Highly Sensitive and Full Range Detectable Humidity Sensor using PEDOT:PSS, Methyl Red and Graphene Oxide Materials

Area of Science:

• Materials Science
• Sensor Technology
• Chemical Engineering

Background:

• Single transducer humidity sensors have limited range and sensitivity.
• Existing materials like graphene oxide (GO), PEDOT:PSS, and Methyl Red show partial RH detection ranges.

Purpose of the Study:

• To develop a highly sensitive, full-range relative humidity (RH) sensor.
• To overcome the limitations of single-material sensors by combining multiple active layers.

Main Methods:

• Fabrication of a humidity sensor using multiple inter-digital transducer (IDT) electrodes connected in series.
• Utilizing poly(3,4-ethylenedioxythiophene) doped poly(styrene sulfonate) anions (PEDOT: PSS), Methyl Red, and graphene oxide (GO) as active sensing materials.
• Employing ink-jet printing and spin coating for sensor fabrication.

Main Results:

• The proposed sensor successfully detects the full relative humidity (RH) range from 0% to 100%.
• Achieved rapid response time of 1 second and recovery time of 3.5 seconds.
• Demonstrated high sensitivity across the entire RH spectrum.

Conclusions:

• A multi-material, multi-transducer sensor design overcomes the range and sensitivity limitations of single-transducer devices.
• This approach enables high-performance humidity sensing applications.
• The combined active materials provide a synergistic effect for comprehensive RH detection.