An electronic-nose sensor node based on polymer-coated surface acoustic wave array for environmental monitoring

We report an electronic-nose sensor node based on polymer-coated surface acoustic wave (SAW) sensor array for environmental monitoring applications. The sensor node consists of a SAW sensor array, its readout circuitry and a Wireless Sensor Network (WSN) platform. The 2 × 2 non-continuous gas SAW sensor array is coated with different polymer composite materials for different gas detection. The frequency signals from the SAW array are processed by the frequency readout circuitry to obtain frequency shift information. The sensor data is transmitted from sensor nodes by Octopus II WSN platform. Experimental results have shown good performance of gas detection and recognition. In order to achieve a high efficient environmental monitoring sensing network, the decision supporting system by implementing weighted voting system (WVS) has also been considered.