Frequency dependence of the lifetime of a surface micromachined microengine driving a load

Experiments have been performed on surface micromachined microengines drivi ng load gears to determine the rotational frequency dependence on median cy cles to failure. A sample of 272 microengines, each driving a load, was str essed at eight different frequencies. Frequency dependence was observed and a model was developed based on fundamental wear mechanisms and forces exhi bited in resonant mechanical systems. Stressing loaded microengines caused observable wear in the rotating joints and in a few instances led to fractu re of the pin joint in the drive gear. (C) 1999 Elsevier Science Ltd. All r ights reserved.