Microcantilevers are commonly used as part of sensor elements in Microelectromechanical Systems (MEMS). Deflection or the shift of resonance frequency of microcantilever beams are regularly used to measure chemical, physical or biological quantities. An important characteristic of any sensor is its sensitivity to a given input. This paper explores the possibility of improving the sensitivity of a microcantilever by modifying the mechanical properties using partial perforations on the surface of the microcantilever. This paper presents two analytical models that quantify the deflection and the fundamental resonant frequency in terms of the perforation dimensions for a microcantilever beam. Beams with a single partial perforation are considered first, and the models are then expanded to include multi-perforated cantilevers. Results obtained from the analytical models are compared to Finite Element Analysis (FEA) simulations of perforated microcantilever beams. The analytical models of a microcantilever with a single perforation show high accuracies compared to the FEA, while the accuracy of results for a cantilever beam with many perforations decrease as the number and size of perforations are increased. The results of the models are used to design a cantilever beam with the desired mechanical properties.

Date Published: 28 February 2005
PDF: 10 pages
Proc. SPIE 5649, Smart Structures, Devices, and Systems II, (28 February 2005); doi: 10.1117/12.582278

Published in SPIE Proceedings Vol. 5649:
Smart Structures, Devices, and Systems II
Said F. Al-Sarawi, Editor(s)