In my master's thesis, we tried to produce a microfluidic chip with optical access using additive technology, more specifically with 3D printing. For the printer, we used a DLP system from BMF with HTL-20 resin from the same manufacturer. We determined Jacob's curve and produced three Y microfluidic mixers. A closed type, one with a glued lid and one printed on a glass substrate. We compared them according to the topology of the cross section. We then tested the influence of certain parameters on adhesion. We tested the energy supplied to the first layer, how geometry affects adhesion and how the number of layers affect adhesion. Based on the tests, we found that printing on a glass substrate and gluing the lid on are the most suitable methods for chips with optical access. We found that increasing energy improves the adhesion of the resin to the substrate, but we can only increase the energy up to a certain value, after that the first layer starts to adhere to the membrane more than the substrate. Geometry has a significant impact on adhesion, there we should try to maximize the surface area of the first layer and minimize the rest. In our case, the best results for printing on substrate were obtained at an intensity of 114 mW/cm$^2$ and an exposure time of 16 s.
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