High quality factor silicon cantilever driven by PZT actuator for resonant based mass detection

A high quality factor (Q-factor) piezoelectric lead zirconat titanate (PZT) film actuated single crystal silicon cantilever was proposed in this paper for resonant based ultra sensitive mass detection. Intrinsic energy dissipation and other negative effects from PZT film were successfully compressed by separating the PZT actuator from the resonant structure. Excellent Q-factor, which is comparable to silicon only cantilever and several times larger than latest reported Q-factor of integrated cantilevers, was successfully obtained under both atmospheric pressure and reduced pressures. For a 30 μm-wide 100 μm-long cantilever, Q-factor was measured as high as 1113 and 7279 under the pressure of 101.2 KPa and 35 Pa, respectively. Moreover, it was found that high mode vibration can be achieved for the pursuit of great Q-factor. However, support loss became significant because of the increase of PZT actuator's vibration amplitude. Therefore, an optimized structure using node-point actuation was discussed and suggested herein.