There is a growing demand for inexpensive, sensitive and reliable humidity sensors with microprocessor-controlled electronics. Next to temperature, humidity is the most important variable in environmental measurement and control applications. In terms of detrimental effects on the life and performance of electronic equipment and quality control in manufacturing, humidity is often the more important parameter. Humidity sensors have broad industrial and domestic applications for increasing the reliability and effective use of electronic equipment, as well as decreasing energy consumption. Most commercially available relative humidity sensors use hydrophilic hydrocarbon-based polymer films as humidity-sensing elements. However, they are not sufficiently resistive to water or to elevated temperatures and cannot be used at high humidities for extended periods of time. In this project, the simple processing steps associated with an organic polymer will be taken advantage of in fabricating a highly sensitive, stable and durable humidity sensor. Shortcomings encountered with hydrocarbon-based polymers will be overcome by using highly stable proton-conducting fluorocarbon polymer materials. These materials have an established performance record in electrochemical system, e.g., fuel cells and chlor-alkali electrolyzers, under highly oxidizing and aggressive environments. The physical and chemical properties associated with proton-conducting fluorocarbon polymers make them very attractive as the sensing elements in humidity sensors.
