Theoretical Studies of Realizing High Sensitivity for Frequency-Change-Type Single-Crystal Silicon Two-Axis Acceleration Sensor

Abstract

Methods for realizing high sensitivity for a frequency-change-type single-crystal silicon two-axis acceleration sensor are proposed. The volume of the prototype sensor is about 4:0 Â 4:2 Â 0:5 mm 3 and the resonance frequency is approximately 80 kHz. The sensor characteristics are analyzed using the finite-element method. Selecting the axis to apply the acceleration and using bent support bars are both effective methods to increase sensor sensitivity. The sensitivity increases 42% when the sensor is rotated and used under the condition of z ¼ À45 . Using the bent support bars and rotating the sensor around the z-axis, a 100% increase in sensitivity was finally obtained in a sensor which has the mass equal to that of the prototype sensor. On the other hand, a 56% increase was finally realized in the sensor which has the outside-dimension equal to that of the prototype sensor.

Construction of Two-Axis Acceleration Sensor Using a Cross-Coupled Vibrator

“…To develop such a sensor, the authors have studied an acceleration sensor utilizes the phenomenon that the resonance frequency of a bending vibrator changes by the axial force. [1][2][3][4][5][6][7][8][9][10][11][12] A new construction of the acceleration sensor using a cross-coupled vibrator is proposed here, and investigated experimentally. The sensor detects the acceleration from a change of vibration amplitude of the cross coupled vibrator.…”

Improvement of Characteristics of Frequency-Change-Type Two-Axis Acceleration Sensor

“…Then, the structures of one-and two-axis acceleration sensors were proposed, and investigated experimentally. [1][2][3][4][5][6][7][8] But, the characteristics of the two-axis sensor shoud be improved on the point that an signal from the other axis is detected. 9) As this reason, it is clarified that mass of the sensor rotates by acceleration in the plane.…”

Analysis of Characteristics of Coupled Bending Vibrators Used as a Force Sensor

“…To develop such a sensor, the authors have studied an acceleration sensor that utilizes the phenomenon that the resonance frequency of a bending vibrator changes by the axial force. [1][2][3][4][5][6][7][8][9][10][11] As one example of these sensors the sensor using a coupled bending vibrator was also proposed. 12) However, the characteristics of this vibrator were not clarified sufficiently.…”

“…As a result, this sensor becomes a flat structure with a high sensitivity and extremely reduced energy leakage. The force sensor can be applied to an acceleration sensor [11][12][13][14][15][16][17][18] and also to an inclination angle sensor. 19) Furthermore, the coupled bending vibrator that linearly connects the two bending vibrators is proposed and then applied to one-axis acceleration sensor as a force sensor.…”