Analysis of a novel method for measuring residual stress in micro-systems

A novel method for measuring residual stress is proposed and analyzed in this study. The method is based on the electromechanical bifurcation response of a clamped–clamped beam. The stressed beam is subjected to a symmetric electrostatic field. The presented analysis shows that the critical voltage which induces the bifurcation response is a monotonic function of the residual stress. Furthermore, the electromechanical bifurcation occurs for both compressive and tensile residual stresses. Ensuring that the postbuckling response is non-stable facilitates the identification of the bifurcation response. To this end, geometrical conditions are derived which ensure that the postbuckling state of the system is non-stable. It is shown that a single test structure can be used to measure residual stress in a continuous wide range.