Nonlinear oscillations of piezoelectric microresonators with curved cross-sections

Nonlinear oscillations of microelectromechanical resonators with curved cross-sections are studied in this effort. The resonators are fabricated as clamped–clamped composite structures, and these structures have both lengthwise and widthwise curvatures induced by residual stresses. Harmonic piezoelectric actuations of these structures were considered in experiments and the spatial responses of these structures were studied. The spatial responses observed for different resonance excitations could not be explained by a previous model of these composite microresonators, where stepwise non-uniform properties along the length and rectangular cross-sections were considered. Here, a curved cross-section model is adopted to refine the previous model and the resulting predictions are found to compare better with the experimental observations. The results show that the cross-section curvature significantly affects the structural stiffness and response, and this is important to consider in system modeling.