Microfluidic devices are used to process and manipulate small amounts of liquids. Applications using biological (aqueous) samples require channels with a hydrophilic surface for a better liquid flow, and/or anti-biofouling properties to avoid unwanted adsorption of biomolecules to the channel walls. Conventional methods for hydrophilization add complexity and cost to the manufacturing process, and are often incompatible with bonding techniques. Moreover, the hydrophilicity may deteriorate over time, and/or the hydrophilized surface may be prone to unwanted adsorption of biomolecules (biofouling). Surfix Diagnostics has developed a proprietary technology called “Coat & Close” (C&C), by which coating and bonding of polymer microfluidic devices are performed in one step. C&C yields bonded microfluidic devices with stable hydrophilic, anti biofouling channels. The C&C technology is also advantageous because it prevents bubble formation and enhances flow by rounding the channel corners, and smoothening surface roughness. In PHOTO-SENS*, the C&C process is further developed into a scalable process for microfluidic device fabrication. * This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 965643. See www.photo-sens.eu for more information.