Polyimide based fiber optic humidity sensor

The control of environmental conditions, such as temperature, pressure, and humidity, are important in many applications ranging from bio-medical to space exploration. Proper humidity control is also important in the conservation of organic materials. Therefore an accurate and sensitive method to characterize the moisture content of the particular environment is of valuable importance. This paper proposes a humidity sensitive polyimide material as a fiber optic sensor for humidity measurements. The spectral analysis and the intensity of transmitted light through the polyimide sensor will represent the humidity measure. The paper also presents the absorption characteristics of the proposed humidity sensitive material. The experimental values on the spectral shift and light intensities are measured at different humidity conditions. This paper will also present the feasibility study for using the proposed fiber optic sensor for humidity measurements.