Three-directional accelerometer and manufacturing method thereof

Abstract

Provided herein are a three-directional accelerometer and a method for manufacturing the same. The three-directional accelerometer includes a three-layer frame, a core mass, three sets of spring leaves and three sets of optic fiber Bragg gratings (FBG's). The spring leaves that react to seismic motion of the mass are aligned perpendicular to one another in three dimensions. The spring leaves are significantly smaller in thickness than width, thus creating significant differences in moments of inertia, making the spring leaves sensitive only to mass vibration or acceleration in one direction. One set of FBG is responsible for sensing the corresponding mass vibration in one direction. The natural frequency in any direction can be adjusted by varying the mass/dimensions of the core mass, corresponding frame and stiffness of the spring leaves.