Functionalization of electrostatic nonlinearities to overcome mode aliasing limitations in the sensitivity of mass microsensors based on energy localization

In order to overcome mode aliasing limitation in linear mode-localized sensors, we demonstrate in this Letter both theoretically and experimentally how to tune the electrostatic nonlinearity and exceed the ultimate sensitivity reachable in the linear regime. A mass sensor composed of two coupled micro-cantilevers with different lengths is considered and the results show that the sensitivity can be significantly enhanced up to 67 %. By performing experiments on the fabricated device and depositing the mass perturbation with a focused ion beam, the same phenomenon was observed. These promising results open the way toward ultrasensitive multimodal microsensors with functionalized nonlinearities.