Fabrication of microwell plates and microfluidic devices in polyester films using a cutting printer

This study reports, for the first time, the possibility to manufacture analytical devices on polyester substrates using a cutting printer. The protocol involves the design of a layout in a graphical software, the cut into polyester films and the lamination against one or multiple polyester films coated with a thermosensitive layer. The feasibility of the proposed approach was demonstrated through the fabrication of 96-microwell plates, 3D microfluidic mixing and distance-based microfluidic devices. The printer has enabled cutting microchannels wider than 300 μm on polyester films and a thickness of 250 μm. Urea and glucose assays were performed on microwell plates aiming for their quantification in artificial urine and serum samples. The presented results revealed good agreement with the expected values. The complexation reaction between Fe²⁺ and o-phenanthroline was selected as model to investigate the feasibility of the 3D mixing device. Absorbance measurements were recorded for the reaction product performed in both on and off-chip modes. Considering the achieved data, the on-chip mixing exhibited similar behavior when compared to off-chip reaction, thus demonstrating to be efficient to perform mixtures due to the turbulence generated inside three-dimensional channels. Lastly, a distance-based device was designed to detect H₂O₂ based on the displacement of a dye plug promoted by the oxygen generation using a copper-modified paper sheet. The distance-based peroxymeter revealed a linear behavior in the concentration range between 1 and 5% (v/v) and a LOD equal to 0.5% (65.2 mM). Based on the results herein reported, the proposed method represents a simple and alternative protocol to produce microdevices, using affordable and inexpensive raw materials, within 10 min, and at a cost lower than US$ 0.10 per unit.