Gedruckte elektronische Strukturen auf Geweben für ein Belastungsmonitoring von Faserverbundwerkstoffen

Die Technologieplattform ,,Functional Printing" ermöglicht eine Funktionalisierung von Geweben, welche zur Herstellung von z.B. funktionsintegrierten Glasfaser- und/ oder Carbonfaserverstärkten Kunststoffen (GFK, CFK) verwendet werden können. Diese Faserverbundstrukturen erlauben so eine integrierte Zustandsüberwachung, mit der Schäden in Form von Faserbrüchen, Matrixrissen und Delaminationen vor einem kompletten Bauteilversagen detektiert werden können

Komposit, Herstellungsverfahren für ein Komposit und aus dem Komposit gebildeter Formkörper

Die Erfindung betrifft ein Verfahren zum Herstellen eines Komposits, wobei das Komposit (1) eine Matrix (2) beinhaltet, die ganz oder zumindest bereichsweise durch ein erstes Material (3) gebildet ist und in die Partikel eines zweiten Materials (5) eingelagert sind,wobei das Verfahren folgende Schritte umfasst:- Bereitstellen eines Zwischenkomposits, wobei das Zwischenkomposit eine Matrix beinhaltet, in die Partikel des zweiten Materials (5) eingelagert sind,- Bereitstellen eines von dem Zwischenkomposit verschiedenen weiteren Materials, welchesPartikel des zweiten Materials (5) beinhaltet oderzumindest bereichsweise durch das erste Material (3) gebildet ist,- Zusammenführen des Zwischenkomposits mit dem weiteren Material und- Vermischen des Zwischenkomposits mit dem weiteren Material.Die Erfindung betrifft außerdem ein Komposit (1) und ein Formteil

Printing technologies for the manufacturing of passive microwave components: Antennas

In this study, the application of printing technologies for the manufacturing of passive microwave components such as antennas is highlighted, and a detailed example is given. Common printing technologies such as inkjet, screen, and gravure printing become adjusted to print conductive inks for the manufacturing of printed antennas on flat substrates or even on threedimensional(3D) surfaces. Especially, printing technologies such as pad printing, micro-jetting, dispensing, and aerosol jetting are candidates for the manufacturing of microwave components onto challenging 3D surfaces, which may facilitate new designs. Depending on the substrate, one technical challenge is to choose a proper metal ink in combination with a suitable thermal treatment to reach critical requirements such as electrical conductivity above 106 S/m or proper adhesion of the printed pattern for an antenna application. This study gives an overview and comparison of the state-of-the-art materials, inks, printing processes, and options of subsequent thermal treatment. The challenges and possibilities for printed-passive microwave components are discussed with regard to microwave applications. The development of a printed radio-frequency identification antenna on a 3D surface is demonstrated, and the performance of the manufactured antenna is discussed in detail

The Effect of Transition Metal Doping on the Photooxidation Process of Titania-Clay Composites

Montmorillonite-TiO2 composites containing various transition metal ions (silver, copper, or nickel) were prepared, and their photocatalytic efficiencies were tested in the degradation of ethanol vapor at 70% relative humidity. Two light sources, UV-rich ( = 254 nm) and visible ( = 435 nm), were used. The kinetics of degradation was monitored by gas chromatography. It was established that, in the case of each catalyst, ethanol degradation was more efficient in UV-C ( = 254 nm) than in visible light, furthermore, these samples containing silver or copper ions were in each case about twice more efficient than P25 TiO2 (Degussa AG.) used as a reference. In photooxidation by visible light, TiO2/clay samples doped with silver or copper were also more efficient than the reference sample, P25 TiO2. We show that doping metal ions can also be delivered to the surface of the support by ion exchange and significantly alters the optical characteristics of the TiO2/clay composite

Customized Smartness: A survey on links between additive manufacturing and sensor integration

In many areas, Additive Manufacturing (AM) has made the decisive steps from prototyping to true manufacturing technology. AM processes excel based on aspects like outstanding geometrical flexibility and lack of tooling, which allows significant lead time reductions both in initial product design and in case of design adaptations. However, in production today, most of these advantages are realized based on homogeneous materials. Attempts at advancing the state of the art address the topic of material combinations and functionally graded materials. The challenges faced by such approaches differ in their level of severity, and are influenced in this respect by the actual AM process chosen. Beyond composites with spatially varying properties, the next level of complexity is the integration of geometrically defined 3D structures within the volume of a part, and specifically functional structures at that. Endeavours of the latter kind are currently receiving increased attention under headlines like “Structural Electronics” or “3D Electronics Printing”. Here, the surface or volume integrated structure typically is a sensor or electronic system. Beyond this system, the AM process then either provides a complex 3D substrate and thus addresses the packaging issue and/or replaces a conventional PCB, or it generates an engineering component directly and closely integrates it with electronic and sensor systems. So far, the backbone of most solutions realized have been hybrid production systems that integrate different manufacturing processes in a single piece of equipment. The present work provides a brief introduction to the various AM techniques and discusses a disambiguation based on their general capability of producing functional structures on a volume integration level. A classification of such structures is suggested that accounts for their level of complexity in relation to the typical, layer-wise manufacturing scheme adopted in AM. Examples stemming from a global research landscape are discussed in the context of this classification. In this, two special foci are selected reflecting related activities at the Fraunhofer Institute for Manufacturing Technology and Advanced Materials (Fraunhofer IFAM): One of these is a combination of manufacturing processes, with functional printing and other direct write techniques linked to AM processes in a dedicated manufacturing cell. The other addresses integration of pre-fabricated electronic components like RFID systems into metal components produced by means of selective laser melting (SLM).The study closes with an overview of future research trends towards producing components with integrated electronics. In doing so, special emphasis is given to AM techniques that allow for in-process switching of materials and thus have the potential of realizing complex systems not by combination of processes, but within the boundaries of a single process. Also addressed are potential application scenarios that profit specifically from the combination of AM and sensor integration