Research on Static Bending Model of Piezoelectric Microcantilever Gas Sensors

Piezoelectric microcantilever is a kind of biological and chemical sensor with high sensitivity and reduced dimensions.Adsorption of molecules on surface of piezoelectric microcantilever can cause the microcantilever bending.Taking advantage of the deflection of the microcantilever,the surface can be gotten.In this paper,the change of neutral layer position caused by adsorption-induced stress is introduced into modeling,then a static bending model of microcantilever with monolayer molecules is established based on energy method.The curvature radius of piezoelectric cantilever decreases with decline of the thickness and Young's modulus of cantilever in the condition of same adsorption surface and mass according to the result,moreover,the smaller microcantilever is,the more significant the effect of change of neutral layer position on static deflection is.And the curve of curvature radius with thickness ratio has a inflexion,the position of inflexion is affected by the ratio of Young's modulus of piezoelectric layer and non-piezoelectric layer.