Garage-Fabricated, Ultrasensitive Capacitive Humidity Sensor Based on Tissue Paper

Area of Science:

• Materials Science
• Sensor Technology
• Environmental Science

Background:

• Traditional humidity sensors often utilize non-degradable materials, contributing to electronic waste.
• There is a need for cost-effective, sustainable, and high-performance humidity sensing solutions.

Purpose of the Study:

• To develop and characterize a novel, eco-friendly capacitive humidity sensor.
• To evaluate the sensor's performance for field applications.

Main Methods:

• Fabrication of a parallel-plate capacitive sensor using copper tape and tissue paper as dielectric.
• Testing sensor performance across a relative humidity range of 40% to 99% using an Arduino.
• Assessing sensor response time, recovery time, stability, and repeatability at varying temperatures.

Main Results:

• The sensor demonstrated a linear capacitance response (240 pF to 720 pF) with relative humidity.
• Achieved rapid response (~1.5 s) and recovery (~2.2 s) times.
• Exhibited high accuracy (±0.1%), stability across temperatures, and excellent repeatability over multiple trials.

Conclusions:

• The developed tissue paper-based humidity sensor is a low-cost, flexible, and sustainable alternative.
• Its performance characteristics make it suitable for diverse field applications, addressing electronic waste concerns.