TY - JOUR A1 - Leiter, Nina A1 - Wohlschläger, Maximilian A1 - Versen, Martin A1 - Laforsch, Christian T1 - An algorithmic method for the identification of wood species and the classification of post-consumer wood using fluorescence lifetime imaging microscopy JF - Journal of Sensors and Sensor Systems N2 - In this contribution the frequency domain fluorescence lifetime imaging microscopy (FD-FLIM) technique is evaluated for post-consumer wood sorting. The fluorescence characteristics of several wood samples were determined, whereby two excitation wavelengths (405 and 488 nm) were used. The measured data were processed using algorithmic methods to identify the wood species and post-consumer wood category. With the excitation wavelength of 405 nm, 16 out of 19 samples could be correctly assigned to the corresponding post-consumer wood category by means of the fluorescence lifetimes. Thus, the experimental results revealed the high potential of the FD-FLIM technique for automated post-consumer wood sorting. Y1 - 2022 U6 - https://doi.org/10.5194/jsss-11-129-2022 VL - 11 IS - 1 SP - 129 EP - 136 ER - TY - CHAP A1 - Wohlschläger, Maximilian A1 - Versen, Martin A1 - Laforsch, Christian T1 - Investigation of the Impact of CaCO3 Concentrations on the Fluorescence Lifetime of Polypropylene T2 - 2022 Conference on Lasers and Electro-Optics (CLEO) N2 - The impact of fillers on the fluorescence lifetime of polymers is still unknown. Investigating polypropylene containing different CaCO 3 concentrations using FD-FLIM show an exponential increase in fluorescence lifetime proportional to the CaCO 3 density in polypropylene. KW - Fluorescence KW - Lasers and electrooptics KW - Plastics KW - Electrooptical waveguides Y1 - 2022 SP - 1 EP - 2 ER - TY - CHAP A1 - Leiter, Nina A1 - Wohlschläger, Maximilian A1 - Versen, Martin T1 - Frequency-domain fluorescence lifetime imaging as method to analyze wood structures T2 - Conference on Lasers and Electro-Optics N2 - The analysis of wood structures using FD-FLIM seems promising for the identification of wood at 488 nm, as lignin has a high impact on the fluorescence lifetime. KW - Diode lasers KW - Fluorescence KW - Fluorescence lifetime imaging KW - Microscopy Y1 - 2022 U6 - https://doi.org/10.1364/CLEO_AT.2022.JW3A.19 SP - JW3A.19 ER - TY - CHAP A1 - Maniyattu, Georgekutty Jose A1 - Geegy, Eldho A1 - Leiter, Nina A1 - Wohlschläger, Maximilian A1 - Versen, Martin A1 - Laforsch, Christian T1 - Development of a neural network to identify plastics using Fluorescence Lifetime Imaging Microscopy T2 - 2022 IEEE Sensors Applications Symposium (SAS) N2 - Plastics have become a major part of human’s daily life. An uncontrolled usage of plastic leads to an accumulation in the environment posing a threat to flora and fauna, if not recycled correctly. The correct sorting and recycling of the most commonly available plastic types and an identification of plastic in the environment are important. Fluorescence lifetime imaging microscopy shows a high potential in sorting and identifying plastic types. A data-based and an image-based classification are investigated using python programming language to demonstrate the potential of a neural network based on fluorescence lifetime images to identify plastic types. The results indicate that the data-based classification has a higher identification accuracy compared to the image-based classification. KW - fluorescence lifetime imaging KW - FLIM KW - neural networks KW - plastic identification Y1 - 2022 U6 - https://doi.org/10.1109/SAS54819.2022.9881372 SP - 1 EP - 6 ER - TY - CHAP A1 - Bernöcker, Anton A1 - Leiter, Nina A1 - Wohlschläger, Maximilian A1 - Versen, Martin T1 - Entwicklung eines neuronalen Netzwerks als Basis zur automatisierten Holzartenerkennung T2 - 18. AALE-Konferenz. Pforzheim, 09.03.-11.03.2022 N2 - Holz ist ein vielseitig einsetzbarer nachwachsender Rohstoff. Neben seinem wirtschaftlichen Nutzen ist er für den Erhalt des Klimas unersetzlich. Eine sortenreine Sortierung für die Weiterverarbeitung von Altholz spielt für einen ressourcenschonenden Umgang eine wichtige Rolle. Um das Potenzial eines neuronalen Netzwerks basierend auf Messdaten der bildgebenden Fluoreszenzabklingzeitmessung für die Altholzsortierung aufzuzeigen, wurden zwei unterschiedliche Klassifikationsansätze auf Basis der Programmiersprache Python gewählt. Die Ergebnisse zeigen, dass die bildbasierte Klassifizierung der Holzart mit einer Genauigkeit von 47,36 % noch ausbaufähig ist. Eine datenbasierte Klassifizierung der Holzart mit einer Identifikationsgenauigkeit von 98,28 % ist dagegen vielversprechend. KW - FD-FLIM KW - Fluoreszenz KW - Fluoreszenzabklingzeit KW - Holzart KW - Neuronales Netz KW - Klassifizierung Y1 - 2022 U6 - https://doi.org/10.33968/2022.11 ER - TY - CHAP A1 - Wohlschläger, Maximilian A1 - Versen, Martin A1 - Laforsch, Christian T1 - Investigation of the Impact of CaCO3 Concentrations on the Fluorescence Lifetime of Polypropylene T2 - Conference on Lasers and Electro-Optics N2 - The impact of fillers on the fluorescence lifetime of polymers is still unknown. Investigating polypropylene containing different CaCO3 concentrations using FD-FLIM show an exponential increase in fluorescence lifetime proportional to the CaCO3 density in polypropylene. KW - Diode lasers KW - Fluorescence KW - Fluorescence lifetime imaging KW - Fourier transforms KW - Phase shift KW - Stray light Y1 - 2022 U6 - https://doi.org/10.1364/CLEO_AT.2022.AM2M.2 SP - AM2M.2 ER - TY - CHAP A1 - Wohlschläger, Maximilian A1 - Holst, Gerhard A1 - Versen, Martin A1 - Laforsch, Christian T1 - An optical method to differentiate wood from polymers using fluorescence lifetime imaging microscopy T2 - OSA Optical Sensors and Sensing Congress 2021 (AIS, FTS, HISE, SENSORS, ES) (2021), paper EW4G.6 N2 - In this contribution investigations with fluorescence lifetime imaging microscopy (FLIM) are made to optically distinguish polymers and wood. The results show that the distinction and identification is possible in a graphical and calculative way. Y1 - 2021 U6 - https://doi.org/10.1364/ES.2021.EW4G.6 SP - EW4G.6 ER - TY - CHAP A1 - Leiter, Nina A1 - Wohlschläger, Maximilian A1 - Auer, Veronika A1 - Versen, Martin A1 - Laforsch, Christian T1 - An algorithmic method to identify multiple wood species in a single image by their specific fluorescence lifetimes T2 - OSA Imaging and Applied Optics Congress 2021 (3D, COSI, DH, ISA, pcAOP) (2021), paper CF2B.3 N2 - Fluorescence lifetime imaging microscopy (FLIM) combined with an image processing algorithm is successfully used for the optical identification and areal separation of three wood species of maple, larch and nut in a single taken image. Y1 - 2021 U6 - https://doi.org/10.1364/COSI.2021.CF2B.3 SP - CF2B.3 ER - TY - JOUR A1 - Leiter, Nina A1 - Wohlschläger, Maximilian A1 - Versen, Martin T1 - Analysis of the phase-dependent fluorescence decay time of treated wood using FD-FLIM JF - tm - Technisches Messen N2 - For sustainable handling of wood and high material utilization, post-consumer wood has to be sorted by post-consumer wood categories in Germany. The non-destructive FD-FLIM method could improve the wood recycling process by automatic classification of waste wood into post-consumer wood classes. Thus, the phase-dependent fluorescence decay time of treated wood is analysed in this study to obtain the impact of the treatment on the fluorescence decay time. It is shown that treated and untreated wood can be differentiated using the fluorescence decay time, although the state-of-the-art theoretical fluorescence decay time differs from the experimentally determined fluorescence decay time. N2 - Für einen nachhaltigen Umgang mit Holz und eine hohe stoffliche Verwertung muss Altholz in Deutschland nach Altholzklassen sortiert werden. Die zerstörungsfreie FD-FLIM-Methode könnte den Holzrecyclingprozess durch eine automatische Klassifizierung von Altholz in Altholzklassen verbessern. Daher wird in dieser Studie die phasenabhängige Fluoreszenzabklingzeit von behandeltem Holz analysiert, um den Einfluss der Behandlung auf die Fluoreszenzabklingzeit zu ermitteln. Es wird gezeigt, dass behandeltes und unbehandeltes Holz anhand der Fluoreszenzabklingzeit unterschieden werden kann, auch wenn die nach dem Stand der Forschung theoretische Fluoreszenzabklingzeit von der experimentell ermittelten Fluoreszenzabklingzeit abweicht. KW - fluorescence KW - decay time KW - FD-FLIM KW - lifetime KW - wood Y1 - 2023 U6 - https://doi.org/10.1515/teme-2022-0114 VL - 90 IS - 6 SP - 401 EP - 406 ER - TY - CHAP A1 - Wohlschläger, Maximilian A1 - Khan, Yamna A1 - Leiter, Nina A1 - Versen, Martin A1 - Löder, Martin A1 - Laforsch, Christian T1 - Combining BLOB-Detection and MLP to Detect and Identify Plastics in an Environmental Matrix T2 - 2023 IEEE Sensors Applications Symposium (SAS) N2 - Environmental pollution by plastics is an increasing problem. However, state-of-the-art methods have significant disadvantages in detecting and identifying plastics directly in an environmental matrix. In this study, we propose a blob detection algorithm in combination with a neural network for fast and automated identification of plastics and non-plastics in a single fluorescence lifetime image. Therefore an artificial environmental matrix is prepared that contains soil, grass, spruce and HDPE (high density polyethylene) particles. Several FD-FLIM (frequency domain fluorescence lifetime imaging microscopy) images are taken, and the detection algorithm and the neural network are applied. We successfully demonstrated the suitability of the thresholding algorithm and the binary classification of the HDPE particles directly in the environmental matrix. KW - Fluorescence KW - Plastics KW - FD-FLIM KW - Neural networks KW - MLP KW - blob detection KW - Classification algorithms KW - Dogs KW - fluorescence lifetime KW - plastics identification KW - Soil KW - Thresholding (Imaging) Y1 - 2023 U6 - https://doi.org/10.1109/SAS58821.2023.10254171 SP - 1 EP - 5 ER -