Design And Fabrication Of Paper-based Three-dimensional Microfluidic Device And Its Application In Heavy Metal Monitoring

Microfluidic paper-based analytical devices (μPADs), as a burgeoning research field,possess attractive features such as low-cost, portable, and easy-to-use, easy-to-fabricate,bio-compatible compared to the conventional microfluidic devices fabricated with silicon,glass, and poly materials, μPADs combine the advantages of microfluidic technology andpaper. By patterning hydrophilic and hydrophobic microfluidic channels and microstructureson paper, micro total analytical systems are fulfilled features with the miniaturization,integration and portability. μPADs also provides a new platform for microfluidic analysis.This work aims at to develop a novel fabrication method of paper-based microfluidic devicesand study the applications of μPAD of heavy metals in aquatic environments. The detailedwork in this thesis includes:1. We presented a simple and low cost production method to generate paper-basedmicrofluidic device with wax for portable metal assay. The wax patterning method weintroduced here was printing by a wax printer directly. Metal assay was carried out to verifythe performance of wax-patterned papers.2. We reported the fabrication of paper based microfluidics devices in nitrocellulosemembrane by wax printing. The use of wax-patterned nitrocellulose membrane such as metalassay was necessary to demonstrate.3. We reported the use of wax-patterned papers and wax-patterned nitrocellulosemembrane by wax printing as substrates for three-dimensional hybrid microfluidic device.The whole process consisted of three steps:1) printing the wax to papers and nitrocellulosemembranes;2) fabricating the papers and membranes to3D paper microfluidics;3) droppingthe reagents onto the paper chip. The whole process can be finished within0.5h. On-chipmetal assay between metal ion and chromogenic agent was performed results can be imagedby camera cell phone. The detection results obtained by camera phone showed excellentcorrelation with the concentration of metal ion and chromogenic agent.