Significant tuning of dispersive mode coupling in doubly clamped MEMS beam resonators using the thermally induced buckling effect

Dispersive mode coupling is a promising mechanism for the development of advanced micro- and nanoelectromechanical devices. However, strong coupling strength remains a key challenge limiting the practical applications of the dispersive mode coupling effect. Here, we experimentally demonstrate the significant tuning of the mode coupling coefficient of two flexural vibrational modes in a doubly clamped microelectromechanical system (MEMS) beam resonator using the thermally induced buckling effect, which enables variable coupling strengths to be implemented for practical applications. Furthermore, a theoretical model is developed to describe the mode coupling coefficient, showing that the tunability is due to the breakdown of the symmetric shape of the MEMS beam caused by buckling. Moreover, the theoretical model defines a simple relation between the coupling coefficient and the nonlinearity of the two coupled modes. These results provide valuable insight into physical mechanisms underlying the dispersive mode coupling effect and pave the way for the development of advanced MEMS devices with application-specific mode coupling strengths.