Abstract
Applications of microfluidics have tremendously increased owing to its fast response, handling of small volumes, ease of integration, portability, and low cost. The increasing demand for microfluidic techniques can be met by the adoption of technologies that allow rapid and demand-specific fabrication of microfluidic devices. The freedom of design and capability of rapid prototyping has made 3D printing one of the obvious choices for fabrication. Conversely, the fundamental microfluidic/fluidic behavior of different fluids can remarkably enhance the existing 3D printing methods. This thesis explored the synergy between the two progressing fields of microfluidics and 3D printing, focusing on identifying ways to improve both. Chapter 1 described the simultaneous evolution of microfluidics and 3D printing, especially introducing different ways in which 3D printing is contributing to microfluidics and further explaining the benefits of integrating microfluidic (fluidic) techniques with 3D printers. Chapter 2 characterized different mechanisms of 3D printers for the fabrication of micromolds. Molds from liquid-based printers represented the designed structures in closeness than solid based printers, however, the printed structures notably deviated from the design. Further Chapter 3 evaluated micromolds from the liquid-based PolyJet printer for their deviation in dimension between designed and printed structures. This evaluation revealed the dependence of printed structures on the designed dimensions and layer thickness of printing. To improve the functionality of 3D printers, two different fluidic techniques were proposed in this thesis. Chapter 4 described a simple approach to fabricate customizable microfluidic flow-focusing nozzles. These nozzles created complex emulsions and templated structures. Chapter 5 combined the fluidic techniques of coiling instability and immersion precipitation to print structures made with coils. The use of surrounding nonsolvent enabled the fabrication of 3D structures with unique morphology using a wide range of operating conditions