Experimental insight into nonlinear dynamics of asymmetric weakly coupled micromachined resonators

This work experimentally analyses a novel tunable asymmetric AlN-Piezoelectric weakly coupled resonator consisting of cantilever and bridge resonators. As tuning the applied electrothermal voltage, the system exhibits two veering points and a buckling point, showing great potential for sensing applications. The results demonstrate that the 1st global mode dominated by the cantilever remains unaltered while the 2nd global mode dominated by the bridge varies with increasing electrothermal voltage, proving the great potential for multi-sensing applications. At both veering points, the system energy confinement on bridge-dominated mode and nonlinear mode exchange could be observed. The system nonlinearity changes from highly hardening behaviour to highly softening behaviour at the buckling point where strong harmonic contributions were demonstrated, which could be exploited as a trigger signal in alarming sensor design.