Platinum (Pt) is an interesting material for many applications due to its high chemical resilience, outstanding catalytic activity, high electrical conductivity, and high melting point. However, microstructuring and especially 3D microstructuring of platinum is a complex process, based on expensive and specialized equipment often suffering from very slow processing speeds. In this work, organic–inorganic photoresins, which can be structured using direct optical lithography as well as two‐photon lithography (TPL) with submicrometer resolution and high‐throughput is presented. The printed structures are subsequently converted to high‐purity platinum using thermal debinding of the binder and reduction of the salt. With this technique, complex 3D structures with a 3D resolution of 300 nm were fabricated. At a layer thickness of 35 nm, the patterns reach a high conductivity of 67% compared to bulk platinum. Microheaters, thermocouple sensors as well as a Lab‐on‐a‐Chip system are presented as exemplary applications. This technology will enable a broad range of application from electronics, sensing and heating elements to 3D photonics and metamaterials.
Polymerizable merocyanine and cyanine dye monomers are synthesized and applied in a statistical copolymerization with methylmethacrylate, giving a series of highly fluorescent poly(methyl methacrylate) (PMMA) copolymers. Photophysical properties of yellow to red merocyanine- and of pink to dark purple cyanine-containing copolymers are studied by fluorescence spectroscopy in solid state as well as in different solvents. The highest quantum yield measured in the solid state is observed for copolymers with the lowest dye content: 16% for merocyanine-based and 13% for cyanine-based copolymers, respectively. Fluorescence properties in solution show positive solvatochromism for both merocyanine monomer and copolymer. Copolymer, in comparison to monomer, is hypsochromically shifted to lower wavelengths which point toward H-aggregation of the chromophores in the copolymer matrix.
Three-dimensional (3D) printing has already shown its high relevance for the fabrication of microfluidic devices in terms of precision manufacturing cycles and a wider range of materials. 3D-printable transparent fluoropolymers are highly sought after due to their high chemical and thermal resistance. Here, we present a simple one-step fabrication process via stereolithography of perfluoropolyether dimethacrylate. We demonstrate successfully printed microfluidic mixers with 800 mm circular channels for chemistry-on-chip applications. The printed chips show chemical, mechanical, and thermal resistance up to 200 °C, as well as high optical transparency. Aqueous and organic reactions are presented to demonstrate the wide potential of perfluoropolyether dimethacrylate for chemical synthesis.
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