New paper-based microfluidic tools for the analysis of blood serum protein and creatinine built via aerosolized deposition of polycaprolactone

This article describes a low-cost method for rapid fabrication of paper-based microfluidic devices using an aerosolized polymeric solution and substrates masked with painter's tape. This approach requires only a few simple tools and uses low-cost supplies to achieve fully functional microfluidic paper-based analytical devices. The method is capable of producing devices with minimum hydrophilic channel widths of 482 +/- 4 m, with the channel height being dictated by the substrate thickness. Complete hydrophobic barriers can be achieved with widths of only 257 +/- 2 m. This technique enables two dimensional (2D) fluidic pattern fabrication on a single membrane while complex three dimensional (3D) fluidic pattern fabrication is possible by simply incorporating a stack and lamination step. Devices built using this approach were applied in two clinical diagnostic applications: quantitative colorimetric assays for protein and for creatinine.