Sensor testing through bias superposition

A novel on-line monitoring technique for integrated MEMS is presented based on injection of an electrical test stimulus into the bias structure through both superposition or modulation. The techniques “bias superposition and bias modulation” both support integrated structural test that targets both production test and on-line condition monitoring through generation of dependability metric. It can in some cases be used to provide the raw data for on-line calibration and compensation. The techniques are demonstrated on three integrated MEMS structures from the field of consumer electronics, aerospace and environmental sensing and have been successfully applied to a thick film conductance sensor.