Enhanced detection resonance frequency shift of a piezoelectric microcantilever sensor by a DC bias electric field in humidity detection

We have examined the relative longitudinal flexural resonance frequency shift of a PMN–PT/tin PEMS with a DC bias electric field, E, in humidity detection. We showed that the relative resonance frequency shift could be enhanced by applying an E to the PMN–PT layer during detection. A maximum enhancement of more than three times in resonance frequency shift was observed at E = −6 kV/cm as compared to the resonance frequency shift without a bias field. The maximal relative resonance frequency shift at E = −6 kV/cm was about 1000 times larger than could be accounted for by mass loading alone.