Rapid fabrication of paper-based microfluidic analytical devices with desktop stereolithography 3D printer

Abstract

In this study, we developed a novel and facile method for fabricating paper-based microfluidic analytical devices (μPADs) with dynamic mask photo curing (DMPC), generated by a desktop stereolithography (SL) three-dimensional printer (3DP). First, we immersed the filter paper in ultraviolet (UV) resin to cover it evenly. Next, we exposed it to UV-light through a dynamic mask of the negative channel pattern. After curing, the UV-exposed regions become highly hydrophobic, creating hydrophobic barriers. Finally, we washed the uncured resin with anhydrous alcohol and fine μPADs were obtained. The resolution of the fabricated hydrophilic channels was 367 ± 20 μm, with a between-channel hydrophobic barrier of 400 ± 21 μm. To verify this method's performance, we fabricated μPADs with DMPC for quantitative analysis of nitrite ion. This new method represents a leap forward in terms of time saved. Since all hydrophobic barriers are cured at a time, the fabrication process can be completed in only two minutes, no matter how complex the patterns are. Compared to the widely used fabrication method of μPADs, wax printing, DMPC provides an alternative way to fabricate μPAD with different hydrophobic barriers materials, which provides the possibility of designing different μPADs according to the application environments.