The field of ,,Adaptronics" combines sensor and actuator effects with electronics. The components furnished with adaptronics shall sense relevant properties and shall adapt in an intelligent way -they shall ,,feel, think and act". For instance, one application is the active vibration compensation of dynamically stressed structures.So far, adaptronics utilises actuators -and partly also sensors -in the mm size range which possess a substantial stiffhess. If such actuators! sensors were to be integrated into light weight structures -e.g. an carbon fibre reinforced aeroplane part or a glass fibre reinforced robot arm -the light weight structures would be severely affected in their advantageous properties. If, however, these specific properties are to be maintained, the actuators! sensors have to feature a small volume and stiffness.The micro manufacturing of such systems is an activity of the Fraunhofer Institute IFAM. The approach chosen includes the utilisation of piezo electric fibres in the diameter range from 20 jim -200j.tm. The micro systems consist of many fibres being contacted by interdigitated electrodes made of electrically conductive adhesives. In addition, structural adhesives and casting polymers are used. These actuator! sensor modules can be both applied onto structures, or integrated into structures. The performance of the different modules will be compared. An interesting approach for the use of sensor!actuator modules especially in prepreg fibre reinforced plastics is to also make the PZT fibre modules in a prepreg state.The presentation will feature the latest results of the developments regarding both, the manufacture and the performance ofcured as well as ofprepreg modules.
The underfilling of CSP and BGA components with area I array lead free and lead containing solder terminals in surface mount technology has been systematically studied and evaluated. One of the goals of the research was to define the particular requirements that have to be put on CSP/BGA underfill materials and to estimate what level of process reliability for underfilling can be achieved. The knowledge and experience with flip chip underfilling could not be directly transferred to CSP and BGA assemblies due to the differences in material combinations and geometry of the joint gap as well as the differences in the nature and magnitude of the stress. Ageing and stress tests on test assemblies with commercially available and alternative underfill materials highlighted the specific advantages of underfilling CSPs and BGAs. The experimental findings and the simulations results allowed the required property profiles of CSP/BGA underfillers to be defined. From the effects of underfill defects, statements about process reliability could be made
In this study, the attachment of microcapsules on the membrane surface and its influence on the flow field for a cross-flow membrane setup are investigated. The microcapsules were placed on the top layer of the membrane. The overall purpose of this modification was the prevention of membrane biofouling. Therefore, in a first step, the influence of such a combination on the fluid flow was investigated using computational fluid dynamics (CFD). Here, different properties, which are discussed as indicators for biofouling in the literature, were considered. In parallel, different fixation strategies for the microcapsules were experimentally tested. Two different methods to add the microcapsules were identified and further investigated. In the first method, the microcapsules are glued to the membrane surface, whereas in the second method, the microcapsules are added during the membrane fabrication. The different membrane modifications were studied and compared using CFD. Therefore, virtual geometries mimicking the real ones were created. An idealized virtual geometry was added to the comparison. Results from the simulation were fed back to the experiments to optimize the combined membrane. For the presented setup, it is shown that the glued configuration provides a lower transmembrane pressure than the configuration where microcapsules are added during fabrication.
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