Flow control in paper-based microfluidic channel by using hydrophobic tape barrier on the paper surface

Paper-based microfluidics offers a simple, cost-effective, and versatile platform for fluid manipulation and analysis. Despite significant advancements in paper fluidics, the flow control in paper channel remains a challenging task. In this regard, we have developed a flow delay channel in paper using rectangular tape patterns on the paper surface. We have investigated the effect of hydrophobic tape barriers with varying widths. The designing and cutting of the hydrophobic tape and paper channel was performed by CO2 laser machine using CorelDraw software. Once cut, the tape barriers were attached to the paper surface and then passed through the roller press machine for proper adhesion of tape pattern onto the paper’s surface. From experiments, we observed that by increasing the width of tape, the delay also increased. The hydrophobic tape on the paper surface caused resistance to the flowing fluid. Due to this surface resistance, flow velocity reduced, and the time delay increased. We believe that our novel approach will provide an alternative method of flow control for paper-based microfluidic devices and can be utilized in various food quality sensors and lateral flow devices.