Digital light processing additive manufacturing for accessible blood-brain barrier organ-on-a-chip fabrication

Abstract

Organ-on-a-Chip (OoC) technologies represent a promising alternative to traditional preclinical models and their actual limitations, yet their widespread adoption remains limited by cost, fabrication complexity, and accessibility. This thesis presents the development of an economically viable microfluidic platform designed to mimic the Blood-Brain Barrier (BBB) using Digital Light Processing (DLP) additive manufacturing. By leveraging the geometric freedom and rapid prototyping capabilities of DLP, a series of chips were fabricated and systematically evaluated through both structural characterization and functional assays. The platform’s performance was assessed via passive diffusion experiments using sodium chloride, providing a quantifiable readout of molecular transport across the chip interface. Particular emphasis was placed on the role of channel geometry in shaping diffusion behavior. Comparative analysis of square and circular layouts demonstrated that structural configuration alone can influence transport dynamics, even under equivalent flow conditions, an observation reinforced by simplified computational simulations. These findings call into question the extent to which current chip designs, often simplified because of the nature of the techniques, truly replicate physiologically relevant transport. Results revealed that the square chip exhibited faster and more direct fluid penetration through the interface, while the circular design induced more distributed flow with attenuated velocity vectors. This divergence also reflected in the diffusion curves, challenges the conventional assumption that greater surface area alone enhances transport, and emphasizes the need to reevaluate geometric decisions in microfluidic design. Beyond functionality, the fabrication process itself validated the feasibility of low-cost and reproducible production of complex microfluidic architectures. Together, these findings reaffirm the potential of DLP printed devices as accessible tools for biomedical research and establish a foundation for more physiologically relevant Organ-on-a-Chip systems.