Mechanical modeling, numerical investigation and design of cantilever beam for low pull-in MEMS switch

The pull-in voltage of an electrostatically actuated cantilever-based series type MEMS switch suitable as a switching device in several applications can be lowered by reducing its cantilever beam stiffness constant ( k ). However, it is a challenging task to lower the pull-in voltage without adversely affecting its mechanical performance parameters like stiffness constant ( k ), resonance frequency ( f 0 ), and stress ( σ ) while meeting manufacturing constraints. Therefore, the design objective of this study is to address by appropriately selecting the cantilever beam profile and its geometric dimensions. cantilever beam profile and its geometric dimensions appropriately. These design objectives are further identified as highly interdisciplinary, involving identifying design variables and advanced modeling of design and manufacturing issues. This work focuses on developing a mechanical (analytical) model of the performance parameters of the cantilever beam based on its profile, properties of materials used for its manufacturing, and dimensions of the geometric variables. The investigation is done through design optimization methodology, which comprises preliminary approximating geometrical dimensions using mechanical modeling, and subsequently fixing these dimensions using 3D modeling and FEM analysis. It is concluded that the unconventional single-step variable-width cantilever beam design is the most suitable design for the low pull-in potential of 11.20 V with performance parameters like k , f 0 and σ as 2.18 N/m, 15.84 kHz and 14.8 MPa, respectively. Furthermore, the methodological steps adopted in this work can address the challenges of MEMS design and manufacturing for any chosen application.