Design and fabrication of a new miniaturized capacitive accelerometer

A novel mercury-based capacitive accelerometer has been designed and fabricated. The accelerometer features a highly symmetrical Cubic structure and capacitive coupling of the high-frequency input voltage, which uses a mercury drop for spring material and flexible interconnection layer between (he capacitor plates. The device is mounted on a standard IC package with dimensions of 5 mill x 5 mm x 5 mill. The structure, working principle, fabrication, and mathematical model of the accelerometer are presented. Since the accelerometer uses a mercury drop as its sensitive electrode instead of a solid, which is commonly used in traditional accelerometers, the conflict between the requirements of high shock and high sensitivity is solved. The measurement results show a sensitivity of 0.2 mV(m s(-2))(-1) with a corresponding resolution of 0.01 ms(-2), off-axis sensitivity of <5% and good linearity in the output voltage for accelerations up to at least 10 ms(-2). (C) 2008 Elsevier B.V. All rights reserved.