Advances in SAW-based gas sensors

This paper deals with some advances in surface acoustic wave (SAW) sensor research relating to the use of both a new chemically interactive material (metal porphyrin) and new amplifiers for low-noise SAW oscillators, which are illustrated and discussed in some detail. The trend toward SAW matrixes, implemented on silicon, required for more sensitive chemical image systems, has led to the observation of coupling effects between adjacent SAW oscillators, even if the electronics were not implemented on Si. This effect must be considered at design level in order to achieve a higher resolution value in detecting either single chemical species or chemical images.