Design, fabrication, and testing of a mechanical time delay micro-mechanism

Arrays of micromechanical sequential-leaf time delay mechanisms based on SOI/DRIE technology have been designed, fabricated, and characterized. The devices were designed as part of an arming train for rifled munitions which must arm following a set delay after a predetermined rotational speed is reached. Analytical models for the micromechanical timing mechanisms have been developed, and a variety of designs were simulated from both linear and nonlinear models, as well as from dynamics simulation software. Fabricated mechanism arrays designed to initiate switching at centripetal accelerations from 44 to 263 g were characterized using a high-speed camera, with delay times of between 0.67 and 0.95 ms achieved for single elements.