Steady-state transition of buckled nano graphite sheets in vibration processes

Nanomechanical resonators crafted from two-dimensional materials exhibit heightened sensitivity to stress. The impact of tensile stress on resonators has received extensive attention. However, relatively little emphasis has been focused on the behavior of resonators under compression stresses, especially in the buckled state. This study explored the vibration of buckled graphite sheets under external excitation using experimental analysis, molecular dynamics (MD) simulations, and nonlinear isotropic plate model (NIPM). Notably, multiple peaks corresponding to the identical mode appeared in the spectrum. The additional peak distinct from the natural frequency arose from transition between two steady states of the film. Remarkably, the frequency of the peak corresponding to the transition exhibited greater sensitivity to external excitations and stress than the natural frequency of the resonator did. This phenomenon opens avenues for developing 2D resonant nanomechanical sensors with enhanced sensitivity, as well as bistable nanoelectromechanical resonators.