High sensitivity piezoresistive cantilever design and optimization for analyte-receptor binding

The mechanical design and optimization of piezoresistive cantilevers for biosensing applications is studied using finite element analysis. The change of relative resistivity of piezoresistive microcantilevers is analyzed in the presence of the chemical reaction at the receptor surface under the condition of oscillating flow. Chemo-mechanical binding forces have been analyzed in order to understand issues of saturation over the cantilever surface. Furthermore, the optimum design using finite element modeling is achieved by modifying the factors pertaining to the geometry of the microcantilevers under the condition of bio-binding. The introduction of stress concentration regions (SCRs) during cantilever fabrication has been discussed, which greatly enhances the detection sensitivity through increased surface stress. Finally, the optimum SCR modified ‘C’ piezocantilever system for biosensing is designed and the optimal parameters are set for high sensitivity. (Some figures in this article are in colour only in the electronic version)