A surface micromachined latching accelerometer

This paper presents a surface micromachined mechanically-latching accelerometer that is used as a peak reading shock recorder covering the range from tens to thousands of G. This new type of accelerometer consists of a seismic-mass-loaded cantilever beam and an array of circularly distributed notches. The cantilever is latched with increasing acceleration into successive notches to provide a stored measure of peak acceleration. The threshold acceleration can then be read out by electrical or optical techniques. A closed form analytical solution of the acceleration sensitivity has been derived and compared with the experimental data. The model is confirmed experimentally for several acceleration levels. The structures are compatible with standard CMOS processing.