A series piezoelectric diaphragm resonator for biosensor applications

In this paper, we have introduced a novel piezoelectric resonator utilizing a flexural vibration mode for biosensor applications. The series piezoelectric diaphragms (SPD) structure has been adopted to replace the single piezoelectric diaphragm structure in a biosensor. The etching process of the piezoelectric films can be skipped by using this structure. Another advantage of the SPD structure is that one of the two diaphragms in series can be used as a reference cell in detection. The responses of the SPD resonator have been simulated. A prototype device was fabricated and characterized. Both the simulated and experimental results are well consistent with the theory.