3D-printed microfluidics on thin Poly(methyl methacrylate) substrates for genetic applications

Additive manufacturing techniques using three dimensional (3D) printing have been shown to be suitable for a wide range of applications. In this study, stereolithography (SLA) is applied to the field of microfluidic fabrication of lab-on-a-chip (LOC) devices. LOCs deal with different milli/microsized channels and chambers, which are the key features of the devices, so an appropriate manufacturing process should provide high precision as well as high versatility. In this work, the goal was to overcome the common drawbacks of 3D printing and multistep processes, by implementing multiple polymeric materials in the same printing process. Using a customized SLA machine, a novel process was developed to print microfluidic channels enclosed between two poly(methyl methacrylate) layers in a sandwichlike structure. For microfluidic walls, two distinct commercial resins with different properties were used. Once thermal and pressure resistance of the obtained LOCs were assessed, deoxyribose nucleic acid was amplified by polymerase chain reaction inside the microfluidic chambers. Test results indicated favorable mechanical and thermal resistance, as well as chemical compatibility with the assay reagents. Such observations suggest that this novel approach can be applied to 3D printing of customized microfluidics with embedded features.