Grantee Research Project Results
Title of Talk:
Low-Cost Organic Gas Sensors on Plastic for Distributed Environmental Monitoring
Abstract of Talk:
The ability to monitor various chemical species in large expanses of currently unmonitored land resources will enable proactive response to environmental problems and will also assist in the development of more accurate models of environmental phenomena. Unfortunately, the widespread deployment of chemical sensors is generally economically unfeasible using currently available sensor technology, primarily since individual sensors are too expensive to be deployed on such large scales.
In recent years, there has been tremendous interest in organic transistors as a means of realizing ultra-low-cost electronics, particularly since they may potentially be printed at extremely low cost on cheap substrates such as plastic and paper. More recently, several groups have demonstrated that organic transistor channels show tremendous environmental sensitivity, though they usually lack specificity. Specificity may be achieved using arrays of organic transistors with different channel materials, thus generating unique, highly specific signatures upon chemical exposure. Since such devices may be formed entirely by solution-based processing techniques including inkjet printing, these are an attractive means of realizing low-cost gas sensors for environmental monitoring.
We report on our success in realizing such a sensor technology. We describe our development of arrayed sensors based on organic transistors. We study the repeatability and robustness of the same, and study their usability in the detection of environmental contaminants, with our initial focus aimed at organic solvents often used in industrial applications. Initial results indicate that robust, albeit slow, cycling of organic sensors for reliable detection of several solvents is highly possible. This is promising, since most environmental monitoring applications will not require high speed of response. We also demonstrate simultaneous differential sensing of various chemicals, thus establishing the potential of these sensors in electronic noses.