A micromachined differential resonant accelerometer based on robust structural design

• A resonant accelerometer with an effective and simplified structure is proposed.
• Mathematical and numerical analyses were conducted to optimize the structures.
• Experimental results showed good agreement with the results of the analysis.

This paper describes design, fabrication, and testing of a micromachined differential resonant accelerometer (DRA), which is one of the most common solid proof mass accelerometers; it exploits a correlation between acceleration and shifts in the resonant frequency of oscillating beams loaded axially. The effective and simplified structure of the DRA amplifies the induced inertial force resulting from applied acceleration, while retaining structural stability and robustness. Mathematical and numerical analyses were conducted to optimize the detailed structures of the DRA under appropriate operating conditions. An experimentally measured differential scale factor of 188.5 Hz/g showed good agreement with the results of the analysis. Utilizing a silicon-on-insulator wafer provided uniform material properties and thickness of the structural layer, resulting in bias stability of 100 μg and a Q factor of 0.37 × 106.

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