Abstract
Traditionally, polyaniline was used for sensing ammonia (NH 3 ) gas due to the change of conductivity. By integrated with surface acoustic wave sensor (SAW) for sensing the amino-group type of gas, a novel bio-chemical sensor had been developed. The mechanism of the SAW sensor is that the change of gravity results in the change of physical characteristics of SAW sensor. In order to increase the absorbability of the polymer, we use the nano structure to increase the surface area ratio that can make gaseous molecular being absorbed onto the nano structure quickly. Three kinds of solvent vapor were tested: ammonium hydroxide, triethylamine, and acetone. ©2005 IEEE.