Measuring morphology of live biofilms under shear using DHMI in eChip microfluidic platform

Understanding biofilm morphology in boundary layer is essential for advancing antifouling strategies and modeling microbe-surface-flow interactions. In this study, biofilms formed by E.coli are characterized using a microfluidic ecology-on-a-chip (eChip) platform that replicates real-world flow conditions with precisely controlled shear rates. Biofilms are formed on a transparent substrate installed within a microchannel, allowing direct optical access. Digital Holographic Microscopy Interferometry (DHMI) is used to capture continuous surface profiles at nanometric vertical resolution (~7 nm), with data acquisition sustained over multiple days. This setup enables uninterrupted monitoring of biofilm growth and surface evolution, facilitating quantitative analysis of spatiotemporal morphological changes under flow. This integrated approach facilitates the quantification of growth dynamics, structural features, and flow-aligned morphological changes, providing a basis for improved understanding of surface fouling mechanisms under controlled shear flow.