TY - JOUR A1 - Amrhein, Frank A1 - Kehrer, Martin A1 - Schreck, Timo A1 - Bochtler, Ulrich A1 - Hellmann, Ralf A1 - Kaloudis, Michael T1 - UV-LED-Bestrahlung von Vergussmaterial: Schnelle Aushärtung auch im Schatten JF - adhäsion KLEBEN & DICHTEN KW - Lumineszenzdiode Y1 - 2011 IS - 5 SP - 38 EP - 41 ER - TY - JOUR A1 - Amrhein, Frank A1 - Kehrer, Martin A1 - Schreck, Timo A1 - Bochtler, Ulrich A1 - Hellmann, Ralf A1 - Kaloudis, Michael T1 - More efficient curing of UV sensitive mounting materials JF - Practical metallography KW - Aushärtung Y1 - 2014 VL - 48 IS - 7 SP - 356 EP - 364 ER - TY - JOUR A1 - Bochtler, Ulrich A1 - Hellmann, Ralf A1 - Kaloudis, Michael A1 - Amrhein, Frank A1 - Glaab, Johannes A1 - Kaloumenos, Mareiki A1 - Sauer, Michael A1 - Gockel, Tilo T1 - LUVLED - UV-Leistungslichtquelle auf Leuchtdiodenbasis JF - Elektor Sonderheft, LEDs 2 KW - Lumineszenzdiode Y1 - 2010 VL - 2011 IS - 2 SP - 57 EP - 63 PB - Elektor-Verlag CY - Aachen ER - TY - JOUR A1 - Amrhein, Frank A1 - Bochtler, Ulrich A1 - Hellmann, Ralf A1 - Kaloudis, Michael A1 - Kaloumenos, Mareiki T1 - Vergleich der thermischen Eigenschaften unterschiedlicher insulated metal substrat-Leiterplatten JF - PLUS, Leiterplattentechnik KW - Gedruckte Schaltung KW - Trägersubstanz Y1 - 2010 IS - 8 SP - 1758 PB - Hanser Verlag CY - München ER - TY - JOUR A1 - Kefer, Stefan A1 - Sauer, Theresia A1 - Hessler, Steffen A1 - Kaloudis, Michael A1 - Hellmann, Ralf T1 - Microstructure-Based Fiber-to-Chip Coupling of Polymer Planar Bragg Gratings for Harsh Environment Applications JF - Sensors (Basel) N2 - This article proposes and demonstrates a robust microstructure-based fiber-to-chip coupling scheme for planar Bragg grating devices. A polymer planar Bragg grating substrate is manufactured and microstructured by means of a micromilling process, while the respective photonic structures are generated by employing a sophisticated single-writing UV-exposure method. A stripped standard single mode fiber is inserted into the microstructure, which is filled with a UV-curable adhesive, and aligned with the integrated waveguide. After curing, final sensor assembly and thermal treatment, the proposed coupling scheme is capable of withstanding pressures up to 10 bar, at room temperature, and pressures up to 7.5 bar at an elevated temperature of 120 °C. Additionally, the coupling scheme is exceedingly robust towards tensile forces, limited only by the tensile strength of the employed single mode fiber. Due to its outstanding robustness, the coupling scheme enables the application of planar Bragg grating devices in harsh environments. This fact is underlined by integrating a microstructure-coupled photonic device into the center of a commercial-grade carbon fiber-reinforced polymer specimen. After its integration, the polymer-based Bragg grating sensor still exhibits a reflection peak with a dynamic range of 24 dB, and can thus be employed for sensing purposes. KW - Bragg grating sensors KW - cyclic olefin copolymers KW - fiber-to-chip coupling KW - microstructures KW - micromilling Y1 - 2020 UR - https://www.mdpi.com/1424-8220/20/19/5452/htm U6 - https://doi.org/10.3390/s20195452 VL - 20 IS - 19 SP - 5452 EP - 5452 ER - TY - CHAP A1 - Kaloumenos, Mareiki A1 - Amrhein, Frank A1 - Glaab, Johannes A1 - Sauer, Michael A1 - Hellmann, Ralf A1 - Kaloudis, Michael T1 - Development of a UV-Light Source with Highest Power Density Based on Light Emitting Diode Technology for Applications in Production Engineering, in Production Engineering and manufacturing Systems T2 - Proceedings of the XXIV International Scientific Conference Miskolc, Ungarn KW - Lumineszenzdiode Y1 - 2010 ER - TY - JOUR A1 - Bochtler, Ulrich A1 - Hellmann, Ralf A1 - Kaloudis, Michael T1 - Neuartige UV-Lichtquelle auf Leuchtdiodenbasis, Packaging und Hybridschaltungen JF - PLUS KW - Lumineszenzdiode Y1 - 2010 IS - 2 PB - Leuze-Verlag ER - TY - JOUR A1 - Schneider, Johannes A1 - Bochtler, Ulrich A1 - Hellmann, Ralf A1 - Kaloudis, Michael A1 - Gockel, Tilo T1 - Effiziente Entwärmung eines Hochleistungs-UV-LED-Moduls JF - Elektor, Sonderheft LEDs 3 KW - Lumineszenzdiode Y1 - 2011 VL - 2011 IS - 9 SP - 12 EP - 17 ER - TY - CHAP A1 - Sauer, Theresia A1 - Kefer, Stefan A1 - Ruppert, Wolfgang A1 - Hellmann, Ralf A1 - Kaloudis, Michael T1 - Integration of Bragg grating sensors in components made of carbon fiber reinforced polymers T2 - Tagungsband der 20. GMA/ITG-Fachtagung Sensoren und Messsysteme 2019, 25.06.2019 - 26.06.2019, Nürnberg, Deutschland N2 - This contribution discusses the integration of polymer planar Bragg grating sensors (PPBG) into carbon fiber reinforced polymer (CFRP) components. For the first time, it is shown that PPBGs based on cyclic olefin copolymers can be integrated into commercial-grade composites, thereby withstanding the demanding production processes. Pre-impregnated fibers are stacked and partially modified to form a sensor pocket. Afterwards, the CFRP specimen containing the optical sensor is cured in a heated mechanical press for 2 hours at a pressure of 7 bar and a temperature of 120 °C. A subsequent evalutaion of the sensor signal shows a Bragg wavelength shift of 1236 pm and a decline in signal amplitude of -2 dB. Three-point flexural tests of the cured sample reveal a linear behavior of the sensor signal towards external loads. The determined sensitivity in dependence of the CFRP specimen's maximum central deflection is -112 pm/mm, while correlation to the applied force results in a sensitivity of -5 pm/N. KW - Bragg grating sensors KW - carbon fiber reinforced polymers KW - cyclic olefin copolymers KW - structural health monitoring KW - Bragg-Reflektor Y1 - 2019 SN - 978-3-9819376-0-2 U6 - https://doi.org/10.5162/sensoren2019/P3.12 SP - 806 EP - 810 ER - TY - JOUR A1 - Kefer, Stefan A1 - Sauer, Theresia A1 - Hessler, Steffen A1 - Kaloudis, Michael A1 - Schmauß, Bernhard A1 - Hellmann, Ralf T1 - Robust Polymer Planar Bragg Grating Sensors Embedded in Commercial-Grade Composites JF - Polymers N2 - This contribution demonstrates the functionality of polymer planar Bragg grating (PPBG) sensors integrated into commercial-grade carbon fiber reinforced polymer (CFRP) components. Multiple CFRP specimens are generated by curing a stack of pre-impregnated fibers inside of a heated mechanical press, exposing the polymer sensor to a pressure of 7 bar and a temperature of 120 °C for 2 h. After integration, the sensor still exhibits a strong and evaluable signal. Subsequent flexural experiments reveal a linear response of the integrated sensor’s Bragg wavelength to the CFRP specimen’s maximum deflection. Additional findings demonstrate that the embedded PPBG can be used to detect plastic deformations of a CFRP workpiece, whereas a linear correlation of plastic deformation to the resulting Bragg signal offset is determined. A plausibility check of the obtained results is delivered by a comparison of three-point flexural experiments on bulk CFRP workpieces, without integrated sensors and additional specimens featuring external optical sensors affixed to their surface. It is found that PPBGs based on cyclic olefin copolymers are able to overcome the temperature-related limitations of traditional polymer-based optical sensors and can thus be directly integrated into commercial-grade composites during production. KW - Bragg grating sensors KW - carbon fiber reinforced polymers KW - cyclic olefin copolymers KW - Bragg-Reflektor KW - Optischer Sensor Y1 - 2020 UR - https://www.mdpi.com/2073-4360/12/3/715/htm U6 - https://doi.org/10.3390/polym12030715 VL - 12 IS - 3 SP - 715 EP - 715 ER -