Odor sensing system using ball SAW devices functionalized with self-assembled lipid-derivatives and GC materials

We present application of a novel method for fabrication of highly sensitive spherical surface acoustic wave (ball-SAW) odor sensors, using self-assembling of lipopolymers, lipids and GC (gas chromatography) materials. The method allows good control over the thickness of the odor-sensitive layer an important feature for sensitivity enhancement of the ball-SAW sensors. The fabrication method consists of (i) chemisorption of a lipid-derivative(s), and (ii) physical sorption of GC stationary-phase materials inside the lipid-derivative's matrix. Ball-SAW sensors fabricated using this method have very high sensitivity to n-butanol in both dry- and humidified-air with detection limits well below human threshold.