Research into the technology of manufacturing microfluidic chips using soft lithography

   Purpose. To explore the specifics of microfluidic chip manufacturing technology using soft lithography, including the following stages: channel structure design; mold fabrication using various methods on glass, foil-clad PCB, and silicon substrates; selection of the required polymer, polymerization modes, mold treatment with a release agent, compound filling and subsequent separation, activation, and subsequent bonding of the resulting chip to the prepared glass.

   Methods. Photolithography experiments were conducted using a monochromatic Anycubic Wash and Cure 2.0 light source on foil-clad PCB substrates, glass slides, and silicon wafers. Formwork for the constructs was fabricated using a FlyingBear Ghost 5 FDM printer. Silagerm 2104 and 2106 were used as PDMS. A Diener PICO low-pressure plasma system with an air environment was used for the bonding process.

   Results. Photolithography studies were conducted to determine the exposure time, the method of covering the transfer template, and the substrate material. Experiments were conducted to create constructs and their viability. The effect of gas pressure in a vacuum chamber during plasma activation of the polymer replica surface was studied.

   Conclusion. The experiments identified a silicon substrate as the best master mold material for soft lithography. Parameters for simplified, cost-effective, and safe plasma bonding of PDMS and glass replicas were determined. The results can be applied as protocols for the fabrication of microfluidic devices by small research laboratories.

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