A SKEW-SYMMETRICAL CANTILEVER ACCELEROMETER FOR AUTOMOTIVE AIRBAG APPLICATIONS

A piezoresistive cantilever-beam microaccelerometer has been designed, fabricated and tested with a hybrid airbag electronic control unit fo r automobile crash detection. A skew-symmetric accelerometer has been proposed and the associated fabrication process has been developed. A simultaneous etching process for beam-thickness control, fillet-roundi ng formation and corner compensation is discussed. The microfabricated device shows a flat response with a resonance frequency of 2.07 kHz a nd a sensitivity of 65 mu V g(-1) V-1. A sensitivity of 67 mV g(-1) ha s been measured from the assembled unit with a non-linearity of 4%. Th e present skew-symmetric design and associated fabrication methods pro vide effective means for improving the robustness and reliability, as well as the transverse sensitivity of cantilever-beam accelerators.