High Aspect Ratio Magnetoimpedance Sensors Fabricated by Micromolding

Multilayered magnetoimpedance sensors have been fabricated using micromolding of NiFe and Cu films with thicknesses up to 10 μm. The influence of a transverse field annealing has been studied. Variation of ΔZ/Z
_sat
of 170% and sensitivity of 4.4%/Oe have been obtained for a 50 μm wide and 20 μm thick sensor at frequencies in the range of 1 MHz. Using the resonance between the sensor and an external capacitance, sensitivity of 7200 Ω/T has been reached at high frequencies.