Starting from commercially‐available, polymer‐based reactive resins like acrylates or unsaturated polyesters, a systematic investigation was carried out as to the influence organic dopants like phenanthrene and its derivatives have on the optical and thermal properties of the mixtures resulting from curing to the final thermoplastic polymer. The refractive index of PMMA at 633 nm can be increased, starting from 1.49 for the pure polymer, up to a value of around 1.55, and, in the case of the polyester, from 1.565 up to 1.6. The transmittance in the visible range is slightly affected at a lower dopant concentration of up to 10 wt.‐%, and remains better than 80% for a sample with a thickness of 1 mm, in the range between 500 and 800 nm. An unwanted side‐effect of larger dopant concentrations is to lower the glass transition temperature significantly.magnified image

Plastic Optical Fibers (POF) show advantageous properties like high flexibility and their cost advantage in comparison to glass fibers. The refractive indices of core and cladding have to be modified in order to get total reflectance. Thus, there is a strong demand for refractive index adjustable polymers with improved transmission properties in the visible and the NIR range. Inorganic nanosized particles or organic dyes homogeniously dispersed or solved in the polymer matrix allow a tailored increase or decrease of the refractive index of various polymers.

The introduction of forming technology into MEMS manufacturing demands forming dies being characterized by a high strength and hardness, a good micro-structurability, a low surface roughness, and a high precision of the microgeometry to be molded. Silicon structured by lithography and etching processes meeting these requirements especially concerning precision and surface roughness. For micro-metalforming silicon dies with different structural dimensions (>1 mum) have been used. The microstructures could be molded in different materials using cold and superplastic embossing. The precision and surface quality of the formed parts correspond to the high quality of the microstructured die. Both the low surface roughness and the accurate edges of the silicon structures are nearly represented in the molded structures. However, in particular during cold embossing die wear or even die failure could be observed limiting the implementation of silicon for micro-metalforming

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Bei der geometrischen Interpretation von gewissen Aufgaben z.B. aus dem Bereiche der Statistik einerseits oder der Matrizenalgebra andererseits treten Simplexe in Riemannschen Räumen konstanter Krümmung auf. Ein spezieller Typus eines solchen Simplexes ist das Orthoschem. Für dieses ergibt sich da nun die Aufgabe, anzugeben, in welcher Weise die Masse der Kanten und der verschiedensten Winkel eines Orthoschems miteinander zusammenhängen.