A new surface acoustic wave humidity sensor based on a polyethynylfluorenol membrane

A device for surface acoustic wave (SAW) measurements, based on a polymeric sensitive membrane, that is polyethynylfluorenol (PEFI), has been realized. The SAW/PEFI sensor shows relatively fast and highly sensitive responses in the range of relative humidity O-60%. The enhanced sensitivity of the SAW/PEFl device, in comparison with that of a SAW sensor which utilized a polyphenylacetylene film, may be attributed to the presence of OH groups belonging to the polymer repeat unit.