A Centimeter-Level 2-D Cross Micro Tensor Used Uniaxial MEMS Fluxgate Chip for Portable Magnetic Detection

In recent years, fluxgate tensor has made several attempts in geological exploration and magnetic target detection. A double-layer 2-D MEMS miniaturization fluxgate tensor is first proposed in this article. From 3-D to 2-D, the micro tensor has a novel measurement theory. The micro tensor consists of 16 fluxgate chips array with cross architecture, which is fabricated combining independent single chips, PCB technology, and bonding technology. Sensitivity of all chips is about 1780 V/T with error of less than 5%, and noise power spectrum density is lower than 50 pT /{\surd } Hz at 1 Hz. The overall size of the micro tensor is about 5\times 5\times1 cm, which is the smallest fluxgate tensor at present. An olive-shaped permanent magnet is detected by the micro tensor. The shape and position of permanent magnet can be clearly seen from the tensor results.