ADVANCED MATERIALS & PROCESSES | MAY/JUNE 2023 72 3D PRINTSHOP AMUG NAMES TECHNICAL COMPETITION WINNERS The Additive Manufacturing Users Group (AMUG) announces the winners of its annual Technical Competition, recognizing excellence in additive manufacturing applications and finishing techniques. A panel of industry veterans selected the University of Dayton Research Institute (UDRI) and Custom Prototypes as Advanced Concepts and Advanced Finishing winners, respectively. AMUG Members also selected UDRI for the Members’ Choice Award. The Technical Competition took place at the annual AMUG Conference in Chicago. Custom Prototypes’ winning entry in the Advanced Finishing category was titled “Tomlinsonus Dimitrii—the oldest fossil of marine animal ever found.” Representing the company’s entry, Daniel Goncalves and Jung Kyu Im spearheaded the work to bring the 450-million-year-old fossil back to life. In collaboration with a University of Toronto science team, the pair created a digital model of the fossil and then printed it with stereolithography. Goncalves and Im stated, “By carefully selecting the materials and post-processing systems, we managed to create various soft, hard, transparent, and opaque tissues of the animal.” The pair noted that Custom Prototypes developed a process that alters the properties of 3D-printed materials in terms of hardness and transparency. With the physical model complete, they then painstakingly prepared the piece and applied color to the delicate features of this sea creature. UDRI won the Advanced Concepts award for an additively manufactured micro-turbine engine submitted by Ben Loerke, who represented the organization’s engineering team. The micro- turbine project used additive manufacturing to produce and test the novel design that has only four main components: rotor, housing, nozzle, and starter-motor mount. The team reduced the part count by nearly 90% compared to traditional designs. Loerke added, “The long-term goal of this project is to fill a growing need for power plants that are sourced in a cost-effective and environmentally friendly manner. Based on a lifecycle analysis of the AM engine and similar traditional engines, it is believed that AM provides a unique opportunity to strike both of these criteria and fill this need in the micro-turbine engine market.” amug.com. INTRICATE 3D-PRINTED POROUS SURFACES Researchers from Tsinghua University, China, are developing a new way to create unique porous surfaces that mimic nature such as leaves, flowers, and human skin. In their paper published in Science, the researchers sought to replicate the way cells are arranged by creating digital lattices composed of tiny triangles and ribbons. They came to these shapes using an inverse design method (curved beam deformation theory) and developed an application to generate desired shapes using their digital lattices. The application was taught how to create such shapes using a machine-learning algorithm. They then printed out a pattern onto a base that could be folded into 3D shapes. The system allowed for creating a wide variety of structures with highly porous surfaces. The team demonstrated their system by first creating simple textured objects such as spheres. They then progressed to creating more complicated objects, such as a bell pepper, an ant, and an octopus. They also note that the objects can be made using a variety of materials, such as single crystal silicon, metals, chitosan, and laser-honed graphene. sciencemag.org. By optimizing the porosity distribution and the size of trian- gular unit cells, the circular markings on the body of cheetah can be well reproduced. Courtesy of Prof. Yihui Zhang/ Tsinghua University. Left, UDRI’s Advanced Concepts winning design of a micro-turbine engine, and right, Custom Prototype’s Advanced Finishing winning design of a marine fossil. Courtesy of AMUG.
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