[hal-01066276] Bifurcation-based micro-/nanoelectromechanical mass detection

This paper investigates an alternative mass-sensing technique based on nonlinear micro-/nanoelectromechanical resonant sensors. The proposed approach takes advantage of multi-stability and bifurcations of the hysteretic frequency responses of the electrostatically actuated resonator. For this purpose, a reduced-order model is considered. Numerical results show that sudden jumps in amplitude make the detection of a very small mass possible. Moreover, the limit of detection can be set with the value of the operating frequency. However, when operating at fixed frequency, the study of basins of attraction indicates that this bifurcation-based mass detection does not exhibit the expected robustness. A possible improvement is proposed, based on the reinitialization of the system by a forced jump down on the hysteretic response curve. Using a frequency sweep which varies slowly in sinusoidal form solves the reinitialization problem and enables automatic real-time detection. Finally, the added mass is located on the beam by using the resonance at the first two natural frequencies.



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