Fig. 4: Performance characterization of MEMS devices under harmonic vibration.

a Photograph of the fabricated MEMS-pVEHs; b resonance curve under the short- and open- circuit condition; output power dependences of c load resistance, and d generalized mechanical coupling factors \({K}^{2}\), where the mechanical quality factors \({Q}_{m}\) = 313, 536, and 766 for the PZT, (100) oriented BFO, and (100) BFMO epitaxial films, respectively