Pump-Free Microfluidic Rapid Mixer Combined with a Paper-Based Channel

Area of Science:

• Microfluidics
• Analytical Chemistry
• Materials Science

Background:

• Paper-based microfluidics utilize capillary forces for fluid transport but face challenges in stable flow functions like mixing due to paper's porous, nonuniform nature.
• Limitations in existing paper-based systems necessitate advancements for reliable fluid manipulation and analysis.

Purpose of the Study:

• To develop a novel pump-free microfluidic device that overcomes the mixing limitations of traditional paper-based platforms.
• To enable rapid and efficient fluid mixing by integrating paper with plastic components.
• To demonstrate the device's utility for sensitive and onsite detection of organophosphate pesticides.

Main Methods:

• Fabrication of a hybrid paper-plastic microfluidic device by laminating transparency film and double-sided adhesive, featuring an overlapping inlet and a paper-based reaction area.
• Experimental validation of mixing performance using aqueous dyes and pH indicators.
• Numerical evaluation of the absolute mixing index by calculating concentration fields.
• Application in a colorimetric enzymatic inhibition assay for organophosphate pesticide detection.

Main Results:

• The developed hybrid device demonstrated effective and rapid fluid mixing.
• Experimental and numerical analyses confirmed the device's mixing capabilities.
• Successful detection of organophosphate pesticides in food samples was achieved using the device coupled with a smartphone application.

Conclusions:

• The integrated paper-plastic microfluidic device offers a promising solution for enhanced fluid mixing in pump-free systems.
• This approach enables sensitive and rapid onsite detection of organophosphate pesticides, with potential for broader analytical applications.
• The developed technology holds significant potential for field-based chemical analysis and diagnostics.