structures.
9:00 AM
Hybrid 3D Printing Technique for Nylon–Silicone Multi-Material Structures Through Dissolvable Molds: Gianni Stano1; Andrea Ladisa1; Gianluca Percoco1; Douglas Smith2; 1Polytechnic of Bari; 2Baylor University
This research presents a hybrid 3D-printing technology combining multi-material extrusion with automated silicone injection to fabricate soft-rigid structures. The method uses dual extrusion of Nylon as the rigid material and water-soluble Polyvinyl Alcohol (PVA) as a sacrificial mold. During the same printing cycle, a nozzle integrated with the printhead injects silicone into the PVA mold through an automated system controlled by g-code and a syringe pump. After silicone curing, printing resumes, and the process can be repeated to create intricate architectures. Once fabrication is completed, the component is immersed in water to dissolve the PVA and reveal the final structure. Simulations and mechanical testing demonstrate that optimized Nylon-silicone interface geometries enhance joint strength between the two materials. This technology bridges 3D printing and silicone injection molding, enabling the accessible fabrication of bio-inspired systems with rigid segments interconnected by flexible silicone joints for advanced soft robotic applications.
9:20 AM
Development of an Inkjet Printing Process to Produce Interpenetrating Polymer Networks with Multiscale Heterogeneity for Additively Manufactured Electronics Applications: Steven DiGregorio1; Georgia Kaufman1; Meghan Kiker1; Emily Huntley1; Benjamin Skultety2; Leah Appelhans1; Adam Cook1; 1Sandia National Laboratories; 2University of Pittsburgh
Inkjet printing is a leading technique for fabricating additively manufactured electronics (AME) due to its design flexibility, high resolution, and scalability. Most commercial AME inkjet systems co-deposit a conductive silver ink and a single photo-curable polymer dielectric ink to build electronic components layer-by-layer. A main limitation is the brittleness of the polymer materials. To address this, we investigate co-jetting two polymer systems to form interpenetrating polymer networks (IPNs), which can achieve superior mechanical and thermal properties over individual polymers. Most commercial inkjet systems have closed hardware and software, limiting such experiments. This presentation focuses on developing a custom multi-material inkjet printing platform designed to facilitate the engineering of multiscale heterogeneity with IPNs. Main topics include printer design and implementation, printing strategies for multiscale heterogeneity, and exploring process parameters to optimize droplet spacing, line widths, and ink spreading/mixing. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.
9:40 AM Break
10:00 AM
Distortion Minimization In Deposition of Continuous Carbon Fibers On Non-Planar Surfaces: Nidhi Munaganuru1; David Trauernicht1; Denis Cormier1; 1Rochester Institute of Technology
This paper explores the topic of 5-axis continuous fiber toolpath generation for reinforcing curved surfaces. When simple 2D unidirectional fiber routing patterns are projected onto non-planar surfaces, the fiber spacing can increase or decrease depending on local curvature of the surfaces. This paper presents algorithms that wrap 2D fiber patterns onto 3D surfaces via coordinate remapping techniques used in the computer graphics industry. The result is fiber routings in which fiber distortions in fiber spacings are minimized. The algorithms will be presented along with preliminary experimental results.
10:20 AM
Development of Multi-Laser Powder Bed Fusion Additive Manufacturing Testbed: Ho Yeung1; Zhuo Yang1; 1NIST
While Laser Powder Bed Fusion (LPBF) is widely adopted for complex metal geometries, industrial growth is hindered by low build rates and thermal instability. Most multi-laser systems merely assign separate lasers to different regions to increase productivity. In contrast, this study utilizes coordinated multi-laser processing on a single part to enable advanced thermal management, such as pre-heating and dynamic gradient control. This work demonstrates a dual-laser LPBF framework built on the Simple Additive Manufacturing (SAM) architecture and implemented on the NIST Additive Manufacturing Metrology Testbed (AMMT). The system achieves precise spatial and temporal synchronization through integrated calibration and real-time control. Experimental results demonstrate synchronized, lead–follow, and parallel operational modes. These capabilities provide critical opportunities to mitigate defects, reduce residual stress, and improve process stability for high-power, multi-laser LPBF applications.
10:40 AM
Bridging Micro-Scale Behavior and Component Level Qualification in Additively Manufactured Metallic Components: Prudhvi Raj Pola1; Kaustubh Deshmukh2; Olukayode Fatoki3; Santhosh Parupelli3; Prahalada Rao2; Salil Desai3; Ranji Vaidyanathan1; 1Oklahoma State University; 2Virginia Tech; 3North Carolina A&T State University
Additive manufacturing (AM) is transforming industries, but qualifying AM parts remains challenging due to the lengthy and costly nature of traditional mechanical testing. This is mainly due to the anisotropy and heterogeneity of AM materials from layer-wise deposition, localized thermal histories, and unique subsurface defects. These factors cause spatial variability in mechanical properties linked to process parameters and geometry. This work presents a micro-scale testing framework to assess local mechanical behavior in additively manufactured metals. Miniature tensile specimens (3 mm × 1 mm × 0.25 mm) from various AM regions are used to measure stiffness, yield strength, ultimate tensile strength, and strain-to-failure, and results are correlated with microstructure and thermal history. Capturing local variability supports more accurate structure–property–process relationships and enables creation of a global property matrix for lifetime prediction under different conditions. This method offers a rapid, efficient way to evaluate AM components and reduce qualification costs.
11:00 AM
Parametric Workflow Design for Rotational Friction Welding of Complex Metal Additively Manufactured Geometries: Matas Kliukas1; August Hausting2; Fatma Nur Depboylu1; Andrei Alexandru Popa1; 1University of Southern Denmark; 2Aviatec
Hybrid integration of Laser-Powder Bed Fusion (L-PBF) with Rotational Friction Welding (RFW) enables the manufacturing of complex assemblies, utilizing the full potential of Additive Manufacturing (AM). However, RFW is conventionally restricted to cylindrical geometries due to strict coaxial alignment and chuck-clamping requirements, resulting in a limited application. The proposed study presents a semi-automated parametric workflow for generating custom holding structures that allow non-standard geometries to undergo RFW. Implemented in a graphical programming environment using implicit modelling, the workflow analyses input geometry and generates a structure. To take full advantage of AM capabilities, the structure incorporates an internally graded lattice, reducing material usage, manufacturing time, and thermal artifacts associated with large solid L-PBF builds. The workflow was validated by generating a holding structure, successfully RFW a non-circular geometry and evaluating the joint with material testing and microstructure analysis. This work demonstrates a scalable path toward hybrid AM-RFW fabrication of complex components.
11:20 AM
Design and Experimental Validation of a Dual Halbach Cylinder for Magnetic Field Assisted Additive Manufacturing.: Sk Sazin Ahmed1; Josh Bosque1; Luke Thibodeaux1; James Villines1; Leo Rodriguez1; Jitendra Tate1; Wilhelmus Geerts1; Muntasir Rashid1; 1Texas State University
A compact dual Halbach cylinder system for Magnetic Field Assisted Additive Manufacturing of Magnetic composites was designed and realized. The Halbach’s magnetic field is tunable (0-1373 Oe) and generates a uniform magnetic field (deltaH<10% across a 2 cm diameter at Hmax), through the relative rotation of two Halbach cylinders. No power supply is required to control the magnetic field direction and magnitude. Three-dimensional finite element simulations were conducted using COMSOL Multiphysics to define the geometry, optimize magnet orientation, and calculate bore field and field uniformity. An additive-manufactured PLA design was realized with an outer cylinder of 16 and an inner cylinder of 12 NdFeB 0.5”-cube magnets, and characterized using a Gauss probe. The design enabled manual rotation and reduced field gradients to limit sedimentation in a strontium-ferrite resin suspension over 30 minutes, providing a practical magnetic platform for SLA MFAAM using a 2 cm diameter VAT.
11:40 AM
Hybrid Additive Manufacturing of High-Performance Materials: from Prototype to Production: Dan Davie1; Matthew Shuttleworth2; Louis Masters2; Mateusz Gora1; Girish Kale1; Robert Kay1; 1University of Leeds; 2Hydra Manufacturing
Despite growing industrial demand for high-performance materials, most ceramic and refractory metal additive manufacturing routes are limited by process constraints. This work outlines a ceramic hybrid additive manufacturing platform (CHAMP) that integrates paste extrusion, green-state machining, and process monitoring within a single system. CHAMP has been proven for a range of technical ceramics, and we now demonstrate its ability to produce cemented tungsten carbide (WC-10Co-4Cr), a material traditionally considered extremely challenging to additively manufacture.Using CHAMP followed by thermal consolidation, components were produced with ~25% linear shrinkage, sintered densities of 12.35 g/cm³, flexural strength of 573 MPa and Vickers hardness of 1430 HV10, without mechanical post processing. These properties enable application in high wear, high temperature environments, with improvements expected with further densification such as using HIP. This work demonstrates the CHAMP technology as a flexible and scalable route for transitioning additive manufacturing of high-performance materials from prototyping to production.