| abstract |
(57) [Summary]nA chemical sensor based on acoustic waves utilizing a crystalline substrate and a coating of at least two mixed materials is disclosed. The mixed material includes a combination of (a) a high glass transition temperature polymer or a material having a high melting point, and (b) a low glass transition temperature polymer or a material having a low melting point. A transducer is connected to the crystal substrate to generate an AC potential across the crystal substrate, which causes the crystal to resonate due to the inverse piezoelectric effect. The mixed coating absorbs the analyte and thus changes the mass of the chemical sensor and changes the resonance frequency accordingly. The transducer detects such a change in resonance frequency and indicates the presence of the analyte. The use of a mixed material results in a thicker coating that combines the desirable properties of the mixed components, such as improved detection sensitivity, faster response time, reduced acoustic attenuation, and higher operating temperature ranges. |