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.

leaf (Nelumbo), superhydrophobic surfaces with a contact angle > 150° and low roll-off angles < 10°, have shown remarkable properties such as selfcleaning (so-called lotus effect), [1,2] antibiofouling [3] and anti-corrosion. [10,11] The surfaces rely on air pockets trapped in the micro-/nano-hierarchical structures to diminish the contact between the surface and the liquid to be repelled (Cassie-Baxter state). However, the composite solid/air interface design of these surfaces is metastable. Extreme conditions such as high pressure, high temperature, and abrasion cause loss of the super repellent properties, when the air is removed from the textured surfaces. Slippery liquid-infused porous surfaces (SLIPS) were developed as an alternative to superhydrophobic surfaces to address these limitations. [12][13][14] The mobility of the lubricant that is infused into the micro-/nanoporous structures allows liquid drops on the surface to easily slide off. These surfaces have shown exceptional omniphobicity, self-healing, [12] selfcleaning, [15] and antifouling properties. [15] However, like the air layer in superhydrophobic surfaces, the lubricant layer can be removed either by evaporation or replacement with other liquids and once the lubrication layer is lost and the solid surface is exposed, the material loses its slippery properties.Liquid repellent surfaces are of high interest in various fields like protective coatings and droplet manipulation due to their outstanding properties from self-cleaning to anti-fouling. Most reported surfaces rely on the fabrication of micro/-nanostructured surfaces, the infusion of porous surfaces with immiscible lubricants, or the grafting of monolayers with low surface energy to achieve repellence of various liquids. However, these methods are limited in terms of their durability and long-term stability. Here, the fabrication of smooth, transparent fluorinated poly (perfluoroalkyl methacrylate) coatings via UV-initiated radical polymerization in a simple one-step procedure is reported. The resulting surfaces show very low surface energies of down to 7 mN m −1 , low contact angle hysteresis below 5°, very good repellence towards various liquids with different polarities as well as self-cleaning and anti-graffiti ability. The fabricated coatings can be applied to various substrates from glass slides to microfiber cloths. This demonstrates that they outperform common commercially available fluorinated coatings, such as, for example, Hyflon AD 40L S, in terms of liquid repellence and their performance in real-world applications.

Polystyrene (PS) is the material of choice for many medical, biological, and biomedical applications given its advantageous properties such as high biocompatibility, optical transparency, and the possibility to shape PS using high‐throughput manufacturing methods at low production costs. Due to its properties, PS is an interesting material for the fabrication of microfluidic systems. In microfluidics, rapid prototyping is of high importance for testing new chip layouts and designs during the product development with the aim of significantly accelerating the manufacturing. To allow transitioning and thus significantly faster translation from research to scalable manufacturing, it would be ideal if the same material could be used throughout the whole design pipeline. However, rapid prototyping and high‐resolution shaping of PS, especially on the micron scale, is still limited. In this work,a novel photocurable polystyrene photoresin, is presented which can be shaped using direct optical lithography. Using this PS photoresin, microfluidic chips with feature sizes down to 50 µm and a high optical transparency can be fabricated. The cured PS photoresin shows comparable surface and material properties to commercial PS. This method will enable researchers in the medical, biological and biomedical fields to produce suitable PS structures with commercial equipment.

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