TY - GEN A1 - Kovacs, Robert A1 - Ion, Alexandra A1 - Lopes, Pedro A1 - Oesterreich, Tim A1 - Filter, Johannes A1 - Otto, Philip A1 - Arndt, Tobias A1 - Ring, Nico A1 - Witte, Melvin A1 - Synytsia, Anton A1 - Baudisch, Patrick T1 - TrussFormer BT - 3D Printing Large Kinetic Structures T2 - UIST '18: Proceedings of the 31st Annual ACM Symposium on User Interface Software and Technology N2 - We present TrussFormer, an integrated end-to-end system that allows users to 3D print large-scale kinetic structures, i.e., structures that involve motion and deal with dynamic forces. TrussFormer builds on TrussFab, from which it inherits the ability to create static large-scale truss structures from 3D printed connectors and PET bottles. TrussFormer adds movement to these structures by placing linear actuators into them: either manually, wrapped in reusable components called assets, or by demonstrating the intended movement. TrussFormer verifies that the resulting structure is mechanically sound and will withstand the dynamic forces resulting from the motion. To fabricate the design, TrussFormer generates the underlying hinge system that can be printed on standard desktop 3D printers. We demonstrate TrussFormer with several example objects, including a 6-legged walking robot and a 4m-tall animatronics dinosaur with 5 degrees of freedom. KW - Fabrication KW - 3D printing KW - variable geometry truss KW - large scale mechanism Y1 - 2018 SN - 978-1-4503-5948-1 U6 - https://doi.org/10.1145/3242587.3242607 SP - 113 EP - 125 PB - Association for Computing Machinery CY - New York ER - TY - JOUR A1 - Schneider, Matthias A1 - Günter, Christina A1 - Taubert, Andreas T1 - Co-deposition of a hydrogel/calcium phosphate hybrid layer on 3D printed poly(lactic acid) scaffolds via dip coating BT - Towards Automated Biomaterials Fabrication JF - Polymers N2 - The article describes the surface modification of 3D printed poly(lactic acid) (PLA) scaffolds with calcium phosphate (CP)/gelatin and CP/chitosan hybrid coating layers. The presence of gelatin or chitosan significantly enhances CP co-deposition and adhesion of the mineral layer on the PLA scaffolds. The hydrogel/CP coating layers are fairly thick and the mineral is a mixture of brushite, octacalcium phosphate, and hydroxyapatite. Mineral formation is uniform throughout the printed architectures and all steps (printing, hydrogel deposition, and mineralization) are in principle amenable to automatization. Overall, the process reported here therefore has a high application potential for the controlled synthesis of biomimetic coatings on polymeric biomaterials. KW - 3D printing KW - dip-coating KW - poly(lactic acid) KW - PLA KW - calcium phosphate KW - gelatin KW - chitosan KW - hydrogel KW - calcium phosphate hybrid material KW - biomaterials Y1 - 2018 U6 - https://doi.org/10.3390/polym10030275 SN - 2073-4360 VL - 10 IS - 3 PB - MDPI CY - Basel ER - TY - GEN A1 - Kovacs, Robert A1 - Ion, Alexandra A1 - Lopes, Pedro A1 - Oesterreich, Tim A1 - Filter, Johannes A1 - Otto, Philip A1 - Arndt, Tobias A1 - Ring, Nico A1 - Witte, Melvin A1 - Synytsia, Anton A1 - Baudisch, Patrick T1 - TrussFormer BT - 3D Printing Large Kinetic Structures T2 - The 31st Annual ACM Symposium on User Interface Software and Technology N2 - We present TrussFormer, an integrated end-to-end system that allows users to 3D print large-scale kinetic structures, i.e., structures that involve motion and deal with dynamic forces. TrussFormer builds on TrussFab, from which it inherits the ability to create static large-scale truss structures from 3D printed connectors and PET bottles. TrussFormer adds movement to these structures by placing linear actuators into them: either manually, wrapped in reusable components called assets, or by demonstrating the intended movement. TrussFormer verifies that the resulting structure is mechanically sound and will withstand the dynamic forces resulting from the motion. To fabricate the design, TrussFormer generates the underlying hinge system that can be printed on standard desktop 3D printers. We demonstrate TrussFormer with several example objects, including a 6-legged walking robot and a 4m-tall animatronics dinosaur with 5 degrees of freedom. KW - fabrication KW - 3D printing KW - variable geometry truss KW - large-scale mechanism Y1 - 2019 SN - 978-1-4503-5971-9 U6 - https://doi.org/10.1145/3290607.3311766 PB - Association for Computing Machinery CY - New York ER - TY - JOUR A1 - Assagra, Yuri A.O. A1 - Altafim, Ruy Alberto Pisani A1 - do Carmo, Joao P. A1 - Altafim, Ruy A.C. A1 - Rychkov, Dmitry A1 - Wirges, Werner A1 - Gerhard, Reimund T1 - A new route to piezo-polymer transducers: 3D printing of polypropylene ferroelectrets JF - IEEE transactions on dielectrics and electrical insulation N2 - Here, a promising approach for producing piezo-polymer transducers in a one-step process is presented. Using 3D-printing technology and polypropylene (PP) filaments, we are able to print a two-layered film structure with regular cavities of precisely controlled size and shape. It is found that the 3D-printed samples exhibit piezoelectric coefficients up to 200 pC/N, similar to those of other PP ferroelectrets, and their temporal and thermal behavior is in good agreement with those known of PP ferroelectrets. The piezoelectric response strongly decreases for applied pressures above 20 kPa, as the pressure in the air-filled cavities strongly influences the overall elastic modulus of ferroelectrets. KW - 3D printing KW - polymer ferroelectrets KW - sensors and actuators KW - piezoelectrets KW - electret polymers KW - soft electro-active materials KW - functional materials KW - soft matter Y1 - 2020 U6 - https://doi.org/10.1109/TDEI.2020.008461 SN - 1070-9878 SN - 1558-4135 VL - 27 IS - 5 SP - 1668 EP - 1674 PB - Inst. of Electr. and Electronics Engineers CY - Piscataway ER - TY - JOUR A1 - Schneider, Matthias A1 - Fritzsche, Nora A1 - Puciul-Malinowska, Agnieszka A1 - Balis, Andrzej A1 - Mostafa, Amr A1 - Bald, Ilko A1 - Zapotoczny, Szczepan A1 - Taubert, Andreas T1 - Surface etching of 3D printed poly(lactic acid) with NaOH: a systematic approach JF - Polymers N2 - The article describes a systematic investigation of the effects of an aqueous NaOH treatment of 3D printed poly(lactic acid) (PLA) scaffolds for surface activation. The PLA surface undergoes several morphology changes and after an initial surface roughening, the surface becomes smoother again before the material dissolves. Erosion rates and surface morphologies can be controlled by the treatment. At the same time, the bulk mechanical properties of the treated materials remain unaltered. This indicates that NaOH treatment of 3D printed PLA scaffolds is a simple, yet viable strategy for surface activation without compromising the mechanical stability of PLA scaffolds. KW - surface modification KW - sodium hydroxide etching KW - poly(lactic acid) KW - 3D printing KW - roughness KW - wettability KW - erosion Y1 - 2020 VL - 12 IS - 8 PB - MDPI CY - Basel ER - TY - JOUR A1 - Loges, Klara A1 - Tiberius, Victor T1 - Implementation Challenges of 3D Printing in Prosthodontics BT - A Ranking-Type Delphi JF - Materials N2 - The reduction in cost and increasing benefits of 3D printing technologies suggest the potential for printing dental prosthetics. However, although 3D printing technologies seem to be promising, their implementation in practice is complicated. To identify and rank the greatest implementation challenges of 3D printing in dental practices, the present study surveys dentists, dental technicians, and 3D printing companies using a ranking-type Delphi study. Our findings imply that a lack of knowledge is the most crucial obstacle to the implementation of 3D printing technologies. The high training effort of staff and the favoring of conventional methods, such as milling, are ranked as the second and third most relevant factors. Investment costs ranked in seventh place, whereas the lack of manufacturing facilities and the obstacle of print duration ranked below average. An inclusive implementation of additive manufacturing could be achieved primarily through the education of dentists and other staff in dental practices. In this manner, production may be managed internally, and the implementation speed may be increased. KW - 3D printing KW - prosthodontics KW - ranking type Delphi study KW - additive manufacturing KW - dentistry Y1 - 2021 U6 - https://doi.org/10.3390/ma15020431 SN - 1996-1944 VL - 15 PB - MDPI CY - Basel ER -