Development of 3D printing technologies for manufacturing microfluidic devices for bioengineering applications

[eng] Advancements in 3D printing have revolutionized microfluidic device fabrication, offering unprecedented flexibility and precision in the design and production of complex geometries. This thesis presents a comprehensive study utilizing a custom-made DLP-SLA 3D printer and commercially available resins to develop and evaluate microfluidic devices for applications in particle separation and fluid mixing under laminar flow conditions. A detailed analysis of printing errors was conducted, highlighting the challenges posed by over-curing effects, which significantly impact the ability to fabricate closed microchannels with high dimensional accuracy. The research involved a dual approach of computational simulations and experimental validations to optimize device performance. Spiral microfluidic devices were designed and tested for particle separation, achieving efficient separation of particles larger than 75 µm under laminar flow conditions, with Reynolds numbers carefully analyzed to ensure optimal performance. Additionally, staggered herringbone mixers were developed to enhance mixing efficiency through chaotic advection. The results demonstrated effective mixing of fluids, confirming the versatility of these devices in achieving homogenous mixing even at low Reynolds numbers. This work underscores the potential of DLP-SLA 3D printing in fabricating both open molds for PDMS replication and fully enclosed microchannels, offering a scalable and customizable alternative to traditional lithographic methods. The findings contribute to advancing the field of microfluidics, providing insights into the interplay between fabrication techniques, material properties, and device functionality. Future applications of these devices extend to biomedical diagnostics, chemical synthesis, and lab-on-a-chip systems, highlighting their relevance and impact in both research and industry.