Meander anisotropic magnetoresistance bridge geomagnetic sensors

Anisotropic magnetoresistive (AMR) sensors have long been used for specific industrial applications. Their field detection sensitivity can be improved using magnetic flux concentrators to amplify the magnetic field strength sensed at the sensor. We report on the design and fabrication of a micrometer-size meander AMR bridge sensor with an effective AMR branch length of 150. This sensor geometry has enabled us to achieve a magnetic sensitivity as high as 1.25 mV/Oe (or 0.45 mV/V/Oe), which is an enhancement by a factor of about 300 compared to conventional AMR thin film-based sensors. Our study paves a new pathway for the design and application of geomagnetic devices.