A Study on Increasing Sensitivity of Rectangular Microcantilevers Used in Biosensors

Sensors (Basel). 2008 Nov 25;8(11):7530-7544. doi: 10.3390/s8117530.

Abstract

This study proposes a new microcantilever design with a rectangular hole at the fixed end of the cantilever that is more sensitive than conventional ones. A commercial finite element analysis software ANSYS is used to analyze it. The Stoney equation is first used to calculate the surface stress induced moment, and then applied to the microcantilever free end to produce deflection. The stress analysis of the proposed and conventional designs is performed, followed by dynamic analysis of the proposed design. We found that the Sader equation is more accurate than Stoney in predicting cantilever deflections, and that for increasing the sensitivity of a microcantilever biosensor increasing the cantilever thickness is more practical.

Keywords: Biosensor; Microcantilever; Sader equation; Stoney equation; Surface stress.