3D-Printed Microfluidic Device for Biological Application

The majority of microfluidic devices are made using the gold standard PDMS material because of their high resolution and transparency. However, there are still an adequate number of barriers hindering their commercial scalability, potentially impeding their widespread adoption in biological research. In contrast, digital light processing (DLP), printing has revolutionized the low-cost and high-resolution fabrication of microfluidic devices by offering a convenient method for producing assembly-free, customizable and intricate designs. This is the first report where the influence of Luria Broth and Tryptic Broth (growth media) was simultaneously studied on the adhesion and subsequent biofilm formation of E.Coli using a DLP-printed microfluidic device fabricated using acrylate-based resin under constant flow rate condition. Unlike static assay, where there is limited growth nutrient, this system can continuously provide nutrients for growth. This platform can be customizable to understand the capability of different bacteria to form biofilm and the effect of a specific molecule of interest adhered on the bacteria. The resin material was characterized using X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), universal testing machine (UTM) and micro-CT. The bacterial growth was studies for an extended time period. As the culture time increased, the density of adhered bacteria also increased. The overall dimensions of the channel were confirmed using micro-CT imaging. The data revealed that this material is not only bio-compatible for bacterial growth but also serves as a novel model system for studying bacterial adhesion and biofilm formation in micro-confinement. These findings were further supported by computational fluid dynamics (CFD) simulations. The shear stress profile demonstrates that, with elevated stress observed in the inlet and outlet sections and a decrease in the central channel. A uniform shear stress (0.004 Pa) along the channel walls, relatively higher than in the central region where shear stress is minimal, promoting bacterial adhesion and biofilm formation.