Analysis of static bending model of microcantilever gas sensor considering the change of neutral layer position

Microcantilever is a kind of biochemical sensor with high sensitivity. In this paper, the change of neutral layer position caused by adsorption-induced stress is introduced into modeling, and the static bending model of microcantilever with monolayer molecules is established based on energy method. On this basis, the relationship between the curvature radius of microcantilever and its thickness, Young's modulus and adsorbed molecules distance and the effect of change of neutral layer position on the performance prediction of microcantilever are investigated using the microcantilever adsorbed with water molecules. The results show that: (1) the relationship between the curvature radius and Young's modulus, thickness and adsorbed molecules distance can be expressed using the linear, quadratic and eight approximation function; (2) the predicted error of bending curvature radius caused by the change of neutral layer position slightly increases with decreasing Young's modulus and thickness, whereas the effect of distance between adsorbed molecules on the error is significant; (3) the change of neutral layer position can significantly affect the sensitivity and surface strain of the microcantilever.