2023 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2023): Process Development: Direct Ink Writing and Jetting
Program Organizers: Joseph Beaman, University of Texas at Austin
Wednesday 8:00 AM
August 16, 2023
Room: 408
Location: Hilton Austin
Session Chair: Richard Hague, University of Nottingham
8:00 AM Cancelled
Understanding Electrospray of MoS2 for Scalable Additive Manufacturing: Bo Shen1; Scott Williamson1; Wan Shou1; 1University of Arkansas
MoS2 is a promising functional material for various applications, including tribological coatings, and flexible electronics. While solution-based coating or printing can realize MoS2 additive manufacturing (AM), the evaporation of the solvent can affect the manufacturability, and post-drying can complicate the manufacturing process. In this paper, we introduce a dry powder-based electrospray process for scalable AM of MoS2 film and surface, which is critical for further functional applications. To achieve optimal performance, we will understand the electrospray process for dry MoS2 powder manufacturing, and establish the relationship between the manufacturing process (e.g., voltage, spray distance, and pressure) and structures (e.g., density, and uniformity).
8:20 AM
Thin Strand Printing of Silicone Ink with Direct Ink Write Process: Siddharthan Selvasekar1; Todd Weisgraber1; Joseph Bartolai2; Joshua Mendoza1; 1Lawrence Livermore National Laboratory; 2The Pennsylvania State University
Direct ink write AM of sub-millimeter diameter thixotropic elastomer struts is discussed. These thin strut films have use cases in applications such as soft robotics and flexible electronics. Consistent dimensional properties are important to ensure performance repeatability for high precision applications. The design features that are analyzed for quality are strut diameter and hatch spacing. Thin strut quality is measured using optical microscopy. Tool feed rate, material deposition rate, and deposition nozzle diameter are shown to each have an effect on thin strut quality. Experimental results for optimal process parameters for production of thin silicone elastomer struts are reported.
8:40 AM
Simulation Based Optimization for High Frequency Piezo-actuated Molten Metal Droplet Jetting: Kareem Tawil1; Irtaza Razvi1; David Trauernicht1; Denis Cormier1; 1Rochester Institute of Technology
Metal additive manufacturing via liquid metal droplet jetting has a range of potential advantages that include use of non-powder feedstock materials (ingot, rod, wire), the potential to fabricate non-weldable alloys, and high material deposition rates with fine feature resolution compared with other high-rate metal AM processes. Typical droplet jetting frequencies for the two commercially available LMJ systems are in the 300-450 Hz range. Inkjet document printers, on the other hand, routinely jet at frequencies in excess of 3 kHz. This talk will present results of multi-physics simulation modeling whose aim is to optimize both ejection chamber geometry and jetting waveforms to allow higher frequency jetting. Simulation results together with experimental validation using a piezo-actuated LMJ test fixture will be presented.
9:00 AM
Liquid Metal Jetting of Aluminum Parts with Salt Support Structures: Benedikt Kirchebner1; Christoph Weidner1; Maximilian Ploetz1; Christoph Rehekampff1; Wolfram Volk1; Philipp Lechner1; 1Technical University of Munich
Liquid metal jetting (LMJ) bears the potential of being a fast part manufacturing technology while using a cheap raw material. LMJ is a subtype of material jetting (MJT) and the parts are built by successively depositing droplets of molten metal onto a build platform. For full 3D capability, support structures are necessary which must be removed in subsequent processes. In previous investigations, we proposed the usage of water-soluble salt as a support material, selected a suitable salt, and analyzed the influence of this material on aluminum parts made in LMJ. In the present work, we show a duplex MJT print head for the processing of aluminum alloys and KCl-NaCl salt. Various printing strategies and support structure types are compared. The results show that the sequence of printing aluminum and salt is crucial. Furthermore, the use of thin layers of support material as a release layer appears promising.
9:20 AM
Further Developments of a Novel Low Cost Material Jetting platform for 3D Printing: Craig Sturgess1; 1Added Scientific Ltd
A talk on the progress of creating a low-cost Material Jetting platform focusing on removing the boundaries for researchers around the hardware cost and closed nature. This talk focuses on the potential advantages of having full control, open system. The system is designed to be simple to use, assemble, and of low cost. It combines the use of Xaar inkjet print heads, with Added Scientific drives and mounts, on a consumer grade FDM printer. This system enables four different materials to be printed, allowing for three unique build materials. The presentation follows the workflow of using a new material on a platform without a drop watcher and how through full control this process is greatly simplified. Finally, the results include data on the accuracy of printed parts, minimum feature sizes, and repeatability when using hobby level FDM platforms.
9:40 AM Break
10:10 AM
Exploring Additively Manufactured Heterostructures of Functional Materials: Focus on Interfaces: Jonathan Austin1; Feiran Wang1; Negar Gilani1; Yundong Zhou2; Gustavo Trindade2; Ian Gilmore2; Christopher Tuck1; Richard Hague1; Ricky Wildman1; Lyudmila Turyanska1; Geoffrey Rivers1; 1University of Nottingham; 2National Physical Laboratory
Inkjet 3D printing offers opportunities for additive manufacturing of multi-material electronic devices, which we successfully demonstrated previously with a variety of low dimensional material heterostructures: 2D/2D [Adv. Funct. Mater. 31, 2007478, 2021], 0D/2D [Nanoscale 15, 2134, 2023], 2D/polymer and 0D/polymer [Addit. Manuf. 66, 103452, 2023]. However, the performance of these devices strongly relies on the quality of the printed material interfaces, which are yet to be fully explored and understood. We explored the interfaces of inkjet-printed heterostructures based on combinations of 2D (graphene, hBN) and 0D (perovskite nanocrystals and metal nanoparticles) materials, and also conductive (PEDOT:PSS) and dielectric [PVP, PEG] polymers using complementary Time-of-Flight Secondary Ion Mass Spectrometry and Focused Ion Beam-Scanning Electron Microscopy, revealing infiltration and intermixing between layers. Furthermore, we examined the effects of the layer composition and deposition/post-deposition parameters on the quality of the interfaces, seeking to establish strategies for control of the interface properties.
10:30 AM
Effects of Double-pulse Waveform on Piezoelectric Inkjet Printing Speed: Chao Sui1; Wenchao Zhou1; 1University of Arkansas
Inkjet technology has gained widespread usage across various industrial applications due to its high resolution and versatility in printing with different materials. However, its printing speed has limited its application in high-volume production. This paper discusses the extension of a previously developed model for predicting the effects of a single-pulse driving signal on inkjet printing speed to include the effects of double-pulse waveforms. It is hypothesized that the use of double-pulse waveforms can further improve the printing speed of inkjet technology by producing large droplets at a higher frequency. The model is then used to understand the effects of double-pulse waveform parameters on the printing speed. Optimization is then performed to obtain parameters that can achieve maximum printing speed. The results are validated experimentally, which indicates the optimized double-pulse signal can successfully achieve jetting with a significant increase in equivalent printing speed compared to the single-pulse waveform.
10:50 AM
Development of Dual-head MetalJet System for Drop-on-demand Multi-metal Deposition: Xiangyun Gao1; Mark East1; Negar Gilani1; Marco Simonelli1; Nesma Aboulkhair1; Richard Hague1; 1University of Nottingham
Recent advancements in liquid metal deposition technologies have fostered innovative additive manufacturing solutions. This study introduces the MetalJet 3.0 system, a dual-head drop-on-demand (DoD) metal deposition platform, which advances upon previous MetalJet research to facilitate multi-material 3D printing in a single build process. The complex mechatronic control system combines an FPGA, integrating two independent deposition heads, an induction heater, a waveform generator, in-situ monitoring cameras, and high-precision linear stages with encoders in a LabVIEW program. The system applies Magnetohydrodynamics (MHD) to create jetting pulses and is equipped with a strobe camera to configure the jetting. This voxel-defined Drop-on-demand process has achieved an accuracy of 50um, giving it the potential to accelerate progress in materials and functional structures across industries such as microelectronics, robotics, and medical implants. Experimental evaluation using Sn in both heads asses printing accuracy and alignment. The dual-head DoD system exhibits promising potential in fabricating voxel-defined complex multi-material structures, free-standing structures and FGMs, underscoring its potential to revolutionize additive manufacturing.
11:10 AM
Investigation of Multi-Material Liquid Metal Jetting with Copper Materials: Maximilian Ploetz1; Florian Heckmeier1; Benedikt Kirchebner1; Wolfram Volk1; Philipp Lechner1; 1Technical University of Munich
Components are typically subject to a variety of requirements that may be in conflict with each other. Multi-material components can be a way to overcome such conflicting goals. For the manufacturing of multi-material copper components with high geometric complexity, Liquid Metal Jetting (LMJ) can be a promising additive manufacturing process. Since LMJ builds up a part droplet by droplet, there are no mixed powders after the building process. In addition, LMJ offers the possibility of changing materials from droplet to droplet. In previous studies, we have shown that it is possible to produce copper alloy components using LMJ. To investigate the manufacturing of multi-material copper components, we developed a duplex print head that can eject droplets of two different copper materials and produced multi-material copper parts. The investigations show that the quality of the compound and the microstructure depend significantly on the thermal process parameters used.
11:30 AM
Comparison of High-resolution Aerosol Jet Printing of Silver Inductors on Rotary and Linear Stages: Max Tafoya1; Joshua Tarantino1; Alfred Thibodeaux1; Lok-Kun Tsui2; Yongkun Sui1; Judith Lavin1; 1SNL New Mexico - Albuquerque; 2University of New Mexico
Aerosol Jet Printing (AJP), a direct write form of additive manufacturing, enables versatile and high-resolution fabrication of printed electronics. Inductors, one of the types of passive electrical components, are used in printed transformers, wireless charging, torque sensors, and electromagnets, etc. AJP can deposit conductive lines with a width of 10–50 microns. For spiral inductor fabrication, the smoothness of the spiral arc determines the smallest pitch. With commonly used X-Y linear stages, the smoothness of arc is limited by the resolution of the motor and the tuning of motion parameters (speed, acceleration, etc.). This work will demonstrate high resolution AJP of silver inductors using a polar system consisting of rotary and linear stages. A comparison of spirals printed using cartesian and polar systems will be made by microscopy and profilometry. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.