A stand-alone pressure-driven 3D microfluidic chemical sensing analytic device

•The pressure-driven flow (PD-PAD) was roughly 300-fold faster than the capillary-driven flow (CD-PAD).•The more the input pressure increased, the more the flow increased.•The curved channels less than 90° led to a decreased flow rate in the CD-PAD, but did not affect the PD-PAD.•The superior flow rate in the PD-PAD was likely due to the concurrence of the pressure- and capillary-driven flows.

This study introduces a new stand-alone pressure-driven 3D microfluidic chemical sensing analytic device (PD-PAD), fabricated by enclosing a cover substrate and inserting a void-channeled substrate on a conventional capillary-driven microfluidic paper-based analytical device (CD-PAD). Adhesive cold-laminating film and filter paper were used as a substrate. The flow rates of 3D PD- and CD-PAD platforms were compared through five different character-shaped microfluidic channels. A single 60-μL drop of fluid inducing 0.4 mbar of pressure showed that the PD-PAD was roughly 300-fold faster than the CD-PAD. The more input pressure in the PD-PAD increased, the more flow increased. The structures with the curved channels less than 90° led to a decreased flow rate in the CD-PAD, but did not affect the PD-PAD. The superior flow rate in the PD-PAD was likely due to the concurrence of the pressure-driven and capillary-driven flows. The glucose and albumin concentrations with a clinically relevant range and pH levels were successfully detected. Therefore, a stand-alone 3D microfluidic PD-PAD platform has great potential for assessing for the presence of diseases in very urgent situations such as the operating room or for use in low-cost and fast point-of-care applications.

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