Polypyrrole Percolation Network Gas Sensors: Improved Reproducibility through Conductance Monitoring during Polymer...

Area of Science:

• Materials Science
• Electrochemistry
• Sensor Technology

Background:

• Conducting polymer percolation networks are key for sensitive chemiresistive devices.
• A major challenge is achieving consistent network properties for reliable sensor performance.
• Current methods often require individual device calibration due to variability.

Purpose of the Study:

• To develop a method for reproducible electrochemical growth of polypyrrole (PPy) percolation networks.
• To utilize in situ conductance monitoring to control network formation.
• To enhance the consistency and reduce calibration needs of chemiresistive sensors.

Main Methods:

• Electrochemical polymerization of polypyrrole (PPy).
• In situ monitoring of drain current (i_d) across interdigitated electrodes (IDEs) during growth.
• Using the i_d curve to identify the percolation region and optimize network formation.

Main Results:

• Successfully created reproducible PPy percolation networks using in situ conductance monitoring.
• Developed optimal ammonia gas percolation sensors with improved consistency.
• Achieved an average sensitivity of 11.3 ± 1.2% ppm⁻¹ and a limit of detection of 15.0 ± 3.6 ppb.

Conclusions:

• In situ conductance monitoring is an effective strategy for reproducible PPy percolation network fabrication.
• This method significantly improves the reliability and performance of chemiresistive gas sensors.
• The developed sensors demonstrate high sensitivity and low detection limits for ammonia gas.