The evolution of stiction repair for microelectromechanical system cantilevers using periodic excitation

In some recent experiments, it has been shown that structural vibrations are an efficient means to repair (i.e., unstick) stiction failed microcantilever beams. The analysis that accompanied these experiments identified excitation parameters (amplitude and frequency) that successfully initiated the debonding process between the microcantilever and the substrate. That analysis relied on coupling a static fracture model to a vibration model. However, that analysis could not describe what happened after the debonding process was initiated. For example, the repair could be partial, where the debonding begins but then arrests—or it could be total, where the beam is returned to its free-standing shape. The present paper examines the post-initiation behavior of stiction failed microcantilevers. A new, coupled fracture/vibration model is formulated and used to track the evolution of the repair, in order to determine the extent of the repair under various conditions. Moreover, this model successfully predicts some unusual (but explainable) behavior seen in the previous experiments, regarding partial and complete vibration repair.