Odor sensing system using ball SAW devices functionalized with self-assembled lipopolymers

We present a novel method for fabrication of highly sensitive spherical surface acoustic wave (SAW) devices, so called Ball-SAW, for odor-sensing. Proper functionalization of the Ball-SAW devices´ surface can allow for realization of miniaturized array of odor sensors. However, conventional techniques used for sensing-film deposition on Ball-SAW devices cause a considerable attenuation of the acoustic wave propagation after many circulations. Here, we propose application of self-assembled lipid derivatives by means of chemisorption from ethanolic solution. The fabrication process is very simple and results in Ball-SAW devices almost without additional attenuation due to coating. This makes for a significant enhancement of sensitivity to odorants as compared to the sensors coated with traditional techniques.