@article{AdomavičiũtėGrabusovėHinkelUsenovetal.2022, author = {Adomavičiũtė-Grabusovė, Sonata and Hinkel, Jonas and Usenov, Iskander and Novikov, Alexander S. and Sakharova, Tatiana and D{\"o}hler, Torsten and Geißler, Ute and Feliksberger, Elena and Artyushenko, Viacheslav}, title = {Microstructuring of the end-surface for silver halide polycrystalline fibers to suppress Fresnel reflection}, series = {Optical Materials Express}, volume = {12}, journal = {Optical Materials Express}, number = {1}, publisher = {Optica Publishing Group}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-15549}, pages = {34 -- 48}, year = {2022}, abstract = {Silver halide polycrystalline infrared fibers (PIR) have unique properties such as excellent transmittance in the spectral range from 3 to 17 µm, while also being highly flexible, non-toxic, and non-hygroscopic. They are used in industry and medicine for CO2-laser power delivery, flexible infrared imaging, and remote process spectroscopy. While PIR fibers possess a quite low attenuation (0.1-0.5 dB/m) in the 8-12 µm range, their total transmittance is limited by significant Fresnel reflections at the fiber end faces due to the high refractive index of silver halide (>2.1). Functionalization of these surfaces with specially designed Anti-Reflective Microstructures (ARMs) enables a striking enhancement of fiber transmittance. In this work, direct imprinting (or embossing) of microstructures to fiber ends and their profiling with a microstructured knife was applied to fabricate such ARMs. The resulting two-dimensional Moth-eye microstructures and one-dimensional microgrooves at the PIR-fiber ends enable to an increase of fiber transmittance in a broadband range of (5-17 µm) as well as to reach up to 20\% improvement for PIR-fiber laser cables used for power delivery of CO2-lasers at 10.6 µm.}, language = {en} } @article{TarabrinBushunovTeslenkoetal.2021, author = {Tarabrin, Mikhail K. and Bushunov, Andrey A. and Teslenko, Andrei A. and Sakharova, Tatiana and Hinkel, Jonas and Usenov, Iskander and D{\"o}hler, Torsten and Geißler, Ute and Artyushenko, Viacheslav and Lazarev, Vladimir A.}, title = {Fabrication of an antireflection microstructure on AgClBr polycrystalline fiber by single pulse femtosecond laser ablation}, series = {Optical Materials Express}, volume = {11}, journal = {Optical Materials Express}, number = {2}, publisher = {Optical Society of America}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-15384}, pages = {487 -- 496}, year = {2021}, abstract = {Polycrystalline infrared (PIR) fibers are used for numerous applications, one of those being power delivery for CO2 lasers. However, the fiber tip surface's transmittance cannot be increased with conventional antireflection coatings due to the surface unevenness. Antireflection microstructures (ARMs) offer an alternative way of increasing transmittance. In this work, ARMs were fabricated on the fiber tip surface of an AgClBr fiber by single-pulse femtosecond laser ablation. A single-surface transmittance of 92.8\% at 10.6 μm, a CO2 laser operation wavelength, was achieved. The proposed method can help significantly improve the systems' efficiency, where power delivery for CO2 lasers or sources operating in the wide wavelength range is required.}, language = {en} } @inproceedings{FriedoHauschultzDoehleretal.2026, author = {Friedo, Maria Helene and Hauschultz, Mike Thomas and D{\"o}hler, Torsten and Erhardt, Tom and Jacobs, Hannes and Richetta, Maria and B{\"o}hme, Andrea and Krenz-Baath, Ren{\´e}}, title = {Development of Intelligent Process Automation Strategies to Enhance Selective Laser Melting Performance and Resource Efficiency}, series = {Tagungsband AALE 2026: Mechatronische Systeme f{\"u}r die Automatisierung: Fortschritt durch Pr{\"a}zision und Qualit{\"a}t}, booktitle = {Tagungsband AALE 2026: Mechatronische Systeme f{\"u}r die Automatisierung: Fortschritt durch Pr{\"a}zision und Qualit{\"a}t}, publisher = {Hochschule f{\"u}r Technik, Wirtschaft und Kultur Leipzig}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-21430}, pages = {299 -- 307}, year = {2026}, abstract = {The research project FASER advances additive manufacturing processes for metallic materials, focusing on Selective Laser Melting (SLM). FASER stands for "Fehlerfreies Additives Fertigen durch adaptive Sensorik zur Optimierung der Energie- und Ressourceneffizienz". Conducted at the Technical University of Applied Sciences Wildau, it implements a comprehensive zero-defect strategy using market-standard equipment like the One Click Metal MPrint+ SLM machine and MPure powder removal station. These systems are enhanced with adaptive multi-sensor technology and intelligent process control to boost quality, cut energy use, and minimize material waste. Central to FASER is flexible camera-based multi-sensor integration, combining optical, thermographic, and spectroscopic methods for real-time monitoring in harsh SLM environments.}, language = {en} } @inproceedings{HauschultzFriedoDoehleretal.2026, author = {Hauschultz, Mike Thomas and Friedo, Maria Helene and D{\"o}hler, Torsten and B{\"o}hme, Andrea and Richetta, Maria and Krenz-Baath, Ren{\´e}}, title = {Layer-by-Layer Process Control in Selective Laser Melting via Customized G-Code Handling}, series = {Tagungsband AALE 2026: Mechatronische Systeme f{\"u}r die Automatisierung: Fortschritt durch Pr{\"a}zision und Qualit{\"a}t}, booktitle = {Tagungsband AALE 2026: Mechatronische Systeme f{\"u}r die Automatisierung: Fortschritt durch Pr{\"a}zision und Qualit{\"a}t}, publisher = {Hochschule f{\"u}r Technik, Wirtschaft und Kultur Leipzig}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-21449}, pages = {309 -- 317}, year = {2026}, abstract = {Selective Laser Melting (SLM), also commonly referred to as laser powder bed fusion (LPBF), has become a widely adopted technology in metal additive manufacturing for both industrial and research applications. However, many commercial LPBF systems are based on closed hardware and software architectures, which limit transparency, process monitoring, and direct parameter manipulation during ongoing builds. While recent industrial machines increasingly provide standardized interfaces such as OPC UA for monitoring purposes, fine-grained, layer-wise process control remains restricted. The One Click Metal MPrint+ exemplifies this paradigm by relying on proprietary container-based job execution prepared using commercial software tools such as Autodesk Netfabb or Autodesk Fusion 360. This contribution presents an alternative approach that enables user-defined control of the MPrint+ system through a custom-developed G-code handling framework. Instead of executing complete print jobs as opaque containers, the proposed method establishes a direct network connection to the printer using its gRPC interface. Externally generated G-code is extracted, processed, and transmitted layer-wise to the machine, enabling direct interaction with the build process beyond standard job execution. The approach allows controlled variation of process parameters such as exposure strategies, hatch patterns, or recoating behavior during an ongoing build, thereby supporting efficient design-ofexperiment studies without requiring multiple independent print jobs. In addition, individual G-code commands can be executed interactively, enabling didactic use cases in which machine behavior can be directly observed and linked to abstract toolpath descriptions.}, language = {en} } @inproceedings{HeinrichKrachtEhrhardtetal.2026, author = {Heinrich, Moritz and Kracht, Christopher and Ehrhardt, Tom and D{\"o}hler, Torsten and B{\"o}hme, Andrea and Krenz-Baath, Ren{\´e}}, title = {Metall-3D-Druck Wissensvermittlung in der Lehre durch den Einsatz von XR-Technologien}, series = {Tagungsband AALE 2026: Mechatronische Systeme f{\"u}r die Automatisierung: Fortschritt durch Pr{\"a}zision und Qualit{\"a}t : Mechatronische Systeme f{\"u}r die Automatisierung: Fortschritt durch Pr{\"a}zision und Qualit{\"a}t}, booktitle = {Tagungsband AALE 2026: Mechatronische Systeme f{\"u}r die Automatisierung: Fortschritt durch Pr{\"a}zision und Qualit{\"a}t : Mechatronische Systeme f{\"u}r die Automatisierung: Fortschritt durch Pr{\"a}zision und Qualit{\"a}t}, publisher = {Hochschule f{\"u}r Technik, Wirtschaft und Kultur Leipzig}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-21427}, pages = {269 -- 278}, year = {2026}, abstract = {Das EU/ILB-gef{\"o}rderte Projekt MINT'oVation verfolgt ein XR-gest{\"u}tztes Lehrkonzept zur Vermittlung von Grundlagen und Prozessen des metallischen 3D-Drucks mit Fokus auf das Selective Laser Melting (SLM). Ziel ist der Aufbau eines fundierten technologischen Verst{\"a}ndnisses dieser industriellen Schl{\"u}sseltechnologie sowie die anschauliche, sichere und niedrigschwellige Vermittlung komplexer metallphysikalischer Zusammenh{\"a}nge. Das didaktische Design orientiert sich am Cognitive-Affective Model of Immersive Learning (CAMIL) und nutzt visuelle Immersion, Interaktion und spielerische Elemente zur F{\"o}rderung von Motivation, Aufmerksamkeit und nachhaltigem Wissenserwerb. In der virtuellen Umgebung k{\"o}nnen Prozesse, Experimente und Demonstrationen risikofrei und ohne kostenintensive Anlagen durchgef{\"u}hrt werden. Der modular aufgebaute Kurs umfasst unter anderem eine Einf{\"u}hrung in XR-Technologien, metallphysikalische Grundlagen, additive Fertigungsverfahren, CAD-Konstruktion sowie den vollst{\"a}ndigen Prozess von der Modellierung bis zur Druckdurchf{\"u}hrung. Zum Einsatz kommen marktg{\"a}ngige, hardwareunabh{\"a}ngige XR-Systeme, beispielhaft Apple Vision Pro oder Meta Quest 3. Das Angebot richtet sich an Studierende, Auszubildende, Sch{\"u}ler* innen, Arbeitssuchende und weitere Interessierte ohne n{\"o}tiges Vorwissen und unterst{\"u}tzt gezielt Inklusion und Chancengleichheit. Zwischen April und Dezember 2025 verzeichnete der Kurs 97 Anmeldungen, davon 82 f{\"u}r den vollst{\"a}ndigen Kurs; 66 Teilnehmende schlossen diesen bereits erfolgreich ab. Die hohe Nachfrage unterstreicht das Potenzial immersiver XR-Lehrformate zur nachhaltigen Qualifizierung im Bereich der additiven Fertigung und zur Vorbereitung auf einen sich wandelnden Arbeitsmarkt.}, language = {de} } @misc{SchmiederDoehlerRolleetal.2013, author = {Schmieder, Benjamin and D{\"o}hler, Torsten and Rolle, Siegfried and Ruede, Frank and Schurig, Thomas and Ketelsen, Helge and Gruska, Bernd}, title = {Photoscanning-Verfahren zur nichtinvasiven Charakterisierung fabrikationsbedingter Defekte in Solarzellen}, series = {Wissenschaftliche Beitr{\"a}ge 2013}, volume = {17}, journal = {Wissenschaftliche Beitr{\"a}ge 2013}, issn = {0949-8214}, doi = {10.15771/0949-8214_2013_1_8}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-3230}, pages = {43 -- 48}, year = {2013}, abstract = {Das Photoscanning-Verfahren dient der zerst{\"o}rungsfreien Detektion von Defekten in Solarzellen. Die Daten erm{\"o}glichen R{\"u}ckschl{\"u}sse auf grundlegende physikalische Parameter der Zelle, wie zum Beispiel den Wirkungsgrad, bzw. mechanische St{\"o}rungen. Es erlaubt eine umfassende Charakterisierung einer Vielzahl von unterschiedlichen Solarzellentypen. Innerhalb des Projektes werden diese Einsatzm{\"o}glichkeiten des Photoscanning-Verfahren verifiziert. Seit 2011 wurde die Weiterentwicklung des Verfahrens innerhalb einer Kooperation mit der Firma SENTECH als Projekttr{\"a}ger, der Physikalisch Technischen Bundesanstalt und der TH Wildau als Projektbeteiligte fortgesetzt.}, language = {de} } @article{BoehmeDoehlerHofmannetal.2023, author = {B{\"o}hme, Andrea and D{\"o}hler, Torsten and Hofmann, Mandy and Neumann, Jens and Bochem, Reinhard and Geißler, Ute and Foitzik, Andreas}, title = {Electrolytical Coating of Inhomogeneous Structures Distributed on Metallic Surfaces}, series = {Materials Science Forum}, volume = {1106}, journal = {Materials Science Forum}, publisher = {Trans Tech Publications}, issn = {0255-5476}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-18825}, pages = {75 -- 80}, year = {2023}, abstract = {In modern electrochemical coating technology, it is common practice to create uniform layers. However, this study focuses on the deposition of non-uniform layers achieved through a deliberate arrangement of micro structured electrodes on the anode side. The "dog bone effect" was employed as the primary approach [1]. When electroplating on an otherwise uniform surface, this effect selectively processes an area influenced by the geometric edge effect (figure 1 left). The coating within this area is intended to be (i) unevenly distributed and (ii) non-reproducible. Process data was obtained through electrochemical simulations and subsequently applied to a specially designed micro-galvanic setup. This enabled the production of suitable micro structured anodes, validation of coating parameters, and the deposition of visually imperceptible structured areas with inhomogeneous properties using "adhesive gold" on appropriate substrates such as silver and nickel. The layers and their local topography were characterized and analyzed using confocal laser microscopy, X-Ray fluorescence analysis (XRF), as well as a self-designed and constructed laser interference device. As a result, this specific galvanic process technology successfully produced metallic layers that (i) cannot be visually confirmed by the naked eye, (ii) exhibit varied microstructural anode geometries, (iii) display unique differences in layer thickness, (iv) possess non-reproducible and chaotic topographies, and (v) can be detected and identified using conventional analysis techniques or a simple interference setup.}, language = {en} } @inproceedings{FriedoHauschultzDoehleretal.2023, author = {Friedo, Maria Helene and Hauschultz, Mike Thomas and D{\"o}hler, Torsten and B{\"o}hme, Andrea and Richetta, Maria and Foitzik, Andreas}, title = {Sustainable production of injection moulds through additive manufacturing and improved application of energy management}, series = {NWK 2023 - Tagungsband zur 23. Nachwuchswissenschaftler*innenkonferenz}, booktitle = {NWK 2023 - Tagungsband zur 23. Nachwuchswissenschaftler*innenkonferenz}, editor = {Stolzenburg, Frieder and Reinboth, Christian and Lohr, Thomas and Vogel, Kathleen}, publisher = {Hochschule Harz}, address = {Wernigerode}, issn = {2627-5708}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-18600}, pages = {298 -- 302}, year = {2023}, abstract = {The concept of this thesis is to optimize the manufacturing process of injection moulding tools by using additive manufacturing and thus contribute to environmental protection. For this purpose, the individual steps of the traditional manufacturing process are identified and analysed to determine which steps can be replaced by additive manufacturing. The first step is to clarify which mould components can benefit from additive manufacturing. In particular, the capabilities and limitations of additive manufacturing technologies must be considered. Furthermore, another focus is on how to optimize the cooling and temperature control of the tools. Potential savings through the use of lightweight or insulating surfaces will be examined. In addition to the technical feasibility, the cost-effectiveness of the concept will also be considered. Finally, the contribution of the concept to the reduction of the environmental impact will be evaluated. In particular, energy savings and the reduction of CO2 emissions are taken into account. The potential to optimize the injection mould manufacturing process and reduce environmental impact is significant. Using additive manufacturing can be an economic and environmental advantage.}, language = {en} } @article{FelkeGrothHempeletal.2024, author = {Felke, Florens and Groth, Anne and Hempel, Martin and Czerny, Bernhard and Khatibi, Golta and D{\"o}hler, Torsten and Geißler, Ute}, title = {Effect of the loop forming process on the lifetime of aluminum heavy wire bonds under accelerated mechanical testing}, series = {Microelectronics Reliability}, volume = {154}, journal = {Microelectronics Reliability}, publisher = {Elsevier}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-18631}, year = {2024}, abstract = {Heavy wire bonding is one of the most common interconnection technologies in manufacturing of high-power electronics. For industrial applications, the long-term reliability of these connections is crucial. Besides the selection of the wire material and the loop geometry itself, the loop forming process parameters also have an influence on the reliability of the wire bond. In this work, the influence of the backward bond head movement during wire bonding process on the quality of wire bond connections was systematically investigated and qualified by cyclic mechanical lifetime tests, surface roughness measurements of the heel area by laser confocal microscopy and static pull tests. The wire bond loops were fabricated with 300 μm aluminum H11 and H14CR wires with different hardness values. The lifetime at low frequency cycle and high frequency cycle regime was determined by means of two different mechanical cyclic test methods operating at 5 Hz and at 60 kHz respectively. The results have shown, that the surface topology of the heel region caused by the initial plastic deformation during the loop forming process has a significant effect on the wire bond failure due to heel cracking. The number of loading cycles to failure shows an inverse correlation with the degree of surface roughness in a so called wrinkling analysis in the low and high frequency cycle regime. The soft wire exhibits different lifetimes compared to the hard ones depending on the testing conditions, while a significant decrease of the lifetime is observed with >30 \% reverse movement during bonding in all cases.}, language = {en} } @inproceedings{HauschultzFriedoDoehleretal.2023, author = {Hauschultz, Mike Thomas and Friedo, Maria Helene and D{\"o}hler, Torsten and B{\"o}hme, Andrea and Richetta, Maria and Foitzik, Andreas}, title = {Additive Manufacturing of Electrodes: Innovative Applications and Opportunities}, series = {NWK 2023 - Tagungsband zur 23. Nachwuchswissenschaftler*innenkonferenz}, booktitle = {NWK 2023 - Tagungsband zur 23. Nachwuchswissenschaftler*innenkonferenz}, editor = {Stolzenburg, Frieder and Reinboth, Christian and Lohr, Thomas and Vogel, Kathleen}, publisher = {Hochschule Harz}, address = {Wernigerode}, issn = {2627-5708}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-18621}, pages = {292 -- 297}, year = {2023}, abstract = {Additive manufacturing, also known as 3D printing, has gained tremendous importance in recent years. One of the areas where additive manufacturing is particularly useful is in the fabrication of electrodes. Electrodes are an important component of a wide range of applications, including electrochemistry, biomedical engineering, energy storage, analytics, electronics as well as life sciences. Traditionally, electrodes have been manufactured through costly processes such as etching, electroplating or cutting and milling. Additive manufacturing offers a new way to fabricate electrodes by depositing materials layer by layer (Yap et al., 2015). This opens up new possibilities for designing electrodes with complex geometries and structures that would not be possible using conventional methods. As a result, 3D printed electrodes are gaining interest in fields such as electromobility, water disinfection, manufacturing, and life sciences, which will be presented in this paper.}, language = {en} }