Fabrication and Application of a Microfluidic Chip for Biofilm Cultivation and Analysis under Controlled Flow

Microbial biofilms present significant challenges in healthcare due to their persistence and resistance to antimicrobial treatments. Microfluidic technologies offer a promising alternative to traditional static systems for studying biofilm dynamics under physiologically relevant conditions. In this study, we present a poly-(dimethylsiloxane) (PDMS)-free microfluidic platform fabricated using off-stoichiometry thiol-ene (OSTE) resin and cyclic olefin copolymer (COC) substrates. The device features five independent growth chambers and is designed for compatibility with standard laboratory setups. It enables controlled flow conditions, optical transparency for real-time imaging, and integration with antimicrobial testing protocols. Biofilms of Staphylococcus aureus and Pseudomonas aeruginosa were cultivated under dynamic flow and compared to static cultures in tissue culture wells. Confocal microscopy was used to assess structural features, viability, and thickness over time. The dynamic environment supported more uniform and spatially organized biofilm growth, while static conditions led to denser but structurally heterogeneous formations. Treatment with different tetracycline concentrations demonstrated effective biofilm disruption, particularly under flow, confirming the platform's utility for evaluating antimicrobial efficacy. With a fabrication cost below five dollars per chip and potential for cleaning and reuse, the platform offers a cost-effective and scalable solution for biofilm research. This study highlights the advantages of OSTE-COC microfluidics in modeling biofilm-associated infections and provides a practical tool for real-time biofilm analysis and therapeutic screening.