@article{ErekathSeidlitzSchreineretal.2024, author = {Erekath, Swathi and Seidlitz, Holger and Schreiner, Monika and Dreyer, Christian}, title = {Food For Future: Exploring Cutting-Edge Technology and Practices in Vertical Farm}, series = {Sustainable Cities and Society}, volume = {106}, journal = {Sustainable Cities and Society}, publisher = {Elsevier}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-18862}, year = {2024}, abstract = {With the growing urbanized population, vertical farming becomes indispensable in eradicating hunger and ensuring food security for the future. Food security has become a major challenge for the future owing to the scarcity of land, rising global population, urbanization, and polluted soil and water resources. In this scenario, vertical farming as an innovative food production technology caters increased productivity with limited resources and improved carbon footprint. The review begins with a brief introduction to the concept of vertical farming, its opportunities and implications on the economy, environment, and society as a whole, following with an in-depth qualitative analysis of the cutting-edge innovations/technologies are presented in detail. Contrary to the numerous research focusing on mere analysis of economic viability and statistical analysis, the aim is to introduce real cutting-edge technologies that address the challenges of vertical farms such as lack of technical skills or energy requirements. The recent advances of vertical farms includes construction of outer vertical structure and growing shelves using light weight and transparent polymer composites, engineered and tunable LEDs lightings, 3-D printed and recyclable growing substrates, AI-integrated IoTs for environment control, harvesting materials for renewable energy storage etc. Such material innovations with inclusion of AI and robotics transform automated vertical farming into 'state of the art' agricultural technology. Production shelf fabricated using UV cured GBOV-glass fiber composite with 60\% transparency can overcome the material weight limitation, corrosion, light obstructions etc. associated with the conventional steel shelves. Replacing non-renewable fossil fuels using renewable energy harvested using carbon dots, florescent materials, and perovskite solar cells is recommended to minimize the high capital investments associated with energy as well as to reduce the environmental impact. Smart materials such as phase change materials and thermoresponsive windows control the amount of energy expended whereas smart substrate promotes resource management. Application of the newest technology AI in vertical farming facilitates precise control of environment, early pest detection, automation of farming processes, data-driven decision making and precision agriculture. In short, vertical farms utilizing modern innovations of science and technology caters enhanced productivity, improved quality, reduced cost, resource management and sustainability. Hence, automated and sustainable vertical farms promoting global food security and circularity have the potential to transform into burgeoning technology of future.}, language = {en} } @article{FrickePsarianosSabbanetal.2022, author = {Fricke, Anna and Psarianos, Marios and Sabban, Jakob and Fitzner, Maria and Reipsch, Riccardo and Schl{\"u}ter, Oliver K. and Dreyer, Christian and Vogt, Julia H.-M. and Schreiner, Monika and Baldermann, Susanne}, title = {Composite materials for innovative urban farming of alternative food sources (macroalgae and crickets)}, series = {Frontiers in Sustainable Food Systems}, volume = {6}, journal = {Frontiers in Sustainable Food Systems}, publisher = {Frontiers}, issn = {2571-581X}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-16822}, year = {2022}, abstract = {Facing an inexorable growth of the human population along with substantial environmental changes, the assurance of food security is a major challenge of the present century. To ensure responsible food consumption and production (SDG 12), new approaches in the food system are required. Thus, environmentally controlled, sustainable production of alternative food sources are of key interest for both urban agriculture and food research. To face the current challenge of integrating food production systems within existing structures, multidisciplinary discourses are required. Here, we bring together novel technologies and indoor farming techniques with the aim of supporting the development of sustainable food production systems. For this purpose, we investigated the feasibility of 10 composite materials for their innovative use as structural support in macroalgal cultivation (settlement substrates) and cricket rearing (housing). Considering material resistance, rigidity, and direct material-organism interactions, the bio-based composite polylactic acid (PLA) was identified as a suitable material for joint farming. For macroalgae cultivation, PLA sustained the corrosive cultivation conditions and provided a suitable substrate without affecting the macroalgal physiology or nutritional composition (carotenoids and chlorophylls). For cricket rearing, PLA provided a suitable and recyclable shelter, which was quickly accepted by the animals without any observed harm. In contrast, other common composite components like phenolic resin or aramid were found to be unsuitable due to being harmful for the cultivated organisms or instable toward the applied sterilization procedure. This multidisciplinary study not only provides profound insights in the developing field of urban indoor food production from a new perspective, but also bridges material science and farming approaches to develop new sustainable and resilient food production systems.}, language = {en} } @article{BauerGutkeHeinrichetal.2020, author = {Bauer, Joachim and Gutke, Marko and Heinrich, Friedhelm and Edling, Matthias and Stoycheva, Vesela and Kaltenbach, Alexander and Burkhardt, Martin and Gruenefeld, Martin and Gamp, Matthias and Gerhard, Christoph and Steglich, Patrick and Steffen, Sebastian and Herzog, Michael and Dreyer, Christian and Schrader, Sigurd}, title = {Novel UV-transparent 2-component polyurethane resin for chip-on-board LED micro lenses}, series = {Optical Materials Express}, volume = {10}, journal = {Optical Materials Express}, number = {9}, issn = {2159-3930}, doi = {10.1364/OME.393844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-13472}, pages = {2085 -- 2099}, year = {2020}, abstract = {In this work we present a novel optical polymer system based on polyurethane elastomer components, which combines excellent UV transparency with high thermal stability, good hardness, high surface tension and long pot life. The material looks very promising for encapsulation and microlensing applications for chip-on-board (CoB) light-emitting diodes (LED). The extinction coefficient k, refractive index n, and bandgap parameters were derived from transmission and reflection measurements in a wavelength range of 200-890 nm. Thermogravimetry and differential scanning calorimetry were used to provide glass transition and degradation temperatures. The surface tension was determined by means of contact angle measurements. As proof of concept, a commercial InGaN-CoB-LED is used to demonstrate the suitability of the new material for the production of microlenses.}, language = {en} } @misc{HartmannTataiKaiseretal.2019, author = {Hartmann, Lutz and Tatai, Tiberiu-Mihai and Kaiser, Mario and Dreyer, Christian}, title = {Erw{\"a}rmung von Materialien und Werkstoffen durch Anwendung von Mikrowellentechnologien}, series = {Wissenschaftliche Beitr{\"a}ge 2019}, volume = {23}, journal = {Wissenschaftliche Beitr{\"a}ge 2019}, issn = {0949-8214}, doi = {10.15771/0949-8214_2019_6}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-10812}, pages = {39 -- 48}, year = {2019}, abstract = {Die Erw{\"a}rmung unterschiedlicher Materialien im ­Kontext verschiedener Anwendungen kann anhand der Bestrahlung mit Mikrowellen in geeignet konstruierten {\"O}fen erfolgen. Der vorliegende Beitrag beginnt mit einer Vorstellung der mikroskopischen Mechanismen der Erw{\"a}rmung von Materie mittels Mikrowellen sowie einem Abriss ihrer theoretischen Beschreibung. Im Folgenden werden die breitbandige dielektrische Spektroskopie und die Simulation elektromagnetischer Felder als Hilfsmittel eingef{\"u}hrt, die Effizienz des mikrowellenbasierten Heizens f{\"u}r bestimmte Materialien vorab einsch{\"a}tzen zu k{\"o}nnen. Nach der Vorstellung zweier unterschiedlicher Mikrowellenanlagen, namentlich eines Kammer- und eines Durchlaufmikrowellenofens, wird die thermische Behandlung unterschiedlicher Materialien mittels Mikrowellen an drei Beispielen illustriert.}, language = {de} } @article{DreyerMotocKoehleretal.2023, author = {Dreyer, Christian and Motoc, Dana Luca and Koehler, Mathias and Goldenberg, Leonid}, title = {UV LED Curable Perfluoropolyether (PFPE)-Urethane Methacrylate Transparent Coatings for Photonic Applications: Synthesis and Characterization}, series = {Polymers}, volume = {15}, journal = {Polymers}, number = {14}, publisher = {MDPI}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-19139}, pages = {1}, year = {2023}, abstract = {The contribution aims to bring forth a novel synthesis route in developing transparent UV LED-curable coatings accounting for various exposure options. A selection of perfluoropolyether (PFPE)-urethane methacrylate and acrylate resins, free-radical photo-initiator Omnirad 2100, and two distinct silane-based crosslinking agents were blended under a weight ratio of 75:20:5 (without crosslinker) and 70:15:5:10, respectively. The coatings were cured under a UV LED 4 × 3 matrix light emitting source, in a chamber under a controlled atmosphere, by means of an in-house developed conveyor belt type platform, at different conveyor belt speeds (5, 50, 150, 250, and 500 mm/s). The morphologies of fabricated coatings were characterized by FTIR revealing high conversion rates (e.g., from 98 to 100\%) for increased exposure time as a result of the 5 or 50 mm/s values, on all combinations. Dynamic-mechanical and optical properties of UV LED-cured transparent coatings were also investigated. A negative shift of the glass transition temperature values with a decrease in exposure time, in all combinations, from about 60 °C to 30 °C, along with storage moduli lowering in the glassy plateau further favors higher exposure times for curing. The refractive indices of poly-mers were from 1.38 to 1.40, whereas the thermo-optic coefficients are showing minor changes around the value of 2.55∙10-4 K-1.}, language = {en} } @article{GoldenbergKoehlerDreyer2021, author = {Goldenberg, Leonid and K{\"o}hler, Mathias and Dreyer, Christian}, title = {SiO2 Nanoparticles-Acrylate Formulations for Core and Cladding in Planar Optical Waveguides}, series = {Nanomaterials}, volume = {11}, journal = {Nanomaterials}, number = {5}, publisher = {MDPI}, issn = {2079-4991}, doi = {10.3390/nano11051210}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-14057}, year = {2021}, abstract = {A combination of acrylate formulations and SiO2 nanoparticles is investigated with the aim to improve the optical properties of low-refractive index polymers that are used for the fabrication of planar optical waveguides. A decrease in refractive index and also in the thermo-optic coefficient of nanocomposite materials is clearly demonstrated, while some formulations exhibit an increase in the glass transition temperature. The possibility of using these nanocomposite materials to fabricate waveguiding layers with low optical propagation losses at telecommunication wavelengths around 1550 nm is also shown. The nanomaterials can be applied in optical microchips on polymer platforms.}, language = {en} } @article{GoldenbergKoehlerKahleetal.2020, author = {Goldenberg, Leonid and K{\"o}hler, Mathias and Kahle, Olaf and Dreyer, Christian}, title = {Impact of inorganic nanoparticles on optical properties of low refractive index waveguiding polymers}, series = {Optical Materials Express}, volume = {10}, journal = {Optical Materials Express}, number = {11}, issn = {2159-3930}, doi = {10.1364/OME.405700}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-13521}, pages = {2987 -- 2997}, year = {2020}, abstract = {The objective of this work is to improve the optical properties of low refractive index polymers used for waveguide by introduction of inorganic nanoparticles. Copolymers of fluorinated monomers and glycidyl methacrylate are used. Introduction of SiO2 nanoparticles into polymer matrix is performed by direct mixing; copolymerization with SiO2 nanoparticles modified by monomer, and in situ sol-gel formation of SiO2 during photochemical cross-linking and annealing catalyzed by photoacid generator. It is demonstrated that nanoparticles are able to decrease thermo-optic coefficient. It is also possible to fabricate waveguiding layers by direct introduction of nanoparticles without compromising of optical propagation losses.}, language = {en} }