Micromachined accelerometer with microprocessor controlled self‐test procedure

This paper describes a self‐test procedure for a micromachined silicon accelerometer realized using a commercially available microprocessor. The accelerometer is fabricated using a combination of thick‐film printing and silicon micromachining. It consists of a silicon structure with thick‐film piezoelectric elements that act as sensors, detecting the deflections of the inertial mass, and also as actuators capable of performing a self‐test routine. The self‐test procedure must be performed at resonance and the microprocessor is used to identify the individual resonant frequency of each device and confirm the operation of the PZT elements. This work has successfully demonstrated the feasibility of a microprocessor implemented procedure and has highlighted some interesting behavioral characteristics of the accelerometer. The microprocessor could also be used in the future to fully test and calibrate the device thereby ensuring correct and accurate operation.