PCB-C⁴D coupled with paper-based microfluidic sampling for the rapid detection of liquid conductivity

Area of Science:

• Analytical Chemistry
• Materials Science
• Microfluidics

Background:

• Traditional liquid electrical conductivity detection methods face challenges with electrode contamination, impacting accuracy.
• Capacitively coupled contactless conductivity detection (C4D) offers a non-contact alternative, but is sensitive to solution impurities.
• Impurity particles in solutions can reduce the consistency and repeatability of C4D measurements.

Purpose of the Study:

• To develop an improved contactless conductivity detection method using paper-based microfluidics and PCB-C4D.
• To enhance the reliability and accuracy of conductivity measurements by addressing the issue of impurity particles.
• To create a practical and compact system for in situ conductivity detection.

Main Methods:

• Integration of paper-based microfluidic technology with printed circuit board-capacitively coupled contactless conductivity detection (PCB-C4D).
• Implementation of in situ rapid filtration to remove impurity particles from solution samples prior to detection.
• Optimization of PCB-C4D parameters, microfluidic channel dimensions, filtration duration, and sample flow rate.

Main Results:

• The combined approach significantly improved the consistency and reliability of conductivity detection by removing impurity particles.
• Optimized parameters and system design facilitated accurate and rapid in situ conductivity measurements.
• Validation of the method using real-world samples including orange juice, cucumber extract, and soil solutions.

Conclusions:

• The developed paper-based microfluidic system with PCB-C4D and integrated filtration offers a robust solution for accurate liquid electrical conductivity detection.
• This technology enhances the practical applicability of contactless conductivity detection in various fields such as food safety, water quality, and agricultural monitoring.
• The study demonstrates a significant advancement in portable and reliable in situ analysis through the synergistic combination of microfluidics and advanced sensor technology.