Adhesive Failure of Micro-Cantilever Beams

One of the most important reliability problems in micro-electromechanical systems (MEMS) is the adhesion of contacting surfaces due to surface forces. Based on the Hamaker hypotheses and the van der Waals interactions of atoms, the adhesive energy and force of sphere-plane are obtained. Employing the deformation theory of micro-cantilever beams, the variations of the elastic energy and force with the deflection of micro-cantilever beams are achieved. With the adhesive energy of sphere-plane and the variation of the elastic energy with the deflection of a micro-cantilever beam, a failure parameter is introduced to estimate the reliability and stability of a randomly given micro-cantilever beam. The micro-cantilever is reliable and stable only if the failure parameter zeta > 1. The simulation results indicate that the failure parameter zeta is valid and reliable in estimating the reliability and stability of a randomly given micro-cantilever beam with a contact pad fixed on its free end