Tuning the dynamic behaviour of cantilever MEMS based sensors and actuators

Purpose - This paper seeks to establish an analytical reference model in order to optimize the frequency response of ME MS cantilever structures using cutouts. Design/methodology/approach - Presented in this work is a method to tune the frequency response of MEMS cantilevers by using single cutouts of various sizes. From an interpretation of the analytical results, mass and stiffness domains are defined as a function of the cutout position on the cantilever. In this regard, the elastic properties of the MEMS cantilever can be trimmed through mechanical tuning by a single cutout incorporated into the device geometry. The Rayleigh-Ritz energy method is used for the modeling. Analytical results are compared with FEM and experimental results. Findings - The eigenvalues are dependent on the position and size of the cutout. Hence, the frequency response of the cantilever can be tuned and optimized through this approach. Research limitations/implications - MEMS microsystems are sensitive to microfabrication limitations especially at the boundary support of suspended structures such as microcantilevers. Practical implications - MEMS cantilevers are resistant to low level vibrations due to their low inertia and the elastic properties of the silicon material. For sensor applications these qualities are highly regarded and explored. This analysis will contribute to the performance optimization of atomic force microscope (AFM) probes and micromechanical resonators. Originality/value - A method to tune, with cutouts, the frequency response of microcantilevers is proposed. The data can provide insight into the performance optimization of micromechanical resonators through mass reduction. For industrial applications requiring optimized responses the cutouts can be incorporated into microcantilevers through focused ion beam (FIB) machining or laser drilling, for example.