A sensitivity study on static and dynamic detection modes of adsorption-induced surface stress in microcantilever biosensors

Microcantilever biosensors may be utilized as a platform for the adsorption induced surface stress measurements. This can be done by measuring either the static deflection of the microcantilever after the adsorption or the adsorption induced shift in its resonance frequency. This paper presents a new method of formulating the adsorption induced surface stress as a function of the static deflection of the microcantilever. Most of the previous works in this area are based on the Stoney's simple equation. In the proposed method, the molecular interactions of the adsorbed biological species are modeled based on the Lennard-Jones attraction/repulsion potential. As a result, the sensitivity of the static detection mode (based on the proposed method) is compared to that of the dynamic mode. It is shown that the dynamic mode of biosensing is much more sensitive to the change in the properties of the adsorbed biological species, when compared to conventional static mode detection mechanism.