Abstract

Next-Generation MicroPADs: Merging 3D Printing with Microfluidic Paper-Based Analytical Devices (MicroPADs)

Brandon Strong, Graduate Research Assistant, California Polytechnic State University, San Luis Obispo

Microfluidic Paper-Based Analytical Devices (MicroPADs) have emerged as useful diagnostic tools. They possess many key characteristics, including portability, cost-effectiveness, ease of use, low sample volume requirements, and ability to operate without supporting equipment. Researchers have modified microPADs in a myriad of ways to increase functionality, however, the use of 3D printing on microPADs has yet to be explored. The purpose of this project was to use 3D printing to expand microPAD functionality and combat current limitations. MicroPADs were fabricated on chromatography paper via wax printing and affixed to the bedplate of a BCN3D Sigma (dual-extrusion 3D printer). Polylactic acid (PLA) and conductive PLA structures were fabricated on microPADs via 3D printing. 3D fluid reservoirs were fabricated from PLA and allowed for larger sample volumes and further wicking distances on microPADs. Electrodes were fabricated from conductive PLA and allowed for simple electroanalysis on paper. Hybrid devices with both PLA channels (100 µm) and paper channels were also created. PLA-backed hemi- and fully-enclosed paper channels were fabricated, which may allow for increased robustness and reduced contamination of biochemical assays on microPADs, as well as the ability to run devices in direct contact with surfaces (i.e., not held in suspension).