| Popis: |
A thickness shear mode (TSM) bulk acoustic wave (BAW) sensor for liquid electrical property (conductivity and dielectric constant) measurements is presented. This sensor, which is configured as a resonator structure, employs a sensing electrode geometry, which allows the accurate measurement of the liquid electrical properties. The frequency response of the sensor has been measured in both conductive (NaCl) and non-conductive (2-proponal) solutions. A theoretical model has been developed to describe the sensor operating in liquids and the calculated impedance is shown to agree well with the measured impedance. The sensitivity of this sensor to the change in liquid dielectric constant has been determined. Compared with other sensing technologies, the present sensor may provide a more reliable, portable and low cost solution for on-line monitoring of the liquid electrical property changes. |
