Study on the polymer-coated Surface Acoustic Wave sensors for organic vapor detection

The Surface Acoustic Wave (SAW) sensor technology using piezoelectric material and surface interdigital electrodes are realized as a 2-port oscillator. To improve the selectivity and sensitivity, three polymers are individually coated onto the SAW oscillators to detect organic vapors. The vapor-sensing capability is evaluated based on a 4-SAW array scheme wherein four kinds of flammable vapor like propylene, ether, butanone and benzene are under tested with polymer films including poly-vinylphenol (PVP), polystyrene (PS) and Ethyl Carbamate (EC). After obtaining the experimental result of vapor sensing, the fingerprint of their sensing characteristics can be successfully demonstrated for vapor recognition application.