Rapid fabrication of microfluidic paper-based analytical devices by microembossing.

Highlights • The microfluidic paper based analytical devices (μPADs) with no need of hydrophobic backside can be fabricated by microembossing within 1 min. • The protruded structure is obtained after embossing, which becomes the channel after heating the wax on the backside of the filter paper. • The μPADs with minimum 2 mm channel width were made by Whatman No. 3 paper at pressure larger than 50 kg/cm2, and wax heating time ranging from 15 to 45 s. • The glucose detection was performed and a linear relationship was obtained between 5–50 mM glucose concentrations. Abstract In this study, fabrication of microfluidic paper based analytical devices (μPADs) by microembossing was proposed. Different from the embossing methods described in the literature, the filter paper was embossed such that a protruded structure was formed, which subsequently became the channel after heating the wax at the backside of the filter paper. It was found that, when using the Whatman No. 3 filter paper, the embossing pressure needed to be larger than 50 kg/cm2 in conjunction with using a minimal 2-mm wide channel, and the wax heating time ranged from 15 to 45 s in order to obtain a reliable μPAD with repetitive and consistent results. In addition, there was no need of a hydrophobic material as the backside support. The glucose detection was demonstrated using the μPADs as fabricated and a linear relationship was obtained between 5 and 50 mM glucose concentrations. With the proposed method, the processing time of fabricating μPADs can be reduced within approximately 1 min. [ABSTRACT FROM AUTHOR]