Recognitions of Micro Non-Magnetic and Ferromagnetic Material with SV-GMR Sensor

This paper describes the recognition of micro non-magnetic (conductive) and ferromagnetic material with spin-valve magneto-resistance (SV-GMR) sensor. High frequency and static magnetic fields were applied to material for the recognition of the micro conductive and ferromagnetic material respectively. The SV-GMR sensor is used to detect the magnetic field variation occurred wherever the material exists. The experimental results were carried out to detect the non-magnetic micro-bead array (PbSn, 125 µm radius) by the SV-GMR sensor and agree with analytical results based on analytical method. Furthermore, the experimental results of ferromagnetic particle (Fe, sizes of 20-60 µm) detection were also performed by the SV-GMR sensor