On the equivalence between mass perturbation and DC voltage bias in coupled MEMS resonators: Theoretical and experimental investigation

In this work, we consider MEMS devices made of mechanically coupled microbeams under electric actuation. We conduct an experimental study to identify the occurrence of veering and then investigate its dynamic response for different electric actuations. A slight change in the DC voltage bias from the veering point is observed to affect significantly the frequency response. Indeed, jump to large orbits occurred when perturbing the applied DC voltage while operating near the cyclic-fold bifurcation point. We also develop and validate a mathematical model to simulate the response of the device. The model showed similarities in the softening effect of the DC voltage bias and an added mass when matching their induced shift in the natural frequency. As such, one can discern the inherent nonlinear effects of DC voltage bias on coupled resonators and exploit them for mass sensing applications without going over the hassle of mass deposition, which requires the deployment of complex processes. We also investigate different mass detection mechanisms. We show the potential of mode localization and the significant and abrupt jumps in the deflection of the coupled microbeams due to mass perturbation to enhance the sensitivity of MEMS mass sensors. Published under an exclusive license by AIP Publishing.

Automated summary

This study investigates MEMS devices made of mechanically coupled microbeams under electric actuation, showing that slight changes in DC voltage bias significantly affect frequency response, and developing a mathematical model for simulation. Furthermore, jumps in deflection due to mass perturbation can enhance the sensitivity of MEMS mass sensors.