TY - CHAP A1 - Gersch, Sebastian A1 - Schulz, Carsten A1 - Kral, Christopher T1 - Verifizierung der Prozessstabilität einer konstruierten WAAM-Anlage zum Induzieren von Eigenspannungen in generativ gefertigten Strukturen T2 - 9. Mitteldeutsches Forum - 3D-Druck in der Anwendung: 29. Juni 2022, Jena N2 - Heutzutage werden Strukturen häufig aufwendig konstruiert und nachträglich mithilfe von numerischen Verfahren optimiert. Dennoch kommt es zu erheblichen Schäden infolge von Ermüdungsbrüchen bei wechselnd beanspruchten Bauteilen. Ein Großteil dieser Schäden hat den Ursprung in den im Inneren herrschenden Spannungszuständen, den sogenannten Eigenspannungen. Diese Eigenspannungen heben sich innerhalb des Bauteils auf und führen zu keiner Formabweichung des Bauteils, weswegen diese Spannungen in Form und Lage nur schwer detektierbar sind und sich häufig negativ auf die Betriebsfestigkeit von Strukturen auswirken. Mithilfe neuartiger numerischer Methoden können thermomechanische Simulationen angefertigt und Verformungen, sowie Spannungszustände abgeleitet werden. Durch diese Optionen ergeben sich neue Anwendungen, die das Potenzial von Fertigungsverfahren in Hinblick auf die Ausnutzung spezieller Eigenschaften neu eröffnen. Durch die geschickte Anwendung und Vernetzung der Simulation mit der Fertigung können Eigenspannungen gezielt in Lage und Richtung schon während der Produktion des Bauteils eingebracht werden. Im theoretischen Vergleich zu konventionell gefertigten Bauteilen entstehen Strukturen, die hinsichtlich ihrer Bauteillebensdauer optimiert sind. KW - 3D-Druck KW - Eigenspannungen KW - Betriebsfestigkeit Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-56006 ER - TY - JOUR A1 - Lorenz, Björn T1 - Cardboard Engineering 2.0 JF - Zeitschrift für wirtschaftlichen Fabrikbetrieb : ZWF N2 - Das Material Karton ist in heutigen Fertigungen für die schnelle Umsetzung von Ideen aus einem Kaizen-Prozess ein gängiger Werkstoff. Die Vorgehensweise wird auch als Cardboard Engineering bezeichnet. Aber die Entwicklung geht weiter. Die immer weiter verbreiteten 3D-Drucktechnologien ermöglichen die schnelle Generierung von Vorrichtungen, die deutlich höhere Anforderungen hinsichtlich Präzision, Robustheit und Komplexität erfüllen. KW - 3D-Druck KW - Herstellungssystem KW - Kaizen KW - Karton KW - kontinuierlicher Verbesserungsprozess KW - Kunststoff KW - Losgröße KW - Modellherstellung KW - Montageteil KW - Pappe Y1 - 2014 U6 - https://doi.org/10.3139/104.111083 VL - 109 IS - 1/2 SP - 26 EP - 28 PB - De Gruyter CY - Berlin ER - TY - CHAP A1 - Seppenhauser, P. ED - Mottok, Jürgen ED - Reichenberger, Marcus T1 - Examinations of the Printer Head Prototype for UV Resins with Continous Fiber-Reinforcement T2 - Applied Research Conference 2019 - ARC 2019, 8 July 2019, Regensburg KW - 3D-Druck KW - Druckkopf KW - Kunstharz KW - Faserverstärkter Kunststoff Y1 - 2019 SN - 978-3-96409-182-6 SP - 241 EP - 248 PB - Pro Business GmbH CY - Berlin ER - TY - CHAP A1 - Afanasev, Anna ED - Mottok, Jürgen ED - Reichenberger, Marcus T1 - Force-oriented 3D printing of continuous fiber-reinforced plastic structures T2 - Applied Research Conference 2019 - ARC 2019, 08 July 2019, Regensburg KW - Faserverbundwerkstoff KW - 3D-Druck Y1 - 2019 SN - 978-3-96409-182-6 SP - 213 EP - 218 PB - Pro Business GmbH CY - Berlin ER - TY - CHAP A1 - Dendorfer, Sebastian A1 - Feldotto, Benedikt A1 - Walch, Blasius A1 - Koch, Patrick A1 - Knoll, Alois T1 - Co-Development of an Infant Prototype in Hardware and Simulation based on CT Imaging Data T2 - IEEE International Conference on Cyborg and Bionic Systems (CBS), 2019, Munich N2 - The development of biomimetic robots has gained research interest in the last years as it may both help under-standing processes of motion execution in biological systems as well as developping a novel generation of intelligent and energy efficient robots. However, exact model generation that builds up on observations and robot design is very time intensive. In this paper we present a novel pipeline for co-development of biomimetic hardware and simulation models based on biological Computer Tomography (CT) data. For this purpose we exploit State of the Art rapid prototyping technologies such as 3D Printing and the Neurorobotics Platform for musculoskeletal simulations in virtual environments. The co-development integrates both advantages of virtual and physical experimental models and is expected to increase development speed of controllers that can be tested on the simulated counterpart before application to a printed robot model. We demonstrate the pipeline by generating a one year old infant model as a musculoskeletal simulation model and a print-in-place 3D printed skeleton as a single movable part. Even though we hereonly introduce the initial body generation and only a first testsetup for a modular sensory and control framework, we can clearly spot advantages in terms of rapid model generation and highly biological related models. Engineering costs are reducedand models can be provided to a wide research community for controller testing in an early development phase. KW - Biomechanische Analyse KW - Robotik KW - Computertomographie KW - 3D-Druck Y1 - 2019 UR - http://mediatum.ub.tum.de/doc/1520042/985669104579.pdf ER - TY - GEN A1 - Maier, Johannes A1 - Weiherer, Maximilian A1 - Huber, Michaela A1 - Palm, Christoph ED - Handels, Heinz ED - Deserno, Thomas M. ED - Maier, Andreas ED - Maier-Hein, Klaus H. ED - Palm, Christoph ED - Tolxdorff, Thomas T1 - Abstract: Imitating Human Soft Tissue with Dual-Material 3D Printing T2 - Bildverarbeitung für die Medizin 2019, Algorithmen - Systeme - Anwendungen. Proceedings des Workshops vom 17. bis 19. März 2019 in Lübeck N2 - Currently, it is common practice to use three-dimensional (3D) printers not only for rapid prototyping in the industry, but also in the medical area to create medical applications for training inexperienced surgeons. In a clinical training simulator for minimally invasive bone drilling to fix hand fractures with Kirschner-wires (K-wires), a 3D printed hand phantom must not only be geometrically but also haptically correct. Due to a limited view during an operation, surgeons need to perfectly localize underlying risk structures only by feeling of specific bony protrusions of the human hand. KW - Handchirurgie KW - 3D-Druck KW - Lernprogramm KW - HaptiVisT Y1 - 2019 SN - 978-3-658-25325-7 U6 - https://doi.org/10.1007/978-3-658-25326-4_48 SP - 218 PB - Springer Vieweg CY - Wiesbaden ER - TY - JOUR A1 - Maier, Johannes A1 - Weiherer, Maximilian A1 - Huber, Michaela A1 - Palm, Christoph T1 - Optically tracked and 3D printed haptic phantom hand for surgical training system JF - Quantitative Imaging in Medicine and Surgery N2 - Background: For surgical fixation of bone fractures of the human hand, so-called Kirschner-wires (K-wires) are drilled through bone fragments. Due to the minimally invasive drilling procedures without a view of risk structures like vessels and nerves, a thorough training of young surgeons is necessary. For the development of a virtual reality (VR) based training system, a three-dimensional (3D) printed phantom hand is required. To ensure an intuitive operation, this phantom hand has to be realistic in both, its position relative to the driller as well as in its haptic features. The softest 3D printing material available on the market, however, is too hard to imitate human soft tissue. Therefore, a support-material (SUP) filled metamaterial is used to soften the raw material. Realistic haptic features are important to palpate protrusions of the bone to determine the drilling starting point and angle. An optical real-time tracking is used to transfer position and rotation to the training system. Methods: A metamaterial already developed in previous work is further improved by use of a new unit cell. Thus, the amount of SUP within the volume can be increased and the tissue is softened further. In addition, the human anatomy is transferred to the entire hand model. A subcutaneous fat layer and penetration of air through pores into the volume simulate shiftability of skin layers. For optical tracking, a rotationally symmetrical marker attached to the phantom hand with corresponding reference marker is developed. In order to ensure trouble-free position transmission, various types of marker point applications are tested. Results: Several cuboid and forearm sample prints lead to a final 30 centimeter long hand model. The whole haptic phantom could be printed faultless within about 17 hours. The metamaterial consisting of the new unit cell results in an increased SUP share of 4.32%. Validated by an expert surgeon study, this allows in combination with a displacement of the uppermost skin layer a good palpability of the bones. Tracking of the hand marker in dodecahedron design works trouble-free in conjunction with a reference marker attached to the worktop of the training system. Conclusions: In this work, an optically tracked and haptically correct phantom hand was developed using dual-material 3D printing, which can be easily integrated into a surgical training system. KW - Handchirurgie KW - 3D-Druck KW - Lernprogramm KW - Zielverfolgung KW - HaptiVisT KW - Dual-material 3D printing KW - hand surgery training KW - metamaterial KW - tissue imitating phantom hand Y1 - 2020 U6 - https://doi.org/10.21037/qims.2019.12.03 N1 - Corresponding author: Christoph Palm VL - 10 IS - 02 SP - 340 EP - 455 PB - AME Publishing Company CY - Hong Kong, China ER - TY - JOUR A1 - Maier, Johannes A1 - Weiherer, Maximilian A1 - Huber, Michaela A1 - Palm, Christoph T1 - Imitating human soft tissue on basis of a dual-material 3D print using a support-filled metamaterial to provide bimanual haptic for a hand surgery training system JF - Quantitative Imaging in Medicine and Surgery N2 - Background: Currently, it is common practice to use three-dimensional (3D) printers not only for rapid prototyping in the industry, but also in the medical area to create medical applications for training inexperienced surgeons. In a clinical training simulator for minimally invasive bone drilling to fix hand fractures with Kirschner-wires (K-wires), a 3D-printed hand phantom must not only be geometrically but also haptically correct. Due to a limited view during an operation, surgeons need to perfectly localize underlying risk structures only by feeling of specific bony protrusions of the human hand. Methods: The goal of this experiment is to imitate human soft tissue with its haptic and elasticity for a realistic hand phantom fabrication, using only a dual-material 3D printer and support-material-filled metamaterial between skin and bone. We present our workflow to generate lattice structures between hard bone and soft skin with iterative cube edge (CE) or cube face (CF) unit cells. Cuboid and finger shaped sample prints with and without inner hard bone in different lattice thickness are constructed and 3D printed. Results: The most elastic available rubber-like material is too firm to imitate soft tissue. By reducing the amount of rubber in the inner volume through support material (SUP), objects become significantly softer. Without metamaterial, after disintegration, the SUP can be shifted through the volume and thus the body loses its original shape. Although the CE design increases the elasticity, it cannot restore the fabric form. In contrast to CE, the CF design increases not only the elasticity but also guarantees a local limitation of the SUP. Therefore, the body retains its shape and internal bones remain in its intended place. Various unit cell sizes, lattice thickening and skin thickness regulate the rubber material and SUP ratio. Test prints with higher SUP and lower rubber material percentage appear softer and vice versa. This was confirmed by an expert surgeon evaluation. Subjects adjudged pure rubber-like material as too firm and samples only filled with SUP or lattice structure in CE design as not suitable for imitating tissue. 3D-printed finger samples in CF design were rated as realistic compared to the haptic of human tissue with a good palpable bone structure. Conclusions: We developed a new dual-material 3D print technique to imitate soft tissue of the human hand with its haptic properties. Blowy SUP is trapped within a lattice structure to soften rubber-like 3D print material, which makes it possible to reproduce a realistic replica of human hand soft tissue. KW - Dual-material 3D printing KW - Hand surgery training KW - Metamaterial KW - Support material KW - Tissue-imitating hand phantom KW - Handchirurgie KW - 3D-Druck KW - Biomaterial KW - Lernprogramm Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-979 N1 - Corresponding author: Christoph Palm VL - 9 IS - 1 SP - 30 EP - 42 PB - AME Publishing Company ER -