Tuning Acoustic Sensing Properties of MEMS Cantilever by Nonlinear Operation

Micro-electromechanical systems (MEMS) offer a wide range of applications, anything from consumer electronics to research on biological samples. With increasingly stringent demands on size, sensitivity, and overall performance, linear design methodologies have reached their limits. Recent research efforts on selected nonlinear effects are promising and indicate that a systematic design of such effects can increase sensitivity and responsiveness while mitigating dynamic distortions and artefacts. We study acoustic sensing properties of MEMS cantilevers with integrated deflection sensing and actuation scheme subject to self-feedback or output signal coupling. The feedback can be used to drive the cantilevers in a nonlinear dynamics regime, which results in up to 10times increased signal-to-noise ratios and increased bandwidth of the coupled resonators (up to 5 times). Thus, sensing properties are largely tunable by changing the feedback parameters. Results show potential to overcome current technological limits of sensors and for utilization in a myriad of MEMS applications, such as for future AFM technology, mass and sound sensors.