Investigating the Static Pull-in Instability of Biosensors Using Modified Adomian Decomposition Method (MAD)

In this study, the behaviour of biosensors is investigated by using the modified coupled stress theory. The biosensor is electrostatically stimulated and also immersed in the fluid. Unlike previous studies, in the present study, the size effect parameters, surface layer, and intermolecular Casimir force are considered simultaneously. In order to solve the nonlinear static equation, the Modified Adomian Decomposition (MAD) method and the numerical method are used. Finally, the effect of the length of the material and also the effect of stress on the pull-in voltage is studied as well. Comparing the results of the Adomian analytical solution with numerical methods and reported results in the literature, show that the method has high accuracy and can be used as an effective and efficient method for analyzing the stability of Nano-bio sensors. The results indicate that by considering the surface effect and also increasing the size effect parameter, the pull-in voltage in both numerical and analytical modes is more than the situation which surface effect is neglected. In addition, with the presence of the surface layer and the increase of the Casimir force, the pull-in voltage is reduced.