A resistive sensor for humidity detection based on cellulose/polyaniline.

Area of Science:

• Materials Science
• Sensor Technology
• Environmental Monitoring

Background:

• Ambient humidity significantly impacts industrial and agricultural goods manufacturing and storage.
• Cost-effective humidity sensors are crucial for the widespread adoption of Internet of Things (IoT) for environmental monitoring.
• Current humidity sensor production faces cost and scalability challenges.

Purpose of the Study:

• To develop and characterize low-cost humidity sensors using cellulose and polyaniline (cell/PANI).
• To evaluate the performance of cell/PANI sensors under controlled environmental conditions.
• To assess the potential of these sensors for various applications, including IoT devices.

Main Methods:

• Cell/PANI sensors were fabricated using an inexpensive and scalable industrial paper process.
• Sensor performance was tested under strictly controlled relative humidity (30-50 RH%) and temperature (21 ± 1 °C) in climatic and lab test chambers.
• Sensor response, sensitivity, and response time were compared against a commercial digital-output sensor (DHT22).

Main Results:

• The cell/PANI sensors exhibited a linear response with a slope of 1.41 μA RH%⁻¹.
• A percentage sensitivity of 13% was achieved, comparable to the commercial DHT22 sensor's 14% sensitivity.
• Response time and sensitivity results were similar to the commercial sensor, indicating competitive performance.

Conclusions:

• The developed cell/PANI sensors are cost-effective, easy to produce, and scalable.
• These sensors demonstrate potential for reliable humidity detection in diverse environments.
• Applications include agriculture, food monitoring, and medical/industrial settings, particularly as disposable sensors.