Abstract
In this dissertation, methods to fabricate paper-based analytical devices (PADs) alternative to solid wax printing were discussed. Laser toner printing and fused deposition modeling (FDM) printing have been identified as potential candidates to fabricate PADs, and they were characterized for the fabrication of PADs with unique applications. Firstly, the development of the microfluidic paper-based analytical device (µPAD) by patterning toner on filter paper for the analysis of glucose and protein was demonstrated. The penetration of the polymers from toner on filter paper was performed by heating. Colorimetric analyses of the glucose and protein solutions were conducted on Benedict’s solution and tetrabromophenol blue (TBPB) respectively. Secondly, the development of PAD with heating capability was demonstrated using exposure to infrared (IR) radiation. The absorption of infrared radiation by printing black toner on filter paper was conducted by heating the heater PAD under the IR lamp and exposure to sunlight. Thirdly, the construction of the three-dimensional paper-based analytical device (3D-PAD) was demonstrated by FDM printing of two polymers. FDM printing of polymer with a low melting temperature is a relatively recent advancement in technology. Polycaprolactone (PCL) and polylactic acid (PLA) were used to fabricate PAD possessing 3D structures that enhanced solvent containment. Fourthly, low-density polyethylene (LDPE) and paraffin were blended into a composite filament for the fabrication of electrochemical paper-based analytical devices (ePADs) by multi-material FDM printing. Overall, laser printing and FDM printing offer capabilities to pattern hydrophobic and functional components, which will make the PADs available to various research communities.