Monday, June 18, 2007
Golden Eagle Eyrie (Boise Centre on the Grove)

Polymer Nanocomposite Based Chemiresistive NOx Sensor

Divakara A.B.S. Meka, Linda A. George, and Shalini Prasad. Portland State University, Portland, OR

The research objective is the development of a portable sensor for monitoring trace gas emissions in the environment. This will be achieved by developing a polymer nanocomposite that undergoes electrical parameter modification to detect the trace gases. The key innovation is the improved signal to noise ratio resulting in enhanced sensitivity in the chemiresistive nanocomposite sensors. The scope of the current application is the demonstration of a sensor platform for detecting NOx with enhanced sensitivity and specificity through innovative functionalization and packaging of nanomaterial. For the current application, the sensor characteristics will be demonstrated for nitrogen dioxide (NO2).

The goal is to improve sensitivity for carbon-based nanomaterial sensors from parts-per-million (ppm) levels to parts-per-billion (ppb) under real world levels of air contaminants.

The principle of operation of these chemiresistive sensors is based on the measurement of resistance change associated with the adsorption of gaseous agents by the nanomaterial matrix. These NOx sensors function on the chemiresistive principle-variations in the resistance of a NOx sensitive polymer encapsulated active sensing element comprising of carbon nanoparticles is observed due to the selective adsorption of the gas molecules

In contrast to the current techniques in gas sensing, the technique that is under development has a simple photolithography based fabrication scheme that can be executed on a non specialized wet bench, thus it is less expensive, highly reproducible and robust.