Performance Analysis of Bridge Type GMR Microaccelerometer by Inverse Method

Abstract

A micro-accelerometer is accomplished by use of a bridge-type structure with a flexible fixed-end beam. A PtFe layer is attached on the beam center surface as a magnetic field source. Giant Magneto-Resistance (GMR) material is used to detect magnetic field variation at different heights arising from the motion of the beam. An inverse numerical scheme is proposed to inversely obtain beam fixed-end boundary conditions, which are also the displacement of the detected object. This scheme employs the Laplace transform and applies numerical techniques to its inversion. Numerical verifications show the proposed scheme is accurate, stable, and tolerates errors arising from measurement, calibration and manufacture. Performance of this sensor is analyzed and sensors of other dimensions satisfying the prescribed performance requirements are designed by the proposed inverse analysis scheme.

Keywords:

• Microaccelerometer
• Giant Magneto-Resistance (GMR)
• Laplace Transform