| abstract |
The invention relates to a device (1) for detecting at least one substance of a fluid (9). The device comprises at least one piezo-acoustic resonator (2) with at least one piezo layer (4), an electrode (5) arranged on the piezo-electric layer, at least one other electrode (6) arranged on the piezo-electric layer and a surface section (8) used for sorption of the substance of the fluid. The piezo-electric layer, the electrodes and the surface section are disposed in such a way that electric control of the electrodes leads to an oscillation (51,52) of the resonator at a resonance frequency which depends upon the amount of the substance which is sorbed on the surface section. The device is characterized in that the thickness (7) of the pioelectric layer is in the region of 0.5 ñm to 20 ñm and the resonance frequency of the oscillation ranges from 500 MHz to 2 GHz. The device is a mass sensor with a piezo-acoustic high-frequency thin film resonator. The device is characterized by high mass sensitivity in the region of a few HzOEpg<-1>OEcm<2> and small lateral expansion. The device is used as a bio sensor or gas sensor. |