Here is the abstract you requested from the DPC_2009_Mems technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Piezoelectric Acoustic Emission Sensor Array for High Impact Characterization|
|Keywords: Shock Sensor, Piezoelectric, Acoustic|
|This paper reports modeling, design, fabrication, and initial test results for a microfabricated piezoelectric acoustic emission sensor designed to characterize impact and shock events. The prototyped devices focused on two technical challenges: 1) The implementation of a thin-film version of a piezoelectric acoustic emission sensor that could survive extremely high strain rates seen in high-velocity impacting systems, and 2) the fabrication of an array of devices that could provide both spatial and spectral discrimination of the acoustic emission event and survive the impact event. The detection of impact events is an important capability in a number of systems including automobile air bags, condition-based maintenance systems, and projectile fuzing, amongst others. Accelerometers, g-switches, microphones, and strain gauges have been employed for this purpose. These devices have primarily detected the amplitude of the impact event. The presented work, however, aims at determining frequency content and spatial wave information in addition to the actual amplitude. This additional information gives the system an understanding of the nature of the impact, and in particular, the angle of the impact and the relative hardness of the impacting materials. Acoustic emission techniques serve this purpose well. Acoustic waves created by the impact propagate through the structure and provide information as to the nature of the event. Challenges being addressed in this work include the design and fabrication of thin-film piezoelectric sensors and packaging those sensors in a fashion that allows low-loss transmission of the acoustic event. The work also addresses operation of the sensor in events that see up to 100,000g shock levels.|
|Michael Kranz, Director R&D