Impacts of Residual Stress on Micro Vibratory Platform Used for Inertial Sensor Calibration

Area of Science:

• * Micro-electro-mechanical systems (MEMS) engineering
• * Piezoelectric materials science
• * Inertial sensor calibration technologies

Background:

• * Micro vibratory platforms utilizing converse piezoelectric effects offer in-situ recalibration for MEMS inertial sensors, crucial for mitigating bias and scale factor drift from long-term storage.
• * Calibration accuracy relies heavily on stable and repeatable platform vibrations, which are susceptible to micro structural residual stress and lead zirconate titanate (PZT) hysteresis.
• * Understanding and mitigating these error sources are vital for reliable MEMS sensor performance in demanding applications.

Purpose of the Study:

• * To analytically investigate the abnormal displacement response observed in micro vibratory platforms during experimental testing.
• * To differentiate the contributions of micro structural residual stress and PZT hysteresis to response errors.
• * To identify the primary cause of response inaccuracies around the zero position for improved platform design.

Main Methods:

• * Analytical investigation employing a stiffness model for micro beams.
• * Utilization of a hysteresis model specific to piezoelectric materials.
• * Experimental observation and analysis of displacement response phenomena.

Main Results:

• * The study analytically modeled the behavior of the micro vibratory platform, considering both beam stiffness and piezoelectric hysteresis.
• * Experimental data revealed abnormal displacement responses that were investigated using the developed analytical models.
• * Initial deflection due to residual stress in the micro structures was identified as the dominant factor causing response errors near zero displacement, outweighing PZT hysteresis.

Conclusions:

• * Residual stress in micro structures, leading to initial beam deflection, is the primary source of response error in micro vibratory platforms around the zero position.
• * Piezoelectric hysteresis was found to be a less significant contributor to the observed errors compared to residual stress.
• * These findings provide critical guidelines for optimizing the design and control of micro vibratory platforms to enhance the performance and accuracy of MEMS inertial sensor recalibration.