Capacitive MEMS accelerometers testing mechanism for auto-calibration and long-term diagnostics

⎯ A test technique for capacitive MEMS accelerometers and electrostatic micro-actuators based on the measurement of pull-in voltages is described. A combination of pull-in voltages and resonance frequency measurements can be used for the estimation of processinduced variations in device dimensions from layout and deviations in material properties from nominal value, which enables auto-calibration. Preliminary measurements on fabricated devices confirm the validity of the proposed technique. Moreover, long-term pull-in measurements have indicated the suitability of the approach as in-system diagnostic tool.

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