Increasing the Sensitivity of Surface Acoustic Wave Chemical Sensors and Other Chemical Sensing Investigations

The work involves the fabrication and testing of three different surface acoustic wave (SAW) device designs, an investigation of nanowires sensitive to chemicals and preconcentrator prototypes to include with chemical sensors. The SAW chemical sensor designs include modifications to a basic SAW device to see if the sensitivity of the SAW device is increased. The modifications consist of etched trenches along the propagation field, coating the device with carbon nanotubes (CNTs) under the chemically sensitive layer and coating CNTs on top of the chemically sensitive layer. SAW devices are coated with Nafion , a polymer sensitive to ethanol. The tests indicate that trenches etched between the transducer fields increase the sensitivity of the SAW devices. The increase of sensitivity is signified by a shift of peak frequency of an extra 100kHz over the unaltered device after five minutes of flowing ethanol.